java - 如果我们使用 try-with-resource 是否需要关闭资源

Question

我在代码中使用了 try-with-resource block ，想知道是否需要在方法结束时关闭资源或不需要？

try (S3Object object = s3.getObject(new GetObjectRequest(bucketName, key));
  BufferedReader br = new BufferedReader(new InputStreamReader(object.getObjectContent()));
  BufferedWriter bw = new BufferedWriter(new FileWriter(new File("output.txt")))){
  String line;

  while((line=br.readLine())!=null){
    bw.write(line);
    bw.newLine();
    bw.flush();
  }
}

Answer 1

没有。

The try-with-resources statement ensures that each resource is closed at the end of the statement. Any object that implements java.lang.AutoCloseable, which includes all objects which implement java.io.Closeable, can be used as a resource.

如果您使用的是 java 6 或更早版本:

Prior to Java SE 7, you can use a finally block to ensure that a resource is closed regardless of whether the try statement completes normally or abruptly.

更新:

You may declare one or more resources in a try-with-resources statement.

正如您在代码中使用的那样。