快捷導(dǎo)航

Android網(wǎng)絡(luò)編程之獲取網(wǎng)絡(luò)上的Json數(shù)據(jù)實例

更新時間：2014年10月10日 10:07:56 投稿：junjie

這篇文章主要介紹了Android網(wǎng)絡(luò)編程之獲取網(wǎng)絡(luò)上的Json數(shù)據(jù)實例,本文用完整的代碼實例講解了在Android中讀取網(wǎng)絡(luò)中Json數(shù)據(jù)的方法,需要的朋友可以參考下

為要獲取網(wǎng)絡(luò)上的Json所以需要服務(wù)器端提供的支持。

一、創(chuàng)建服務(wù)器端：

服務(wù)器端項目結(jié)構(gòu)：

服務(wù)器端運行效果圖：

第一步：創(chuàng)建業(yè)務(wù)所需的JavaBean

復(fù)制代碼代碼如下:

 package com.jph.sj.model;

import java.util.Date;

/**

 * 新聞實體類

 * @author jph

 * Date:2014.09.26

 */

public class News {

    private Integer id;

    private String title;

    private Date publishDate;

    public News(Integer id, String title, Date publishDate) {

        this.id = id;

        this.title = title;

        this.publishDate = publishDate;

    }

    public Integer getId() {

        return id;

    }

    public void setId(Integer id) {

        this.id = id;

    }

    public String getTitle() {

        return title;

    }

    public void setTitle(String title) {

        this.title = title;

    }

    public Date getPublishDate() {

        return publishDate;

    }

    public void setPublishDate(Date publishDate) {

        this.publishDate = publishDate;

    }

}

第二步：創(chuàng)建業(yè)務(wù)邏輯接口和具體實現(xiàn)類

業(yè)務(wù)接口：

復(fù)制代碼代碼如下:

package com.jph.sj.service;

import java.util.List;

import com.jph.sj.model.News;

public interface NewsService {

    /**

     * 獲取最新的資訊

     * @return

     */

    public List<News> getLastNews();

}

業(yè)務(wù)接口的實現(xiàn)類：

復(fù)制代碼代碼如下:

  package com.jph.sj.service.impl;

import java.util.ArrayList;

import java.util.Date;

import java.util.List;

import com.jph.sj.model.News;

import com.jph.sj.service.NewsService;

public class NewsServiceBean implements NewsService {

    /**

     * 獲取最新的視頻資訊

     * @return

     */

    public List<News> getLastNews(){       

        List<News> newes = new ArrayList<News>();

        newes.add(new News(1, "李白", new Date(System.currentTimeMillis())));

        newes.add(new News(2, "杜甫", new Date(System.currentTimeMillis()+8200)));

        newes.add(new News(3, "賈寶玉",new Date(System.currentTimeMillis()-6000)));

        return newes;

    }

}

第三步：創(chuàng)建控制器Servlet

復(fù)制代碼代碼如下:

 package com.jph.sj.servlet;

import java.io.IOException;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.jph.sj.model.News;

import com.jph.sj.service.NewsService;

import com.jph.sj.service.impl.NewsServiceBean;

/**

 * 負責(zé)響應(yīng)客戶端的請求:http://xxx/NewsListServlet/NewsListServlet

 */

public class NewsListServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    private NewsService newsService = new NewsServiceBean();

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doPost(request, response);

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        List<News> newes = newsService.getLastNews();//獲取最新的視頻資訊

            //[{id:20,title:"xxx",timelength:90},{id:10,title:"xbx",timelength:20}]

            StringBuilder sbJson = new StringBuilder();

            //將list集合封裝成Json格式的字符串

            sbJson.append('[');

            for(News news : newes){

                sbJson.append('{');

                sbJson.append("id:").append(news.getId()).append(",");

                sbJson.append("title:\"").append(news.getTitle()).append("\",");

                sbJson.append("publishDate:").append(news.getPublishDate().getTime());

                sbJson.append("},");

            }

            sbJson.deleteCharAt(sbJson.length() - 1);//刪除字符串末尾的逗號

            sbJson.append(']');

            request.setAttribute("json", sbJson.toString());

            request.getRequestDispatcher("/WEB-INF/page/jsonnewslist.jsp").forward(request, response);

    }

}

第四步：創(chuàng)建jsonnewslist.jsp頁面

復(fù)制代碼代碼如下:

<%@ page language="java" contentType="text/plain; charset=UTF-8" pageEncoding="UTF-8"%>

${json}

至此服務(wù)器端項目已經(jīng)完成。下面開始創(chuàng)建Android端項目。

二、創(chuàng)建Android端：

Android端項目結(jié)構(gòu)：

第一步：創(chuàng)建業(yè)務(wù)所需的JavaBean

提示：因為服務(wù)器端和Android端項目都是用Java語言實現(xiàn)的，所以一些組件可以共用，JavaBean便是其中之一。此時我們在搭建Android端項目的時候，完全可以將服務(wù)器端項目中JavaBean拿來用。

第二步：創(chuàng)建Android端項目的業(yè)務(wù)邏輯層

核心代碼：GetAndParseJson:

復(fù)制代碼代碼如下:

  package com.jph.gj.service;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.ArrayList;

import java.util.Date;

import java.util.List;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import com.jph.model.News;

import android.os.Handler;

import android.os.Message;

/**

 * 獲取并解析網(wǎng)絡(luò)上的Json

 * @author jph

 * Date:2014.09.26

 */

public class GetAndParseJson {

    private String url="http://10.219.61.117:8080/ServerForJSON/NewsListServlet";  

    public static final int PARSESUCCWSS=0x2001;

    private Handler handler;

    public GetAndParseJson(Handler handler) {

        // TODO Auto-generated constructor stub

        this.handler=handler;

    }

    /**

     * 獲取網(wǎng)絡(luò)上的XML

     */

    public void getJsonFromInternet () {

        new Thread(new Runnable() {        

            @Override

            public void run() {

                // TODO Auto-generated method stub

                try {

                    HttpURLConnection conn=(HttpURLConnection) new URL(url).openConnection();

                    conn.setConnectTimeout(5000);

                    conn.setRequestMethod("GET");

                    if (conn.getResponseCode()==200) {

                        InputStream inputStream=conn.getInputStream();                     

                        List<News>listNews=parseJson(inputStream);

                        if (listNews.size()>0) {

                            Message msg=new Message();

                            msg.what=PARSESUCCWSS;//通知UI線程Json解析完成

                            msg.obj=listNews;//將解析出的數(shù)據(jù)傳遞給UI線程

                            handler.sendMessage(msg);

                        }

                    }

                } catch (Exception e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }              

            }

        }).start();

    }

    /**

     * 解析json格式的輸入流轉(zhuǎn)換成List

     * @param inputStream

     * @return List

     */

    protected List<News> parseJson(InputStream inputStream) {

        // TODO Auto-generated method stub

        List<News>listNews=new ArrayList<News>();

        byte[]jsonBytes=convertIsToByteArray(inputStream);

        String json=new String(jsonBytes);

        try {

            JSONArray jsonArray=new JSONArray(json);

            for (int i = 0; i < jsonArray.length(); i++) {

                JSONObject jObject=jsonArray.getJSONObject(i);

                int id=jObject.getInt("id");

                String title=jObject.getString("title");           

                long time=jObject.getLong("publishDate");

                News news=new News(id, title, new Date(time));

                listNews.add(news);

            }

        } catch (JSONException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return listNews;

    }

    /**

     * 將輸入流轉(zhuǎn)化成ByteArray

     * @param inputStream

     * @return ByteArray

     */

    private byte[] convertIsToByteArray(InputStream inputStream) {

        // TODO Auto-generated method stub     

        ByteArrayOutputStream baos=new ByteArrayOutputStream();

        byte buffer[]=new byte[1024];

        int length=0;

        try {

            while ((length=inputStream.read(buffer))!=-1) {

                baos.write(buffer, 0, length);             

            }

            inputStream.close();

            baos.flush();

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return baos.toByteArray();

    }

}

第三步：創(chuàng)建Activity

復(fù)制代碼代碼如下:

package com.jph.gj.activity;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.jph.gj.R;
import com.jph.gj.service.GetAndParseJson;
import com.jph.model.News;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.widget.ListView;
import android.widget.SimpleAdapter;

/**
* 獲取網(wǎng)絡(luò)上的Json
* @author jph
* Date:2014.09.26
*/
public class MainActivity extends Activity {
    private List<News>listNews;
    private ListView list;
    Handler mHandler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            // TODO Auto-generated method stub
            switch (msg.what) {
            case GetAndParseJson.PARSESUCCWSS:
                listNews=(List<News>) msg.obj;
                initData();
                break;
            }
            super.handleMessage(msg);
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        list=(ListView)findViewById(R.id.list);
        GetAndParseJson getAndParseJson=new GetAndParseJson(mHandler);
        getAndParseJson.getJsonFromInternet();
    }
    /**
     * 將解析后的xml填充到ListView
     */
    protected void initData() {
        // TODO Auto-generated method stub
        List<Map<String, Object>>items=new ArrayList<Map<String,Object>>();
        for (News news:listNews) {
            Map<String, Object>item=new HashMap<String, Object>();
            item.put("id", news.getId());
            item.put("title", news.getTitle());
            item.put("time", convertDate(news.getPublishDate()));
            items.add(item);
        }
        SimpleAdapter adapter=new SimpleAdapter(this, items, R.layout.line, new String[]
                {"id","title","time"}, new int[]{R.id.tvId,R.id.tvTitle,R.id.tvTime});
        list.setAdapter(adapter);
    }
    private String convertDate(Date publishDate) {
        // TODO Auto-generated method stub
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH-mm-ss");
        return sdf.format(publishDate);
    }
}

至此Android端項目已經(jīng)完成了。下面就讓我們看一下APP運行效果吧：
Android運行效果圖：