Android施用客户端自动升级教程

import java.io.File;　　import java.io.FileOutputStream;　　import java.io.IOException;　　import java.io.InputStream;　　import org.apache.http.HttpEntity;　　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 android.app.AlertDialog;　　import android.app.Dialog;　　import android.app.ProgressDialog;　　import android.content.DialogInterface;　　import android.content.Intent;　　import android.net.Uri;　　import android.os.Bundle;　　import android.os.Environment;　　import android.os.Handler;　　public class Update extends BaseActivity {　　public ProgressDialog pBar;　　private Handler handler = new Handler();[email protected]　　protected void onCreate(Bundle savedInstanceState) {　　super.onCreate(savedInstanceState);　　setContentView(R.layout.update);　　Dialog dialog = new AlertDialog.Builder(Update.this).setTitle("系统更新")　　.setMessage("发现新版本，请更新!")// 设置内容　　.setPositiveButton("确定",// 设置确定按钮　　new DialogInterface.OnClickListener() {[email protected]　　public void onClick(DialogInterface dialog,　　int which) {　　pBar = new ProgressDialog(Update.this);　　pBar.setTitle("正在下载");　　pBar.setMessage("请稍候...");　　pBar　　.setProgressStyle(ProgressDialog.STYLE_SPINNER);　　downFile("http://url:8765/OA.apk");　　}　　}).setNegativeButton("取消",　　new DialogInterface.OnClickListener() {　　public void onClick(DialogInterface dialog,int whichButton) {　　// 点击"取消"按钮之后退出程序　　}　　}).create();// 创建　　// 显示对话框　　dialog.show();　　}　　void downFile(final String url) {　　pBar.show();　　new Thread() {　　public void run() {　　HttpClient client = new DefaultHttpClient();　　// params[0]代表连接的url　　HttpGet get = new HttpGet(url);　　HttpResponse response;　　try {　　response = client.execute(get);　　HttpEntity entity = response.getEntity();　　long length = entity.getContentLength();　　InputStream is = entity.getContent();　　FileOutputStream fileOutputStream = null;　　if (is != null) {　　File file = new File(Environment　　.getExternalStorageDirectory(), "OA.apk");　　fileOutputStream = new FileOutputStream(file);　　byte[] buf = new byte[1024];　　int ch = -1;　　int count = 0;　　while ((ch = is.read(buf)) != -1) {　　// baos.write(buf, 0, ch);　　fileOutputStream.write(buf, 0, ch);　　count += ch;　　if (length > 0) {　　}　　}　　}　　fileOutputStream.flush();　　if (fileOutputStream != null) {　　fileOutputStream.close();　　}　　down();　　} catch (ClientProtocolException e) {　　// TODO Auto-generated catch block　　e.printStackTrace();　　} catch (IOException e) {　　// TODO Auto-generated catch block　　e.printStackTrace();　　}　　}　　}.start();　　}　　void down() {　　handler.post(new Runnable() {　　public void run() {　　pBar.cancel();　　update();　　}　　});　　}　　void update() {　　Intent intent = new Intent(Intent.ACTION_VIEW);　　intent.setDataAndType(Uri.fromFile(new File("/sdcard/OA.apk")),　　"application/vnd.android.package-archive");　　startActivity(intent);　　}　　}