输入流和输出流读取文件列表

发布于 2024-11-03 13:47:04 字数 362 浏览 1 评论 0原文

我有这个 ArrayList 文件，

for(File file : files){

    InputStream in = FileInputStream(file);
    // process each file and save it to file
    OutputStream out = FileOutputStream(file);
    try{

    } finally {
       in.close();
       out.close();
    }
}

性能非常慢，因为每个循环都有一个 in/out close()，有没有更好的方法来做到这一点？我试图将输出流置于循环之外，但它不起作用。

原文

I have this ArrayList files

for(File file : files){

    InputStream in = FileInputStream(file);
    // process each file and save it to file
    OutputStream out = FileOutputStream(file);
    try{

    } finally {
       in.close();
       out.close();
    }
}

the performance is really slow since every loop there is a in/out close(), is there a better way to do this? I tried to put outputstream oustide of the loop, it doesn't work.

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霞映澄塘 2024-11-10 13:47:04

使用缓冲流会产生巨大的差异。

试试这个：

for(final File file : files) {

    final InputStream in = new BufferedInputStream(new FileInputStream(file));
    final OutputStream out = new BufferedOutputStream(new FileOutputStream(new File(...)));
    try {
        // Process each file and save it to file
    }
    finally {
        try {
            in.close();
        }
        catch (IOException ignored) {}
        try {
            out.close();
        }
        catch (IOException ignored) {}
    }
}

请注意，关闭流时可能抛出的 IOException 必须被忽略，否则您将丢失潜在的初始异常。

另一个问题是两个流都在同一个文件上，这是行不通的。所以我想你正在使用两个不同的文件。

Using buffered streams makes a huge difference.

Try this:

for(final File file : files) {

    final InputStream in = new BufferedInputStream(new FileInputStream(file));
    final OutputStream out = new BufferedOutputStream(new FileOutputStream(new File(...)));
    try {
        // Process each file and save it to file
    }
    finally {
        try {
            in.close();
        }
        catch (IOException ignored) {}
        try {
            out.close();
        }
        catch (IOException ignored) {}
    }
}

Note that the IOExceptions that can be thrown when closing the streams must be ignored, or you will lose the potential initial exception.

Another problem is that both streams are on the same file, which doesn't work. So I suppose you're using two different files.

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