android之程序自动更新的实现

package com.cloay.update;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
/**
* 程序自动更新
* UpdateTestActivity.java
* @author Cloay
* 2011-11-23
*/
public class UpdateTestActivity extends Activity {
private Button button;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

button = (Button) findViewById(R.id.check);
button.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
try {
checkVersion();
} catch (NameNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}

/**
* 检查是否需要更新程序
* @throws NameNotFoundException
*/
private void checkVersion() throws NameNotFoundException{
UpdateInfo updateInfo = new UpdateInfo();
URL url;
try {
url = new URL("http://localhost:8080/update.xml");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//			connection.setConnectTimeout(5000);
updateInfo = ParseXmlUtils.parseXml(connection.getInputStream());

} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
if(updateInfo.getVersion().equals(VersionUtil.getVersionName(this))){
Toast.makeText(this, "版本相同,不需要升级!", Toast.LENGTH_SHORT).show();
}
else{
showUpdateDialog(updateInfo);
}
}

private void showUpdateDialog(UpdateInfo updateInfo) {
AlertDialog alertDialog = new AlertDialog.Builder(this)
.setTitle("提示检测到新版本,确定升级吗?")
.setIcon(R.drawable.ask)
.setMessage(updateInfo.getDescription())
.setPositiveButton("确定",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
})
.setNegativeButton("取消",
new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
}).create();
alertDialog.show();
}
}

package com.cloay.update;

import java.io.IOException;
import java.io.InputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
/**
* 解析Xml文件
* ParseXmlUtils.java
* @author Cloay
* 2011-11-7
*/
public class ParseXmlUtils {
/**
* 通过InputStream 解析文件
* @param in
* @return
*/
public static UpdateInfo parseXml(InputStream in){
UpdateInfo updateInfo = new UpdateInfo();
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = null;
try {
db = dbf.newDocumentBuilder();
Document doc = null;
doc = db.parse(in);
Element root = doc.getDocumentElement();
NodeList resultNode = root.getElementsByTagName("info");
for(int i = 0; i < resultNode.getLength();i++){
Element res = (Element)resultNode.item(i);
updateInfo.setVersion(res.getElementsByTagName("version").item(0).getFirstChild().getNodeValue());
updateInfo.setUrl(res.getElementsByTagName("url").item(0).getFirstChild().getNodeValue());
updateInfo.setDescription(res.getElementsByTagName("description").item(0).getFirstChild().getNodeValue());
}
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return updateInfo;
}
}

package com.cloay.update;
/**
* 更新信息实体类
* UpdateInfo.java
* @author Cloay
* 2011-11-23
*/
public class UpdateInfo {
private String version;    //版本号
private String url;  	//新版本存放url路径
private String description;   //更新说明信息，比如新增什么功能特性等
public String getVersion() {
return version;
}
public void setVersion(String version) {
this.version = version;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}

package com.cloay.update;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;

/**
* 版本工具类
* VersionUtil.java
* @author Cloay
* 2011-11-23
*/
public class VersionUtil {
/**
* 获取版本号
* @param context
* 			上下文
* @return
* @throws NameNotFoundException
*/
public static String getVersionName(Context context) throws NameNotFoundException{
//获取PackageManager 实例
PackageManager packageManager = context.getPackageManager();
//获得context所属类的包名，0表示获取版本信息
PackageInfo packageInfo = packageManager.getPackageInfo(context.getPackageName(), 0);
return packageInfo.versionName;
}
}