我举了一些在互联网上发现的用于socket编程的例子，并试图为支持以太网的arduino服务器构建自己的android客户端。但是我有两个问题。
首先，我主要活动的代码：
package com.domiflichi.TesterProject;
import java.io.BufferedWriter; // output
import java.io.BufferedReader; // input
import java.io.InputStreamReader; // input
import java.io.OutputStreamWriter; // output
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class TesterProjectMain extends Activity implements OnClickListener
{
private Button connectPhones;
private TextView myTextView; // represents the 'status text'
private String serverIpAddress = "";
private boolean connected = false;
private Handler handler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.client);
connectPhones = (Button) findViewById(R.id.connect_phones);
connectPhones.setOnClickListener(connectListener);
connectPhones.setOnClickListener(this);
myTextView = (TextView) findViewById(R.id.text1);
}
// This was created when using the 'implements OnClickListener' in the class
public void onClick(View v) {
if (v.getId() == R.id.connect_phones) {
if (!connected) {
serverIpAddress = "192.168.0.178";
if (!serverIpAddress.equals("")) {
Thread cThread = new Thread(new ClientThread());
cThread.start();
connectPhones.setEnabled(false); // Once the button is pressed, disable it. :)
}
}
} else if (v.getId() == R.id.status_req) {
// CODE HERE FOR STATUS REQUEST BUTTON?
} else if (v.getId() == R.id.cmd_toggle) {
// CODE HERE FOR TOGGLE DOOR BUTTON?
} else if (v.getId() == R.id.cmd_crack) {
// CODE HERE FOR CRACK BUTTON?
} else if (v.getId() == R.id.disconnect) {
// CODE HERE FOR DISCONNECT BUTTON?
}
}
public class ClientThread implements Runnable {
public void run() {
try {
InetAddress serverAddr = InetAddress.getByName(serverIpAddress);
Log.d("ClientActivity", "C: Connecting...");
Socket socket = new Socket(serverAddr, 23);
connected = true;
while (connected) {
try {
Log.d("ClientActivity", "C: Sending command.");
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
out.println("mypass*");
Log.d("ClientActivity", "C: Sent.");
BufferedReader r = new BufferedReader(new InputStreamReader(socket.getInputStream()));
final StringBuilder total = new StringBuilder();
String line;
while ((line = r.readLine()) != null) {
total.append(line);
Log.d("Server response", line.toString());
}
handler.post(new Runnable() {
public void run() {
if (total.toString().contentEquals("status:open")) {
myTextView.setText(R.string.status_open);
} else {
myTextView.setText(R.string.status_closed);
}
}
});
connected = false;
} catch (Exception e) {
Log.e("ClientActivity", "S: Error", e);
}
}
socket.close();
Log.d("ClientActivity", "C: Closed.");
} catch (Exception e) {
Log.e("ClientActivity", "C: Error", e);
connected = false;
}
}
}
}
所以我的两个问题是：
我不知道如何让我的按钮与我向服务器发送命令的套接字交互。连接后，我有（4）个按钮需要通过套接字发送各种命令（套接字运行在一个单独的线程中，该线程是通过单击“连接”按钮启动的）。（在此处查找“/”代码以获取状态请求按钮？“我希望将各种按钮的代码放在哪里的注释）
我需要移动
'handler.post（new runnable（）{'
进入主循环的代码块：
(while ((line = r.readLine()) != null) {
total.append(line);
Log.d("Server response", line.toString());
}
但是，当我这样做，并改变：
if (total.toString().contentEquals("status:open")) {
到
if (line.toString().contentEquals("status:open")) {
（因为我想一次只读一行）
eclipse发出以下消息：
不能引用在其他方法中定义的内部类中的非最终变量行
如果我想把上面的线改一下…
串线；
到
静态弦线；
eclipse在下一行抱怨：
while（（line=r.readline（））！{NULL）{
说：
可能已经分配了最后一个局部变量行
我甚至不敢相信我已经走到了这个地步，因为我是一个完全的新手，但现在我已经撞到了墙。
最佳答案
对于第二个问题：创建一个新的final以在runnable中使用
while ((line = r.readLine()) != null) {
total.append(line);
Log.d("Server response", line.toString());
final String status = line;
handler.post(new Runnable() {
public void run() {
if (status.contentEquals("status:open")) {
myTextView.setText(R.string.status_open);
} else {
myTextView.setText(R.string.status_closed);
}
}
});
}
对于你的第一个问题：
你挑了一个相当复杂的任务。您的线程需要检查您从外部设置的某些条件，以便线程可以决定他接下来需要做什么。从这些按钮，你可以改变，例如，一个AtomicInteger是0，只要没有事情可做，1，如果你想打开灯，2…等
您的线程将检查该值，将其重置为0（在一个
.getAndSet(0)）并执行他应该执行的操作。编辑：就是这样
线程
public class LoopingNetworkThread extends Thread {
public static final int TASK_END = -1;
public static final int TASK_NOOP = 0;
public static final int TASK_LIGHTS_ON = 1;
public static final int TASK_LIGHTS_OFF = 2;
private final AtomicInteger mNextTask = new AtomicInteger(0);
/* Executed in this threads context */
@Override
public void run() {
openSocket();
int currentTask;
while ((currentTask = mNextTask.getAndSet(TASK_NOOP)) != TASK_END) {
switch (currentTask) {
case TASK_LIGHTS_ON:
sendLightsOn();
break;
case TASK_LIGHTS_OFF:
sendLightsOff();
break;
default:
keepAlive();
break;
}
// depending on your requirements sleep some time inbetween.
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// ignore
}
}
// the while ends once you set task to TASK_END
closeSocket();
}
private void openSocket() { }
private void closeSocket() { }
private void keepAlive() { }
private void sendLightsOn() { }
private void sendLightsOff() { }
/* Executed in a different thread context */
public int setNextTask(int task){
// return what we overwrite here, maybe that is useful.
return mNextTask.getAndSet(task);
}
}
你的活动
public class YourActivity extends Activity {
private LoopingNetworkThread mThread;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mThread = new LoopingNetworkThread();
View startButton = findViewById(R.id.button1);
View stopButton = findViewById(R.id.button2);
startButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mThread.start();
}
});
stopButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mThread.setNextTask(LoopingNetworkThread.TASK_END);
}
});
}
}