转：Android应用的自动升级、更新模块的实现

Android应用的自动升级、更新模块的实现



我们看到很多Android应用都具有自动更新功能，用户一键就可以完成软件的升级更新。得益于Android系统的软件包管理和安装机制，这一功能实现起来相当简单，下面我们就来实践一下。首先给出界面效果：


1. 准备知识
在AndroidManifest.xml里定义了每个Android apk的版本标识：
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.myapp"
      android:versionCode="1"
      android:versionName="1.0.0">
<application></application>
</manifest>
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其中，android:versionCode和android:versionName两个字段分别表示版本代码，版本名称。versionCode是整型数字，versionName是字符串。由于version是给用户看的，不太容易比较大小，升级检查时，可以以检查versionCode为主，方便比较出版本的前后大小。
那么，在应用中如何读取AndroidManifest.xml中的versionCode和versionName呢？可以使用PackageManager的API，参考以下代码：
public static int getVerCode(Context context) {
        int verCode = -1;
        try {
            verCode = context.getPackageManager().getPackageInfo(
                    "com.myapp", 0).versionCode;
        } catch (NameNotFoundException e) {
            Log.e(TAG, e.getMessage());
        }
        return verCode;
    }
  
    public static String getVerName(Context context) {
        String verName = "";
        try {
            verName = context.getPackageManager().getPackageInfo(
                    "com.myapp", 0).versionName;
        } catch (NameNotFoundException e) {
            Log.e(TAG, e.getMessage());
        }
        return verName;  
}
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或者在AndroidManifest中将android:versionName="1.2.0"写成android:versionName="@string/app_versionName"，然后在values/strings.xml中添加对应字符串，这样实现之后，就可以使用如下代码获得版本名称：
public static String getVerName(Context context) {
        String verName = context.getResources()
        .getText(R.string.app_versionName).toString();
        return verName;
}
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同理，apk的应用名称可以这样获得：
public static String getAppName(Context context) {
        String verName = context.getResources()
        .getText(R.string.app_name).toString();
        return verName;
}
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2. 流程框架

3. 版本检查
在服务端放置最新版本的apk文件，如：http://localhost/myapp/myapp.apk
同时，在服务端放置对应此apk的版本信息调用接口或者文件，如:http://localhost/myapp/ver.json
ver.json中的内容为：
[{"appname":"jtapp12","apkname":"jtapp-12-updateapksamples.apk","verName":1.0.1,"verCode":2}]
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然后，在手机客户端上进行版本读取和检查：
private boolean getServerVer () {
        try {
            String verjson = NetworkTool.getContent(Config.UPDATE_SERVER
                    + Config.UPDATE_VERJSON);
            JSONArray array = new JSONArray(verjson);
            if (array.length() > 0) {
                JSONObject obj = array.getJSONObject(0);
                try {
                    newVerCode = Integer.parseInt(obj.getString("verCode"));
                    newVerName = obj.getString("verName");
                } catch (Exception e) {
                    newVerCode = -1;
                    newVerName = "";
                    return false;
                }
            }
        } catch (Exception e) {
            Log.e(TAG, e.getMessage());
            return false;
        }
        return true;
    }
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比较服务器和客户端的版本，并进行更新操作。
   if (getServerVerCode()) {
            int vercode = Config.getVerCode(this); // 用到前面第一节写的方法
            if (newVerCode > vercode) {
                doNewVersionUpdate(); // 更新新版本
            } else {
                notNewVersionShow(); // 提示当前为最新版本
            }
        }       
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详细方法：
private void notNewVersionShow() {
                int verCode = Config.getVerCode(this);
                String verName = Config.getVerName(this);
                StringBuffer sb = new StringBuffer();
                sb.append("当前版本:");
                sb.append(verName);
                sb.append(" Code:");
                sb.append(verCode);
                sb.append(",/n已是最新版,无需更新!");
                Dialog dialog = new AlertDialog.Builder(Update.this).setTitle("软件更新")
                                .setMessage(sb.toString())// 设置内容
                                .setPositiveButton("确定",// 设置确定按钮
                                                new DialogInterface.OnClickListener() {
                                                        @Override
                                                        public void onClick(DialogInterface dialog,
                                                                        int which) {
                                                                finish();
                                                        }
                                                }).create();// 创建
                // 显示对话框
                dialog.show();
        }
        private void doNewVersionUpdate() {
                int verCode = Config.getVerCode(this);
                String verName = Config.getVerName(this);
                StringBuffer sb = new StringBuffer();
                sb.append("当前版本:");
                sb.append(verName);
                sb.append(" Code:");
                sb.append(verCode);
                sb.append(", 发现新版本:");
                sb.append(newVerName);
                sb.append(" Code:");
                sb.append(newVerCode);
                sb.append(", 是否更新?");
                Dialog dialog = new AlertDialog.Builder(Update.this)
                                .setTitle("软件更新")
                                .setMessage(sb.toString())
                                // 设置内容
                                .setPositiveButton("更新",// 设置确定按钮
                                                new DialogInterface.OnClickListener() {
                                                        @Override
                                                        public void onClick(DialogInterface dialog,
                                                                        int which) {
                                                                pBar = new ProgressDialog(Update.this);
                                                                pBar.setTitle("正在下载");
                                                                pBar.setMessage("请稍候...");
                                                                pBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                                                                downFile(Config.UPDATE_SERVER + Config.UPDATE_APKNAME);
                                                        }
                                                })
                                .setNegativeButton("暂不更新",
                                                new DialogInterface.OnClickListener() {
                                                        public void onClick(DialogInterface dialog,
                                                                        int whichButton) {
                                                                // 点击"取消"按钮之后退出程序
                                                                finish();
                                                        }
                                                }).create();// 创建
                // 显示对话框
                dialog.show();
        }
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4. 下载模块
注，本部分参考了前人的相关实现，
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.AlertDialog;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;

public class Update extends BaseActivity {
public ProgressDialog pBar;
private Handler handler = new Handler();

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.update);
  Dialog dialog = new AlertDialog.Builder(Update.this).setTitle("系统更新")
    .setMessage("发现新版本，请更新！")// 设置内容
    .setPositiveButton("确定",// 设置确定按钮
      new DialogInterface.OnClickListener() {

       @Override
       public void onClick(DialogInterface dialog,
         int which) {
        pBar = new ProgressDialog(Update.this);
        pBar.setTitle("正在下载");
        pBar.setMessage("请稍候...");
        pBar
          .setProgressStyle(ProgressDialog.STYLE_SPINNER);
        downFile("http://url:8765/OA.apk");
       

       }

      }).setNegativeButton("取消",
      new DialogInterface.OnClickListener() {
       public void onClick(DialogInterface dialog,
         int whichButton) {
        // 点击"取消"按钮之后退出程序
       
       }
      }).create();// 创建
  // 显示对话框
  dialog.show();

}

void downFile(final String url) {
  pBar.show();
  new Thread() {
   public void run() {
    HttpClient client = new DefaultHttpClient();
    // params[0]代表连接的url
    HttpGet get = new HttpGet(url);
    HttpResponse response;
    try {
     response = client.execute(get);
     HttpEntity entity = response.getEntity();
     long length = entity.getContentLength();
     InputStream is = entity.getContent();
     FileOutputStream fileOutputStream = null;
     if (is != null) {

      File file = new File(Environment
        .getExternalStorageDirectory(), "OA.apk");
      fileOutputStream = new FileOutputStream(file);
     
      byte[] buf = new byte[1024];
      int ch = -1;
      int count = 0;
      while ((ch = is.read(buf)) != -1) {
       // baos.write(buf, 0, ch);
       fileOutputStream.write(buf, 0, ch);
       count += ch;
       if (length > 0) {
      
       }

      }

     }
     fileOutputStream.flush();
     if (fileOutputStream != null) {
      fileOutputStream.close();
     }
     down();
    } catch (ClientProtocolException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }

  }.start();

}

void down() {
  handler.post(new Runnable() {
   public void run() {
    pBar.cancel();
    update();
   }
  });

}

void update() {

  Intent intent = new Intent(Intent.ACTION_VIEW);
  intent.setDataAndType(Uri.fromFile(new File("/sdcard/OA.apk")),
    "application/vnd.android.package-archive");
  startActivity(intent);
}

}
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```````````````````````
    void downFile(final String url) {
        pBar.show();
        new Thread() {
            public void run() {
                HttpClient client = new DefaultHttpClient();
                HttpGet get = new HttpGet(url);
                HttpResponse response;
                try {
                    response = client.execute(get);
                    HttpEntity entity = response.getEntity();
                    long length = entity.getContentLength();
                    InputStream is = entity.getContent();
                    FileOutputStream fileOutputStream = null;
                    if (is != null) {
                        File file = new File(
                                Environment.getExternalStorageDirectory(),
                                Config.UPDATE_SAVENAME);
                        fileOutputStream = new FileOutputStream(file);
                        byte[] buf = new byte[1024];
                        int ch = -1;
                        int count = 0;
                        while ((ch = is.read(buf)) != -1) {
                            fileOutputStream.write(buf, 0, ch);
                            count += ch;
                            if (length > 0) {
                            }
                        }
                    }
                    fileOutputStream.flush();
                    if (fileOutputStream != null) {
                        fileOutputStream.close();
                    }
                    down();
                } catch (ClientProtocolException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }.start();
    }
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下载完成，通过handler通知主ui线程将下载对话框取消。
void down() {
        handler.post(new Runnable() {
            public void run() {
                pBar.cancel();
                update();
            }
        });
}
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5. 安装应用
    void update() {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.fromFile(new File(Environment
                .getExternalStorageDirectory(), Config.UPDATE_SAVENAME)),
                "application/vnd.android.package-archive");
        startActivity(intent);
    }
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果你将apk应用发布到market上，那么，你会发现market内建了类似的模块，可以自动更新或者提醒你是否更新应用。那么，对于你自己的应用需要自动更新的话，自己内建一个是不是更加方便了呢？本文提到的代码大多是在UpdateActivity.java中实现，为了能够使更新过程更加友好，可以在最初launcher的Activity中建立一个线程，用来检查服务端是否有更新。有更新的时候就启动UpdateActivity，这样的使用体验更加平滑。

本文例程源码查看/下载：