Gson 是 Google 提供的用来在 Java 对象和 JSON 数据之间进行映射的 Java 类库。可以将一个 JSON 字符串转成一个 Java 对象，或者反过来。
先下载对应jar包：gson-1.6.jar
实体类:
-
public class Student {
-
private int id;
-
private String name;
-
private Date birthDay;
-
-
public int getId() {
-
return id;
-
}
-
-
public void setId(int id) {
-
this.id = id;
-
}
-
-
public String getName() {
-
return name;
-
}
-
-
public void setName(String name) {
-
this.name = name;
-
}
-
-
public Date getBirthDay() {
-
return birthDay;
-
}
-
-
public void setBirthDay(Date birthDay) {
-
this.birthDay = birthDay;
-
}
-
-
@Override
-
public String toString() {
-
return "Student [birthDay=" + birthDay + ", id=" + id + ", name="
-
+ name + "]";
-
}
-
-
}
测试类:
-
import java.util.ArrayList;
-
import java.util.Date;
-
import java.util.List;
-
-
import com.google.gson.Gson;
-
import com.google.gson.reflect.TypeToken;
-
-
public class GsonTest1 {
-
-
public static void main(String[] args) {
-
Gson gson = new Gson();
-
-
Student student1 = new Student();
-
student1.setId(1);
-
student1.setName("李坤");
-
student1.setBirthDay(new Date());
-
-
// //////////////////////////////////////////////////////////
-
System.out.println("----------简单对象之间的转化-------------");
-
// 简单的bean转为json
-
String s1 = gson.toJson(student1);
-
System.out.println("简单Bean转化为Json===" + s1);
-
-
// json转为简单Bean
-
Student student = gson.fromJson(s1, Student.class);
-
System.out.println("Json转为简单Bean===" + student);
-
// 结果:
-
// 简单Bean转化为Json==={"id":1,"name":"李坤","birthDay":"Jun 22, 2012 8:27:52 AM"}
-
// Json转为简单Bean===Student [birthDay=Fri Jun 22 08:27:52 CST 2012, id=1,
-
// name=李坤]
-
// //////////////////////////////////////////////////////////
-
-
Student student2 = new Student();
-
student2.setId(2);
-
student2.setName("曹贵生");
-
student2.setBirthDay(new Date());
-
-
Student student3 = new Student();
-
student3.setId(3);
-
student3.setName("柳波");
-
student3.setBirthDay(new Date());
-
-
List<Student> list = new ArrayList<Student>();
-
list.add(student1);
-
list.add(student2);
-
list.add(student3);
-
-
System.out.println("----------带泛型的List之间的转化-------------");
-
// 带泛型的list转化为json
-
String s2 = gson.toJson(list);
-
System.out.println("带泛型的list转化为json==" + s2);
-
-
// json转为带泛型的list
-
List<Student> retList = gson.fromJson(s2,
-
new TypeToken<List<Student>>() {
-
}.getType());
-
for (Student stu : retList) {
-
System.out.println(stu);
-
}
-
-
// 结果:
-
// 带泛型的list转化为json==[{"id":1,"name":"李坤","birthDay":"Jun 22, 2012 8:28:52 AM"},{"id":2,"name":"曹贵生","birthDay":"Jun 22, 2012 8:28:52 AM"},{"id":3,"name":"柳波","birthDay":"Jun 22, 2012 8:28:52 AM"}]
-
// Student [birthDay=Fri Jun 22 08:28:52 CST 2012, id=1, name=李坤]
-
// Student [birthDay=Fri Jun 22 08:28:52 CST 2012, id=2, name=曹贵生]
-
// Student [birthDay=Fri Jun 22 08:28:52 CST 2012, id=3, name=柳波]
-
-
}
-
}
Json转换利器Gson——简单对象转化和带泛型的List转化
原文：http://blog.csdn.net/wolongdede/article/details/44674265
