Android应用自动更新功能的实现！！！

大家好，发现半年没有更新博客了，最近一直都比较忙，决定在凌晨 英超 阿森纳VS富勒姆 中场休息的时候，给大家分享Android里应用版本更新功能这一块的实现。

一个好的应用软件都是需要好的维护，从初出版本到最后精品，这个过程需要版本不停的更新，那么如何让用户第一时间获取最新的应用安装包呢？那么就要求我们从第一个版本就要实现升级模块这一功能。

自动更新功能的实现原理，就是我们事先和后台协商好一个接口，我们在应用的主Activity里，去访问这个接口，如果需要更新，后台会返回一些数据(比如，提示语；最新版本的url等)。然后我们给出提示框，用户点击开始下载，下载完成开始覆盖安装程序，这样用户的应用就保持最新的拉。

为了让大家容易理解，我像往常一样准备一个小例子，这里为了方便我就省去了和后台交互部分了。步骤分别如下：

第一步：新建一个Android工程命名为:UpdateDemo.代码结构如下图所示：

第二步：新建一个UpdateManager.java类，负责软件更新功能模块，代码如下：

[java] view plaincopyprint?

1. package com.tutor.update;
3. import java.io.File;
4. import java.io.FileOutputStream;
5. import java.io.IOException;
6. import java.io.InputStream;
7. import java.net.HttpURLConnection;
8. import java.net.MalformedURLException;
9. import java.net.URL;
12. import android.app.AlertDialog;
13. import android.app.Dialog;
14. import android.app.AlertDialog.Builder;
15. import android.content.Context;
16. import android.content.DialogInterface;
17. import android.content.Intent;
18. import android.content.DialogInterface.OnClickListener;
19. import android.net.Uri;
20. import android.os.Handler;
21. import android.os.Message;
22. import android.view.LayoutInflater;
23. import android.view.View;
24. import android.widget.ProgressBar;
26. public class UpdateManager {
28. private Context mContext;
30. //提示语
31. private String updateMsg ="有最新的软件包哦，亲快下载吧~";
33. //返回的安装包url
34. private String apkUrl = "http://softfile.3g.qq.com:8080/msoft/179/24659/43549/qq_hd_mini_1.4.apk";
37. private Dialog noticeDialog;
39. private Dialog downloadDialog;
40. /* 下载包安装路径 */
41. private staticfinal String savePath = "/sdcard/updatedemo/";
43. private staticfinal String saveFileName = savePath + "UpdateDemoRelease.apk";
45. /* 进度条与通知ui刷新的handler和msg常量 */
46. private ProgressBar mProgress;
49. private staticfinal int DOWN_UPDATE =1;
51. private staticfinal int DOWN_OVER =2;
53. private int progress;
55. private Thread downLoadThread;
57. private boolean interceptFlag =false;
59. private Handler mHandler =new Handler(){
60. public void handleMessage(Message msg) {
61. switch (msg.what) {
62. case DOWN_UPDATE:
63. mProgress.setProgress(progress);
64. break;
65. case DOWN_OVER:
67. installApk();
68. break;
69. default:
70. break;
71. }
72. };
73. };
75. public UpdateManager(Context context) {
76. this.mContext = context;
77. }
79. //外部接口让主Activity调用
80. public void checkUpdateInfo(){
81. showNoticeDialog();
82. }
85. private void showNoticeDialog(){
86. AlertDialog.Builder builder = new Builder(mContext);
87. builder.setTitle("软件版本更新");
88. builder.setMessage(updateMsg);
89. builder.setPositiveButton("下载",new OnClickListener() {
90. @Override
91. public void onClick(DialogInterface dialog,int which) {
92. dialog.dismiss();
93. showDownloadDialog();
94. }
95. });
96. builder.setNegativeButton("以后再说",new OnClickListener() {
97. @Override
98. public void onClick(DialogInterface dialog,int which) {
99. dialog.dismiss();
100. }
101. });
102. noticeDialog = builder.create();
103. noticeDialog.show();
104. }
106. private void showDownloadDialog(){
107. AlertDialog.Builder builder = new Builder(mContext);
108. builder.setTitle("软件版本更新");
110. final LayoutInflater inflater = LayoutInflater.from(mContext);
111. View v = inflater.inflate(R.layout.progress, null);
112. mProgress = (ProgressBar)v.findViewById(R.id.progress);
114. builder.setView(v);
115. builder.setNegativeButton("取消",new OnClickListener() {
116. @Override
117. public void onClick(DialogInterface dialog,int which) {
118. dialog.dismiss();
119. interceptFlag = true;
120. }
121. });
122. downloadDialog = builder.create();
123. downloadDialog.show();
125. downloadApk();
126. }
128. private Runnable mdownApkRunnable =new Runnable() {
129. @Override
130. public void run() {
131. try {
132. URL url = new URL(apkUrl);
134. HttpURLConnection conn = (HttpURLConnection)url.openConnection();
135. conn.connect();
136. int length = conn.getContentLength();
137. InputStream is = conn.getInputStream();
139. File file = new File(savePath);
140. if(!file.exists()){
141. file.mkdir();
142. }
143. String apkFile = saveFileName;
144. File ApkFile = new File(apkFile);
145. FileOutputStream fos = new FileOutputStream(ApkFile);
147. int count = 0;
148. byte buf[] = newbyte[1024];
150. do{
151. int numread = is.read(buf);
152. count += numread;
153. progress =(int)(((float)count / length) *100);
154. //更新进度
155. mHandler.sendEmptyMessage(DOWN_UPDATE);
156. if(numread <= 0){
157. //下载完成通知安装
158. mHandler.sendEmptyMessage(DOWN_OVER);
159. break;
160. }
161. fos.write(buf,0,numread);
162. }while(!interceptFlag);//点击取消就停止下载.
164. fos.close();
165. is.close();
166. } catch (MalformedURLException e) {
167. e.printStackTrace();
168. } catch(IOException e){
169. e.printStackTrace();
170. }
172. }
173. };
175. /**
176. * 下载apk
177. * @param url
178. */
180. private void downloadApk(){
181. downLoadThread = new Thread(mdownApkRunnable);
182. downLoadThread.start();
183. }
184. /**
185. * 安装apk
186. * @param url
187. */
188. private void installApk(){
189. File apkfile = new File(saveFileName);
190. if (!apkfile.exists()) {
191. return;
192. }
193. Intent i = new Intent(Intent.ACTION_VIEW);
194. i.setDataAndType(Uri.parse("file://" + apkfile.toString()),"application/vnd.android.package-archive");
195. mContext.startActivity(i);
197. }
198. }

package com.tutor.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 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.net.Uri;import android.os.Handler;import android.os.Message;import android.view.LayoutInflater;import android.view.View;import android.widget.ProgressBar;public class UpdateManager {private Context mContext;//提示语private String updateMsg = "有最新的软件包哦，亲快下载吧~";//返回的安装包urlprivate String apkUrl = "http://softfile.3g.qq.com:8080/msoft/179/24659/43549/qq_hd_mini_1.4.apk";private Dialog noticeDialog;private Dialog downloadDialog; /* 下载包安装路径 */    private static final String savePath = "/sdcard/updatedemo/";        private static final String saveFileName = savePath + "UpdateDemoRelease.apk";    /* 进度条与通知ui刷新的handler和msg常量 */    private ProgressBar mProgress;        private static final int DOWN_UPDATE = 1;        private static final int DOWN_OVER = 2;        private int progress;        private Thread downLoadThread;        private boolean interceptFlag = false;        private Handler mHandler = new Handler(){    public void handleMessage(Message msg) {    switch (msg.what) {case DOWN_UPDATE:mProgress.setProgress(progress);break;case DOWN_OVER:installApk();break;default:break;}    };    };    public UpdateManager(Context context) {this.mContext = context;}//外部接口让主Activity调用public void checkUpdateInfo(){showNoticeDialog();}private void showNoticeDialog(){AlertDialog.Builder builder = new Builder(mContext);builder.setTitle("软件版本更新");builder.setMessage(updateMsg);builder.setPositiveButton("下载", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {dialog.dismiss();showDownloadDialog();}});builder.setNegativeButton("以后再说", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {dialog.dismiss();}});noticeDialog = builder.create();noticeDialog.show();}private void showDownloadDialog(){AlertDialog.Builder builder = new Builder(mContext);builder.setTitle("软件版本更新");final LayoutInflater inflater = LayoutInflater.from(mContext);View v = inflater.inflate(R.layout.progress, null);mProgress = (ProgressBar)v.findViewById(R.id.progress);builder.setView(v);builder.setNegativeButton("取消", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {dialog.dismiss();interceptFlag = true;}});downloadDialog = builder.create();downloadDialog.show();downloadApk();}private Runnable mdownApkRunnable = new Runnable() {@Overridepublic void run() {try {URL url = new URL(apkUrl);HttpURLConnection conn = (HttpURLConnection)url.openConnection();conn.connect();int length = conn.getContentLength();InputStream is = conn.getInputStream();File file = new File(savePath);if(!file.exists()){file.mkdir();}String apkFile = saveFileName;File ApkFile = new File(apkFile);FileOutputStream fos = new FileOutputStream(ApkFile);int count = 0;byte buf[] = new byte[1024];do{          int numread = is.read(buf);    count += numread;        progress =(int)(((float)count / length) * 100);        //更新进度        mHandler.sendEmptyMessage(DOWN_UPDATE);    if(numread <= 0){    //下载完成通知安装    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();} /**     * 安装apk     * @param url     */private void installApk(){File apkfile = new File(saveFileName);        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);}}

第三步：在MainActivity.java也就是主Activity调用,代码如下:

[java] view plaincopyprint?

1. package com.tutor.update;
3. import android.app.Activity;
4. import android.os.Bundle;
6. public class MainAcitivityextends Activity {
9. private UpdateManager mUpdateManager;
10. @Override
11. public void onCreate(Bundle savedInstanceState) {
12. super.onCreate(savedInstanceState);
13. setContentView(R.layout.main);
15. //这里来检测版本是否需要更新
16. mUpdateManager = new UpdateManager(this);
17. mUpdateManager.checkUpdateInfo();
18. }
19. }

package com.tutor.update;import android.app.Activity;import android.os.Bundle;public class MainAcitivity extends Activity {    private UpdateManager mUpdateManager;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                //这里来检测版本是否需要更新        mUpdateManager = new UpdateManager(this);        mUpdateManager.checkUpdateInfo();    }     }

第四步：添加程序所用的资源与权限：

下载的时候用到了ProgressBar,所以事先写了一个progress.xml布局文件，代码如下:

[java] view plaincopyprint?

1. <?xml version="1.0" encoding="utf-8"?>
2. <LinearLayout
3. xmlns:android="http://schemas.android.com/apk/res/android"
4. android:layout_width="fill_parent"
5. android:layout_height="wrap_content">
7. <ProgressBar
8. android:id="@+id/progress"
9. android:layout_width="fill_parent"
10. android:layout_height="wrap_content"
11. style="?android:attr/progressBarStyleHorizontal"
12. />
13. </LinearLayout>

<?xml version="1.0" encoding="utf-8"?><LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="fill_parent"  android:layout_height="wrap_content">    <ProgressBar  android:id="@+id/progress"  android:layout_width="fill_parent"  android:layout_height="wrap_content"  style="?android:attr/progressBarStyleHorizontal"  /></LinearLayout>

下载的时候用到了网络部分，所以要在AndroidManifest.xml中添加网络权限，代码如下:

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1. <uses-permission android:name="android.permission.INTERNET" />

<uses-permission android:name="android.permission.INTERNET" />

第五步:运行查看效果如下:

图一:提示有最新包 图二：点击开始下载

图三：下载完开始安装，我这里模拟器空间不足了。

OK~大功告成了，继续看球，阿森纳已经0:1了，希望范大将军救驾！大家晚安~稍后将会为大家分享更多内容，尽请期待！