本文讲解android解析json数据。客户端接收服务端发来的4种json数据，分别解析成四种类型Person , List<Person> , List<String> , List<Map<String,Object>>，从MainActivity传递到OtherActivity.
接收的服务器端的4种json数据分别为：
1. {"person":{"address":"香港","id":1001,"name":"刘德华"}}
2. {"persons":[{"address":"香港","id":1001,"name":"刘德华"},{"address":"韩国","id":1001,"name":"宋慧乔"}]}
3. {"listString":["美国","中国","俄罗斯"]}
4. {"listMap":[{"id":1001,"address":"香港","name":"刘德华"},{"id":1002,"address":"韩国","name":"宋慧乔"}]}
客户端相应4种操作 ：
1. MainActivity 将json数据解析成Person类，用Intent将Peson对象传递给OtherActvity. 设置标记click_flag = person
2. MainActivity 将json数据解析成List<Person>，用Intent将List<Person>传递给OtherActvity. 设置标记click_flag = persons
3. MainActivity 将json数据解析成List<String>，用Intent将List<String>传递给OtherActvity. 设置标记click_flag = listString
4. MainActivity 将json数据解析成List<Map<String,Object>>，用Intent将List<Map<String,Object>>传递给OtherActvity. 设置标记click_flag = listMap
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三点重点注意点：
1. 在AndroidManifest.xml中 加上
<!-- 添加访问网络的授权 -->
<uses-permission android:name="android.permission.INTERNET" />
2. android中Http访问时 connection.getResponseCode()不被执行 。添加访问网络的授权后，仍不能执行
3. 在android的两个activity中，如何用Intent传递Person对象，List<Person>,List<Map<String,Object>>类型。
一.Intent 传递 Person对象
传递 intent.putExtra("person", (Serializable)person);
接收 Person person =(Person) intent.getSerializableExtra("person");
二.Intent 传递 List<Person>对象
传递 intent.putExtra("persons", (Serializable) list);
接收 List<Person> list = (List<Person>) intent.getSerializableExtra("persons");
三. Intent传递 List<Map<String,Object>>类型
传递 intent.putExtra("listMap", (Serializable) list);
接收 List<Map<String, Object>> list = (List<Map<String, Object>>) intent.getSerializableExtra("listMap");
注意：Intent 传递的对象object必须都实现Serializable接口，List<Object>内的object也必须要实现Serializable接口.
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1.点击“解析person数据”，反馈结果如下：
2. 点击“解析persons数据”，反馈结果如下：
3. 点击“解析listString数据”，反馈结果如下：
4.点击“解析listMap数据”，反馈结果如下：
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程序思路：
1.服务器端产生4种类型的json数据，客户端android用GET方式分别获取服务器端返回的json数据，http 请求传递参数action_flag. 服务器端根据action_flag 返回不同的json数据给客户端。
2.客户端将4种不同的json数据解析成4中不同的结果类型(Person,List<Person>,List<String>,List<Map<String,Object>>)，用Intent方式由MainActivity传递给OtherActivity,在OtherActvity中显示解析的结果。
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客户端android工程目录(左)和服务器端web工程目录(右)
1. AndroidManifest.xml 加上网络访问权限
<!-- 添加访问网络的授权 -->
<uses-permission android:name="android.permission.INTERNET" />
2.activity_main.xml 主机面
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical">" <Button android:id="@+id/person" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="解析Person数据" /> <Button android:id="@+id/persons" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="解析Persons数据" /> <Button android:id="@+id/listString" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="解析listString数据" /> <Button android:id="@+id/listMap" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="解析listMap数据" /> </LinearLayout>
3. avtivity_other.xml 点击主界面的按钮后相应的界面
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <TextView android:id="@+id/msg" android:layout_width="match_parent" android:layout_height="wrap_content" /> </LinearLayout>
4.MainActivity.java
package com.android.myjson;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.json.data.Person;
import com.json.http.HttpUtils;
import com.json.tools.JsonTools;
import android.os.Bundle;
import android.os.StrictMode;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity implements OnClickListener {
private Button person, persons, listString, listMap;
private static final String TAG = "MainActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
closeStrictMode();
person = (Button) findViewById(R.id.person);
persons = (Button) findViewById(R.id.persons);
listString = (Button) findViewById(R.id.listString);
listMap = (Button) findViewById(R.id.listMap);
person.setOnClickListener(this);
persons.setOnClickListener(this);
listString.setOnClickListener(this);
listMap.setOnClickListener(this);
}
@Override
public void onClick(View v) {
String url_path = "";
String jsonString = "";
switch (v.getId()) {
case R.id.person:
url_path = "http://192.168.0.102:8080/json_Project/servlet/JsonAction?action_flag=person";
jsonString = HttpUtils.getJsonContent(url_path, "utf-8");
Person person = JsonTools.getPerson("person", jsonString);
Intent intent = new Intent(MainActivity.this, OtherActivity.class);
intent.putExtra("click_flag", "person"); // 标记当前intent是按钮 person
intent.putExtra("person", (Serializable)person);
startActivity(intent);
break;
case R.id.persons:
url_path = "http://192.168.0.102:8080/json_Project/servlet/JsonAction?action_flag=persons";
jsonString = HttpUtils.getJsonContent(url_path, "utf-8");
try {
List<Person> list = JsonTools.getPersons("persons", jsonString);
Intent intent2 = new Intent(MainActivity.this,
OtherActivity.class);
intent2.putExtra("click_flag", "persons"); // 标记当前intent按钮是persons
intent2.putExtra("persons", (Serializable) list);
startActivity(intent2);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
case R.id.listString:
url_path = "http://192.168.0.102:8080/json_Project/servlet/JsonAction?action_flag=listString";
jsonString = HttpUtils.getJsonContent(url_path, "utf-8");
List<String> list = new ArrayList<String>();
try {
list = (ArrayList<String>) JsonTools.getListString(
"listString", jsonString);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Intent intent2 = new Intent(this, OtherActivity.class);
intent2.putExtra("click_flag", "listString"); // 标记
// 当前intent按钮是listString
intent2.putStringArrayListExtra("listString",
(ArrayList<String>) list); // 参数中的list要加强制转换
startActivity(intent2);
break;
case R.id.listMap:
url_path = "http://192.168.0.102:8080/json_Project/servlet/JsonAction?action_flag=listMap";
jsonString = HttpUtils.getJsonContent(url_path, "utf-8");
List<Map<String, Object>> list2 = new ArrayList<Map<String, Object>>();
try {
list2 = JsonTools.getListMap("listMap", jsonString);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Intent intent3 = new Intent(MainActivity.this, OtherActivity.class);
intent3.putExtra("click_flag", "listMap"); // 标记 当前intent按钮是listMap
// 用Intent传递List<Map<String,Object>> 对象，其中HashMap实现了Serializable
intent3.putExtra("listMap", (Serializable) list2);
startActivity(intent3);
break;
}
}
@SuppressLint("NewApi")
public static void closeStrictMode() {
StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
.detectAll().penaltyLog().build());
}
}
5.OtherActivity.java
package com.android.myjson;
import java.util.List;
import java.util.Map;
import com.json.data.Person;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
public class OtherActivity extends Activity {
private TextView textView;
public OtherActivity() {
// TODO Auto-generated constructor stub
}
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_other);
textView = (TextView) findViewById(R.id.msg);
Intent intent = getIntent();
String click_flag = intent.getStringExtra("click_flag");
if ("person".equals(click_flag)) { // 如果是点击 person按钮
// 接收Intent传递的Person对象
Person person =(Person) intent.getSerializableExtra("person");
textView.setText(person.toString());
} else if ("persons".equals(click_flag)) {// 如果是点击 persons按钮
// 接收Intent传递的List<Person>参数
@SuppressWarnings("unchecked")
List<Person> list = (List<Person>) intent
.getSerializableExtra("persons");
String persons = "";
for (Person person : list) {
persons += person.toString() + "\n";
}
textView.setText(persons);
} else if ("listString".equals(click_flag)) {
List<String> list = (List<String>) intent
.getStringArrayListExtra("listString");
String listString = "";
for (String s : list) {
listString += s + "\n";
}
textView.setText(listString);
} else if ("listMap".equals(click_flag)) {
//接收Intent传递的List<Map<String,Object>>参数
@SuppressWarnings("unchecked")
List<Map<String, Object>> list = (List<Map<String, Object>>) intent
.getSerializableExtra("listMap");
String listMapString = "";
for (Map<String, Object> map : list) {
// 遍历一个Map
for (Map.Entry<String, Object> entry : map.entrySet()) {
String key = entry.getKey();
Object value = entry.getValue();
listMapString += " " + key + " : " + value + " ";
}
listMapString += "\n";
}
textView.setText(listMapString);
}
}
}
6.Person.java
package com.json.data;
import java.io.Serializable;
public class Person implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private int id;
private String name;
private String address;
public Person() {
// TODO Auto-generated constructor stub
}
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 String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public Person(int id, String name, String address) {
super();
this.id = id;
this.name = name;
this.address = address;
}
@Override
public String toString() {
return "Person [id=" + id + ", name=" + name + ", address=" + address
+ "]";
}
}
7.HttpUtils.java
package com.json.http;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.annotation.SuppressLint;
import android.os.StrictMode;
public class HttpUtils {
public HttpUtils() {
// TODO Auto-generated constructor stub
}
public static String getJsonContent(String url_path ,String encode){
String jsonString = "";
try {
URL url = new URL(url_path);
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setConnectTimeout(3000);
connection.setRequestMethod("GET");
connection.setDoInput(true); //从服务器获得数据
int responseCode = connection.getResponseCode();
if (200 == responseCode) {
jsonString = changeInputStream(connection.getInputStream(),encode);
}
} catch (Exception e) {
// TODO: handle exception
}
//
return jsonString;
}
private static String changeInputStream(InputStream inputStream , String encode) throws IOException {
// TODO Auto-generated method stub
String jsonString = null;
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
byte[] data = new byte[1024];
int len = 0;
while((len=inputStream.read(data))!=-1){
outputStream.write(data, 0, len);
}
jsonString = new String(outputStream.toByteArray(), encode);
inputStream.close();
return jsonString;
}
}
8.JsonTools.java
package com.json.tools;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.json.data.Person;
/**
* 完成对json数据的解析
*
* @author ben
*
*/
public class JsonTools {
private static final String TAG = "JsonTools";
public JsonTools() {
// TODO Auto-generated constructor stub
}
public static Person getPerson(String key, String jsonString) {
Person person = new Person();
try {
// jsonObject ={"person":{"address":"香港","id":1001,"name":"刘德华"}}
JSONObject jsonObject = new JSONObject(jsonString);
// personObject = {"address":"香港","id":1001,"name":"刘德华"}
JSONObject personObject = jsonObject.getJSONObject(key); // 此处key = "person"
person.setId(personObject.getInt("id"));
person.setName(personObject.getString("name"));
person.setAddress(personObject.getString("address"));
} catch (Exception e) {
// TODO: handle exception
}
return person;
}
public static List<Person> getPersons(String key , String jsonString) throws Exception{
List<Person> list = new ArrayList<Person>();
//jsonObject={"persons":[{"address":"香港","id":1001,"name":"刘德华"},{"address":"韩国","id":1002,"name":"宋慧乔"}]}
JSONObject jsonObject = new JSONObject(jsonString);
//jsonArray =[{"address":"香港","id":1001,"name":"刘德华"},{"address":"韩国","id":1002,"name":"宋慧乔"}]
JSONArray jsonArray = jsonObject.getJSONArray(key); //此处key = persons,取得
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject personObject = jsonArray.getJSONObject(i);
Person person = new Person();
person.setId(personObject.getInt("id"));
person.setName(personObject.getString("name"));
person.setAddress(personObject.getString("address"));
list.add(person);
}
return list;
}
public static List<String> getListString(String key,String jsonString) throws Exception{
List<String> list = new ArrayList<String>();
// jsonObject = {"listString":["美国","中国","俄罗斯"]}
JSONObject jsonObject = new JSONObject(jsonString);
// jsonArray = ["美国","中国","俄罗斯"]
JSONArray jsonArray = jsonObject.getJSONArray(key);
for (int i =0 ; i<jsonArray.length();i++) {
String s = jsonArray.getString(i);
list.add(s);
}
return list;
}
public static List<Map<String, Object>> getListMap(String key , String jsonString) throws Exception{
List<Map<String, Object>> list = new ArrayList<Map<String,Object>>();
JSONObject jsonObject = new JSONObject(jsonString);
JSONArray jsonArray = jsonObject.getJSONArray(key);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject2 = jsonArray.getJSONObject(i);
Map<String, Object> map = new HashMap<String, Object>();
//重点：如何遍历json 对象中的key
Iterator<String> iterator = jsonObject2.keys(); // 获取json对象中的key，返回一个string集合。
while(iterator.hasNext()){
String json_key = iterator.next();
Object json_value = jsonObject2.get(json_key);
if (json_value == null) { //因为JSON value可为 null;
json_value = "";
}
map.put(json_key, json_value);
}
list.add(map);
}
return list;
}
}
服务器端 json_Project
1.JsonAction.java
package com.json.action;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.json.service.JsonService;
import com.json.tools.JsonTools;
public class JsonAction extends HttpServlet {
JsonService jsonService ;
/**
* Constructor of the object.
*/
public JsonAction() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
PrintWriter out = response.getWriter();
// 获取 person的 list , 保存为json数据
// String jsonString = JsonTools.creatJsonString("persons", jsonService.getListPersons());
String jsonString ="";
String action_flag = request.getParameter("action_flag");
if ("person".equals(action_flag)) {
jsonString = JsonTools.creatJsonString("person", jsonService.getPerson());
} else if("persons".equals(action_flag)) {
jsonString = JsonTools.creatJsonString("persons", jsonService.getListPersons());
}else if("listString".equals(action_flag)) {
jsonString = JsonTools.creatJsonString("listString", jsonService.getListString());
}else if("listMap".equals(action_flag)) {
jsonString = JsonTools.creatJsonString("listMap", jsonService.getListMap());
}
out.println(jsonString);
System.out.println("jsonString"+jsonString);
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
jsonService = new JsonService();
}
}
2.Person.java
package com.json.data;
public class Person {
private int id;
private String name;
private String address;
public Person() {
// TODO Auto-generated constructor stub
}
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 String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public Person(int id, String name, String address) {
super();
this.id = id;
this.name = name;
this.address = address;
}
@Override
public String toString() {
return "Person [id=" + id + ", name=" + name + ", address=" + address
+ "]";
}
}
3.JsonService.java
package com.json.service;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
import java.util.List;
import com.json.data.Person;
public class JsonService {
public JsonService() {
// TODO Auto-generated constructor stub
}
public static Person getPerson() {
Person person = new Person(1001, "刘德华", "香港");
return person;
}
public static List<Person> getListPersons() {
List<Person> persons = new ArrayList<Person>();
Person person1 = new Person(1001, "刘德华", "香港");
Person person2 = new Person(1002, "宋慧乔", "韩国");
persons.add(person1);
persons.add(person2);
return persons;
}
public static List<String> getListString(){
List<String> list = new ArrayList<String>();
list.add("美国");
list.add("中国");
list.add("俄罗斯");
return list;
}
public static List<java.util.Map<String, Object>> getListMap(){
List<java.util.Map<String, Object>> list = new ArrayList<Map<String,Object>>();
java.util.Map<String,Object> map1 = new HashMap<String,Object>();
map1.put("id",1001);
map1.put("name","刘德华");
map1.put("address","香港");
java.util.Map<String,Object> map2 = new HashMap<String,Object>();
map2.put("id",1002);
map2.put("name","宋慧乔");
map2.put("address","韩国");
list.add(map1);
list.add(map2);
return list;
}
}
4.TestJson.java
package com.json.test;
import com.json.service.JsonService;
import com.json.tools.JsonTools;
public class TestJson {
public TestJson() {
// TODO Auto-generated constructor stub
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
//Test1 Person
System.out.println("Json数据格式测试结果：\n");
String jsonString1 = JsonTools.creatJsonString("person", JsonService.getPerson());
//Test2 persons
String jsonString2 = JsonTools.creatJsonString("persons", JsonService.getListPersons());
//Test3 listString
String jsonString3 = JsonTools.creatJsonString("listString",JsonService.getListString());
//Test 4 listMap
String jsonString4 = JsonTools.creatJsonString("listMap",JsonService.getListMap());
System.out.println("测试结果1："+jsonString1+"\n");
System.out.println("测试结果2："+jsonString2+"\n");
System.out.println("测试结果3："+jsonString3+"\n");
System.out.println("测试结果4："+jsonString4);
}
}
5.JsonTools.java
package com.json.tools;
import net.sf.json.JSONObject;
public class JsonTools {
/**
* @param key 表示json字符串的头信息
* @param value 表示解析几何的类型
* @return
*/
public static String creatJsonString(String key, Object value) {
JSONObject jsonObject = new JSONObject();
jsonObject.put(key, value);
return jsonObject.toString();
}
}
android解析json数据,布布扣,bubuko.com
原文：http://blog.csdn.net/neu_yousei/article/details/22959703