这期内容当中小编将会给大家带来有关怎么在Android应用中实现一个程序更新下载功能，文章内容丰富且以专业的角度为大家分析和叙述，阅读完这篇文章希望大家可以有所收获。
创建一个新类，名为UpdateManager，代码如下：
import java.io.BufferedReader;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import com.af.mobile.R;import android.app.AlertDialog;import android.app.Dialog;import android.app.AlertDialog.Builder;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.os.Message;import android.view.LayoutInflater;import android.view.View;import android.widget.ProgressBar;import android.widget.Toast;public class UpdateManager{private URL url=null; private static final int DOWNLOAD = 1; private static final int DOWNLOAD_FINISH = 2; //HashMap<String, String> mHashMap; private String mSavePath; private int progress; private boolean cancelUpdate = false; private Context mContext; private ProgressBar mProgress; private Dialog mDownloadDialog; private Handler mHandler = new Handler() { public void handleMessage(Message msg) { switch (msg.what) { // 正在下载 case DOWNLOAD: // 设置进度条位置 mProgress.setProgress(progress); break; case DOWNLOAD_FINISH: // 安装文件 installApk(); break; default: break; } }; }; public UpdateManager(Context context) { this.mContext = context; } public void checkUpdate() { if (isUpdate()) { showNoticeDialog(); } else { } } private boolean isUpdate() { // 获取当前软件版本 Double versionCode = getVersionCode(mContext); Double serviceCode = 1.2; // 版本判断 if (serviceCode > versionCode) { return true; } return false; } // 获取软件版本号 private Double getVersionCode(Context context) { Double versionCode = 0.0; try { // 获取软件版本号，对应AndroidManifest.xml下android:versionCode versionCode = (double) context.getPackageManager().getPackageInfo("com.af.mobile", 0).versionCode; } catch (NameNotFoundException e) { e.printStackTrace(); } return versionCode; } //显示软件更新对话框 private void showNoticeDialog() { AlertDialog.Builder builder = new Builder(mContext); builder.setTitle("软件更新"); String string=download("http://192.168.0.102:9313/daojuserver/uploads/version.xml");//xml的下载地址 builder.setMessage(string); builder.setPositiveButton("更新", new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); // 显示下载对话框 showDownloadDialog(); } }); // 稍后更新 builder.setNegativeButton("稍后更新", new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }); Dialog noticeDialog = builder.create(); noticeDialog.show(); } // 显示软件下载对话框 private void showDownloadDialog() { // 构造软件下载对话框 AlertDialog.Builder builder = new Builder(mContext); builder.setTitle("djfkjd");//提示信息内容 // 给下载对话框增加进度条 final LayoutInflater inflater = LayoutInflater.from(mContext); View v = inflater.inflate(R.layout.softupdate_progress, null); mProgress = (ProgressBar) v.findViewById(R.id.update_progress); builder.setView(v); // 取消更新 builder.setNegativeButton("取消更新", new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); // 设置取消状态 cancelUpdate = true; } }); mDownloadDialog = builder.create(); mDownloadDialog.show(); // 现在文件 downloadApk(); } private void downloadApk() { // 启动新线程下载软件 new downloadApkThread().start(); } 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)) { // 获得存储卡的路径 String sdpath = Environment.getExternalStorageDirectory() + "/"; mSavePath = sdpath + "download"; URL url = new URL("http://192.168.0.102:9313/daojuserver/uploads/SpMobile.apk");//apk下载地址地址 // 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); if (!file.exists()) { file.mkdir(); } File apkFile = new File(mSavePath, "dhfudh"); 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; // 计算进度条位置 progress = (int) (((float) count / length) * 100); // 更新进度 mHandler.sendEmptyMessage(DOWNLOAD); if (numread <= 0) { mHandler.sendEmptyMessage(DOWNLOAD_FINISH); break; } fos.write(buf, 0, numread); } while (!cancelUpdate); 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(); } }; private void installApk() { File apkfile = new File(mSavePath, "dhfudh"); if (!apkfile.exists()) { return; } // 通过Intent安装APK文件 Intent i = new Intent(Intent.ACTION_VIEW); i.setDataAndType(Uri.parse("file://" + apkfile.toString()), "application/vnd.android.package-archive"); mContext.startActivity(i); } public String download(String urlString) { StringBuffer sbBuffer=new StringBuffer(); String line=null; BufferedReader buffer=null; try { url=new URL(urlString); HttpURLConnection urlConn=(HttpURLConnection) url.openConnection(); buffer=new BufferedReader(new InputStreamReader(urlConn.getInputStream())); while((line=buffer.readLine())!=null) { sbBuffer.append(line); } } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } finally { try { buffer.close(); } catch (Exception e2) { // TODO: handle exception e2.printStackTrace(); } } return sbBuffer.toString(); }}在Android应用程序Main界面
if(isOpenNetwork())//判断是否有网络 { UpdateManager manager = new UpdateManager(Main.this); // 检查软件更新 manager.checkUpdate(); }判断移动端是否有网络
private boolean isOpenNetwork() { ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo networkInfo = connManager.getActiveNetworkInfo(); if (networkInfo != null) { // 2.获取当前网络连接的类型信息 int networkType = networkInfo.getType(); if (ConnectivityManager.TYPE_WIFI == networkType) { // 当前为wifi网络 } else if (ConnectivityManager.TYPE_MOBILE == networkType) { // 当前为mobile网络 } return connManager.getActiveNetworkInfo().isAvailable(); } return false; }上述就是小编为大家分享的怎么在Android应用中实现一个程序更新下载功能了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注编程网行业资讯频道。
