从assets文件夹加载大于1M的文件 [英] Load files bigger than 1M from assets folder

问题描述

我快疯了，我创建了一个文件对象，所以它可以用ObjectInputStream读取，然后我放置了assets文件夹.该方法适用于小于 1M 的文件，并在文件较大时出错.我读到这是 Android 平台的限制，但我也知道可以轻松"避免.例如，下载过雷霆迅雷游戏的人很容易看到，在他们的assets文件夹中，有一个18.9M大的文件.这是我从 ObjecInputStream 读取 1 个对象的代码

I'm going crazy, I created a file object, so it can be read with ObjectInputStream, and I placed the assets folder. The method works with a file smaller than 1M, and give error with larger files. I read that is a limit of Android platform, but I also know that can be "easily" avoided. Those who have downloaded the game Reging Thunder, for example, can easily see that in their assets folder is a file 18.9M large. This is my code for read 1 object from a ObjecInputStream

File f = File.createTempFile("mytempfile", "dat");
FileOutputStream fos = new FileOutputStream(f);

InputStream is = mc.getAssets().open(path,3);

ObjectInputStream ois=new ObjectInputStream(is);
byte[] data = (byte[]) ois.readObject();
fos.write(data);

fos.flush();
fos.close();
ois.close();
is.close();

现在我有一个未压缩的文件，我可以使用它而不必担心此文件无法作为文件描述符打开；它可能已压缩"的错误

now I have an uncompressed file and I can use it without worrying about the error "This file can not be opened as a file descriptor; it is probably compressed"

此函数适用于小于 1M 的文件，较大的文件返回一个java.io.IOException 在线ObjectInputStream ois=new ObjectInputStream(is);"

This function works well with files smaller than 1M, with bigger files return an java.io.IOException on line "ObjectInputStream ois=new ObjectInputStream(is);"

为什么??

推荐答案

面临同样的问题.我已将 4MB 文件切成 1MB 块，并在第一次运行时将这些块加入手机上的数据文件夹中.作为额外的奖励，APK 被正确压缩.块文件称为1.db、2.db等，代码如下:

Faced the same issue. I've cut up my 4MB file into 1 MB chunks, and on the first run I join the chunks into a data folder on the phone. As an added bonus, the APK is properly compressed. The chunk files are called 1.db, 2.db, etc. The code goes like this:

File Path = Ctxt.getDir("Data", 0);
File DBFile = new File(Path, "database.db");

if(!DBFile.exists() || DatabaseNeedsUpgrade)  //Need to copy...
    CopyDatabase(Ctxt, DBFile);


static private void CopyDatabase(Context Ctxt, File DBFile) throws IOException
{
    AssetManager assets = Ctxt.getAssets();
    OutputStream outstream = new FileOutputStream(DBFile);
    DBFile.createNewFile();
    byte []b = new byte[1024];
    int i, r;
    String []assetfiles = assets.list("");
    Arrays.sort(assetfiles);
    for(i=1;i<10;i++) //I have definitely less than 10 files; you might have more
    {
        String partname = String.format("%d.db", i);
        if(Arrays.binarySearch(assetfiles, partname) < 0) //No such file in assets - time to quit the loop
            break;
        InputStream instream = assets.open(partname);
        while((r = instream.read(b)) != -1)
            outstream.write(b, 0, r);
        instream.close();
    }
    outstream.close();
}

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