fastjson新手必看

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>x.x.x</version>
</dependency>


package com.json.fastjson;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.json.bean.Person;
/*
* 这里将json的转化和解析都放在一起了，大家可以根据实际需要来转化json字符串和解析json字符串
*/
public class FastjsonClass {
public static void main(String[] args) {
method1();
method2();
method3();
method4();
}

static void method1(){
System.out.println("javabean转化示例开始----------");
Person person = new Person("1","fastjson",1);

//这里将javabean转化成json字符串
String jsonString = JSON.toJSONString(person);
System.out.println(jsonString);
//这里将json字符串转化成javabean对象,
person =JSON.parseObject(jsonString,Person.class);
System.out.println(person.toString());

System.out.println("javabean转化示例结束----------");
}

static void method2(){
System.out.println("List<javabean>转化示例开始----------");

Person person1 = new Person("1","fastjson1",1);
Person person2 = new Person("2","fastjson2",2);
List<Person> persons = new ArrayList<Person>();
persons.add(person1);
persons.add(person2);
String jsonString = JSON.toJSONString(persons);
System.out.println("json字符串:"+jsonString);

//解析json字符串
List<Person> persons2 = JSON.parseArray(jsonString,Person.class);
//输出解析后的person对象，也可以通过调试模式查看persons2的结构
System.out.println("person1对象："+persons2.get(0).toString());
System.out.println("person2对象："+persons2.get(1).toString());

System.out.println("List<javabean>转化示例结束----------");
}

static void method3(){
System.out.println("List<String>转化示例开始----------");
List<String> list = new ArrayList<String>();
list.add("fastjson1");
list.add("fastjson2");
list.add("fastjson3");
String jsonString = JSON.toJSONString(list);
System.out.println("json字符串:"+jsonString);

//解析json字符串
List<String> list2 = JSON.parseObject(jsonString,new TypeReference<List<String>>(){});
System.out.println(list2.get(0)+"::"+list2.get(1)+"::"+list2.get(2));
System.out.println("List<String>转化示例结束----------");

}

static void method4(){
System.out.println(" List<Map<String,Object>>转化示例开始 ----------");
Map<String,Object> map = new HashMap<String,Object>();
map.put("key1", "value1");
map.put("key2", "value2");
Map<String,Object> map2 = new HashMap<String,Object>();
map2.put("key1", 1);
map2.put("key2", 2);
List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();
list.add(map);
list.add(map2);
String jsonString = JSON.toJSONString(list);
System.out.println("json字符串:"+jsonString);
//解析json字符串
List<Map<String,Object>> list2 = JSON.parseObject(jsonString,new TypeReference<List<Map<String,Object>>>(){});

System.out.println("map的key1值"+list2.get(0).get("key1"));
System.out.println("map的key2值"+list2.get(0).get("key2"));
System.out.println("ma2p的key1值"+list2.get(1).get("key1"));
System.out.println("map2的key2值"+list2.get(1).get("key2"));
}

}







package com.json.bean;

public class Person {
private String id ;
private String name;
private int age ;

public Person(){

}
public Person(String id,String name,int age){
this.id=id;
this.name=name;
this.age=age;
}
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;
}
@Override
public String toString() {
return "解析json字符串后获取的person对象：id的值是" + id + ", name的值是" + name + ", age的值是" + age + "";
}

}
====================================================================
package jsonTest;

public class Student {

private String name;
private int age;

public Student() {
// TODO Auto-generated constructor stub
}

public Student(String name,int age){
this.name=name;
this.age=age;
}

public void setName(String name){
this.name=name;

}

public String getName(){
return name;
}

public void setAge(int age){
this.age=age;
}

public int getAge(){
return age;
}

@Override
public String toString() {
// TODO Auto-generated method stub
return "student [name="+name+" , "+"age="+age+"]";
}

}
-=================================

package jsonTest;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.TypeReference;


public class MyJson {

public static void main(String[] args) {

List<Student> list=new ArrayList<>();
Student student=new Student("bob",24);
Student student12=new Student("lily", 23);
list.add(student);
list.add(student12);
System.out.println("*******javaBean  to jsonString*******");
String str1=JSON.toJSONString(student);
System.out.println(str1);
System.out.println(JSON.toJSONString(list));
System.out.println();

System.out.println("******jsonString to javaBean*******");
//Student stu1=JSON.parseObject(str1,new TypeReference<Student>(){});
Student stu1=JSON.parseObject(str1,Student.class);
System.out.println(stu1);
System.out.println();

System.out.println("******javaBean to jsonObject******");
JSONObject jsonObject1=(JSONObject)JSON.toJSON(student);
System.out.println(jsonObject1.getString("name"));
System.out.println();

System.out.println("******jsonObject to javaBean******");
Student student2=JSON.toJavaObject(jsonObject1, Student.class);
System.out.println(student2);
System.out.println();

System.out.println("*******javaBean to jsonArray******");
List<Student> stulist=new ArrayList<>();
for(int i=0;i<5;i++){
stulist.add(new Student("student"+i, i));

}
JSONArray jsonArrays=(JSONArray)JSON.toJSON(stulist);
for(int i=0;i<jsonArrays.size();i++){
System.out.println(jsonArrays.getJSONObject(i));
}
System.out.println();

System.out.println("*****jsonArry to javalist******");
List<Student> myList=new ArrayList<>();
for(int i=0;i<jsonArrays.size();i++){

Student student3=JSON.toJavaObject(jsonArrays.getJSONObject(i), Student.class);
myList.add(student3);
}
for(Student stu:myList){
System.out.println(stu);
}

        System.out.println();

System.out.println("*****jsonObject to jsonString*****");
String str4=JSON.toJSONString(jsonObject1);
System.out.println(str4);
System.out.println();

System.out.println("*******jsonString to jsonObject*****");
JSONObject jso1=JSON.parseObject(str1);
System.out.println(jso1.getString("name"));
System.out.println();

System.out.println("*****jsonString to jsonArray*****");
JSONArray jArray=JSON.parseArray(JSON.toJSONString(stulist));
for(int i=0;i<jArray.size();i++){
System.out.println(jArray.getJSONObject(i));
}
System.out.println();
}

}
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