GSON的使用:JSON与实体对象之间的转化

import java.util.List;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

/**
 * JSON与实体对象之间的互相转化
 * @author hoodoo
 * @data 2012年12月22日
 *
 */
public class JsonTest {
	public static void main(String[] args) {
		String s="{'gradeId':1,'subjects':[{'id':1,'name':'语文'},{'id':2,'name':'数学'}]}";
		Gson g=new Gson();
		Beans b=new Beans();
		b.setGradeId(1);
		b.setSubjects(new Subject[]{new Subject(1,"语文"),new Subject(2,"数学")});
		//将实体对象 转化成json
		System.out.println(g.toJson(b));
		//从json 解析成单一对象实体
		Beans bs=g.fromJson(s, Beans.class);
		for(Subject sb:bs.getSubjects()){
			System.out.println(sb.getName());
		}
		
		String s1="[{'gradeId':1,'subjects':[{'id':1,'name':'语文'},{'id':2,'name':'数学'},{'id':3,'name':'英语'},{'id':4,'name':'物理'},{'id':5,'name':'化学'}]},{'gradeId':2,'subjects':[{'id':1,'name':'语文'},{'id':2,'name':'数学'},{'id':3,'name':'英语'},{'id':4,'name':'物理'},{'id':5,'name':'化学'}]},{'gradeId':3,'subjects':[{'id':1,'name':'语文'},{'id':2,'name':'数学'},{'id':3,'name':'英语'},{'id':4,'name':'物理'},{'id':5,'name':'化学'}]},{'gradeId':4,'subjects':[{'id':1,'name':'语文'},{'id':2,'name':'数学'},{'id':3,'name':'英语'},{'id':4,'name':'物理'},{'id':5,'name':'化学'}]},{'gradeId':5,'subjects':[{'id':1,'name':'语文'},{'id':2,'name':'数学'},{'id':3,'name':'英语'},{'id':4,'name':'物理'},{'id':5,'name':'化学'}]}]";
		//从json 解析成对象列表
		List<Beans> bss=g.fromJson(s1, new TypeToken<List<Beans>>(){}.getType());
		for(Beans b1:bss){
			System.out.println(b1.getGradeId()+"年级");
			for(Subject sb:b1.getSubjects()){
				System.out.println(sb.getId()+":"+sb.getName());
			}
		}
	}
}

import java.io.Serializable;
/**
 * Json与实体对象转化
 * @author hoodoo
 * @data 2012年12月22日
 *
 */
public class Beans implements Serializable{
 private static final long serialVersionUID = 1L;
 private int gradeId;
 private Subject[] subjects;
 public int getGradeId() {
 return gradeId;
 }
 public Subject[] getSubjects() {
 return subjects;
 }
 public void setSubjects(Subject[] subjects) {
 this.subjects = subjects;
 }
 public void setGradeId(int gradeId) {
 this.gradeId = gradeId;
 }
 
}

 
 
 

 

 
 
 
 
  
  
  
  



 
 
 

 

 
 
 
 
  
  
  
  

import java.io.Serializable;


/**
 * Json与实体对象转化
 * @author hoodoo
 * @data 2012年12月22日
 *
 */
public class Subject implements Serializable {
 private static final long serialVersionUID = 1L;
 private int id;
 private String name;
 public Subject() {
 }
 public Subject(int id,String name) {
 this.id=id;
 this.name=name;
 }
 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;
 }


}