2-3-1 Java Web基础-JSON

JSON与JavaScript

JSON.parse()方法将字符串转换为JSON对象

        var str = "{\"class_name\":\"五年级四班\"}";//str.ename
        var json = JSON.parse(str);
        console.log(str);
        console.log(json);
        document.write("班级:" + json.class_name);

JSON.stringify()方法将JSON对象转换为字符串

    var json1 = {"class_name" : "五年级四班"};
    var str1 = JSON.stringify(json1);
    console.info(json1);
    console.info(str1);
    var json2 = {};
    json2.class_name = "五年级五班";
    json2.floor = "逸夫楼四层";
    json2.teacher = "王义夫";
    console.info(json2);

JSON与FastJSON

实体类

import java.util.Date;

import com.alibaba.fastjson.annotation.JSONField;

public class Employee {
    private Integer empno;
    private String ename;
    private String job;
    //@JSONField(format="yyyy-MM-dd HH:mm:ss SSS")
    @JSONField(name = "hiredate" , format="yyyy-MM-dd")
    private Date hdate;
    private Float salary;
    @JSONField(serialize = false)
    private String dname;
    public Integer getEmpno() {
        return empno;
    }
    public void setEmpno(Integer empno) {
        this.empno = empno;
    }
    public String getEname() {
        return ename;
    }
    public void setEname(String ename) {
        this.ename = ename;
    }
    public String getJob() {
        return job;
    }
    public void setJob(String job) {
        this.job = job;
    }
    public Date getHdate() {
        return hdate;
    }
    public void setHdate(Date hdate) {
        this.hdate = hdate;
    }
    public Float getSalary() {
        return salary;
    }
    public void setSalary(Float salary) {
        this.salary = salary;
    }
    public String getDname() {
        return dname;
    }
    public void setDname(String dname) {
        this.dname = dname;
    }
    
    
}

import java.util.Calendar;

import com.alibaba.fastjson.JSON;

public class FastJsonSample1 {
    public static void main(String[] args) {
        Employee employee = new Employee();
        employee.setEmpno(4488);
        employee.setEname("王晓东");
        employee.setJob("客户经理");
        employee.setSalary(10000f);
        employee.setDname("市场部");
        Calendar c = Calendar.getInstance();
        c.set(2019, 0, 30, 0, 0, 0);
        employee.setHdate(c.getTime());
        //FastJSON中提供了JSON对象，完成对象与JSON字符串的互相转换
        String json = JSON.toJSONString(employee);
        System.out.println(json);
        Employee emp = JSON.parseObject(json, Employee.class);
        System.out.println(emp.getEname());
    }
}

import java.util.ArrayList;
import java.util.List;

import com.alibaba.fastjson.JSON;

public class FastJsonSample2 {
    public static void main(String[] args) {
        List emplist = new ArrayList();
        for (int i = 1 ; i <= 100 ; i++) {
            Employee employee = new Employee();
            employee.setEmpno(4488 + i);
            employee.setEname("员工" + i);
            emplist.add(employee);
        }
        String json = JSON.toJSONString(emplist);
        System.out.println(json);
        List<Employee> emps = JSON.parseArray(json , Employee.class);
        for(Employee e : emps) {
            System.out.println(e.getEmpno() + ":" + e.getEname());
        }
    }
}