Json与 List、map、javaBean 间相互转换

爱被打了一巴掌 2023-07-04 12:58 9阅读 0赞

maven依赖：

<dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.47</version>
            </dependency>

### 1、java 对象(List、Map、javaBean)转 json 字符串 ###

public static void main(String[] args)
    
            List<String> list = new ArrayList<String>();
            list.add("hello");
            list.add("word");
            list.add("six");
            //list to jsonString
            String jsonSTR1 =JSON.toJSONString(list);
            System.out.println(jsonSTR1);
    
    
            //map to jsonString
            Map<String,Object> map =new HashMap<String, Object>();
            map.put("key",list);
            String jsonSTR2 =JSON.toJSONString(map);
            System.out.println(jsonSTR2);
    
    
            //javaBean to jsonString
            Map<String,Integer> car =new HashMap<String, Integer>();
            car.put("car1",100000);
            car.put("car2",230000);
            Person person=new Person();
            person.setAge(28);
            person.setName("tony");
            person.setCar(car);
    
            String jsonSTR3 =JSON.toJSONString(person);
            System.out.println(jsonSTR3);
    }

## ##

### 2 、JsonString 转 Object 、JSONObject  ###

public static void main(String[] args)
    
            String jsonString="{\"car\":  {\"car2\":150000,\"car1\":98000},\"name\":\"tome\",\"age\":30}";
            
            Object object=JSON.parse(jsonString);
            System.out.println(object);
    
    
            JSONObject jsonObject=JSON.parseObject(jsonString);
            System.out.println(jsonObject.get("car"));
    }

### 3 、JsonString 转 javaBean ###

public static void main(String[] args)
    
            String jsonString="{\"car\":{\"car2\":150000,\"car1\":98000},\"name\":\"tome\",\"age\":30}";
            JSONObject jsonObject=JSON.parseObject(jsonString);
            Person p=JSON.toJavaObject(jsonObject,Person.class);
            System.out.println(p.toString());
    
    }
    
    
          class  Person{
               private String name;
               private int age;
               private Map<String,Integer> car;
    
               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 Map<String, Integer> getCar() {return car;}
               public void setCar(Map<String, Integer> car) {this.car = car;}
    
              @Override
              public String toString() {
                 return "Person{" +
                    "name='" + name + '\'' +
                    ", age=" + age +
                    ", car=" + car +
                    '}';
             }
    }