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。
jar和源码下载地址: http://code.google.com/p/google-gson/downloads/list
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();
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();
student2.setName("曹贵生");
student2.setBirthDay(new Date()); Student student3 = new Student();
student3.setId();
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] }
}
执行结果:
----------简单对象之间的转化-------------
简单Bean转化为Json==={"id":,"name":"李坤","birthDay":"Jun 22, 2012 9:10:31 PM"}
Json转为简单Bean===Student [birthDay=Fri Jun :: CST , id=, name=李坤]
----------带泛型的List之间的转化-------------
带泛型的list转化为json==[{"id":,"name":"李坤","birthDay":"Jun 22, 2012 9:10:31 PM"},{"id":,"name":"曹贵生","birthDay":"Jun 22, 2012 9:10:31 PM"},{"id":,"name":"柳波","birthDay":"Jun 22, 2012 9:10:31 PM"}]
Student [birthDay=Fri Jun :: CST , id=, name=李坤]
Student [birthDay=Fri Jun :: CST , id=, name=曹贵生]
Student [birthDay=Fri Jun :: CST , id=, name=柳波]
Json转换利器Gson之实例一-简单对象转化和带泛型的List转化 (http://blog.csdn.net/lk_blog/article/details/7685169)
Json转换利器Gson之实例二-Gson注解和GsonBuilder (http://blog.csdn.net/lk_blog/article/details/7685190)
Json转换利器Gson之实例三-Map处理(上) (http://blog.csdn.net/lk_blog/article/details/7685210)
Json转换利器Gson之实例四-Map处理(下) (http://blog.csdn.net/lk_blog/article/details/7685224)
Json转换利器Gson之实例五-实际开发中的特殊需求处理 (http://blog.csdn.net/lk_blog/article/details/7685237)
Json转换利器Gson之实例六-注册TypeAdapter及处理Enum类型 (http://blog.csdn.net/lk_blog/article/details/7685347)