diff --git a/docs/spring/cse3ef992a-8c1e-11ee-8a91-acde48001122.java b/docs/spring/cse3ef992a-8c1e-11ee-8a91-acde48001122.java
new file mode 100644
index 00000000..bb80dba4
--- /dev/null
+++ b/docs/spring/cse3ef992a-8c1e-11ee-8a91-acde48001122.java
@@ -0,0 +1,31 @@
+/**
+ * Copyright 2009-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.ibatis.submitted.foreach_map;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+public class MapParam {
+ private Map map = new LinkedHashMap<>();
+
+ public Map getMap() {
+ return map;
+ }
+
+ public void setMap(Map map) {
+ this.map = map;
+ }
+}
diff --git a/docs/spring/cse434f1b4-8c1e-11ee-8a91-acde48001122.java b/docs/spring/cse434f1b4-8c1e-11ee-8a91-acde48001122.java
new file mode 100644
index 00000000..05e76110
--- /dev/null
+++ b/docs/spring/cse434f1b4-8c1e-11ee-8a91-acde48001122.java
@@ -0,0 +1,166 @@
+/**
+ * Copyright 2009-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.ibatis.transaction.jdbc;
+
+import org.apache.ibatis.logging.Log;
+import org.apache.ibatis.logging.LogFactory;
+import org.apache.ibatis.session.TransactionIsolationLevel;
+import org.apache.ibatis.transaction.Transaction;
+import org.apache.ibatis.transaction.TransactionException;
+
+import javax.sql.DataSource;
+import java.sql.Connection;
+import java.sql.SQLException;
+
+/**
+ *
+ *
+ *
+ *
这部分的内容是数据JDBC操作
+ * {@link Transaction} that makes use of the JDBC commit and rollback facilities directly.
+ * It relies on the connection retrieved from the dataSource to manage the scope of the transaction.
+ * Delays connection retrieval until getConnection() is called.
+ * Ignores commit or rollback requests when autocommit is on.
+ *
+ * @author Clinton Begin
+ * @see JdbcTransactionFactory
+ */
+public class JdbcTransaction implements Transaction {
+
+ private static final Log log = LogFactory.getLog(JdbcTransaction.class);
+
+ protected Connection connection;
+ protected DataSource dataSource;
+ protected TransactionIsolationLevel level;
+ protected boolean autoCommit;
+
+ public JdbcTransaction(DataSource ds, TransactionIsolationLevel desiredLevel, boolean desiredAutoCommit) {
+ dataSource = ds;
+ level = desiredLevel;
+ autoCommit = desiredAutoCommit;
+ }
+
+ public JdbcTransaction(Connection connection) {
+ this.connection = connection;
+ }
+
+ /**
+ * 获取连接对象
+ * @return
+ * @throws SQLException
+ */
+ @Override
+ public Connection getConnection() throws SQLException {
+ if (connection == null) {
+ openConnection();
+ }
+ return connection;
+ }
+
+ /**
+ * 提交
+ * @throws SQLException
+ */
+ @Override
+ public void commit() throws SQLException {
+ if (connection != null && !connection.getAutoCommit()) {
+ if (log.isDebugEnabled()) {
+ log.debug("Committing JDBC Connection [" + connection + "]");
+ }
+ connection.commit();
+ }
+ }
+
+ /**
+ * 回滚
+ * @throws SQLException
+ */
+ @Override
+ public void rollback() throws SQLException {
+ if (connection != null && !connection.getAutoCommit()) {
+ if (log.isDebugEnabled()) {
+ log.debug("Rolling back JDBC Connection [" + connection + "]");
+ }
+ connection.rollback();
+ }
+ }
+
+ @Override
+ public void close() throws SQLException {
+ if (connection != null) {
+ resetAutoCommit();
+ if (log.isDebugEnabled()) {
+ log.debug("Closing JDBC Connection [" + connection + "]");
+ }
+ connection.close();
+ }
+ }
+
+ protected void setDesiredAutoCommit(boolean desiredAutoCommit) {
+ try {
+ if (connection.getAutoCommit() != desiredAutoCommit) {
+ if (log.isDebugEnabled()) {
+ log.debug("Setting autocommit to " + desiredAutoCommit + " on JDBC Connection [" + connection + "]");
+ }
+ connection.setAutoCommit(desiredAutoCommit);
+ }
+ } catch (SQLException e) {
+ // Only a very poorly implemented driver would fail here,
+ // and there's not much we can do about that.
+ throw new TransactionException("Error configuring AutoCommit. "
+ + "Your driver may not support getAutoCommit() or setAutoCommit(). "
+ + "Requested setting: " + desiredAutoCommit + ". Cause: " + e, e);
+ }
+ }
+
+ protected void resetAutoCommit() {
+ try {
+ if (!connection.getAutoCommit()) {
+ // MyBatis does not call commit/rollback on a connection if just selects were performed.
+ // Some databases start transactions with select statements
+ // and they mandate a commit/rollback before closing the connection.
+ // A workaround is setting the autocommit to true before closing the connection.
+ // Sybase throws an exception here.
+ if (log.isDebugEnabled()) {
+ log.debug("Resetting autocommit to true on JDBC Connection [" + connection + "]");
+ }
+ connection.setAutoCommit(true);
+ }
+ } catch (SQLException e) {
+ if (log.isDebugEnabled()) {
+ log.debug("Error resetting autocommit to true "
+ + "before closing the connection. Cause: " + e);
+ }
+ }
+ }
+
+ protected void openConnection() throws SQLException {
+ if (log.isDebugEnabled()) {
+ log.debug("Opening JDBC Connection");
+ }
+ connection = dataSource.getConnection();
+ if (level != null) {
+ connection.setTransactionIsolation(level.getLevel());
+ }
+ setDesiredAutoCommit(autoCommit);
+ }
+
+ @Override
+ public Integer getTimeout() throws SQLException {
+ return null;
+ }
+
+}
diff --git a/docs/spring/cse47cec4e-8c1e-11ee-8a91-acde48001122.java b/docs/spring/cse47cec4e-8c1e-11ee-8a91-acde48001122.java
new file mode 100644
index 00000000..08f3f3c6
--- /dev/null
+++ b/docs/spring/cse47cec4e-8c1e-11ee-8a91-acde48001122.java
@@ -0,0 +1,37 @@
+/**
+ * Copyright 2009-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.ibatis.reflection;
+
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.UndeclaredThrowableException;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ExceptionUtilTest {
+
+ @Test
+ void shouldUnwrapThrowable() {
+ Exception exception = new Exception();
+ assertEquals(exception, ExceptionUtil.unwrapThrowable(exception));
+ assertEquals(exception, ExceptionUtil.unwrapThrowable(new InvocationTargetException(exception, "test")));
+ assertEquals(exception, ExceptionUtil.unwrapThrowable(new UndeclaredThrowableException(exception, "test")));
+ assertEquals(exception, ExceptionUtil.unwrapThrowable(new InvocationTargetException(new InvocationTargetException(exception, "test"), "test")));
+ assertEquals(exception, ExceptionUtil.unwrapThrowable(new InvocationTargetException(new UndeclaredThrowableException(exception, "test"), "test")));
+ }
+
+}
diff --git a/docs/spring/cse4c3851e-8c1e-11ee-8a91-acde48001122.java b/docs/spring/cse4c3851e-8c1e-11ee-8a91-acde48001122.java
new file mode 100644
index 00000000..d7cbe115
--- /dev/null
+++ b/docs/spring/cse4c3851e-8c1e-11ee-8a91-acde48001122.java
@@ -0,0 +1,43 @@
+/**
+ * Copyright 2009-2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.ibatis.domain.blog;
+
+public class Tag {
+
+ private int id;
+ private String name;
+
+ public int getId() {
+ return id;
+ }
+
+ public void setId(int id) {
+ this.id = id;
+ }
+
+ public String getName() {
+ return name;
+ }
+
+ public void setName(String name) {
+ this.name = name;
+ }
+
+ @Override
+ public String toString() {
+ return "Tag: " + id + " : " + name;
+ }
+}
diff --git a/docs/spring/cse5138316-8c1e-11ee-8a91-acde48001122.java b/docs/spring/cse5138316-8c1e-11ee-8a91-acde48001122.java
new file mode 100644
index 00000000..0c4ce062
--- /dev/null
+++ b/docs/spring/cse5138316-8c1e-11ee-8a91-acde48001122.java
@@ -0,0 +1,142 @@
+package com.huifer.data.list.doubleLinkedList;
+
+/**
+ *
Title : DoubleLinkedList
+ * Description : 双向循环链表
+ *
+ * @author huifer
+ * @date 2019-04-18
+ */
+public class DoubleLinkedList {
+
+ private DoubleNode first;
+ private DoubleNode last;
+ private int size = 0;
+
+ public static void main(String[] args) {
+ DoubleLinkedList d = new DoubleLinkedList();
+ d.add(0);
+ d.add(1);
+ d.add(2);
+
+ d.add(1, 999);
+ d.delete(999);
+ System.out.println();
+ }
+
+ public void add(Integer data) {
+ addLast(data);
+ }
+
+
+ public boolean delete(Integer data) {
+ if (data == null) {
+ throw new RuntimeException("参数不能空");
+ } else {
+ for (DoubleNode d = first; d != null; d = d.next) {
+ if (d.data.equals(data)) {
+ deleteNode(d);
+ return true;
+ }
+ }
+ }
+ return false;
+ }
+
+ private Integer deleteNode(DoubleNode d) {
+ DoubleNode next = d.next;
+ DoubleNode prev = d.prev;
+
+ if (prev == null) {
+ first = next;
+ } else {
+ // 当前结点上一个结点等与当前结点的下一个
+ prev.next = next;
+ d.prev = null;
+ }
+
+ if (next == null) {
+ last = prev;
+ } else {
+ // 当前结点的下一个结点等与当前结点的上一个结点
+ next.prev = prev;
+ d.next = null;
+ }
+
+ d.data = null;
+ size--;
+ return d.data;
+ }
+
+
+ public DoubleNode get(int index) {
+ return node(index);
+ }
+
+
+ private void addLast(Integer data) {
+ // 原来的最后一个结点
+ DoubleNode l = this.last;
+ // 新增节点 ,新增节点的上一个结点是最后一个 没有下一个结点
+ DoubleNode newNode = new DoubleNode(data, l, null);
+ last = newNode;
+ if (l == null) {
+ // 如果最后一个结点等于空 那么只有一个结点 第一个结点等于新节点
+ first = newNode;
+ } else {
+ // 否则l的下一个结点等于新节点
+ l.next = newNode;
+ }
+ size++;
+ }
+
+
+ public void add(int index, Integer data) {
+ if (!(index >= 0 && index <= size)) {
+ throw new IndexOutOfBoundsException();
+ }
+ if (size == index) {
+ addLast(data);
+ } else {
+ addbefor(data, node(index));
+ }
+
+ }
+
+
+ private void addbefor(Integer data, DoubleNode node) {
+ // 输入结点的上一个结点
+ DoubleNode pred = node.prev;
+ // 新节点构造 (数据, 上一个结点是输入结点的下一个,下一个结点时输入结点)
+ DoubleNode newNode = new DoubleNode(data, pred, node);
+ // 输入结点的下一个结点时新结点
+ node.prev = newNode;
+ if (pred == null) {
+ first = newNode;
+ } else {
+ pred.next = newNode;
+ }
+ size++;
+ }
+
+
+ private DoubleNode node(int index) {
+ // 一半一半的去查询找到这个结点
+ if (index < (size >> 1)) {
+ // 当index这个值小于总量的一半从头查询 反之从尾部开始
+ DoubleNode d = first;
+ for (int i = 0; i < index; i++) {
+ d = d.next;
+ }
+ return d;
+ } else {
+ DoubleNode d = this.last;
+ for (int i = size - 1; i < index; i--) {
+ d = d.prev;
+ }
+ return d;
+ }
+ }
+
+
+}