典型应用之——将数据打进apk

 

1.    介绍
需要安装一些资源到系统中，比如多媒体文件，配置文件或者某种数据文件，可以把它打包放在资源raw目录中，然后在程序中读取解包，并安装在指定目录下

2.    android框架对多媒体的支持
apk包中的数据一般都放在res/raw目录下，只有它的拥有者能通过openRawResourceFd的方式访问，如果不在java层访问，或者要将其安装在其它位置，就需要在java程序中对其进行处理

3.    例程

1)        功能
把多媒体及数据文件打在zip包放在res/raw下，并将其打在安装包apk中，在程序中点击按钮时将其安装在指定目录下

2)        可从此处下载可独立运行的代码
http://download.csdn.net/source/2841538

3)        核心代码及说明
package com.android.mydata;

import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.TextView;
import android.content.res.AssetFileDescriptor;
import android.content.res.Resources;
import android.view.View.OnClickListener;
import android.view.View;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class MyDataActivity extends Activity {
         String rootDirectory = "/data/data/com.android.mydata/data/"; // 安装的目录
         TextView status;

         @Override
         public void onCreate(Bundle savedInstanceState) {
                   super.onCreate(savedInstanceState);
                   setContentView(R.layout.main);
                   Button btn = (Button) findViewById(R.id.button);
                   status = (TextView) findViewById(R.id.status);
                   btn.setText("install"); // 点击此按钮开始安装
                   status.setText("wait...");
                   btn.setOnClickListener(new OnClickListener() {
                            public void onClick(View v) {
                                     unpack();
                                     status.setText("okey...");
                            }
                   });
         }

         boolean unpack() {
                   FileOutputStream out;
                   byte buf[] = new byte[16384];
                   try {
                            Resources res = getResources();  // 获得资源句柄
                            AssetFileDescriptor fd = res.openRawResourceFd(R.raw.test); // 压缩文件为test.zip
                            InputStream stream = fd.createInputStream();
                            ZipInputStream zis = new ZipInputStream(stream);
                            ZipEntry entry = zis.getNextEntry();
                            while (entry != null) {
                                     if (entry.isDirectory()) {       // 对文件夹处理
                                               File newDir = new File(rootDirectory + entry.getName());
                                               newDir.mkdir();
                                     } else {       // 对文件处理
                                               String name = entry.getName();
                                               File outputFile = new File(rootDirectory + name);
                                               String outputPath = outputFile.getCanonicalPath();
                                               name = outputPath
                                                                 .substring(outputPath.lastIndexOf("/") + 1);
                                               outputPath = outputPath.substring(0, outputPath
                                                                 .lastIndexOf("/"));
                                               File outputDir = new File(outputPath);
                                               outputDir.mkdirs();
                                               outputFile = new File(outputPath, name);
                                               outputFile.createNewFile();
                                               out = new FileOutputStream(outputFile);

                                               int numread = 0;
                                               do {
                                                        numread = zis.read(buf);
                                                        if (numread <= 0) {
                                                                 break;
                                                        } else {
                                                                 out.write(buf, 0, numread);
                                                        }
                                               } while (true);
                                               out.close();
                                     }
                                     entry = zis.getNextEntry();
                            }
                            return true;
                   } catch (IOException e) {
                            e.printStackTrace();
                            return false;
                   }
         }
}

4)        注意：打包数据不能太小，否则会出错。数据打包使用如下命令
zip -r ../test.zip *

4.    参考

1)        源代码语音合成external/svox/picolanginstaller对语音数据的安装

2)        http://cnmsdn.com/html/201010/1287296527ID8341.html