Android - 软件自动更新的实现(转)

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

[java] view plaincopy

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

[java] view plaincopy

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);

}

}

原文地址：/article/1470851.html