在 Java 6 中将 InputStream 写入文件的有效方法
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Efficient way to write InputStream to a File in Java 6
提问by Awesome
I will get input stream from third party library to my application. I have to write this input stream to a file.
我将从第三方库获取输入流到我的应用程序。我必须将此输入流写入文件。
Following is the code snippet I tried:
以下是我尝试过的代码片段：
private void writeDataToFile(Stub stub) {
OutputStream os = null;
InputStream inputStream = null;
try {
inputStream = stub.getStream();
os = new FileOutputStream("test.txt");
int read = 0;
byte[] bytes = new byte[1024];
while ((read = inputStream.read(bytes)) != -1) {
os.write(bytes, 0, read);
}
} catch (Exception e) {
log("Error while fetching data", e);
} finally {
if(inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
log("Error while closing input stream", e);
}
}
if(os != null) {
try {
os.close();
} catch (IOException e) {
log("Error while closing output stream", e);
}
}
}
}
Is there any better approach to do this ?
有没有更好的方法来做到这一点？
采纳答案by fge
Since you are stuck with Java 6, do yourself a favour and use Guava and its Closer:
由于您坚持使用 Java 6，帮自己一个忙并使用 Guava 及其Closer：
final Closer closer = Closer.create();
final InputStream in;
final OutputStream out;
final byte[] buf = new byte[32768]; // 32k
int bytesRead;
try {
in = closer.register(createInputStreamHere());
out = closer.register(new FileOutputStream(...));
while ((bytesRead = in.read(buf)) != -1)
out.write(buf, 0, bytesRead);
out.flush();
} finally {
closer.close();
}
Had you used Java 7, the solution would have been as simple as:
如果您使用 Java 7，解决方案将非常简单：
final Path destination = Paths.get("pathToYourFile");
try (
final InputStream in = createInputStreamHere();
) {
Files.copy(in, destination);
}
And yourInputStreamwould have been automatically closed for you as a "bonus"; Fileswould have handled destinationall by itself.
并且yourInputStream会作为“奖金”自动为您关闭；Files本来可以自己处理destination的。
回答by Brad Gardner
It can get cleaner with an OutputStreamWriter:
使用 OutputStreamWriter 可以变得更清晰：
OutputStream outputStream = new FileOutputStream("output.txt");
Writer writer = new OutputStreamWriter(outputStream);
writer.write("data");
writer.close();
Instead of writing a string, you can use a Scanner on your inputStream
您可以在 inputStream 上使用 Scanner，而不是编写字符串
Scanner sc = new Scanner(inputStream);
while (sc.HasNext())
//read using scanner methods
回答by Melou
If you're not on Java 7 and can't use fge's solution, you may want to wrap your OutputStream in a BufferedOutputStream
如果您不是在 Java 7 上并且不能使用 fge 的解决方案，您可能需要将您的 OutputStream 包装在 BufferedOutputStream 中
BufferedOutputStream os = new BufferedOutputStream(new FileOutputStream("xx.txt"));
Such buffered output stream will write bytes in blocks to the file, which is more efficient than writing byte per byte.
这种缓冲的输出流会将字节以块的形式写入文件，这比逐字节写入更有效。
