java - 我可以避免这种麻烦的 try...catch block 吗

Question

通常在处理Java IO代码时，我是这样写的

    FileOutputStream out = null;
    try
    {
        out = new FileOutputStream("myfile.txt");
        // More and more code goes here...
    }
    catch (Exception e)
    {
    }
    finally 
    {
        // I put the close code in finally block, to enture the opened
        // file stream is always closed even there is exception happened.
        if (out != null) {
            // Another try catch block, troublesome.
            try {
                out.close();
            } catch (IOException ex) {
            }
        }
    }

如您所见，当我尝试关闭文件流时，我需要处理另一个 try...catch block 。

看起来很麻烦:(

有什么办法可以避免吗？我不太愿意将关闭代码放在非 finally block 中，因为由其他代码引起的异常将没有机会调用“关闭”。

Answer 1

在 finally 中关闭流非常重要。您可以使用实用方法简化此过程，例如:

public static void closeStream(Closeable closeable) {
    if(null != closeable) {
      try {
        closeable.close();
      } catch(IOException ex) {
        LOG.warning("Failed to properly close closeable.", ex);
      }
    }
  }

我至少要记录一个流关闭失败。然后用法变为:

FileOutputStream out = null;
try
{
    out = new FileOutputStream("myfile.txt");
    // More and more code goes here...
}
catch (Exception e)
{
}
finally 
{
    closeStream(out);
}

在 Java 7 中，我相信流将自动关闭，对此类 block 的需求应该是多余的。