那如何实现软件自动更新，具体过程：
效果图：
具体步骤：
1. 在服务器上部署更新所用的xml文件：version.xml
<update> <version>2</version> <name>baiduxinwen.apk</name> <url>http://gdown.baidu.com/data/wisegame/e5f5c3b8e59401c8/baiduxinwen.apk</url> </update>
2. 在客户端实现更新操作
涉及到三个技术：
1.xml文件的解析
2.HttpURLConnection连接
3.文件流I/O
这里创建一个解析xml文件的服务类:ParXmlService.java
package com.xiaowu.news.update; import java.io.InputStream; import java.util.HashMap; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; public class ParseXmlService { public HashMap<String, String> parseXml (InputStream inStream) throws Exception{ HashMap<String, String> hashMap = new HashMap<String, String>(); //创建DocumentBuilderFactory，该对象将创建DocumentBuilder。 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); //创建DocumentBuilder，DocumentBuilder将实际进行解析以创建Document对象 DocumentBuilder builder = factory.newDocumentBuilder(); //解析该文件以创建Document对象 Document document = builder.parse(inStream); //获取XML文件根节点 Element root = document.getDocumentElement(); //获得所有子节点 NodeList childNodes = root.getChildNodes(); for(int i = 0; i < childNodes.getLength(); i++) { Node childNode = (Node) childNodes.item(i); if(childNode.getNodeType() == Node.ELEMENT_NODE) { Element childElement = (Element) childNode; //版本号 if("version".equals(childElement.getNodeName())) { hashMap.put("version", childElement.getFirstChild().getNodeValue()); //软件名称 } else if("name".equals(childElement.getNodeName())) { hashMap.put("name", childElement.getFirstChild().getNodeValue()); //下载地址 } else if("url".equals(childElement.getNodeName())) { hashMap.put("url", childElement.getFirstChild().getNodeValue()); } } } return hashMap; } }
实现更新操作的管理类：UpdateManager.java
package com.xiaowu.news.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 java.util.HashMap; import javax.net.ssl.HttpsURLConnection; 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.pm.PackageManager.NameNotFoundException; import android.net.Uri; import android.os.Environment; import android.os.Handler; import android.view.LayoutInflater; import android.view.View; import android.widget.ProgressBar; import android.widget.Toast; import com.xiaowu.news.R; /** * * @author wwj * @date 2012/11/17 * 实现软件更新的管理类 */ public class UpdateManager { //下载中... private static final int DOWNLOAD = 1; //下载完成 private static final int DOWNLOAD_FINISH = 2; //保存解析的XML信息 HashMap<String , String> mHashMap; //下载保存路径 private String mSavePath; //记录进度条数量 private int progress; //是否取消更新 private boolean cancelUpdate = false; //上下文对象 private Context mContext; //进度条 private ProgressBar mProgressBar; //更新进度条的对话框 private Dialog mDownloadDialog; private Handler mHandler = new Handler() { public void handleMessage(android.os.Message msg) { switch(msg.what){ //下载中。。。 case DOWNLOAD: //更新进度条 System.out.println(progress); mProgressBar.setProgress(progress); break; //下载完成 case DOWNLOAD_FINISH: // 安装文件 installApk(); break; } }; }; public UpdateManager(Context context) { super(); this.mContext = context; } /** * 检测软件更新 */ public void checkUpdate() { if (isUpdate()) { //显示提示对话框 showNoticeDialog(); } else { Toast.makeText(mContext, R.string.soft_update_no, Toast.LENGTH_SHORT).show(); } } private void showNoticeDialog() { // TODO Auto-generated method stub //构造对话框 AlertDialog.Builder builder = new Builder(mContext); builder.setTitle(R.string.soft_update_title); builder.setMessage(R.string.soft_update_info); //更新 builder.setPositiveButton(R.string.soft_update_updatebtn, new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub dialog.dismiss(); // 显示下载对话框 showDownloadDialog(); } }); // 稍后更新 builder.setNegativeButton(R.string.soft_update_later, new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub dialog.dismiss(); } }); Dialog noticeDialog = builder.create(); noticeDialog.show(); } private void showDownloadDialog() { // 构造软件下载对话框 AlertDialog.Builder builder = new Builder(mContext); builder.setTitle(R.string.soft_updating); // 给下载对话框增加进度条 final LayoutInflater inflater = LayoutInflater.from(mContext); View view = inflater.inflate(R.layout.softupdate_progress, null); mProgressBar = (ProgressBar) view.findViewById(R.id.update_progress); builder.setView(view); builder.setNegativeButton(R.string.soft_update_cancel, new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub dialog.dismiss(); // 设置取消状态 cancelUpdate = true; } }); mDownloadDialog = builder.create(); mDownloadDialog.show(); //下载文件 downloadApk(); } /** * 下载APK文件 */ private void downloadApk() { // TODO Auto-generated method stub // 启动新线程下载软件 new DownloadApkThread().start(); } /** * 检查软件是否有更新版本 * @return */ public boolean isUpdate() { // 获取当前软件版本 int versionCode = getVersionCode(mContext); //把version.xml放到网络上，然后获取文件信息 InputStream inStream = ParseXmlService.class.getClassLoader().getResourceAsStream("version.xml"); // 解析XML文件。 由于XML文件比较小，因此使用DOM方式进行解析 ParseXmlService service = new ParseXmlService(); try { mHashMap = service.parseXml(inStream); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } if(null != mHashMap) { int serviceCode = Integer.valueOf(mHashMap.get("version")); //版本判断 if(serviceCode > versionCode) { return true; } } return false; } /** * 获取软件版本号 * @param context * @return */ private int getVersionCode(Context context) { // TODO Auto-generated method stub int versionCode = 0; // 获取软件版本号，对应AndroidManifest.xml下android:versionCode try { versionCode = context.getPackageManager().getPackageInfo( "com.xiaowu.news", 0).versionCode; } catch (NameNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } return versionCode; } /** * 下载文件线程 * @author Administrator * */ private class DownloadApkThread extends Thread { @Override public void run() { try { //判断SD卡是否存在，并且是否具有读写权限 if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { // 获取SDCard的路径 String sdpath = Environment.getExternalStorageDirectory() + "/"; mSavePath = sdpath + "download"; URL url = new URL(mHashMap.get("url")); // 创建连接 HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.connect(); // 获取文件大小 int length = conn.getContentLength(); // 创建输入流 InputStream is = conn.getInputStream(); File file = new File(mSavePath); // 如果文件不存在，新建目录 if (!file.exists()) { file.mkdir(); } File apkFile = new File(mSavePath, mHashMap.get("name")); FileOutputStream fos = new FileOutputStream(apkFile); int count = 0; // 缓存 byte buf[] = new byte[1024]; // 写入到文件中 do { int numread = is.read(buf); count += numread; // 计算进度条的位置 progress = (int) (((float) count / length) * 100); // 更新进度 mHandler.sendEmptyMessage(DOWNLOAD); if (numread <= 0) { // 下载完成 mHandler.sendEmptyMessage(DOWNLOAD_FINISH); break; } // 写入文件 fos.write(buf, 0, numread); } while (!cancelUpdate);//点击取消就停止下载 fos.close(); is.close(); } } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } // 取消下载对话框显示 mDownloadDialog.dismiss(); } } /** * 安装APK文件 */ private void installApk() { File apkfile = new File(mSavePath, mHashMap.get("name")); if (!apkfile.exists()) { return; } Intent i = new Intent(Intent.ACTION_VIEW); i.setDataAndType(Uri.parse("file://" + apkfile.toString()), "application/vnd.android.package-archive"); mContext.startActivity(i); } }
参考：http://blog.csdn.net/wwj_748/article/details/8195565
http://blog.csdn.net/android_tutor/article/details/7015986