使用GSON序列化Java对象

为了获得所需的结果，您需要像这样编写串行器：

public static class PersonSerializer implements JsonSerializer<Person> {    public JsonElement serialize(final Person person, final Type type, final JsonSerializationContext context) {        JsonObject result = new JsonObject();        result.add("id", new JsonPrimitive(person.getId()));        result.add("name", new JsonPrimitive(person.getName()));        Person parent = person.getParent();        if (parent != null) { result.add("parent", new JsonPrimitive(parent.getId()));        }        return result;    }}

的结果

    Person p = new Person(1, "Joe", new Person(2, "Mike"));    com.google.gson.Gson gson = new GsonBuilder().registerTypeAdapter(Person.class, new PersonSerializer()) .create();    System.out.println(gson.toJson(p));

将会

{"id":1,"name":"Joe","parent":2}

完整的代码：

import java.lang.reflect.Type;import com.google.gson.GsonBuilder;import com.google.gson.JsonElement;import com.google.gson.JsonObject;import com.google.gson.JsonPrimitive;import com.google.gson.JsonSerializationContext;import com.google.gson.JsonSerializer;public class GsonSimpleTest {    public static class Person {        public int id;        public String name;        public Person parent;        public Person(final int id, final String name) { super(); this.id = id; this.name = name;        }        public Person(final int id, final String name, final Person parent) { super(); this.id = id; this.name = name; this.parent = parent;        }        public int getId() { return id;        }        public void setId(final int id) { this.id = id;        }        public String getName() { return name;        }        public void setName(final String name) { this.name = name;        }        public Person getParent() { return parent;        }        public void setParent(final Person parent) { this.parent = parent;        }    }    public static class PersonSerializer implements JsonSerializer<Person> {        public JsonElement serialize(final Person person, final Type type, final JsonSerializationContext context) { JsonObject result = new JsonObject(); result.add("id", new JsonPrimitive(person.getId())); result.add("name", new JsonPrimitive(person.getName())); Person parent = person.getParent(); if (parent != null) {     result.add("parent", new JsonPrimitive(parent.getId())); } return result;        }    }    public static void main(final String[] args) {        Person p = new Person(1, "Joe", new Person(2, "Mike"));        com.google.gson.Gson gson = new GsonBuilder().registerTypeAdapter(Person.class, new PersonSerializer())     .create();        System.out.println(gson.toJson(p));    }}