Question

我在Java中使用FileOutputStream和BufferedWriter时遇到了问题。

如果我的磁盘空间已满并且我正在尝试写入，它将抛出IOException（这是正确的），但是当调用writer.close（）时，它将无法关闭资源，抛出另一个IOException并保持资源打开！

以下是writer.flush()的解决方法。它似乎有效，但是有更好的方法来解决这个问题吗？

BufferedWriter writer = null;

    try {
         writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), encoding));
         StringBuilder buff = new StringBuilder();
         writeToStream(buff, separator, data);
         writer.write(buff.toString());
         writer.flush(); // flush before closing to make sure there is enough space on disk to complete the close()
         logger.trace("writeFile: file written, file={}", file);
    } catch (IOException e) {
         logger.error("writeFile: cannot write to file: {}", file, e);
         throw new ... //some exception wrapper here
    } finally {
         if (writer != null) {
               try {
                     writer.close();
               } catch (IOException e) {
                     // ignore
               }
          }
     }

Answer 1

您应该尝试按照打开它们的相反顺序关闭所有资源。在这里，您只尝试关闭一个。

如果您使用的是Java 7，请使用try-with-resources语句。如果不这样做，最好的方法是使用Guava's Closer（从版本14.0开始提供）：

final Closer closer = Closer.create();
final FileOutputStream out;
final OutputStreamWriter writer;
final BufferedWriter buffered;

try {
    out = closer.register(new FileOutputStream(file), encoding));
    writer = closer.register(new OutputStreamWriter(out));
    buffered = closer.register(new BufferedWriter(writer));
    // do stuff
} catch (IOException e) {
    throw closer.rethrow(e);
} finally {
    closer.close();
}

如果您没有Closer，则很容易重新创建。

FileOutputStream在空间不足时关闭

1 个答案: