Android软件自动更新实现代码

<update>
 <version>2</version>
 <name>baiduxinwen.apk</name>
 <url>http://gdown.baidu.com/data/wisegame/e5f5c3b8e59401c8/baiduxinwen.apk</url>
</update>

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;
 }
}

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);
 }
}