//获取apk包文件的管理者对象

PackageManager manager = getPackageManager();

String apkVersion = ""；

try{

      PackageInfo packageInfo = manager.getPackageInfo(getPackagename,PackageManager.GET_ACTIVITIES);

     //获取到当前apk版本

     apkVersion=packageInfo.versionName;

    } catch (NameNotFoundException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

    }

//开始服务的跳转，到service类

Intent intent=new Intent(this,UpdateApkService.class);

intent.putExtra("apkVersion", apkVersion);

startService(intent);    

package com.example.queryencyclopediademo01.service;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import org.apache.http.HttpResponse;

import org.apache.http.client.ClientProtocolException;

import org.apache.http.client.HttpClient;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.impl.client.DefaultHttpClient;

import org.json.JSONException;

import org.json.JSONObject;

import android.app.IntentService;

import android.content.Intent;

import android.os.Environment;

import android.os.Looper;

import android.widget.Toast;

import com.example.queryencyclopediademo01.common.CBKApi;

import com.example.queryencyclopediademo01.domain.Apk;

import com.example.queryencyclopediademo01.utils.HttpUtils;

/**

 * 自定义更新Apk的服务类

 * @author dell

 *

 */

public class UpdateApkService extends IntentService {

    public UpdateApkService() {

        super("");

        // TODO Auto-generated constructor stub

    }

    /**

     *  声明Apk对象

     */

    private Apk apk;

    @Override

    protected void onHandleIntent(Intent intent) {

        System.out.println("onHandleIntent中线程的名称："+Thread.currentThread().getName());

        String apkVersion=intent.getStringExtra("apkVersion");

        System.out.println("当前应用程序的版本名称："+apkVersion);

        try {

            byte[] buffer=HttpUtils.getNetBytes(CBKApi.UPDATE_APK_PATH);

            if(buffer!=null){

                JSONObject jsonObject=new JSONObject(new String(buffer));

                this.apk=Apk.jsonParseApk(jsonObject);

                this.downLoadApk(apkVersion);

            }else{

                System.out.println("====获取最新APK文件失败！===");

                //Toast.makeText(this, "获取最新APK文件失败！", Toast.LENGTH_LONG).show();

            }

        } catch (JSONException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

    /**

     * 下载最新apk,尽量不要在3G网络下使用，会浪费用户很多流量

     * @param apkVersion

     */

    private void downLoadApk(String apkVersion) {

        //如果网上最新版本和当前运行版本不相同，则下载

        if(!this.apk.getVersion().equals(apkVersion)){

            HttpClient httpClient=new DefaultHttpClient();

            HttpGet httpGet=new HttpGet(apk.getUrl());

            HttpResponse httpResponse=null;

            InputStream inputStream=null;

            File file=new File(Environment.getExternalStorageDirectory().getAbsolutePath()+File.separator+"new.apk");

            OutputStream outputStream=null;

            byte[] buffer=new byte[1024];

            int len=0;

            try {

                httpResponse=httpClient.execute(httpGet);

                if(httpResponse.getStatusLine().getStatusCode()==200){

                    inputStream=httpResponse.getEntity().getContent();

                    outputStream=new FileOutputStream(file);

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

                        outputStream.write(buffer, 0, len);

                    }

                    outputStream.flush();

                    Toast.makeText(getApplicationContext(), "最新APK下载成功！", Toast.LENGTH_LONG).show();

                    System.out.println("最新APK下载成功！");

                }

            } catch (Exception e) {

                Toast.makeText(getApplicationContext(), "最新APK下载失败！", Toast.LENGTH_LONG).show();

                e.printStackTrace();

            }finally{

                httpClient.getConnectionManager().shutdown();

                try {

                    inputStream.close();

                    outputStream.close();

                } catch (IOException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

            }

        }

    }

}

public static Apk jsonParseApk(JSONObject jsonObject){

        JSONObject jsonObjectApk=jsonObject.optJSONObject("info");

        String version=jsonObjectApk.optString("version");

        String url=jsonObject.optString("url");

        String createTime=jsonObject.optString("createTime");

        return new Apk(version,url,createTime);

    }