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Json Hello World examples

The Json parsers libraries offer 3 main methods for processing JSON and 1 additional:

Data Binding converts JSON to and from POJOs based either on property accessor conventions or annotations.
Tree Model provides a mutable in-memory tree representation of a JSON document.
Streaming API (aka "Incremental parsing/generation") reads and writes JSON content as discrete events.
(additional) XPath analog - working with a JSON structure in the same way as XPath expression are used in combination with an XML document.

1. Json parsers overview

Property	Fastjson	Gson	LoganSquare	JSON java	Moshi	Ig json parser	Jackson	Genson	JsonPath	JSON.simple

Data bind | Yes| Yes | Yes | - | Yes | Yes | Yes | Yes | - | -
Tree Model | - | Yes| - | Yes | - | - | Yes | - | - | Yes
Streaming API | - | Yes| - | - | - | - | Yes | - | -
Analog XPath | Yes | - | - | - | - | - | Yes | - | Yes| -
Generation classes at compile-time | - | - | Yes | - | - | Yes | - | - | -| -
Github's star | 4851 | 4120 | 2188 | 1937 | 1732 | 921 | 881 | 108 | 849 | 161
Working with static inner class | Yes | Yes | No | - | Yes | No | Yes | Yes | - | -
Required annotations | No | No | Yes | - | No | Yes | No | No | - | -

From useful-java-links:

JSON Parsers

Alibaba Fastjson Fast JSON Processor , github's star - 4851. User guide and Hello World examples. License: Apache 2.
Gson - Serializes objects to JSON and vice versa. Good performance with on-the-fly usage, github's star - 4120. User guide and Hello World examples. License: Apache 2.
LoganSquare - JSON parsing and serializing library based on Jackson's streaming API. Outpeforms GSON & Jackson's library, github's star - 2188. User guide and Hello World examples. License: Apache 2.
JSON java A reference implementation of a JSON package in Java, github's star - 1937. User guide and Hello World examples. License: Crockford's license (MIT License + "Good, not Evil").
Square Moshi A modern JSON library for Android and Java , github's star - 1732. User guide and Hello World examples. License: Apache 2
Instagram Ig json parser Fast JSON parser for java projects, github's star - 921. User guide and Hello World examples. License: BSD 3.
Jackson - Similar to GSON but has performance gains if you need to instantiate the library more often. Subprojects: Jackson core Core part of Jackson, Jackson databind Core part of Jackson that defines Streaming API as well as basic shared abstractions, github's star - 881. User guide and Hello World examples. License: Apache 2.
JSON.simple - A simple Java toolkit for JSON. You can use json-simple to encode or decode JSON text, github's star - 161. User guide and Hello World examples. License: Apache 2.
Genson -Powerful and easy to use Java to JSON conversion library, github's star - 108. User guide and Hello World examples. License: Apache 2.

Analog XPath for JSON

Jayway JsonPath Java JsonPath implementation, github's star - 849. User guide and Hello World examples. License: Apache 2.
Alibaba Fastjson Fast JSON Processor , github's star - 4851. User guide and Hello World examples. License: Apache 2.

Generates Java types from JSON or JSON Schema or JSON validation

Jsonschema2pojo Generates Java types from JSON Schema (or example JSON) and annotates those types for data-binding with Jackson 1.x or 2.x, Gson, etc. , github's star - 1664. User guide and Hello World examples. License: Apache 2.
Json schema validator A JSON Schema validation implementation in pure Java, which aims for correctness and performance, in that order, also can generate Java types from JSON Schema or versa versa, github's star - 547. User guide and Hello World examples. License: GNU Lesser 3/Apache 2.

2. Json parsers using Data bind

Methods	Fastjson	Gson	LoganSquare	Moshi	Ig json parser	Jackson	Genson
Initialization	---	`Gson gson = new Gson()`	---	`Moshi moshi = new Moshi.`
`Builder().build(); JsonAdapter<Human>`
`jsonAdapter = moshi.adapter(Human.class)`	---	`ObjectMapper mapper = new ObjectMapper()`	`Genson genson = new Genson()`
Building json	`JSON.toJSONString(human)`	`gson.toJson(human)`	`LoganSquare.serialize(human)`	`jsonAdapter.toJson(human)`	`Human__JsonHelper.serializeToJson(human)`	`mapper.writeValueAsString(human)`	`genson.serialize(human)`
Parsing json	`JSON.parseObject(jsonString, Human.class)`	`gson.fromJson(jsonString, Human.class)`	`LoganSquare.parse(jsonString, Human.class)`	`jsonAdapter.fromJson(jsonString)`	`Human__JsonHelper.parseFromJson(jsonString)`	`mapper.readValue(jsonString, Human.class)`	`genson.deserialize(jsonString, Human.class)`

Arguments for every example (Json and Java classes):

json:

javascript

jsonString =
{
  "message": "Hi",
  "place": {
    "name": "World"
  }
}

Java classes

java

    class Human {
        private String message;
        private Place place;

        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }

        public Place getPlace() {
            return place;
        }

        public void setPlace(Place place) {
            this.place = place;
        }

        public void say() {
            System.out.println();
            System.out.println(getMessage() + " , " + getPlace().getName() + "!");
        }
    }

    class Place {
        private String name;

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }
    }

    // init class
    Place place = new Place();
    place.setName("World");

    Human human = new Human();
    human.setMessage("Hi");
    human.setPlace(place);

Examples:

1) Fastjson:

java

        // convert to json
        String jsonString = JSON.toJSONString(human);
        System.out.println("json " + jsonString); //  print "json {"message":"Hi","place":{"name":"World"}}"

        // convert from json
        Human newHuman = JSON.parseObject(jsonString, Human.class);
        newHuman.say(); //  print "Hi , World!"

Full example

2) Gson

java

        // convert to json
        Gson gson = new Gson();
        String jsonString = gson.toJson(human);
        System.out.println("json " + jsonString); //  print   "json {"message":"Hi","place":{"name":"World"}}"

        // convert from json
        Human newHuman = gson.fromJson(jsonString, Human.class);
        newHuman.say(); //  print   "Hi , World!"

Full example

3) LoganSquare

java

@JsonObject
public class Human {
    @JsonField(name="message")
    public String message;
    @JsonField(name="place")
    public Place place;

       ....

        // convert to json
        String jsonString = LoganSquare.serialize(human);
        System.out.println("json " + jsonString); // print  "json {"place":{"name":"World"},"message":"Hi"}"

        // convert from json
        Human newHuman = LoganSquare.parse(jsonString, Human.class);
        newHuman.say(); // print  "Hi , World!"

Full example

4) Moshi

java

        // convert to json
        Moshi moshi = new Moshi.Builder().build();
        JsonAdapter<Human> jsonAdapter = moshi.adapter(Human.class);

        String jsonString = jsonAdapter.toJson(human);
        System.out.println("json " + jsonString); // print   "json {"message":"Hi","place":{"name":"World"}}"

        // convert from json
        Human newHuman = jsonAdapter.fromJson(jsonString);
        newHuman.say(); //  print  "Hi , World!"

Full example

5) Ig json parser

java

@JsonType
public class Human {
    @JsonField(fieldName="message")
    public String message;
    @JsonField(fieldName="place")
    public Place place;

        ...

        // convert to json
        String jsonString = Human__JsonHelper.serializeToJson(human);
        System.out.println("json " + jsonString); // print   "json {"place":{"name":"World"},"message":"Hi"}"

        // convert from json
        Human newHuman = Human__JsonHelper.parseFromJson(jsonString);
        newHuman.say(); //  print  "Hi , World!"

Full example

5. Jackson

java

        // convert to json
        ObjectMapper mapper = new ObjectMapper();
        String jsonString = mapper.writeValueAsString(human);
        System.out.println("json " + jsonString); //  print   "json {"message":"Hi","place":{"name":"World"}}"

        // convert from json
        Human newHuman = mapper.readValue(jsonString, Human.class);
        newHuman.say(); //  print  "Hi , World!"

Full example

6. Genson

java

        // convert to json
        String jsonString = new Genson().serialize(human);

        System.out.println("json " + jsonString); // print   "json {"message":"Hi","place":{"name":"World"}}"

        // convert from json
        Human newHuman =  new Genson().deserialize(jsonString, Human.class);
        newHuman.say(); //  print   "Hi , World!"

Full example

3. Json parsers using Tree Model

Parsing json:

Methods	Gson	Jackson	JSON java	JSON.simple
Initialization	`JsonParser parser = new JsonParser()`	`new ObjectMapper()`	-	-
Json parsing	`parser.parse(<string>)`	`mapper.readValue(<string>, JsonNode.class)`	`new JSONObject(<string>)`	`(JSONObject) JSONValue.parse(<string>)`
Get main object	`root.getAsJsonObject()`	-	-	-
Get string value	`root.get(<name>).getAsString()`	`root.get(<name>).asText()`	`root.getString(<name>)`	`(String) root.get(<name>)`
Get child object	`root.getAsJsonObject(<name>)`	`root.get(<name>)`	`root.getJSONObject(<name>)`	`(JSONObject) root.get(<name>)`

Building json:

Methods	Gson	Jackson	JSON java	JSON.simple
Initialization	-	`new ObjectMapper()`	-	-
Create main object	`new JsonObject()`	`mapper.createObjectNode()`	`new JSONObject()`	`new JSONObject()`
Add string field	`root.addProperty(<name>, <string>)`	`root.put(<name>, <string>)`	`root.put(<name>, <string>)`	`root.put(<name>, <string>)`
Add child object	`root.add(<name>, <object>);`	`root.putObject(<name>)`	`root.put(<name>, <object>)`	`root.put(<name>, <object>)`

Examples:

Parsing json using gson

java

        JsonParser parser = new JsonParser();
        JsonElement jsonElement = parser.parse("{\"message\":\"Hi\",\"place\":{\"name\":\"World!\"}}");

        JsonObject rootObject = jsonElement.getAsJsonObject(); // get main object
        String message = rootObject.get("message").getAsString(); // get field "message" as string
        JsonObject childObject = rootObject.getAsJsonObject("place"); // get Place object 
        String place = childObject.get("name").getAsString(); // get field "name"
        System.out.println(message + " " + place); // pring "Hi World!"*/

Full example

Building json using Gson

java

        JsonObject rootObject = new JsonObject(); // create main object
        rootObject.addProperty("message", "Hi"); 
        JsonObject childObject = new JsonObject(); // create "Place" object
        childObject.addProperty("name", "World!"); 
        rootObject.add("place", childObject); // save child object to "place" field

        Gson gson = new Gson();
        String json = gson.toJson(rootObject); 
        System.out.println(json); // print "{"message":"Hi","place":{"name":"World!"}}"

Full example

Parsing json using Jackson

java

        ObjectMapper mapper = new ObjectMapper();
        JsonNode rootNode = mapper.readValue("{\"message\":\"Hi\",\"place\":{\"name\":\"World!\"}}", JsonNode.class); 
        String message = rootNode.get("message").asText(); 
        JsonNode childNode =  rootNode.get("place"); // get "Place" object
        String place = childNode.get("name").asText(); 
        System.out.println(message + " " + place); // print "Hi World!"

Full example

Building json using Jackson

java

        OutputStream outputStream = new ByteArrayOutputStream();

        ObjectMapper mapper = new ObjectMapper();
        ObjectNode rootNode = mapper.createObjectNode(); // create main object
        rootNode.put("message", "Hi");
        ObjectNode childNode = rootNode.putObject("place"); // create child object
        childNode.put("name", "World!");
        mapper.writeValue(outputStream, childNode); 

        System.out.println(outputStream.toString()); // print "{"message":"Hi","place":{"name":"World!"}}"

Full example

Parsing and building json using Json Java

java

        // convert Java to json
        JSONObject root = new JSONObject(); // create main object
        root.put("message", "Hi");
        JSONObject place = new JSONObject(); // create "Place" object
        place.put("name", "World!");
        root.put("place", place); 
        String json = root.toString();
        System.out.println(json); // print "{"message":"Hi","place":{"name":"World!"}}"

        System.out.println();
        // convert json to Java
        JSONObject jsonObject = new JSONObject(json); 
        String message = jsonObject.getString("message");
        String name = jsonObject.getJSONObject("place").getString("name");
        System.out.println(message + " " + name); // print "Hi World!"

Full example

Parsing json using JSON.simple

java


       JSONObject obj = (JSONObject) JSONValue.parse(json);
       String message = (String) obj.get("message");
       place = (JSONObject) obj.get("place");
       String name = (String) place.get("name");
       System.out.println(message + " " + name);

Full example

Building json using JSON.simple

java


        JSONObject root = new JSONObject();
        root.put("message", "Hi");
        JSONObject place = new JSONObject();
        place.put("name", "World!");
        root.put("place", place);
        String json = root.toJSONString();
        System.out.println(json);

Full example

4 Json parsers using Streaming API

Parsing json:

Methods	Gson	Jackson
Initialization	-	`new JsonFactory()`
Parsing json	`reader = new JsonReader((<input_stream>)`	`parser = jsonFactory.createParser(<string>)`
Has next token	`reader.hasNext()`	`parser.hasCurrentToken()`
Get token type	`reader.peek()`	`parser.nextToken()`
Get next token	`reader.nextString()`
`reader.beginObject()`
`reader.endObject()` and so on	`parser.nextToken()`
Skip token	`reader.skipValue()`	`parser.nextToken()`
Get string	`reader.nextString()`	`parser.getText()`

Building json:

Methods	Gson	Jackson
Initialization	writer = new JsonWriter(<output_stream>)	`generator = new JsonFactory().createGenerator(<output_stream>, <code_page>)`
Start object token	`writer.beginObject()`	`generator.writeStartObject()`
End object token	`writer.endObject()`	`generator.writeEndObject()`
Name field token	`writer.name(<name>)`	`generator.writeFieldName(<name>)`
String value token	`writer.value(<string>)`	`generator.writeStringField(<name>, <string>)`

Examples:

Parsing json using Gson

java

        String str = "{\"message\":\"Hi\",\"place\":{\"name\":\"World!\"}}";
        InputStream in = new ByteArrayInputStream(str.getBytes(Charset.forName("UTF-8")));
        JsonReader reader = new JsonReader(new InputStreamReader(in, "UTF-8"));
        while (reader.hasNext()) { 
            JsonToken jsonToken = reader.peek(); 
            if(jsonToken == JsonToken.BEGIN_OBJECT) { 
                reader.beginObject();
            } else if(jsonToken == JsonToken.END_OBJECT) { 
                reader.endObject();
            } if(jsonToken == JsonToken.STRING) {  
                System.out.print(reader.nextString() + " "); // print Hi World!
            } else {
                reader.skipValue(); 
            }
        }
        reader.close();

Full example

Building json using Gson

java

        OutputStream outputStream = new ByteArrayOutputStream();
        JsonWriter writer = new JsonWriter(new OutputStreamWriter(outputStream, "UTF-8"));
        writer.beginObject(); 
        writer.name("message"); 
        writer.value("Hi");
        writer.name("place"); 
        writer.beginObject(); 
        writer.name("name");
        writer.value("World!");
        writer.endObject(); 
        writer.endObject(); 
        writer.close();
        System.out.println(outputStream.toString()); // print "{"message":"Hi","place":{"name":"World!"}}"

Full example

Parsing json using Jackson

java

        JsonFactory jsonFactory = new JsonFactory();
        JsonParser jsonParser = jsonFactory.createParser("{\"message\":\"Hi\",\"place\":{\"name\":\"World!\"}}");
        JsonToken jsonToken = jsonParser.nextToken();
        while(jsonParser.hasCurrentToken()) { 
            if(jsonToken == VALUE_STRING) {  
                System.out.print(jsonParser.getText() + " "); // print "Hi World!"
            }
            jsonToken = jsonParser.nextToken();
        }

Full example

Building json using Jackson

java

        JsonFactory jsonFactory = new JsonFactory();
        OutputStream outputStream = new ByteArrayOutputStream();
        JsonGenerator jsonGenerator = jsonFactory.createGenerator(outputStream, JsonEncoding.UTF8); 
        jsonGenerator.writeStartObject(); 
        jsonGenerator.writeStringField("message", "Hi"); 
        jsonGenerator.writeFieldName("place");
        jsonGenerator.writeStartObject(); 
        jsonGenerator.writeStringField("name", "World!");
        jsonGenerator.writeEndObject(); 
        jsonGenerator.writeEndObject(); 
        jsonGenerator.close();
        System.out.println(outputStream.toString()); // print "{"message":"Hi","place":{"name":"World!"}}"

Full example

5 XPath analogs for json

Methods:	JsonPath	FastJson	Jackson
Type	XPath-like	XPath-like	JSON Pointer-like
Initialization	-	-	mapper = new ObjectMapper()
Get value using template	`JsonPath.read(<json>, <template>)`	`JSONPath.eval(<java_object>, <template>)`	`mapper.readTree(<json>).at(<template>)`
Get collection using template	`JsonPath.read(<json>, <template>)`	`JSONPath.eval(<java_object>, <template>)`	`mapper.readTree(<json>).at(<template>)`

Using JsonPath

java

        String jsonHiWorld = "{\"message\":\"Hi\",\"place\":{\"name\":\"World!\"}}\"";

        String message = JsonPath.read(jsonHiWorld, "$.message");
        String place = JsonPath.read(jsonHiWorld, "$.place.name");
        System.out.println(message + " " + place); // print "Hi World!"

Full example

Using FastJson

java

        String jsonString = "{\"message\":\"Hi\",\"place\":{\"name\":\"World!\"}}\"";
        Human newHuman = JSON.parseObject(jsonString, Human.class);

        Object message = JSONPath.eval(newHuman, "$.message");
        Object world = JSONPath.eval(newHuman, "$.place.name");
        System.out.println(message + " " + world); // print Hi World

Full example

More complex example using JsonPath

java

        List<String> authors = JsonPath.read(json, "$.store.book[*].author");
        System.out.println("authors: " + authors); // print ["Nigel Rees","Evelyn Waugh","Herman Melville","J. R. R. Tolkien"]

        List<Map<String, Object>> expensiveBooks = JsonPath
                .using(Configuration.defaultConfiguration())
                .parse(json)
                .read("$.store.book[?(@.price > 22)].title", List.class);

        System.out.println(expensiveBooks); // print ["Hello, Middle-earth! "]

java

 String json = "{\n" +
            "    \"store\": {\n" +
            "        \"book\": [\n" +
            "            {\n" +
            "                \"category\": \"reference\",\n" +
            "                \"author\": \"Nigel Rees\",\n" +
            "                \"title\": \"Sayings of the Century\",\n" +
            "                \"price\": 8.95\n" +
            "            },\n" +
            "            {\n" +
            "                \"category\": \"fiction\",\n" +
            "                \"author\": \"Evelyn Waugh\",\n" +
            "                \"title\": \"Sword of Honour\",\n" +
            "                \"price\": 12.99\n" +
            "            },\n" +
            "            {\n" +
            "                \"category\": \"fiction\",\n" +
            "                \"author\": \"Herman Melville\",\n" +
            "                \"title\": \"Moby Dick\",\n" +
            "                \"isbn\": \"0-553-21311-3\",\n" +
            "                \"price\": 8.99\n" +
            "            },\n" +
            "            {\n" +
            "                \"category\": \"fiction\",\n" +
            "                \"author\": \"J. R. R. Tolkien\",\n" +
            "                \"title\": \"Hello, Middle-earth! \",\n" +
            "                \"isbn\": \"0-395-19395-8\",\n" +
            "                \"price\": 22.99\n" +
            "            }\n" +
            "        ],\n" +
            "        \"bicycle\": {\n" +
            "            \"color\": \"red\",\n" +
            "            \"price\": 19.95\n" +
            "        }\n" +
            "    },\n" +
            "    \"expensive\": 10\n" +
            "}";

Full example

Using Jackson

java

        ObjectMapper mapper = new ObjectMapper();
        String jsonHiWorld = "{\"message\":\"Hi\",\"place\":{\"name\":\"World!\"}}\"";
        String message = mapper.readTree(jsonHiWorld).at("/message").asText();
        String place = mapper.readTree(jsonHiWorld).at("/place/name").asText();
        System.out.println(message + " " + place); // print "Hi World!"

Full example

Using Jackson ( More complex example)

java

        ObjectMapper mapper = new ObjectMapper();
        JsonNode root = mapper.readTree(json);
        String author = root.at("/store/book/3/title").asText();
        System.out.println(author); // print ["Hello, Middle-earth! "]
        ...
        private final static String json = "{\n" +
            "    \"store\": {\n" +
            "        \"book\": [\n" +
            "            {\n" +
            "                \"category\": \"reference\",\n" +
            "                \"author\": \"Nigel Rees\",\n" +
            "                \"title\": \"Sayings of the Century\",\n" +
            "                \"price\": 8.95\n" +
            "            },\n" +
            "            {\n" +
            "                \"category\": \"fiction\",\n" +
            "                \"author\": \"Evelyn Waugh\",\n" +
            "                \"title\": \"Sword of Honour\",\n" +
            "                \"price\": 12.99\n" +
            "            },\n" +
            "            {\n" +
            "                \"category\": \"fiction\",\n" +
            "                \"author\": \"Herman Melville\",\n" +
            "                \"title\": \"Moby Dick\",\n" +
            "                \"isbn\": \"0-553-21311-3\",\n" +
            "                \"price\": 8.99\n" +
            "            },\n" +
            "            {\n" +
            "                \"category\": \"fiction\",\n" +
            "                \"author\": \"J. R. R. Tolkien\",\n" +
            "                \"title\": \"Hello, Middle-earth! \",\n" +
            "                \"isbn\": \"0-395-19395-8\",\n" +
            "                \"price\": 22.99\n" +
            "            }\n" +
            "        ],\n" +
            "        \"bicycle\": {\n" +
            "            \"color\": \"red\",\n" +
            "            \"price\": 19.95\n" +
            "        }\n" +
            "    },\n" +
            "    \"expensive\": 10\n" +
            "}";

Full example

6 Generates Java classes from JSON or JSON Schema and JSON validation

Online resources:

jsonschema2pojo.org - generate Java classes from json or json schema with annotations Jackson 1, Jackson2 and Gson,
json-schema-validator.herokuapp.com - validation json using json schema, generate json/Java classes from json schema and so on,

Examples:

Generation Java classes using jsonschema2pojo from Java code

java

        // Init json
        String source = "{\n" +
                "  \"type\":\"object\",\n" +
                "  \"properties\": {\n" +
                "    \"messageHiWorld\": {\n" +
                "      \"type\": \"string\"\n" +
                "    },\n" +
                "    \"bar\": {\n" +
                "      \"type\": \"integer\"\n" +
                "    },\n" +
                "    \"baz\": {\n" +
                "      \"type\": \"boolean\"\n" +
                "    }\n" +
                "  }\n" +
                "}";

        // Init config
        JCodeModel codeModel = new JCodeModel();

        GenerationConfig config = new DefaultGenerationConfig() {
            @Override
            public boolean isGenerateBuilders() { // set config option by overriding method
                return true;
            }
        };

        // Generate Java POJO from json
        SchemaMapper mapper = new SchemaMapper(new RuleFactory(config, new Jackson2Annotator(), new SchemaStore()), new SchemaGenerator());
        mapper.generate(codeModel, "HelloWorldClass", "com.github.vedenin", source);

        // Save generated class to file
        File directory = new File("helloworlds/3.8-json/jsonschema2pojo/output");
        directory.mkdirs();
        codeModel.build(directory);

        // Show generated class
        File cls = new File("helloworlds/3.8-json/jsonschema2pojo/output/com/github/vedenin/HelloWorldClass.java");
        String codeHelloWorld = Files.toString(cls, Charsets.UTF_8);
        System.out.println(codeHelloWorld);

Full example

Validate Json using json schema (using jsonschema2pojo)

java

        final JsonNode fstabSchema = Utils.loadResource("/fstab.json");
        final JsonNode good = Utils.loadResource("/fstab-good.json");
        final JsonNode bad = Utils.loadResource("/fstab-bad.json");
        final JsonNode bad2 = Utils.loadResource("/fstab-bad2.json");

        final JsonSchemaFactory factory = JsonSchemaFactory.byDefault();

        final JsonSchema schema = factory.getJsonSchema(fstabSchema);

        ProcessingReport report;

        report = schema.validate(good);
        System.out.println(report);

        report = schema.validate(bad);
        System.out.println(report);

        report = schema.validate(bad2);
        System.out.println(report);

Full example

Generation Java classes using jsonschema2pojo and maven plugin

Using this maven pom.xml, change sourceDirectory and targetPackage

xml

   <build>
        <plugins>
            <plugin>
                <groupId>org.jsonschema2pojo</groupId>
                <artifactId>jsonschema2pojo-maven-plugin</artifactId>
                <version>0.4.22</version>
                <configuration>
                    <sourceDirectory>${basedir}/src/main/resources</sourceDirectory>
                    <targetPackage>com.github.vedenin</targetPackage>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

Save json shema to sourceDirectory
After maven/install Java classes will be generated

Full example

7. Documentations

Documentations for every library:

JSON parsers

Analog XPath for JSON

Generates Java types from JSON or JSON Schema or JSON validation

All examples:

If you want to help this project, see this guidelines