Android解析JASON方式

JSON数据格式的定义：

JSON的全称是：JavaScript Object Notation，是一种轻量级的数据交换格式。它构建于两种结构：

1、"名称/值" 对的集合(a collection of name / value pairs)。不同的语言中，它被理解为对象(Object)，记录(Record)，结构(struct)，字典(Dictionary)，哈希表(HashTable)，有键列表(Keyed list)，或者关联数组(Associative array)。

2、值的有序列表(An ordered list of values)。在大部分语言中，它被理解为数组(array)。

JSON数据格式的特点：

JSON对象时一个无序的" '名称/值' 对"的集合，一个对象以“{”(左括号)开始，以"}"(右括号)结束，每个"名称"后跟一个"："(冒号)，名称/值对之间使用"，"(逗号)分隔。

如：

{

"name":"jackson",

"age":100

}

稍微复杂一点的情况，数组是值的有序集合，一个数组以“[”(左中括号)开始，以"]"(右中括号)结束。值之间使用","(逗号)分隔。

如：

{

"studengs":

[

{"name": "jackson", "age": 100},

{"name": "michael", "age": 51},

]

}

首先，我们搭建一个服务器的工程：JsonProject这个项目，工程目录结构：

源代码：

Person.java

1.package com.json.domain;
2.
3.public class Person {
4.    private int id;
5.    private String name;
6.    private String address;
7.
8.    public Person() {
9.        super();
10.    }
11.    public Person(int id, String name, String addrss) {
12.        super();
13.        this.id = id;
14.        this.name = name;
15.        this.address = addrss;
16.    }
17.    public int getId() {
18.        return id;
19.    }
20.    public void setId(int id) {
21.        this.id = id;
22.    }
23.    public String getName() {
24.        return name;
25.    }
26.    public void setName(String name) {
27.        this.name = name;
28.    }
29.    public String getAddress() {
30.        return address;
31.    }
32.    public void setAddress(String address) {
33.        this.address = address;
34.    }
35.    @Override
36.    public String toString() {
37.        return "Person [addrss=" + address + ", id=" + id + ", name=" + name
38.                + "]";
39.    }
40.
41.}
JsonService.java

1.package com.json.service;
2.
3.import java.util.ArrayList;
4.import java.util.HashMap;
5.import java.util.List;
6.import java.util.Map;
7.
8.import com.json.domain.Person;
9.
10.public class JsonService {
11.
12.    public JsonService() {
13.    }
14.
15.    public Person getPerson(){
16.        Person person = new Person(1001,"jack","上海黄浦区");
17.        return person;
18.    }
19.    public List<Person> getListPerson(){
20.        List<Person> list = new ArrayList<Person>();
21.        Person person1 = new Person(1001,"jack","上海黄浦区");
22.        Person person2 = new Person(1002,"rose","上海闵行区");
23.        Person person3 = new Person(1003,"mick","上海黄浦区");
24.        list.add(person1);
25.        list.add(person2);
26.        list.add(person3);
27.        return list;
28.    }
29.
30.    public List<String> getListString(){
31.        List<String> list = new ArrayList<String>();
32.        list.add("北京");
33.        list.add("上海");
34.        list.add("湖南");
35.        return list;
36.    }
37.
38.    public List<Map<String,Object>> getListMaps(){
39.        List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();
40.        Map<String,Object> map1 = new HashMap<String, Object>();
41.        Map<String,Object> map2 = new HashMap<String, Object>();
42.        map1.put("id", 1001);
43.        map1.put("name", "jack");
44.        map1.put("address", "北京");
45.        map2.put("id", 1001);
46.        map2.put("name", "rose");
47.        map2.put("address", "上海");
48.        list.add(map1);
49.        list.add(map2);
50.        return list;
51.    }
52.}
JsonServlet.java

1.package com.json.servlet;
2.
3.import java.io.IOException;
4.import java.io.PrintWriter;
5.
6.import javax.servlet.ServletException;
7.import javax.servlet.http.HttpServlet;
8.import javax.servlet.http.HttpServletRequest;
9.import javax.servlet.http.HttpServletResponse;
10.
11.import com.json.service.JsonService;
12.import com.json.tools.JsonTools;
13.
14.public class JsonServlet extends HttpServlet {
15.    private JsonService service;
16.    /**
17.     * Constructor of the object.
18.     */
19.    public JsonServlet() {
20.        super();
21.    }
22.
23.    /**
24.     * Destruction of the servlet. <br>
25.     */
26.    public void destroy() {
27.        super.destroy(); // Just puts "destroy" string in log
28.        // Put your code here
29.    }
30.
31.    /**
32.     * The doGet method of the servlet. <br>
33.     *
34.     * This method is called when a form has its tag value method equals to get.
35.     *
36.     * @param request the request send by the client to the server
37.     * @param response the response send by the server to the client
38.     * @throws ServletException if an error occurred
39.     * @throws IOException if an error occurred
40.     */
41.    public void doGet(HttpServletRequest request, HttpServletResponse response)
42.            throws ServletException, IOException {
43.
44.        this.doPost(request, response);
45.    }
46.
47.    /**
48.     * The doPost method of the servlet. <br>
49.     *
50.     * This method is called when a form has its tag value method equals to post.
51.     *
52.     * @param request the request send by the client to the server
53.     * @param response the response send by the server to the client
54.     * @throws ServletException if an error occurred
55.     * @throws IOException if an error occurred
56.     */
57.    public void doPost(HttpServletRequest request, HttpServletResponse response)
58.            throws ServletException, IOException {
59.
60.        response.setContentType("text/html;charset=utf-8");
61.        request.setCharacterEncoding("utf-8");
62.        response.setCharacterEncoding("utf-8");
63.        PrintWriter out = response.getWriter();
64.
65.        String jsonString = "";
66.        String action_flag = request.getParameter("action_flag");
67.        if(action_flag.equals("person")){
68.            jsonString = JsonTools.createJsonString("person", service.getPerson());
69.        }else if(action_flag.equals("persons")){
70.            jsonString = JsonTools.createJsonString("persons", service.getListPerson());
71.        }else if(action_flag.equals("listString")){
72.            jsonString = JsonTools.createJsonString("listString", service.getListString());
73.        }else if(action_flag.equals("listMap")){
74.            jsonString = JsonTools.createJsonString("listMap", service.getListMaps());
75.        }
76.        out.println(jsonString);
77.        out.flush();
78.        out.close();
79.    }
80.
81.    /**
82.     * Initialization of the servlet. <br>
83.     *
84.     * @throws ServletException if an error occurs
85.     */
86.    public void init() throws ServletException {
87.        service = new JsonService();
88.    }
89.
90.}
web.xml中servlet映射

1.<servlet>
2.    <description>This is the description of my J2EE component</description>
3.    <display-name>This is the display name of my J2EE component</display-name>
4.    <servlet-name>JsonServlet</servlet-name>
5.    <servlet-class>com.json.servlet.JsonServlet</servlet-class>
6. </servlet>
7.
8. <servlet-mapping>
9.    <servlet-name>JsonServlet</servlet-name>
10.    <url-pattern>/servlet/JsonServlet</url-pattern>
11. </servlet-mapping>
我们通过浏览器

访问地址一：http://wulianghuan-pc:8080/JsonProject/servlet/JsonServlet?action_flag=person

输出以下结果：

{"persons":{"address":"上海黄浦区","id":1001,"name":"jack"}}

访问地址二：http://wulianghuan-pc:8080/JsonProject/servlet/JsonServlet?action_flag=persons

输出以下结果：

{"persons":[{"address":"上海黄浦区","id":1001,"name":"jack"},{"addrss":"上海闵行区","id":1002,"name":"rose"},{"address":"上海黄浦区","id":1003,"name":"mick"}]}

访问地址三：http://wulianghuan-pc:8080/JsonProject/servlet/JsonServlet?action_flag=listString

输出以下结果：

{"persons":["北京","上海","湖南"]}

访问地址四：http://wulianghuan-pc:8080/JsonProject/servlet/JsonServlet?action_flag=listMap

输出以下结果：

{"persons":[{"id":1001,"address":"北京","name":"jack"},{"id":1001,"address":"上海","name":"rose"}]}