diff --git a/src/main/java/cn/edu/tsinghua/tsfile/common/utils/Binary.java b/src/main/java/cn/edu/tsinghua/tsfile/common/utils/Binary.java
index efe5070a..42d50d66 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/common/utils/Binary.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/common/utils/Binary.java
@@ -21,7 +21,7 @@ public class Binary implements Comparable<Binary>, Serializable {
 
     /**
      * if the bytes v is modified, the modification is visable to this binary.
-     * @param v
+     * @param v value
      */
     public Binary(byte[] v) {
         this.values = v;
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/common/utils/ReadWriteForEncodingUtils.java b/src/main/java/cn/edu/tsinghua/tsfile/common/utils/ReadWriteForEncodingUtils.java
index c919c3ae..4f49177c 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/common/utils/ReadWriteForEncodingUtils.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/common/utils/ReadWriteForEncodingUtils.java
@@ -130,7 +130,7 @@ public static void writeUnsignedVarInt(int value, OutputStream out) throws IOExc
      *
      *
      * @param value value to write into stream
-     * @param buffer where to store the result. buffer.remaining() needs to >= 32.
+     * @param buffer where to store the result. buffer.remaining() needs to larger than or equal to 32.
      *               Notice: (1) this function does not check buffer's remaining().
      *              (2) the position will be updated.
      * @return the number of bytes that the value consume.
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/common/utils/ReadWriteIOUtils.java b/src/main/java/cn/edu/tsinghua/tsfile/common/utils/ReadWriteIOUtils.java
index a4034078..36514e3f 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/common/utils/ReadWriteIOUtils.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/common/utils/ReadWriteIOUtils.java
@@ -255,6 +255,10 @@ public static String readStringFromDirectByteBuffer(ByteBuffer buffer) throws Ch
 
     /**
      * unlike InputStream.read(bytes), this method makes sure that you can read length bytes or reach to the end of the stream.
+     * @param inputStream input stream
+     * @param length read length
+     * @return read Bytes
+     * @throws IOException IOException
      */
     public static byte[] readBytes(InputStream inputStream, int length) throws IOException {
         byte[] bytes=new byte[length];
@@ -268,6 +272,9 @@ public static byte[] readBytes(InputStream inputStream, int length) throws IOExc
 
     /**
      * unlike InputStream.read(bytes), this method makes sure that you can read length bytes or reach to the end of the stream.
+     * @param inputStream input stream
+     * @return read Bytes
+     * @throws IOException IOException
      */
     public static byte[] readBytesWithSelfDescriptionLength(InputStream inputStream) throws IOException {
         int length=readInt(inputStream);
@@ -326,11 +333,6 @@ public static int readAsPossible(FileChannel channel, ByteBuffer buffer, int len
         return length;
     }
 
-
-
-    /**
-     * List<Integer>
-     */
     public static List<Integer> readIntegerList(InputStream inputStream) throws IOException {
         int size = readInt(inputStream);
         if(size <= 0)return null;
@@ -341,6 +343,7 @@ public static List<Integer> readIntegerList(InputStream inputStream) throws IOEx
 
         return list;
     }
+
     public static List<Integer> readIntegerList(ByteBuffer buffer) throws IOException {
         int size = readInt(buffer);
         if(size <= 0)return null;
@@ -371,9 +374,12 @@ public static List<String> readStringList(ByteBuffer buffer) throws IOException
         return list;
     }
 
-
     /**
-     * CompressionType
+     * write Compression
+     * @param compressionType Compression Type
+     * @param outputStream outputStream
+     * @return bytes length
+     * @throws IOException IOException
      */
     public static int write(CompressionType compressionType, OutputStream outputStream) throws IOException {
         short n = compressionType.serialize();
@@ -394,9 +400,6 @@ public static CompressionType readCompressionType(ByteBuffer buffer) {
     }
 
 
-    /**
-     * TSDataType
-     */
     public static int write(TSDataType dataType, OutputStream outputStream) throws IOException {
         short n = dataType.serialize();
         return write(n, outputStream);
@@ -416,9 +419,6 @@ public static TSDataType readDataType(ByteBuffer buffer) {
     }
 
 
-    /**
-     * TSEncoding
-     */
     public static int write(TSEncoding encoding, OutputStream outputStream) throws IOException {
         short n = encoding.serialize();
         return write(n, outputStream);
@@ -438,9 +438,6 @@ public static TSEncoding readEncoding(ByteBuffer buffer) {
     }
 
 
-    /**
-     * TSFreqType
-     */
     public static int write(TSFreqType freqType, OutputStream outputStream) throws IOException {
         short n = freqType.serialize();
         return write(n, outputStream);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/compress/Compressor.java b/src/main/java/cn/edu/tsinghua/tsfile/compress/Compressor.java
index c01ca355..39251251 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/compress/Compressor.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/compress/Compressor.java
@@ -42,12 +42,12 @@ public static Compressor getCompressor(CompressionType name) {
 
     /**
      *
-     * @param data
-     * @param offset
-     * @param length
-     * @param compressed
+     * @param data MUST be byte[]
+     * @param offset offset of data
+     * @param length length of data
+     * @param compressed MUST be byte[]
      * @return byte length of compressed data.
-     * @throws IOException
+     * @throws IOException IOException
      */
     public abstract  int  compress(byte[] data, int offset, int length, byte[] compressed) throws IOException;
 
@@ -56,7 +56,7 @@ public static Compressor getCompressor(CompressionType name) {
      * @param data MUST be DirectByteBuffer  for Snappy.
      * @param compressed MUST be DirectByteBuffer for Snappy.
      * @return byte length of compressed data.
-     * @throws IOException
+     * @throws IOException IOException
      */
     public abstract int compress(ByteBuffer data, ByteBuffer compressed) throws IOException;
 
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/compress/UnCompressor.java b/src/main/java/cn/edu/tsinghua/tsfile/compress/UnCompressor.java
index 209497e6..2fb315e1 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/compress/UnCompressor.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/compress/UnCompressor.java
@@ -38,8 +38,8 @@ public static UnCompressor getUnCompressor(CompressionType name) {
     /**
      *
      * @param buffer MUST be DirectByteBuffer
-     * @return
-     * @throws IOException
+     * @return Uncompressed length
+     * @throws IOException IOException
      */
     public abstract int getUncompressedLength(ByteBuffer buffer) throws IOException;
 
@@ -52,12 +52,13 @@ public static UnCompressor getUnCompressor(CompressionType name) {
 
     /**
      *
-     * @param byteArray
-     * @param offset
-     * @param length
-     * @param output
-     * @param outOffset
+     * @param byteArray to be uncompressed bytes
+     * @param offset offset
+     * @param length length
+     * @param output MUST be byte[]
+     * @param outOffset output offset
      * @return the valid length of the output array
+     * @throws IOException IOException
      */
     public abstract  int uncompress(byte[] byteArray, int offset, int length, byte[] output, int outOffset)  throws IOException ;
 
@@ -65,7 +66,8 @@ public static UnCompressor getUnCompressor(CompressionType name) {
      * if the data is large, using this function is better.
      * @param compressed MUST be DirectByteBuffer
      * @param uncompressed MUST be DirectByteBuffer
-     * @return
+     * @return the valid length
+     * @throws IOException IOException
      */
     public abstract int uncompress(ByteBuffer compressed, ByteBuffer uncompressed)   throws IOException ;
 
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/file/footer/RowGroupFooter.java b/src/main/java/cn/edu/tsinghua/tsfile/file/footer/RowGroupFooter.java
index 87cde980..15ef6a83 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/file/footer/RowGroupFooter.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/file/footer/RowGroupFooter.java
@@ -61,10 +61,10 @@ public int serializeTo(OutputStream outputStream) throws IOException {
     }
 
     /**
-     * @param inputStream
+     * @param inputStream input stream
      * @param markerRead  Whether the marker of the RowGroupFooter is read ahead.
-     * @return
-     * @throws IOException
+     * @return deserialized RowGroupFooter
+     * @throws IOException IOException
      */
     public static RowGroupFooter deserializeFrom(InputStream inputStream, boolean markerRead) throws IOException {
         if (!markerRead) {
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/file/header/ChunkHeader.java b/src/main/java/cn/edu/tsinghua/tsfile/file/header/ChunkHeader.java
index 7824124b..9a8ae21f 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/file/header/ChunkHeader.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/file/header/ChunkHeader.java
@@ -97,10 +97,10 @@ public int serializeTo(ByteBuffer buffer) {
     }
 
     /**
-     * @param inputStream
+     * @param inputStream input stream
      * @param markerRead  Whether the marker of the ChunkHeader has been read
-     * @return
-     * @throws IOException
+     * @return deserialized ChunkHeader
+     * @throws IOException IOException
      */
     public static ChunkHeader deserializeFrom(InputStream inputStream, boolean markerRead) throws IOException {
         if (!markerRead) {
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/file/metadata/TsFileMetaData.java b/src/main/java/cn/edu/tsinghua/tsfile/file/metadata/TsFileMetaData.java
index fdc52ea3..3f9f4212 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/file/metadata/TsFileMetaData.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/file/metadata/TsFileMetaData.java
@@ -39,6 +39,8 @@ public TsFileMetaData() {
     }
 
     /**
+     *
+     * @param deviceMap         - device map (String, TsDeviceMetadata)
      * @param measurementSchema - time series info list
      * @param currentVersion    - current version
      */
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/file/metadata/statistics/Statistics.java b/src/main/java/cn/edu/tsinghua/tsfile/file/metadata/statistics/Statistics.java
index 4e31753a..ff210f5b 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/file/metadata/statistics/Statistics.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/file/metadata/statistics/Statistics.java
@@ -170,7 +170,7 @@ public void reset() {
      *     boolean - 1 <br>
      *     No - 0 <br>
      *     binary - -1 which means uncertainty
-     *     </>
+     *
      */
     abstract public int sizeOfDatum();
 
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/TsFileSequenceReader.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/TsFileSequenceReader.java
index ff4c0c17..81d40f3c 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/TsFileSequenceReader.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/TsFileSequenceReader.java
@@ -37,10 +37,8 @@ public TsFileSequenceReader(String file) throws IOException {
     }
 
     /**
-     * After open the file, the reader position is at the end of the  magic string in the header.
-     *
-     * @return
-     * @throws IOException
+     * After open the file, the reader position is at the end of the magic string in the header.
+     * @throws IOException IOException
      */
     private void open() throws IOException {
         channel = FileChannel.open(path, StandardOpenOption.READ);
@@ -55,8 +53,8 @@ private void open() throws IOException {
     /**
      * this function does not modify the position of the file reader.
      *
-     * @return
-     * @throws IOException
+     * @return magic string bytes array in string format
+     * @throws IOException IOException
      */
     public String readTailMagic() throws IOException {
         long totalSize = channel.size();
@@ -69,8 +67,8 @@ public String readTailMagic() throws IOException {
     /**
      * this function does not modify the position of the file reader.
      *
-     * @return
-     * @throws IOException
+     * @return magic string bytes array in string format
+     * @throws IOException IOException
      */
     public String readHeadMagic() throws IOException {
         ByteBuffer magicStringBytes = ByteBuffer.allocate(TSFileConfig.MAGIC_STRING.length());
@@ -82,8 +80,8 @@ public String readHeadMagic() throws IOException {
     /**
      * this function does not modify the position of the file reader.
      *
-     * @return
-     * @throws IOException
+     * @return deserialized TsFile metadata
+     * @throws IOException IOException
      */
     public TsFileMetaData readFileMetadata() throws IOException {
         ByteBuffer buffer = ByteBuffer.allocate(fileMetadtaSize);
@@ -104,8 +102,8 @@ public RowGroupFooter readRowGroupFooter() throws IOException {
      * After reading the footer of a RowGroup, call this method to set the file pointer to the start of the data of this
      * RowGroup if you want to read its data next.
      *
-     * @param footer
-     * @throws IOException
+     * @param footer row group footer
+     * @throws IOException IOException
      */
     public void prepareReadRowGroup(RowGroupFooter footer) throws IOException {
         channel.position(channel.position() - footer.getDataSize() - footer.getSerializedSize());
@@ -119,8 +117,8 @@ public ChunkHeader readChunkHeader() throws IOException {
      * notice, this function will modify channel's position.
      *
      * @param offset the file offset of this chunk's header
-     * @return
-     * @throws IOException
+     * @return deserialized chunk header
+     * @throws IOException IOException
      */
     public ChunkHeader readChunkHeader(long offset) throws IOException {
         channel.position(offset);
@@ -130,9 +128,9 @@ public ChunkHeader readChunkHeader(long offset) throws IOException {
     /**
      * notice, the position of the channel MUST be at the end of this header.
      *
-     * @param header
+     * @param header chunk header
      * @return the pages of this chunk
-     * @throws IOException
+     * @throws IOException IOException
      */
     public ByteBuffer readChunk(ChunkHeader header) throws IOException {
         ByteBuffer buffer = ByteBuffer.allocate(header.getDataSize());
@@ -144,9 +142,9 @@ public ByteBuffer readChunk(ChunkHeader header) throws IOException {
     /**
      * notice, this function will modify channel's position.
      *
-     * @param position
-     * @return
-     * @throws IOException
+     * @param position read chunk header position
+     * @return chunk and header in ByteBuffer format
+     * @throws IOException IOException
      */
     public ByteBuffer readChunkAndHeader(long position) throws IOException {
         ChunkHeader header = readChunkHeader(position);
@@ -158,13 +156,13 @@ public ByteBuffer readChunkAndHeader(long position) throws IOException {
     }
 
     /**
-     * notice, the function will midify channel's position.
+     * notice, the function will modify channel's position.
      *
-     * @param position
-     * @param length
-     * @param output
-     * @return
-     * @throws IOException
+     * @param position channel start position
+     * @param length read length of raw ByteBuffer
+     * @param output output in ByteBuffer format
+     * @return read length
+     * @throws IOException IOException
      */
     public int readRaw(long position, int length, ByteBuffer output) throws IOException {
         channel.position(position);
@@ -174,9 +172,10 @@ public int readRaw(long position, int length, ByteBuffer output) throws IOExcept
     /**
      * notice, this function will modify channel's position.
      *
-     * @param header
+     * @param header chunk header
+     * @param positionOfChunkHeader position of chunk header
      * @return the pages of this chunk
-     * @throws IOException
+     * @throws IOException IOException
      */
     public ByteBuffer readChunk(ChunkHeader header, long positionOfChunkHeader) throws IOException {
         channel.position(positionOfChunkHeader);
@@ -190,9 +189,10 @@ public PageHeader readPageHeader(TSDataType type) throws IOException {
     /**
      * notice, this function will modify channel's position.
      *
+     * @param type time series data type
      * @param offset the file offset of this page header's header
-     * @return
-     * @throws IOException
+     * @return page header
+     * @throws IOException IOException
      */
     public PageHeader readPageHeader(TSDataType type, long offset) throws IOException {
         channel.position(offset);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/controller/SeriesChunkLoader.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/controller/SeriesChunkLoader.java
index 6708f581..24350e17 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/controller/SeriesChunkLoader.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/controller/SeriesChunkLoader.java
@@ -12,6 +12,9 @@ public interface SeriesChunkLoader {
 
     /**
      * read all content of any chunk
+     * @param chunkMetaData chunk meta data
+     * @return SeriesChunk
+     * @throws IOException IOException
      */
     SeriesChunk getMemSeriesChunk(ChunkMetaData chunkMetaData) throws IOException;
 }
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/datatype/RowRecord.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/datatype/RowRecord.java
index 1562b647..c2ccc48f 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/datatype/RowRecord.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/datatype/RowRecord.java
@@ -23,7 +23,7 @@ private RowRecord() {
 
     /**
      * init this.fields and set time stamp
-     * @param timestamp
+     * @param timestamp timestamp
      */
     public RowRecord(long timestamp) {
         this();
@@ -31,9 +31,9 @@ public RowRecord(long timestamp) {
     }
 
     /**
-     * add one <path, field>
-     * @param path
-     * @param tsPrimitiveType
+     * add one (path, field) tuple to fields map which contains all value fields of the record
+     * @param path a series in delta system
+     * @param tsPrimitiveType time series primitive type
      */
     public void putField(Path path, TsPrimitiveType tsPrimitiveType) {
         fields.put(path, tsPrimitiveType);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/datatype/TsPrimitiveType.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/datatype/TsPrimitiveType.java
index ea84a2e2..31861d35 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/datatype/TsPrimitiveType.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/datatype/TsPrimitiveType.java
@@ -13,7 +13,7 @@
 public abstract class TsPrimitiveType implements Serializable {
     /**
      * implemented in subclasses
-     * @return
+     * @return currently only throw an exception
      */
     public boolean getBoolean() {
         throw new UnsupportedOperationException("getBoolean() is not supported for current sub-class");
@@ -21,7 +21,7 @@ public boolean getBoolean() {
 
     /**
      * implemented in subclasses
-     * @return
+     * @return currently only throw an exception
      */
     public int getInt() {
         throw new UnsupportedOperationException("getInt() is not supported for current sub-class");
@@ -29,7 +29,7 @@ public int getInt() {
 
     /**
      * implemented in subclasses
-     * @return
+     * @return currently only throw an exception
      */
     public long getLong() {
         throw new UnsupportedOperationException("getLong() is not supported for current sub-class");
@@ -37,7 +37,7 @@ public long getLong() {
 
     /**
      * implemented in subclasses
-     * @return
+     * @return currently only throw an exception
      */
     public float getFloat() {
         throw new UnsupportedOperationException("getFloat() is not supported for current sub-class");
@@ -45,7 +45,7 @@ public float getFloat() {
 
     /**
      * implemented in subclasses
-     * @return
+     * @return currently only throw an exception
      */
     public double getDouble() {
         throw new UnsupportedOperationException("getDouble() is not supported for current sub-class");
@@ -53,7 +53,7 @@ public double getDouble() {
 
     /**
      * implemented in subclasses
-     * @return
+     * @return currently only throw an exception
      */
     public Binary getBinary() {
         throw new UnsupportedOperationException("getBinary() is not supported for current sub-class");
@@ -69,13 +69,13 @@ public Binary getBinary() {
 
     /**
      * get value in String format
-     * @return
+     * @return value in string format
      */
     public abstract String getStringValue();
 
     /**
      * get corresponding data type of subclasses
-     * @return
+     * @return corresponding data type of subclasses
      */
     public abstract TSDataType getDataType();
 
@@ -94,7 +94,7 @@ public static class TsBoolean extends TsPrimitiveType {
 
         /**
          * init value
-         * @param value
+         * @param value MUST be boolean
          */
         public TsBoolean(boolean value) {
             this.value = value;
@@ -132,7 +132,7 @@ public static class TsInt extends TsPrimitiveType {
 
         /**
          * init value
-         * @param value
+         * @param value MUST be int
          */
         public TsInt(int value) {
             this.value = value;
@@ -170,7 +170,7 @@ public static class TsLong extends TsPrimitiveType {
 
         /**
          * init value
-         * @param value
+         * @param value MUST be long
          */
         public TsLong(long value) {
             this.value = value;
@@ -208,7 +208,7 @@ public static class TsFloat extends TsPrimitiveType {
 
         /**
          * init value
-         * @param value
+         * @param value MUST be float
          */
         public TsFloat(float value) {
             this.value = value;
@@ -246,7 +246,7 @@ public static class TsDouble extends TsPrimitiveType {
 
         /**
          * init value
-         * @param value
+         * @param value MUST be double
          */
         public TsDouble(double value) {
             this.value = value;
@@ -284,7 +284,7 @@ public static class TsBinary extends TsPrimitiveType {
 
         /**
          * init value
-         * @param value
+         * @param value MUST be Binary
          */
         public TsBinary(Binary value) {
             this.value = value;
@@ -318,8 +318,8 @@ public TSDataType getDataType() {
 
     /**
      * get corresponding subclass of input data type and set its value
-     * @param dataType
-     * @param v
+     * @param dataType  data type
+     * @param v         value
      * @return corresponding implementation of {@code TsPrimitiveType}
      */
     public static TsPrimitiveType getByType(TSDataType dataType, Object v) {
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/query/QueryDataSet.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/query/QueryDataSet.java
index 0f5f900e..0068666f 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/query/QueryDataSet.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/query/QueryDataSet.java
@@ -11,16 +11,16 @@ public interface QueryDataSet {
 
     /**
      * check if unread data still exists
-     * @return
-     * @throws IOException
+     * @return whether the QueryDataSet has the next data
+     * @throws IOException IOException
      */
     boolean hasNext() throws IOException;
 
     /**
      * get the next unread data
      * another data will be returned when calling this method next time
-     * @return
-     * @throws IOException
+     * @return the next RowRecord
+     * @throws IOException IOException
      */
     RowRecord next() throws IOException;
 
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/query/timegenerator/node/AndNode.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/query/timegenerator/node/AndNode.java
index a431e2a8..3a365253 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/query/timegenerator/node/AndNode.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/query/timegenerator/node/AndNode.java
@@ -51,10 +51,8 @@ public boolean hasNext() throws IOException {
     }
 
     /**
-     * If there is no value in current Node, -1 will be returned if {@code next()} is invoked
-     *
-     * @return
-     * @throws IOException
+     * @return If there is no value in current Node, -1 will be returned if {@code next()} is invoked
+     * @throws IOException IOException
      */
     @Override
     public long next() throws IOException {
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/SeriesReader.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/SeriesReader.java
index c33cc3ee..bc62a73a 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/SeriesReader.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/SeriesReader.java
@@ -10,17 +10,22 @@
 public interface SeriesReader {
 
     /**
-     * if there is a next time-value pair
+     *
+     * @return if there is a next time-value pair
+     * @throws IOException IOException
      */
     boolean hasNext() throws IOException;
 
     /**
+     *
      * @return next time value pair
+     * @throws IOException IOException
      */
     TimeValuePair next() throws IOException;
 
     /**
      * skip the current time value pair, just call next()
+     * @throws IOException IOException
      */
     void skipCurrentTimeValuePair() throws IOException;
 
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/SeriesReaderByTimeStamp.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/SeriesReaderByTimeStamp.java
index e7f8316c..07183716 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/SeriesReaderByTimeStamp.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/SeriesReaderByTimeStamp.java
@@ -6,9 +6,10 @@
 
 public interface SeriesReaderByTimeStamp extends SeriesReader {
     /**
-     * @param timestamp
+     *
+     * @param timestamp timestamp
      * @return If there is no TimeValuePair whose timestamp equals to given timestamp, then return null.
-     * @throws IOException
+     * @throws IOException IOException
      */
     TsPrimitiveType getValueInTimestamp(long timestamp) throws IOException;
 
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/impl/SeriesReaderFromSingleFile.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/impl/SeriesReaderFromSingleFile.java
index 150dfd8b..de1d48d3 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/impl/SeriesReaderFromSingleFile.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/impl/SeriesReaderFromSingleFile.java
@@ -42,8 +42,8 @@ public SeriesReaderFromSingleFile(TsFileSequenceReader fileReader,
 
     /**
      * Using this constructor cannot close corresponding FileStream
-     * @param seriesChunkLoader
-     * @param chunkMetaDataList
+     * @param seriesChunkLoader series chunk loader
+     * @param chunkMetaDataList chunk metadata list
      */
     public SeriesReaderFromSingleFile(SeriesChunkLoader seriesChunkLoader, List<ChunkMetaData> chunkMetaDataList) {
         this.seriesChunkLoader = seriesChunkLoader;
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/impl/SeriesReaderFromSingleFileByTimestampImpl.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/impl/SeriesReaderFromSingleFileByTimestampImpl.java
index 5f60b9de..9b38cf09 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/impl/SeriesReaderFromSingleFileByTimestampImpl.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/read/reader/impl/SeriesReaderFromSingleFileByTimestampImpl.java
@@ -88,9 +88,9 @@ public TimeValuePair next() throws IOException {
     }
 
     /**
-     * @param timestamp
+     * @param timestamp timestamp
      * @return If there is no TimeValuePair whose timestamp equals to given timestamp, then return null.
-     * @throws IOException
+     * @throws IOException IOException
      */
     @Override
     public TsPrimitiveType getValueInTimestamp(long timestamp) throws IOException {
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/utils/cache/LRUCache.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/utils/cache/LRUCache.java
index 8adf0656..fd7e33c0 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/utils/cache/LRUCache.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/utils/cache/LRUCache.java
@@ -57,8 +57,8 @@ private void removeFirstObject() throws CacheException {
 
     /**
      * Do something before remove object from cache.
-     *
-     * @param object
+     * @param object removed object
+     * @throws CacheException CacheException
      */
     public abstract void beforeRemove(T object) throws CacheException;
 
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/TsFileWriter.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/TsFileWriter.java
index 8bb79e09..6820902c 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/TsFileWriter.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/TsFileWriter.java
@@ -62,7 +62,7 @@ public class TsFileWriter {
      * init this TsFileWriter
      *
      * @param file the File to be written by this TsFileWriter
-     * @throws IOException
+     * @throws IOException IOException
      */
     public TsFileWriter(File file) throws IOException {
         this(new TsFileIOWriter(file), new FileSchema(), TSFileDescriptor.getInstance().getConfig());
@@ -73,7 +73,7 @@ public TsFileWriter(File file) throws IOException {
      *
      * @param file   the File to be written by this TsFileWriter
      * @param schema the schema of this TsFile
-     * @throws IOException
+     * @throws IOException IOException
      */
     public TsFileWriter(File file, FileSchema schema) throws IOException {
         this(new TsFileIOWriter(file), schema, TSFileDescriptor.getInstance().getConfig());
@@ -84,7 +84,7 @@ public TsFileWriter(File file, FileSchema schema) throws IOException {
      *
      * @param file the File to be written by this TsFileWriter
      * @param conf the configuration of this TsFile
-     * @throws IOException
+     * @throws IOException IOException
      */
     public TsFileWriter(File file, TSFileConfig conf) throws IOException {
         this(new TsFileIOWriter(file), new FileSchema(), conf);
@@ -96,7 +96,7 @@ public TsFileWriter(File file, TSFileConfig conf) throws IOException {
      * @param file   the File to be written by this TsFileWriter
      * @param schema the schema of this TsFile
      * @param conf   the configuration of this TsFile
-     * @throws IOException
+     * @throws IOException IOException
      */
     public TsFileWriter(File file, FileSchema schema, TSFileConfig conf)
             throws IOException {
@@ -119,6 +119,8 @@ protected TsFileWriter(TsFileIOWriter tsfileWriter, FileSchema schema, TSFileCon
 
     /**
      * add a MeasurementSchema to this TsFile
+     * @param measurementSchema measurement schema
+     * @throws WriteProcessException WriteProcessException
      */
     public void addMeasurement(MeasurementSchema measurementSchema)
             throws WriteProcessException {
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/desc/MeasurementSchema.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/desc/MeasurementSchema.java
index e723aeb5..23ed8344 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/desc/MeasurementSchema.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/desc/MeasurementSchema.java
@@ -48,6 +48,9 @@ public MeasurementSchema() {}
 
   /**
    * set properties as an empty Map
+   * @param measurementId measurement Id
+   * @param type data type
+   * @param encoding enum encoding type
    */
   public MeasurementSchema(String measurementId, TSDataType type, TSEncoding encoding) {
     this(measurementId, type, encoding, CompressionType.valueOf(TSFileDescriptor.getInstance().getConfig().compressor), Collections.emptyMap());
@@ -58,12 +61,13 @@ public MeasurementSchema(String measurementId, TSDataType type, TSEncoding encod
 
   /**
    *
-   * @param measurementId
-   * @param type
-   * @param encoding
-   * @param props         information in encoding method.
-   *                      For RLE, Encoder.MAX_POINT_NUMBER
-   *                      For PLAIN, Encoder.MAX_STRING_LENGTH
+   * @param measurementId   measurement Id
+   * @param type            data type
+   * @param encoding        enum encoding type
+   * @param compressionType compression type
+   * @param props           information in encoding method.
+   *                        For RLE, Encoder.MAX_POINT_NUMBER
+   *                        For PLAIN, Encoder.MAX_STRING_LENGTH
    */
   public MeasurementSchema(String measurementId, TSDataType type, TSEncoding encoding, CompressionType compressionType,
                            Map<String, String> props) {
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/io/TsFileIOWriter.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/io/TsFileIOWriter.java
index f85cd535..d7148a1b 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/io/TsFileIOWriter.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/io/TsFileIOWriter.java
@@ -72,10 +72,11 @@ private void startFile() throws IOException {
 
     /**
      * start a {@linkplain ChunkGroupMetaData ChunkGroupMetaData}.
-     *
      * @param deviceId delta object id
-     * @param dataSize      the serialized size of all chunks
+     * @param dataSize the serialized size of all chunks
+     * @param numberOfChunks number of chunks
      * @return the serialized size of RowGroupFooter
+     * @throws IOException IOException
      */
     public RowGroupFooter startFlushRowGroup(String deviceId, long dataSize, int numberOfChunks) throws IOException {
         LOG.debug("start row group:{}, file position {}", deviceId, out.getChannel().position());
@@ -87,14 +88,15 @@ public RowGroupFooter startFlushRowGroup(String deviceId, long dataSize, int num
 
     /**
      * start a {@linkplain ChunkMetaData ChunkMetaData}.
-     *
-     * @param descriptor           - measurement of this time series
-     * @param compressionCodecName - compression name of this time series
-     * @param tsDataType           - data type
-     * @param statistics           - statistic of the whole series
-     * @param maxTime              - maximum timestamp of the whole series in this stage
-     * @param minTime              - minimum timestamp of the whole series in this stage
-     * @param datasize             -  the serialized size of all pages
+     * @param descriptor            - measurement of this time series
+     * @param compressionCodecName  - compression name of this time series
+     * @param tsDataType            - data type
+     * @param encodingType          - encoding type
+     * @param statistics            - statistic of the whole series
+     * @param maxTime               - maximum timestamp of the whole series in this stage
+     * @param minTime               - minimum timestamp of the whole series in this stage
+     * @param datasize              - the serialized size of all pages
+     * @param numOfPages            - number of pages
      * @return the serialized size of CHunkHeader
      * @throws IOException if I/O error occurs
      */
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/BooleanDataPoint.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/BooleanDataPoint.java
index a13dc167..3854670b 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/BooleanDataPoint.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/BooleanDataPoint.java
@@ -20,6 +20,8 @@ public class BooleanDataPoint extends DataPoint {
 
     /**
      * constructor of BooleanDataPoint, the value type will be set automatically
+     * @param measurementId measurement ID (sensor name)
+     * @param v value
      */
     public BooleanDataPoint(String measurementId, boolean v) {
         super(TSDataType.BOOLEAN, measurementId);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/DoubleDataPoint.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/DoubleDataPoint.java
index d112305d..9e09c6ee 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/DoubleDataPoint.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/DoubleDataPoint.java
@@ -20,6 +20,8 @@ public class DoubleDataPoint extends DataPoint {
 
     /**
      * constructor of DoubleDataPoint, the value type will be set automatically
+     * @param measurementId measurement id
+     * @param v value
      */
     public DoubleDataPoint(String measurementId, double v) {
         super(TSDataType.DOUBLE, measurementId);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/FloatDataPoint.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/FloatDataPoint.java
index 92188a94..c1874a09 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/FloatDataPoint.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/FloatDataPoint.java
@@ -20,6 +20,8 @@ public class FloatDataPoint extends DataPoint {
 
     /**
      * constructor of FloatDataPoint, the value type will be set automatically
+     * @param measurementId measurement Id
+     * @param v value
      */
     public FloatDataPoint(String measurementId, float v) {
         super(TSDataType.FLOAT, measurementId);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/IntDataPoint.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/IntDataPoint.java
index 5f45b7af..17abba33 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/IntDataPoint.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/IntDataPoint.java
@@ -20,6 +20,8 @@ public class IntDataPoint extends DataPoint {
 
     /**
      * constructor of IntDataPoint, the value type will be set automatically
+     * @param measurementId measurement Id
+     * @param v value
      */
     public IntDataPoint(String measurementId, int v) {
         super(TSDataType.INT32, measurementId);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/LongDataPoint.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/LongDataPoint.java
index 00e8d08b..420f406e 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/LongDataPoint.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/LongDataPoint.java
@@ -20,6 +20,9 @@ public class LongDataPoint extends DataPoint {
 
     /**
      * constructor of LongDataPoint, the value type will be set automatically
+     *
+     * @param measurementId measurement Id
+     * @param v value
      */
     public LongDataPoint(String measurementId, long v) {
         super(TSDataType.INT64, measurementId);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/StringDataPoint.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/StringDataPoint.java
index 2c3b7764..cf5d2d06 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/StringDataPoint.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/record/datapoint/StringDataPoint.java
@@ -21,6 +21,8 @@ public class StringDataPoint extends DataPoint {
 
     /**
      * constructor of StringDataPoint, the value type will be set automatically
+     * @param measurementId measurement Id
+     * @param v value
      */
     public StringDataPoint(String measurementId, Binary v) {
         super(TSDataType.TEXT, measurementId);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/schema/FileSchema.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/schema/FileSchema.java
index 680cf52b..aefe3238 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/schema/FileSchema.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/schema/FileSchema.java
@@ -63,6 +63,7 @@ public FileSchema() {
    *   };
    *
    * @param jsonSchema file schema in json format
+   * @throws InvalidJsonSchemaException invalid JSON schema
    */
   @Deprecated
   public FileSchema(JSONObject jsonSchema) throws InvalidJsonSchemaException {
@@ -71,6 +72,7 @@ public FileSchema(JSONObject jsonSchema) throws InvalidJsonSchemaException {
 
   /**
    * init additionalProperties and register measurements
+   * @param measurements (measurements id, measurement schema) map
    */
   public FileSchema(Map<String, MeasurementSchema> measurements) {
     this();
@@ -87,14 +89,13 @@ public TSDataType getMeasurementDataTypes(String measurementUID) {
 
   }
 
-
   public Map<String, MeasurementSchema> getAllMeasurementSchema() {
     return measurementSchema;
   }
 
-
   /**
    * register a MeasurementSchema
+   * @param descriptor measurement schema descriptor
    */
   public void registerMeasurement(MeasurementSchema descriptor) {
     // add to measurementSchema as <measurementID, MeasurementSchema>
@@ -103,6 +104,7 @@ public void registerMeasurement(MeasurementSchema descriptor) {
 
   /**
    * register all MeasurementSchema in input map
+   * @param measurements measurements name and schema map
    */
   private void registerMeasurements(Map<String, MeasurementSchema> measurements) {
     measurements.forEach((id, md) -> registerMeasurement(md));
@@ -110,6 +112,8 @@ private void registerMeasurements(Map<String, MeasurementSchema> measurements) {
 
   /**
    * check is this schema contains input measurementID
+   * @param measurementId measurement ID
+   * @return if measurementSchema has the measurement ID
    */
   public boolean hasMeasurement(String measurementId) {
     return measurementSchema.containsKey(measurementId);
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/schema/SchemaBuilder.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/schema/SchemaBuilder.java
index 22b56e27..3cd302e7 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/schema/SchemaBuilder.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/schema/SchemaBuilder.java
@@ -26,6 +26,7 @@ public SchemaBuilder() {
     /**
      * add one series to TsFile schema
      *
+     * @param type          compression type
      * @param measurementId (not null) id of the series
      * @param dataType      (not null) series data type
      * @param tsEncoding    (not null) encoding method you specified
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/ChunkBuffer.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/ChunkBuffer.java
index 90317725..6ca06295 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/ChunkBuffer.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/ChunkBuffer.java
@@ -63,7 +63,7 @@ public void setNumOfPages(int numOfPages) {
      * @param maxTimestamp  - timestamp maximum in given data
      * @param minTimestamp  - timestamp minimum in given data
      * @return  byte size of the page header and uncompressed data in the page body.
-     * @throws PageException
+     * @throws PageException PageException
      */
     public int writePageHeaderAndDataIntoBuff(ByteBuffer data, int valueCount, Statistics<?> statistics,
                                               long maxTimestamp, long minTimestamp) throws PageException {
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/IChunkWriter.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/IChunkWriter.java
index 2a779e5b..1dc3763a 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/IChunkWriter.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/IChunkWriter.java
@@ -15,57 +15,81 @@ public interface IChunkWriter {
 
     /**
      * write a time value pair
+     * @param time data timestamp
+     * @param value MUST be int
+     * @throws IOException IOException
      */
     void write(long time, int value) throws IOException;
 
     /**
      * write a time value pair
+     * @param time data timestamp
+     * @param value MUST be long
+     * @throws IOException IOException
      */
     void write(long time, long value) throws IOException;
 
     /**
      * write a time value pair
+     * @param time data timestamp
+     * @param value MUST be boolean
+     * @throws IOException IOException
      */
     void write(long time, boolean value) throws IOException;
 
     /**
      * write a time value pair
+     * @param time data timestamp
+     * @param value MUST be float
+     * @throws IOException IOException
      */
     void write(long time, float value) throws IOException;
 
     /**
      * write a time value pair
+     * @param time data timestamp
+     * @param value MUST be double
+     * @throws IOException IOException
      */
     void write(long time, double value) throws IOException;
 
     /**
      * write a time value pair
+     * @param time data timestamp
+     * @param value MUST be BigDecimal
+     * @throws IOException IOException
      */
     void write(long time, BigDecimal value) throws IOException;
 
     /**
      * write a time value pair
+     * @param time data timestamp
+     * @param value MUST be Binary
+     * @throws IOException IOException
      */
     void write(long time, Binary value) throws IOException;
 
     /**
      * flush data to TsFileIOWriter
+     * @param tsfileWriter Must be TsFileIOWriter
+     * @throws IOException IOException
      */
     void writeToFileWriter(TsFileIOWriter tsfileWriter) throws IOException;
 
     /**
      * estimate memory used size of this series
+     * @return estimated max series memory size
      */
     long estimateMaxSeriesMemSize();
 
     /**
      * return the serialized size of the chunk header + all pages
+     * @return current chunk size
      */
     long getCurrentChunkSize();
 
     /**
      * prepare to flush data into file.
-     *
      */
     void preFlush();
 
diff --git a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/PageWriter.java b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/PageWriter.java
index 59d4bea9..6173a395 100644
--- a/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/PageWriter.java
+++ b/src/main/java/cn/edu/tsinghua/tsfile/timeseries/write/series/PageWriter.java
@@ -30,6 +30,9 @@ public PageWriter() {
 
     /**
      * write a time value pair into encoder
+     * @param time data timestamp
+     * @param value MUST be boolean
+     * @throws IOException IOException
      */
     public void write(long time, boolean value) throws IOException {
         timeEncoder.encode(time, timeOut);
@@ -38,6 +41,9 @@ public void write(long time, boolean value) throws IOException {
 
     /**
      * write a time value pair into encoder
+     * @param time data timestamp
+     * @param value MUST be short
+     * @throws IOException IOException
      */
     public void write(long time, short value) throws IOException {
         timeEncoder.encode(time, timeOut);
@@ -46,6 +52,9 @@ public void write(long time, short value) throws IOException {
 
     /**
      * write a time value pair into encoder
+     * @param time data timestamp
+     * @param value MUST be int
+     * @throws IOException IOException
      */
     public void write(long time, int value) throws IOException {
         timeEncoder.encode(time, timeOut);
@@ -54,6 +63,9 @@ public void write(long time, int value) throws IOException {
 
     /**
      * write a time value pair into encoder
+     * @param time data timestamp
+     * @param value MUST be long
+     * @throws IOException IOException
      */
     public void write(long time, long value) throws IOException {
         timeEncoder.encode(time, timeOut);
@@ -62,6 +74,9 @@ public void write(long time, long value) throws IOException {
 
     /**
      * write a time value pair into encoder
+     * @param time data timestamp
+     * @param value MUST be float
+     * @throws IOException IOException
      */
     public void write(long time, float value) throws IOException {
         timeEncoder.encode(time, timeOut);
@@ -70,6 +85,9 @@ public void write(long time, float value) throws IOException {
 
     /**
      * write a time value pair into encoder
+     * @param time data timestamp
+     * @param value MUST be double
+     * @throws IOException IOException
      */
     public void write(long time, double value) throws IOException {
         timeEncoder.encode(time, timeOut);
@@ -78,6 +96,9 @@ public void write(long time, double value) throws IOException {
 
     /**
      * write a time value pair into encoder
+     * @param time data timestamp
+     * @param value MUST be BigDecimal
+     * @throws IOException IOException
      */
     public void write(long time, BigDecimal value) throws IOException {
         timeEncoder.encode(time, timeOut);
@@ -86,6 +107,9 @@ public void write(long time, BigDecimal value) throws IOException {
 
     /**
      * write a time value pair into encoder
+     * @param time data timestamp
+     * @param value MUST be Binary
+     * @throws IOException IOException
      */
     public void write(long time, Binary value) throws IOException {
         timeEncoder.encode(time, timeOut);
@@ -94,17 +118,18 @@ public void write(long time, Binary value) throws IOException {
 
     /**
      * flush all data remained in encoders.
+     * @throws IOException IOException
      */
     private void prepareEndWriteOnePage() throws IOException {
         timeEncoder.flush(timeOut);
         valueEncoder.flush(valueOut);
     }
 
-
     /**
      * getUncompressedBytes return data what it has been written in form of <code>size of time list, time list, value list</code>
      *
      * @return a new readable ByteBuffer whose position is 0.
+     * @throws IOException IOException
      */
     public ByteBuffer getUncompressedBytes() throws IOException {
         prepareEndWriteOnePage();