日常开发问题解决

对象类型转换2：

com.alibaba.fastjson.JSONObject时经常会用到它的转换方法，包括Java对象转成JSON串、JSON对象，JSON串转成java对象、JSON对象，JSON对象转换Java对象、JSON串等，使用方法总结如下

1、Java对象-->JSON对象

(JSONObject)JSONObject.toJSON(Java对象实例)

public classJSON2JavaTest{public static voidmain(String[] args) {
Student stu= new Student("公众号编程大道", "m", 2);//Java对象转化为JSON对象

JSONObject jsonObject =(JSONObject) JSONObject.toJSON(stu);

System.out.println("Java对象转化为JSON对象 " + jsonObject);//{"name":"公众号编程大道","age":2,"sex":"m"}

}

}

2、Java对象-->JSON字符串

JSONObject.toJSONString(Java对象实例)

public classJSON2JavaTest{public static voidmain(String[] args) {
Student stu= new Student("公众号编程大道", "m", 2);//Java对象转换成JSON字符串

String stuString =JSONObject.toJSONString(stu);

System.out.println("Java对象转换成JSON字符串 " + stuString);//{"age":2,"name":"公众号编程大道","sex":"m"}

}

}

3、JSON对象-->JSON字符串

JSONObject.toJSONString();

public classJSON2JavaTest{public static voidmain(String[] args) {
Student stu= new Student("公众号编程大道", "m", 2);//先转成JSON对象

JSONObject jsonObject =(JSONObject) JSONObject.toJSON(stu);//JSON对象转换为JSON字符串

String jsonString =jsonObject.toJSONString();

System.out.println("JSON对象转换为JSON字符串 " + jsonString);//{"name":"公众号编程大道","age":2,"sex":"m"}

}

}

4、JSON对象-->Java对象

JSONObject.toJavaObject(JSON对象实例, Java对象.class);

public classJSON2JavaTest{public static voidmain(String[] args) {
Student stu= new Student("公众号编程大道", "m", 2);//先转成JSON对象

JSONObject jsonObject =(JSONObject) JSONObject.toJSON(stu);//JSON对象转换成Java对象

Student student = JSONObject.toJavaObject(jsonObject, Student.class);

System.out.println("JSON对象转换成Java对象 " + student);//Student{name='公众号编程大道', sex='m', age=2}

}

}

5、JSON字符串-->JSON对象

JSONObject.parseObject(JSON字符串)

public classJSON2JavaTest{public static voidmain(String[] args) {
String stuString= "{"age":2,"name":"公众号编程大道","sex":"m"}";//JSON字符串转换成JSON对象

JSONObject jsonObject1 =JSONObject.parseObject(stuString);

System.out.println("JSON字符串转换成JSON对象 " + jsonObject1);//{"sex":"m","name":"公众号编程大道","age":2}

}

}

6、JSON字符串-->Java对象

JSONObject.parseObject(JSON字符串, Java对象.class);

public classJSON2JavaTest{public static voidmain(String[] args) {
String stuString= "{"age":2,"name":"公众号编程大道","sex":"m"}";//JSON字符串转换成Java对象

Student student1 = JSONObject.parseObject(stuString, Student.class);

System.out.println("JSON字符串转换成Java对象 " + student1);//Student{name='公众号编程大道', sex='m', age=2}

}

}