java - 为什么我的代码运行在主线程上？

Question

我在 onCreate 方法中使用了以下代码:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button button = (Button) findViewById(R.id.button1);
        button.setOnClickListener(new OnClickListener() {


            @Override
            public void onClick(View arg0) {
                Thread thread = new Thread(new Runnable() {

                    @Override
                    public void run() {
                        try {
                            ServerSocket serverSocket = new ServerSocket(9002);
                            Socket s = serverSocket.accept();

                            DataOutputStream outputStream = new DataOutputStream(
                                    s.getOutputStream());
                            BufferedReader inputStream = new BufferedReader(
                                    new InputStreamReader(s.getInputStream()));

                            outputStream.write("Howdy! newbie".getBytes());

                            s.close();

                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                });
                thread.run();
            }
        });
    }

它给了我一个 NetworkOnMainThreadException!

当我使用以下行删除限制时，它确实有效:

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy); 

但我为什么要使用它呢？

我用的线程，为什么不运行在分离的线程上，而是运行在UI线程上？!

Answer 1

改变

thread.run();

到

thread.start();

区别:

Thread.run() does not spawn a new thread whereas Thread.start() does, i.e Thread.run actually runs on the same thread as that of the caller whereas Thread.start() creates a new thread on which the task is run.

有关详细信息，请参阅 Difference between running and starting a thread