android检测新版本并下载安装的方法
很多客户端程序都有检测是否有更新的功能，本文大体介绍了其实现过程。此功能模块也是开源中国客户端中的源码，个人感觉用到的安卓基础知识还是比较全面的，很适合初学者学习进阶。
/**
* 检查App更新
* @param context
* @param isShowMsg 是否显示提示消息
*/
public void checkAppUpdate(Context context, final boolean isShowMsg){
this.mContext = context;
getCurrentVersion();
if(isShowMsg){
if(mProDialog == null)
mProDialog = ProgressDialog.show(mContext, null, "正在检测，请稍侯...", true, true);
else if(mProDialog.isShowing() || (latestOrFailDialog!=null && latestOrFailDialog.isShowing()))
return;
}
final Handler handler = new Handler(){
public void handleMessage(Message msg) {
//进度条对话框不显示 - 检测结果也不显示
if(mProDialog != null && !mProDialog.isShowing()){
return;
}
//关闭并释放进度条对话框
if(isShowMsg && mProDialog != null){
mProDialog.dismiss();
mProDialog = null;
}
//显示检测结果
if(msg.what == 1){
mUpdate = (Update)msg.obj;
if(mUpdate != null){
if(curVersionCode < mUpdate.getVersionCode()){
apkUrl = mUpdate.getDownloadUrl();
updateMsg = mUpdate.getUpdateLog();
showNoticeDialog();
}else if(isShowMsg){
showLatestOrFailDialog(DIALOG_TYPE_LATEST);
}
}
}else if(isShowMsg){
showLatestOrFailDialog(DIALOG_TYPE_FAIL);
}
}
};
new Thread(){
public void run() {
Message msg = new Message();
try {
Update update = ApiClient.checkVersion((AppContext)mContext.getApplicationContext());
msg.what = 1;
msg.obj = update;
} catch (AppException e) {
e.printStackTrace();
}
handler.sendMessage(msg);
}
}.start();
}
这是入口方法，布尔类型的isShowMsg 表示是否显示“正在检测”这样一个对话框，一般在程序刚进入进行初始化时不需要显示提示，在后台默认进行。在设置中进行手动更新检测时为了良好的用户体验一般设置提示对话框可见。
/**
* 获取当前客户端版本信息
*/
private void getCurrentVersion(){
try {
PackageInfo info = mContext.getPackageManager().getPackageInfo(mContext.getPackageName(), 0);
curVersionName = info.versionName;
curVersionCode = info.versionCode;
} catch (NameNotFoundException e) {
e.printStackTrace(System.err);
}
}用于稍后和最新版本进行对比，决定是否需要更新。
/**
* 显示'已经是最新'或者'无法获取版本信息'对话框
*/
private void showLatestOrFailDialog(int dialogType) {
if (latestOrFailDialog != null) {
//关闭并释放之前的对话框
latestOrFailDialog.dismiss();
latestOrFailDialog = null;
}
AlertDialog.Builder builder = new Builder(mContext);
builder.setTitle("系统提示");
if (dialogType == DIALOG_TYPE_LATEST) {
builder.setMessage("您当前已经是最新版本");
} else if (dialogType == DIALOG_TYPE_FAIL) {
builder.setMessage("无法获取版本更新信息");
}
builder.setPositiveButton("确定", null);
latestOrFailDialog = builder.create();
latestOrFailDialog.show();
}
/**
* 显示版本更新通知对话框
*/
private void showNoticeDialog(){
AlertDialog.Builder builder = new Builder(mContext);
builder.setTitle("软件版本更新");
builder.setMessage(updateMsg);
builder.setPositiveButton("立即更新", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
showDownloadDialog();
}
});
builder.setNegativeButton("以后再说", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
noticeDialog = builder.create();
noticeDialog.show();
} /**
* 显示下载对话框
*/
private void showDownloadDialog(){
AlertDialog.Builder builder = new Builder(mContext);
builder.setTitle("正在下载新版本");
final LayoutInflater inflater = LayoutInflater.from(mContext);
View v = inflater.inflate(R.layout.update_progress, null);
mProgress = (ProgressBar)v.findViewById(R.id.update_progress);
mProgressText = (TextView) v.findViewById(R.id.update_progress_text);
builder.setView(v);
builder.setNegativeButton("取消", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
interceptFlag = true;
}
});
builder.setOnCancelListener(new OnCancelListener() {
@Override
public void onCancel(DialogInterface dialog) {
dialog.dismiss();
interceptFlag = true;
}
});
downloadDialog = builder.create();
downloadDialog.setCanceledOnTouchOutside(false);
downloadDialog.show();
downloadApk();
}以上是更新过程中需要用到的几种对话框。
private Runnable mdownApkRunnable = new Runnable() {
@Override
public void run() {
try {
String apkName = "OSChinaApp_"+mUpdate.getVersionName()+".apk";
String tmpApk = "OSChinaApp_"+mUpdate.getVersionName()+".tmp";
//判断是否挂载了SD卡
String storageState = Environment.getExternalStorageState();
if(storageState.equals(Environment.MEDIA_MOUNTED)){
savePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/OSChina/Update/";
File file = new File(savePath);
if(!file.exists()){
file.mkdirs();
}
apkFilePath = savePath + apkName;
tmpFilePath = savePath + tmpApk;
}
//没有挂载SD卡，无法下载文件
if(apkFilePath == null || apkFilePath == ""){
mHandler.sendEmptyMessage(DOWN_NOSDCARD);
return;
}
File ApkFile = new File(apkFilePath);
//是否已下载更新文件
if(ApkFile.exists()){
downloadDialog.dismiss();
installApk();
return;
}
//输出临时下载文件
File tmpFile = new File(tmpFilePath);
FileOutputStream fos = new FileOutputStream(tmpFile);
URL url = new URL(apkUrl);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.connect();
int length = conn.getContentLength();
InputStream is = conn.getInputStream();
//显示文件大小格式：2个小数点显示
DecimalFormat df = new DecimalFormat("0.00");
//进度条下面显示的总文件大小
apkFileSize = df.format((float) length / 1024 / 1024) + "MB";
int count = 0;
byte buf[] = new byte[1024];
do{
int numread = is.read(buf);
count += numread;
//进度条下面显示的当前下载文件大小
tmpFileSize = df.format((float) count / 1024 / 1024) + "MB";
//当前进度值
progress =(int)(((float)count / length) * 100);
//更新进度
mHandler.sendEmptyMessage(DOWN_UPDATE);
if(numread <= 0){
//下载完成 - 将临时下载文件转成APK文件
if(tmpFile.renameTo(ApkFile)){
//通知安装
mHandler.sendEmptyMessage(DOWN_OVER);
}
break;
}
fos.write(buf,0,numread);
}while(!interceptFlag);//点击取消就停止下载
fos.close();
is.close();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch(IOException e){
e.printStackTrace();
}
}
};
/**
* 下载apk
* @param url
*/
private void downloadApk(){
downLoadThread = new Thread(mdownApkRunnable);
downLoadThread.start();
} private Handler mHandler = new Handler(){
public void handleMessage(Message msg) {
switch (msg.what) {
case DOWN_UPDATE:
mProgress.setProgress(progress);
mProgressText.setText(tmpFileSize + "/" + apkFileSize);
break;
case DOWN_OVER:
downloadDialog.dismiss();
installApk();
break;
case DOWN_NOSDCARD:
downloadDialog.dismiss();
Toast.makeText(mContext, "无法下载安装文件，请检查SD卡是否挂载", 3000).show();
break;
}
};
};新开启线程进行最新APK文件的下载和过程中对UI的更新。先将文件下载到后缀.tmp的文件中，下载完成后将后缀改为.apk。过程中更新进度条进度和文字提示。
/**
* 安装apk
* @param url
*/
private void installApk(){
File apkfile = new File(apkFilePath);
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);
}用到的全局变量如下
private static final int DOWN_NOSDCARD = 0;
private static final int DOWN_UPDATE = 1;
private static final int DOWN_OVER = 2;
private static final int DIALOG_TYPE_LATEST = 0;
private static final int DIALOG_TYPE_FAIL = 1;
private static UpdateManager updateManager;
private Context mContext;
//通知对话框
private Dialog noticeDialog;
//下载对话框
private Dialog downloadDialog;
//'已经是最新' 或者 '无法获取最新版本' 的对话框
private Dialog latestOrFailDialog;
//进度条
private ProgressBar mProgress;
//显示下载数值
private TextView mProgressText;
//查询动画
private ProgressDialog mProDialog;
//进度值
private int progress;
//下载线程
private Thread downLoadThread;
//终止标记
private boolean interceptFlag;
//提示语
private String updateMsg = "";
//返回的安装包url
private String apkUrl = "";
//下载包保存路径
private String savePath = "";
//apk保存完整路径
private String apkFilePath = "";
//临时下载文件路径
private String tmpFilePath = "";
//下载文件大小
private String apkFileSize;
//已下载文件大小
private String tmpFileSize;
private String curVersionName = "";
private int curVersionCode;
private Update mUpdate;另外需要在配置文件中声明读写权限