JSON

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　HTML控制台显示
<script type="text/javascript">
    var student  = JSON.parse(‘{"student":"小明","age":"19岁"}‘);
    console.log(student)

    var user = {
        user:"小明",
        age:"19",
        sex:"男"
    }
    console.log(user);
    /*转换成java字符串  {"student":"小明","age":"19岁"}   */
    var obj = JSON.stringify(student);
    console.log(obj)
    /*转换成字符串  {"user":"小明","age":"19","sex":"男"}   */
    var s = JSON.stringify(user);
    console.log(s)
    /*从字符串转换成json格式*/
    var parse = JSON.parse(s);
    console.log(parse)
</script>

jsp  显示JSON

1.通过attribute  只能是jsp，如果是html ，html不支持java代码，不能直接传对象

@WebServlet("/jsonServlet")
public class JsonServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Student student = new Student();
        student.setId(1);
        student.setAge(19);
        student.setName("小明");

        req.setAttribute("student",student);
        req.getRequestDispatcher("/index.jsp").forward(req,resp);
    }

2.通过 resp 写入json
@WebServlet("/jsonServlet")
public class JsonServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Student student = new Student();
        student.setId(1);
        student.setAge(19);
        student.setName("小明");
       resp.setContentType("text/html;charset=UTF-8");
       resp.setCharacterEncoding("UTF-8");
        resp.getWriter().print(new Gson().toJson(student));
    }

这个需要google gson-2.5.jar（谷歌） 

public class Student {

    private int id;
    private String name;
    private int age;
    private String sex;
    private float height;

    private Date birthday;
    public int getId() {
        return id;
    }
    public void setId(int 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;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public float getHeight() {
        return height;
    }
    public void setHeight(float height) {
        this.height = height;
    }
    public Date getBirthday() {
        return birthday;
    }
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name=‘" + name + ‘\‘‘ +
                ", age=" + age +
                ", sex=‘" + sex + ‘\‘‘ +
                ", weight=" + height +
                ", birthday=‘" + birthday + ‘\‘‘ +

                ‘}‘;
    }
}

    var heros =JSON.parse(‘[{"name":"提莫","hp":"1000","cd":"10","op":"11"},{‘ +
        ‘"name":"盖伦","hp":"1000","cd":"10","op":"11"},‘ +
        ‘{"name":"诺手","hp":"1000","cd":"10","op":"11"},‘ +
        ‘{"name":"琴女","hp":"1000","cd":"10","op":"11"},‘ +
        ‘{"name":"布隆","hp":"1000","cd":"10","op":"11"},‘ +
        ‘{"name":"冰女","hp":"1000","cd":"10","op":"11"},‘ +
        ‘{"name":"死歌","hp":"1000","cd":"10","op":"11"}‘ +
        ‘]‘);
    /*获取json数组输出*/
    var z=0;
    for (var i = 0; i <heros.length-1 ; i++) {
        console.log(heros[i].name,heros[i].hp,heros[i].cd,heros[i].op);
        console.log(z++);
    }