table of Contents
Learn JSON
Introducing JSON
The JSON: the JavaScript Object Notation (the JavaScript Object Notation) lightweight text data interchange format.
JSON syntax rules : JSON an object is stored in the form of key-value pairs { "key": "value"} represents an array manner as [{target} JSON, JSON objects {}]
Example : Object {"ename":"Jack","age":"25"}
Array [{"ename":"Jack","age":"25"},{"ename":"Lucy","age":"24"}]
JSON and JavaScript interaction
- Converts a string to a JSON object
JSON.parse()
demo1.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>字符串转JSON</title>
<script type="text/javascript">
var str = "{\"name\":\"张三\"}";
var json = JSON.parse(str);
console.log(str);
console.log(json);
document.write("姓名:" + json.name);//姓名：张三
</script>
</head>
<body>
</body>
</html>- Converting a string JSON object
JSON.stringify()
demo2.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>JSON转字符串</title>
<script type="text/javascript">
var json1 = {"name" : "张三"};
var str= JSON.stringify(json1);
document.write(str);//{"name":"张三"}
</script>
</head>
<body>
</body>
</html>JSON interact with Java
FastJSON parser
FastJSON jar package download: https://repo1.maven.org/maven2/com/alibaba/fastjson/1.2.53/fastjson-1.2.53.jar
Student.java
package JSON;
public class Student {
private String name;
private Integer age;
public Student() {
}
public Student(String name, Integer age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
}
FastJSON serialization
The JavaBean object into a JSON-formatted string JSON.toJSONString(Object)
JSONdemo1.java
package JSON;
import com.alibaba.fastjson.JSON;
public class JSONdemo1 {
public static void main(String[] args) {
Student stu = new Student();
stu.setName("张三");
stu.setAge(20);
String s = JSON.toJSONString(stu);
System.out.println(s);//{"age":20,"name":"张三"}
}
}
FastJSON deserialization
The JSON-formatted string into a Java Bean objects JSON.parseArray(list, Object.class)
JSONdemo2.java
package JSON;
import com.alibaba.fastjson.JSON;
import java.util.ArrayList;
import java.util.List;
public class JSONdemo2 {
public static void main(String[] args) {
List list=new ArrayList();
list.add(new Student("张三",18));
list.add(new Student("李四",19));
String s = JSON.toJSONString(list);
System.out.println(s);//[{"age":18,"name":"张三"},{"age":19,"name":"李四"}]
List<Student> stu = JSON.parseArray(s, Student.class);
for (Student student : stu) {
System.out.println(student.getName()+":"+student.getAge());
}//张三:18 李四:19
}
}
FastJSON comment
@JSONField(serialize="true/false") Serialize set value set whether true or false to the following properties of the sequence
@JSONField(format="0,000.00") Formatting attribute format