Read and write JSON and YAML data from and to files or streams.
Validation by JsonSchema (see http://json-schema.org for specifications).
Sequential read of JsonArray and YamlSequence items (like SAX parser for XML data).
JsonWriter writer = null;
ByteArrayOutputStream output = null;
JsonReader reader = null;
try {
output = new ByteArrayOutputStream();
writer = new JsonWriter(output, StandardCharsets.UTF_8);
writer.openJsonObject();
writer.openJsonObjectProperty("abc");
writer.addSimpleJsonObjectPropertyValue("1");
writer.openJsonObjectProperty("def");
writer.addSimpleJsonObjectPropertyValue(2);
writer.openJsonObjectProperty("ghi");
writer.addSimpleJsonObjectPropertyValue(3.00);
writer.closeJsonObject();
writer.close();
output.close();
final String result = new String(output.toByteArray(), StandardCharsets.UTF_8);
reader = new JsonReader(new ByteArrayInputStream(result.getBytes(StandardCharsets.UTF_8)));
final JsonNode nodevalue = reader.read();
System.out.println(nodevalue.getJsonDataType() == JsonDataType.OBJECT);
// true
final JsonObject jsonObject = (JsonObject) nodevalue;
for (final Map.Entry<String, Object> jsonObjectProperty : jsonObject) {
System.out.println(jsonObjectProperty.getKey() + ": " + jsonObjectProperty.getValue().getClass().getSimpleName() + ": " + jsonObjectProperty.getValue());
// abc: String: 1
// def: Integer: 2
// ghi: Float: 3.0
}
} catch (final Exception e) {
e.printStackTrace();
} finally {
Utilities.closeQuietly(output);
Utilities.closeQuietly(writer);
Utilities.closeQuietly(reader);
}
JsonWriter writer = null;
ByteArrayOutputStream output = null;
JsonReader reader = null;
try {
output = new ByteArrayOutputStream();
writer = new JsonWriter(output, StandardCharsets.UTF_8);
writer.openJsonArray();
writer.addSimpleJsonArrayValue("1");
writer.addSimpleJsonArrayValue(2);
writer.addSimpleJsonArrayValue(3.00);
writer.closeJsonArray();
writer.close();
output.close();
final String result = new String(output.toByteArray(), StandardCharsets.UTF_8);
reader = new JsonReader(new ByteArrayInputStream(result.getBytes(StandardCharsets.UTF_8)));
final JsonNode nodevalue = reader.read();
System.out.println(nodevalue.getJsonDataType() == JsonDataType.ARRAY);
// true
final JsonArray jsonArray = (JsonArray) nodevalue;
for (final Object jsonArrayItem : jsonArray) {
System.out.println(jsonArrayItem.getClass().getSimpleName() + ": " + jsonArrayItem);
// String: 1
// Integer: 2
// Float: 3.0
}
} catch (final Exception e) {
e.printStackTrace();
} finally {
Utilities.closeQuietly(output);
Utilities.closeQuietly(writer);
Utilities.closeQuietly(reader);
}
JsonReader jsonReader = null;
try {
final String data = ""
+ "{"
+ " \"level1\":"
+ " ["
+ " {"
+ " \"property1\": \"value11\","
+ " \"property2\": \"value12\","
+ " \"property3\": \"value13\""
+ " },"
+ " {"
+ " \"property1\": \"value21\","
+ " \"property2\": \"value22\","
+ " \"property3\": \"value23\""
+ " }"
+ " ]"
+ "}";
jsonReader = new JsonReader(new ByteArrayInputStream(data.getBytes(StandardCharsets.UTF_8)));
jsonReader.readUpToJsonPath("$.level1");
jsonReader.readNextToken();
JsonNode nextJsonNode;
int count = 0;
while ((nextJsonNode = jsonReader.readNextJsonNode()) != null) {
count++;
final String property1 = (String) ((JsonObject) nextJsonNode).getSimpleValue("property1");
final String property2 = (String) ((JsonObject) nextJsonNode).getSimpleValue("property2");
final String property3 = (String) ((JsonObject) nextJsonNode).getSimpleValue("property3");
Assertions.assertEquals(("value" + count + "1"), (property1));
Assertions.assertEquals(("value" + count + "2"), (property2));
Assertions.assertEquals(("value" + count + "3"), (property3));
}
} catch (final Exception e) {
e.printStackTrace();
Assertions.fail(e.getMessage());
} finally {
Utilities.closeQuietly(jsonReader);
}
JsonWriter writer = null;
ByteArrayOutputStream output = null;
JsonReader reader = null;
try {
output = new ByteArrayOutputStream();
writer = new JsonWriter(output, StandardCharsets.UTF_8);
writer.openJsonObject();
writer.openJsonObjectProperty("abc");
writer.addSimpleJsonObjectPropertyValue("1");
writer.openJsonObjectProperty("def");
writer.addSimpleJsonObjectPropertyValue(2);
writer.openJsonObjectProperty("ghi");
writer.addSimpleJsonObjectPropertyValue(3.00);
writer.closeJsonObject();
writer.close();
output.close();
final String result = new String(output.toByteArray(), StandardCharsets.UTF_8);
reader = new JsonReader(new ByteArrayInputStream(result.getBytes(StandardCharsets.UTF_8)));
final JsonNode nodevalue = reader.read();
System.out.println(nodevalue.getJsonDataType() == JsonDataType.OBJECT);
// true
final JsonObject jsonObject = (JsonObject) nodevalue;
for (final Map.Entry<String, Object> jsonObjectProperty : jsonObject) {
System.out.println(jsonObjectProperty.getKey() + ": " + jsonObjectProperty.getValue().getClass().getSimpleName() + ": " + jsonObjectProperty.getValue());
// abc: String: 1
// def: Integer: 2
// ghi: Float: 3.0
}
} catch (final Exception e) {
e.printStackTrace();
} finally {
Utilities.closeQuietly(output);
Utilities.closeQuietly(writer);
Utilities.closeQuietly(reader);
}
YamlWriter writer = null;
ByteArrayOutputStream output = null;
YamlReader reader = null;
try {
output = new ByteArrayOutputStream();
writer = new YamlWriter(output, StandardCharsets.UTF_8);
final YamlMapping outputSequence = new YamlMapping();
outputSequence.put("abc", "1");
outputSequence.put("def", 2);
outputSequence.put("ghi", 3.00);
final YamlDocument outputDocument = new YamlDocument().setRoot(outputSequence);
writer.writeDocument(outputDocument);
final String result = new String(output.toByteArray(), StandardCharsets.UTF_8);
reader = new YamlReader(new ByteArrayInputStream(result.getBytes(StandardCharsets.UTF_8)));
final YamlDocument document = reader.readDocument();
System.out.println(document.getRoot() instanceof YamlMapping);
// true
final YamlMapping yamlMapping = (YamlMapping) document.getRoot();
for (final Map.Entry<String, Object> yamlObjectProperty : yamlMapping) {
System.out.println(yamlObjectProperty.getKey() + ": " + yamlObjectProperty.getValue().getClass().getSimpleName() + ": " + yamlObjectProperty.getValue());
// String: 1
// Integer: 2
// Float: 3.0
}
} catch (final Exception e) {
e.printStackTrace();
} finally {
Utilities.closeQuietly(output);
Utilities.closeQuietly(writer);
Utilities.closeQuietly(reader);
}
final String testData = ""
+ "level1:\n"
+ " items:\n"
+ " - property1: \"property 01\"\n"
+ " property2: \"property 02\"\n"
+ " property3: \"property 03\"\n"
+ " - property1: \"property 11\"\n"
+ " property2: \"property 12\"\n"
+ " property3: \"property 13\"\n";
try (InputStream testDataStream = new ByteArrayInputStream(testData.getBytes(StandardCharsets.UTF_8))) {
try (final YamlReader yamlReader = new YamlReader(testDataStream)) {
yamlReader.readUpToPath("$.level1.items");
YamlNode nextYamlNode;
int count = 0;
while ((nextYamlNode = yamlReader.readNextYamlNode()) != null) {
final String property1 = (String) ((YamlScalar) ((YamlMapping) nextYamlNode).get("property1")).getValue();
final String property2 = (String) ((YamlScalar) ((YamlMapping) nextYamlNode).get("property2")).getValue();
final String property3 = (String) ((YamlScalar) ((YamlMapping) nextYamlNode).get("property3")).getValue();
Assertions.assertTrue(("property " + count + "1").equals(property1));
Assertions.assertTrue(("property " + count + "2").equals(property2));
Assertions.assertTrue(("property " + count + "3").equals(property3));
count++;
}
}
} catch (final Exception e) {
e.printStackTrace();
}
For other simple examples see test class "de.soderer.json.JsonTest" and class "de.soderer.yaml.YamlTest":
https://github.com/hudeany/json/blob/master/src/test/java/de/soderer/json/JsonTest.java
This library is also available via Maven2 repository
<repositories>
<repository>
<id>de.soderer</id>
<url>https://soderer.de/maven2</url>
</repository>
</repositories>
<dependency>
<groupId>de.soderer</groupId>
<artifactId>json</artifactId>
<version>RELEASE</version>
</dependency>