WIP simple JSON load/write, but write is broken

src/main/java/edu/umich/soar/visualsoar/files/SoarDatamapJson.java

@@ -0,0 +1,90 @@
+package edu.umich.soar.visualsoar.files;
+
+import static edu.umich.soar.visualsoar.files.Util.JSON_OBJECT_MAPPER;
+import static edu.umich.soar.visualsoar.files.Util.saveToFile;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonPOJOBuilder;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+@JsonDeserialize(builder = SoarDatamapJson.Builder.class)
+public class SoarDatamapJson {
+
+  private enum VertexType {
+    SOAR_ID,
+    ENUMERATION,
+    INTEGER_RANGE,
+    INTEGER,
+    FLOAT_RANGE,
+    FLOAT,
+    STRING,
+    FOREIGN,
+  }
+
+  private final String id;
+  private final VertexType vertexType;
+
+  SoarDatamapJson(String id, VertexType vertexType) {
+    this.id = id;
+    this.vertexType = vertexType;
+  }
+
+  @JsonPOJOBuilder(buildMethodName = "build", withPrefix = "with")
+  static class Builder {
+    private String id;
+    private SoarDatamapJson.VertexType vertexType;
+
+    public Builder withId(String id) {
+      this.id = id;
+      return this;
+    }
+
+    public Builder withVertexType(SoarDatamapJson.VertexType vertexType) {
+      this.vertexType = vertexType;
+      return this;
+    }
+
+    public SoarDatamapJson build() {
+      return new SoarDatamapJson(id, vertexType);
+    }
+  }
+
+  public static SoarDatamapJson loadFromJson(String json) throws JsonProcessingException {
+    return JSON_OBJECT_MAPPER.readValue(json, SoarDatamapJson.class);
+  }
+
+  private static class JsonWriter implements Util.Writer {
+    private final SoarDatamapJson json;
+
+    private JsonWriter(SoarDatamapJson json) {
+      this.json = json;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+      JSON_OBJECT_MAPPER.writerFor(SoarDatamapJson.class).writeValue(out, json);
+    }
+  }
+
+  public static void writeJsonToFile(Path destination, SoarDatamapJson json) throws IOException {
+    saveToFile(destination, new JsonWriter(json));
+  }
+
+  public static void main(String[] args) throws IOException {
+    SoarDatamapJson json =
+        SoarDatamapJson.loadFromJson("{\"id\":\"XYZ\", \"vertexType\":\"FLOAT\"}");
+    System.out.println(json.id);
+    System.out.println(json.vertexType);
+    assert json.id.equals("XYZ");
+    assert json.vertexType.equals(VertexType.FLOAT);
+    Path destination = Paths.get("sample-output.json");
+    writeJsonToFile(destination, json);
+//    TODO: NEXT: output file contains empty object!
+    System.err.println("Please inspect " + destination + " for JSON output");
+  }
+}

src/main/java/edu/umich/soar/visualsoar/files/Util.java

@@ -1,28 +1,58 @@
 package edu.umich.soar.visualsoar.files;
 
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.io.File;
 import java.io.FileOutputStream;
+import java.io.IOException;
 import java.io.OutputStream;
 import java.nio.file.AtomicMoveNotSupportedException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.logging.Logger;
 
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_JAVA_COMMENTS;
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_LEADING_DECIMAL_POINT_FOR_NUMBERS;
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_LEADING_PLUS_SIGN_FOR_NUMBERS;
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_LEADING_ZEROS_FOR_NUMBERS;
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_NON_NUMERIC_NUMBERS;
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_SINGLE_QUOTES;
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_TRAILING_COMMA;
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_TRAILING_DECIMAL_POINT_FOR_NUMBERS;
+import static com.fasterxml.jackson.core.json.JsonReadFeature.ALLOW_UNQUOTED_FIELD_NAMES;
 import static java.nio.file.StandardCopyOption.ATOMIC_MOVE;
 import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;
 
 public class Util {
   private static final Logger LOGGER = Logger.getLogger(Util.class.getName());
+  public static final JsonFactory JSON_FACTORY =
+    JsonFactory.builder()
+      // configure, if necessary:
+      .enable(ALLOW_JAVA_COMMENTS)
+      .enable(ALLOW_UNQUOTED_FIELD_NAMES)
+      .enable(ALLOW_TRAILING_COMMA)
+      .enable(ALLOW_SINGLE_QUOTES)
+      // TODO: are we sure that NaN's could be used for anything?
+      .enable(ALLOW_NON_NUMERIC_NUMBERS)
+      .enable(ALLOW_LEADING_ZEROS_FOR_NUMBERS)
+      .enable(ALLOW_LEADING_PLUS_SIGN_FOR_NUMBERS)
+      .enable(ALLOW_LEADING_DECIMAL_POINT_FOR_NUMBERS)
+      .enable(ALLOW_TRAILING_DECIMAL_POINT_FOR_NUMBERS)
+      .build();
+
+  public static final ObjectMapper JSON_OBJECT_MAPPER = new ObjectMapper(JSON_FACTORY);
 
   @FunctionalInterface
   public interface Writer {
-    void write(OutputStream out);
+    void write(OutputStream out) throws IOException;
   }
 
-  /**
-   * Write to the destination file from {@code writer} as atomically as possible.
-   */
-  public void Save(Path destination, Writer writer) throws java.io.IOException {
+  /** Write to the destination file from {@code writer} as atomically as possible. */
+  public static void saveToFile(Path destination, Writer writer) throws java.io.IOException {
     // Write to a temp file first, then make the final changes via a rename,
     // which can often be done atomically. This prevents issues such as overwriting a file with a
     // incomplete data, as could be the case if we hit an IO exception in the middle of writing the
@@ -46,4 +76,17 @@ public void Save(Path destination, Writer writer) throws java.io.IOException {
       Files.move(tempPath, destination, REPLACE_EXISTING);
     }
   }
+
+  /**
+   * Load JSON file with very lenient parser settings in the direction of natural JavaScript syntax
+   * (so JSON5)
+   */
+  public void loadJson() {
+    try (JsonParser parser = JSON_FACTORY.createParser(new File("TODO"))) {
+    } catch(JsonParseException e) {
+
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
 }