半小时学会Android版本更新

package com.doublejun.update;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.DialogInterface.OnClickListener;
import android.content.IntentFilter;
import android.net.Uri;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ProgressBar;

public class UpdateManager {
	private Context mContext;
	private final String updateMsg = "亲，有新版本，快下载吧！";			//下载消息提示
	private Dialog noticeDialog;										//下载提示对话框
	private Dialog downloadDialog;										//下载进度对话框
	private ProgressBar mProgressBar;									//进度条
	private Boolean interceptFlag = false;								//标记用户是否在下载过程中取消下载
	private Thread downloadApkThread = null;							//下载线程
	private final String apkUrl = "http://www.ypdm.com/hyjj.apk";		//apk的URL地址
	private final String savePath = "/sdcard/UpdateDemo/";				//下载的apk存放的路径
	private final String saveFileName = savePath + "hyjjrelease.apk";	//下载的apk文件
	private int progress = 0;											//下载进度
	private final int DOWNLOAD_ING = 1;									//标记正在下载
	private final int DOWNLOAD_OVER = 2;								//标记下载完成
	private final String TAG="版本更新";									//日志打印标签
	private Handler mhandler = new Handler() {							//更新UI的handler

		@Override
		public void handleMessage(Message msg) {
			super.handleMessage(msg);
			switch (msg.what) {
			case DOWNLOAD_ING:
				// 更新进度条
				mProgressBar.setProgress(progress);
				break;
			case DOWNLOAD_OVER:
				downloadDialog.dismiss();
				installApk();
				//安装
				break;
			default:
				break;
			}
		}

	};
	
	/*
	 * 构造方法
	 */
	public UpdateManager(Context context) {
		this.mContext = context;
	}

	/*
	 * 检查是否有需要更新，具体比较版本xml
	 */
	public void checkUpdate() {
		// 到服务器检查软件是否有新版本
		//如果有则
		showNoticeDialog();
	}

	/*
	 * 显示版本更新对话框
	 */
	private void showNoticeDialog() {
		AlertDialog.Builder builder = new Builder(mContext);
		builder.setTitle("版本更新");
		builder.setMessage(updateMsg);
		builder.setPositiveButton("更新", new OnClickListener() {

			public void onClick(DialogInterface dialog, int which) {
				noticeDialog.dismiss();
				showDownloadDialog();
			}
		});
		builder.setNegativeButton("以后再说", new OnClickListener() {

			public void onClick(DialogInterface dialog, int which) {
				noticeDialog.dismiss();
			}
		});
		noticeDialog = builder.create();
		noticeDialog.show();

	}

	/*
	 * 弹出下载进度对话框
	 */
	private void showDownloadDialog() {
		AlertDialog.Builder builder = new Builder(mContext);
		builder.setTitle("软件更新");
		final LayoutInflater inflater = LayoutInflater.from(mContext);
		View v = inflater.inflate(R.layout.progress, null);
		mProgressBar = (ProgressBar) v.findViewById(R.id.updateProgress);
		builder.setView(v);
		builder.setNegativeButton("取消", new OnClickListener() {

			public void onClick(DialogInterface dialog, int which) {
				downloadDialog.dismiss();
				interceptFlag = true;
			}
		});
		downloadDialog = builder.create();
		downloadDialog.show();
		downloadLatestVersionApk();

	}
	
	/*
	 * 下载最新的apk文件
	 */
	private void downloadLatestVersionApk() {
		downloadApkThread = new Thread(downloadApkRunnable);
		downloadApkThread.start();
	}
	
	//匿名内部类，apk文件下载线程
	private Runnable downloadApkRunnable = new Runnable() {

		public void run() {
			try {
				URL url = new URL(apkUrl);
				HttpURLConnection conn = (HttpURLConnection) url
						.openConnection();
				conn.connect();
				int length = conn.getContentLength();
				Log.e(TAG, "总字节数:"+length);
				InputStream is = conn.getInputStream();
				File file = new File(savePath);
				if (!file.exists()) {
					file.mkdir();
				}
				File apkFile = new File(saveFileName);
				FileOutputStream out = new FileOutputStream(apkFile);
				int count = 0;
				int readnum = 0;
				byte[] buffer = new byte[1024];
				do {
					readnum = is.read(buffer);
					count += readnum;
					progress = (int) (((float) count / length) * 100);
					Log.e(TAG, "下载进度"+progress);
					mhandler.sendEmptyMessage(DOWNLOAD_ING);
					if (readnum <= 0) {
						// 下载结束
						mhandler.sendEmptyMessage(DOWNLOAD_OVER);
						break;
					}
					out.write(buffer,0,readnum);
				} while (!interceptFlag);
				is.close();
				out.close();
			} catch (MalformedURLException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}

		}
	};
	/*
	 * 安装下载的apk文件
	 */
	private void installApk() {
		File file= new File(saveFileName);
		if(!file.exists()){
			return;
		}
		Intent intent= new Intent(Intent.ACTION_VIEW);
		intent.setDataAndType(Uri.parse("file://"+file.toString()), "application/vnd.android.package-archive");
		mContext.startActivity(intent);
	}
}

<?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" >

    <ProgressBar
        android:id="@+id/updateProgress"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

package com.doublejun.update;

import android.app.Activity;
import android.os.Bundle;

public class Main extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        UpdateManager update = new UpdateManager(this);
        update.checkUpdate();
    }
}