Gson具体用法

来自： http://xuexizhishen.blog.51cto.com/2687197/744910

package com.lupeng.javase.json.bean;
import java.io.Serializable;
/**
 * 普通JavaBean类
 * @author 翔林小刚
 * @date   2011-12-18
 */
public class JavaBean implements Serializable{
 private static final long serialVersionUID = 8720431164344424704L;
 
 private String id;
 private String name;
 private int age;
 private String addr;
 
 public JavaBean() {
  super();
 }
 
 public JavaBean(String id, String name, int age, String addr) {
  super();
  this.id = id;
  this.name = name;
  this.age = age;
  this.addr = addr;
 }
 public String getId() {
  return id;
 }
 public void setId(String id) {
  this.id = id;
 }
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 public int getAge() {
  return age;
 }
 public void setAge(int age) {
  this.age = age;
 }
 public String getAddr() {
  return addr;
 }
 public void setAddr(String addr) {
  this.addr = addr;
 }
 @Override
 public String toString() {
  return "User [id=" + id + ", name=" + name + ", age=" + age + ", addr=" + addr + "]";
 }
 
}

 
-------------------------------------------------无情分割线--------------------------------------------
 
package com.lupeng.javase.json.bean;
import java.io.Serializable;
import java.util.Date;
/**
 * 带日期属性的JavaBean类
 * @author 翔林小刚
 * @date   2011-12-18
 */
public class DateBean implements Serializable {
 private static final long serialVersionUID = -2071405788146467301L;
 
 private String id;
 private String name;
 private int age;
 private Date birth;
 
 public DateBean() {
  super();
 }
 
 public DateBean(String id, String name, int age, Date birth) {
  super();
  this.id = id;
  this.name = name;
  this.age = age;
  this.birth = birth;
 }
 public String getId() {
  return id;
 }
 public void setId(String id) {
  this.id = id;
 }
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 public int getAge() {
  return age;
 }
 public void setAge(int age) {
  this.age = age;
 }
 public Date getBirth() {
  return birth;
 }
 public void setBirth(Date birth) {
  this.birth = birth;
 }
 @Override
 public String toString() {
  return "DateBean [age=" + age + ", birth=" + birth + ", id=" + id
    + ", name=" + name + "]";
 }
 
}
 
-------------------------------------------------无情分割线--------------------------------------------
 
package com.lupeng.javase.json.util;
import java.lang.reflect.Type;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
/**
 * 日期序列化实用工具类
 * @author 翔林小刚
 * @date   2011-12-18
 */
public class DateDeserializerUtils implements JsonDeserializer<java.util.Date>{
 @Override
 public java.util.Date deserialize(JsonElement json, Type type,
   JsonDeserializationContext context) throws JsonParseException {
  return new java.util.Date(json.getAsJsonPrimitive().getAsLong());
 }
}
 
 
 
-------------------------------------------------无情分割线--------------------------------------------
package com.lupeng.javase.json.util;
import java.lang.reflect.Type;
import java.util.Date;
import com.google.gson.JsonElement;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
/**
 * 日期解序列实用工具类
 * @author 翔林小刚
 * @date   2011-12-18
 */
public class DateSerializerUtils implements JsonSerializer<java.util.Date>{
 @Override
 public JsonElement serialize(Date date, Type type, JsonSerializationContext content) {
  return new JsonPrimitive(date.getTime());
 }
}

-------------------------------------------------无情分割线--------------------------------------------
 
 
 
 
 
package com.lupeng.javase.apps.json;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.junit.Before;
import org.junit.Test;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.lupeng.javase.json.bean.DateBean;
import com.lupeng.javase.json.bean.JavaBean;
import com.lupeng.javase.json.util.DateDeserializerUtils;
import com.lupeng.javase.json.util.DateSerializerUtils;
/**
 * Google Gson解析Json数据实例
 * 
 * 1.Bean、Json转换 testBeanJson() 2.List -> Json转换 testList2Json()
 * 3.泛型List、Json相互转换 testGenericList2Json() 4.Map -> Json转换 testMap2Json()
 * 5.泛型Map、Json相互转换 testGenericMap2Json() 6.带日期属性Bean、Json转换 testDateBeanJson()
 * 7.带日期属性泛型List、Json转换 testDateGenericListJson()
 * 
 * @author 翔林小刚
 * @create 2011-08-05
 * @modify 2011-12-18
 */
@SuppressWarnings("unchecked")
public class GsonTester {
 private Gson gson = null;
 private GsonBuilder gsonBuilder = null;
 @Before
 public void setUp() {
  gson = new Gson();
  gsonBuilder = new GsonBuilder();
 }
 /**
  * JavaBean、Json相互转换
  */
 @Test
 public void testBeanJson() {
  JavaBean bean = new JavaBean("1001", "scott", 20, "TL");
  // Bean -> Json
  String json = gson.toJson(bean);
  System.out.println(json);
  // Json -> Bean
  bean = gson.fromJson(json, JavaBean.class);
  System.out.println(bean);
 }
 /**
  * List转换成Json字符串
  */
 @Test
 public void testList2Json() {
  // List
  List list = new ArrayList();
  for (int i = 0; i < 5; i++) {
   list.add("element" + i);
  }
  System.out.println(list);
  // List -> Json
  String json = gson.toJson(list);
  System.out.println(json);
 }
 /**
  * 泛型List、Json相互转换
  */
 @Test
 public void testGenericListJson() {
  // 泛型List
  List<JavaBean> list = new ArrayList<JavaBean>();
  for (int i = 0; i < 3; i++) {
   JavaBean user = new JavaBean("100" + i, "name" + i, 20 + i, "BJ"
     + i);
   list.add(user);
  }
  System.out.println(list);
  // 泛型List -> Json
  java.lang.reflect.Type type = new com.google.gson.reflect.TypeToken<List<JavaBean>>() {
  }.getType();
  String json = gson.toJson(list, type);
  System.out.println(json);
  // Json -> 泛型List
  List<JavaBean> users = gson.fromJson(json.toString(), type);
  System.out.println(users);
 }
 /**
  * Map转换成Json字符串
  */
 @Test
 public void testMap2Json() {
  // Map数据
  Map map = new HashMap();
  map.put("id", "1001");
  map.put("name", "scott");
  map.put("age", 20);
  map.put("addr", "BJ");
  System.out.println(map);
  // Map -> Json
  String json = gson.toJson(map);
  System.out.println(json);
 }
 /**
  * 泛型Map、Json相互转换
  */
 @Test
 public void testGenericMapJson() {
  // 泛型Map数据
  Map<String, JavaBean> map = new HashMap<String, JavaBean>();
  for (int i = 0; i < 5; i++) {
   JavaBean user = new JavaBean("100" + i, "name" + i, 20 + i, "LN"
     + i);
   map.put("100" + i, user);
  }
  System.out.println(map);
  // 泛型Map -> Json
  java.lang.reflect.Type type = new com.google.gson.reflect.TypeToken<Map<String, JavaBean>>() {
  }.getType();
  String json = gson.toJson(map, type);
  System.out.println(json);
  // Json -> Map
  Map<String, JavaBean> users = gson.fromJson(json.toString(), type);
  System.out.println(users);
 }
 /**
  * 带日期类型Bean、Json相互转换
  */
 @Test
 public void testDateBeanJson() {
  // 日期Bean数据
  DateBean bean = new DateBean("1001", "scott", 20, new Date());
  // Bean(带日期属性) -> Json
  gson = gsonBuilder.registerTypeAdapter(java.util.Date.class,
    new DateSerializerUtils()).setDateFormat(DateFormat.LONG)
    .create();
  // gson = new
  // GsonBuilder().setDateFormat("yyyy-MM-dd HH:mm:ss").create();
  String json = gson.toJson(bean);
  System.out.println("_________________________" + json);
  // Json -> Bean(带日期类型属性)
  gson = gsonBuilder.registerTypeAdapter(java.util.Date.class,new DateDeserializerUtils()).setDateFormat("yyyy/MM/dd")
    .create();
  java.lang.reflect.Type type = new com.google.gson.reflect.TypeToken<DateBean>() {
  }.getType();
  DateBean b = gson.fromJson(json, type);
  System.out.println(b);
 }
 /**
  * 泛型日期List、Json相互转换
  */
 @Test
 public void testDateGenericListJson() {
  // 泛型日期List
  List<DateBean> list = new ArrayList<DateBean>();
  for (int i = 0; i < 3; i++) {
   DateBean user = new DateBean("100" + i, "name" + i, 20 + i,
     new Date());
   list.add(user);
  }
  System.out.println(list);
  // 泛型日期List -> Json
  gson = gsonBuilder.registerTypeAdapter(java.util.Date.class,
    new DateSerializerUtils()).setDateFormat(DateFormat.LONG)
    .create();
  java.lang.reflect.Type type = new com.google.gson.reflect.TypeToken<List<DateBean>>() {
  }.getType();
  String json = gson.toJson(list, type);
  System.out.println(json);
  // Json -> 泛型日期List
  gson = gsonBuilder.registerTypeAdapter(java.util.Date.class,
    new DateDeserializerUtils()).setDateFormat(DateFormat.LONG)
    .create();
  List<DateBean> users = gson.fromJson(json.toString(), type);
  System.out.println(users);
 }
}