尝试使用资源vs尝试捕获

Question

我一直在查看代码，并且已经尝试使用资源。我之前使用过标准的try-catch语句，看起来它们在做同样的事情。所以我的问题是“ 尝试使用资源”与“尝试捕获 ”之间的区别是什么，哪个更好。这是尝试使用资源：objects jar = new objects("brand");objects can= new objects("brand");try (FileOutputStream outStream = new FileOutputStream("people.bin")){    ObjectOutputStream stream = new ObjectOutputStream(outStream);    stream.writeObject(jar);    stream.writeObject(can);    stream.close();} catch(FileNotFoundException e) {    System.out.println("sorry it didn't work out");} catch(IOException f) {    System.out.println("sorry it didn't work out");}

Answer 1

你错过了什么，finally街区。在try-with-resouces将使它像，

FileOutputStream outStream = null;

try {

  outStream = new FileOutputStream("people.bin");

  ObjectOutputStream stream = new ObjectOutputStream(outStream);

  stream.writeObject(jar);

  stream.writeObject(can);

  stream.close();

} catch(FileNotFoundException e) {

    System.out.println("sorry it didn't work out");

} catch(IOException f) {

    System.out.println("sorry it didn't work out");

} finally {

  if (outStream != null) { 

    try { 

      outStream.close(); 

    } catch (Exception e) {

    } 

  }

}

这意味着您确实想要这样的东西（永远不要吞下异常），

try (FileOutputStream outStream = new FileOutputStream("people.bin");

     ObjectOutputStream stream = new ObjectOutputStream(outStream);) {

  stream.writeObject(jar);

  stream.writeObject(can);

  // stream.close(); // <-- closed by try-with-resources.

} catch(FileNotFoundException e) {

    System.out.println("sorry it didn't work out");

    e.printStackTrace();

} catch(IOException f) {

    System.out.println("sorry it didn't work out");

    e.printStackTrace();

}