通过Android应用程序向Apache服务器发送请求,摆脱无限循环

冲天香阵透长安,满城尽带黄金甲。这篇文章主要讲述通过Android应用程序向Apache服务器发送请求,摆脱无限循环相关的知识,希望能为你提供帮助。
这是我的项目的架构:
1)android应用程序 - > 2)RPi上的Apache服务器 - > 3)控制 - > 4)我的设备的python脚本
1)Android应用程序 -2个简单的开关,每个都在RPi上向Apache发送不同的请求:

public class MainActivity extends Activity{private static final String TAG = "MainActivity"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Switch switch_auto = findViewById(R.id.switch_auto); Switch switch_manual = findViewById(R.id.switch_manual); switch_auto.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) { new Background_get().execute("led1=1"); } else { new Background_get().execute("led1=0"); } } }); switch_manual.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) { Log.d(TAG, "onCheckedChanged: SET TO TRUE"); new Background_get().execute("led2=1"); Log.d(TAG, "onCheckedChanged: EXIT"); } else { Log.d(TAG, "onCheckedChanged: SET TO FALSE"); new Background_get().execute("led2=0"); Log.d(TAG, "onCheckedChanged: EXIT"); } } }); }private class Background_get extends AsyncTask< String, Void, String> { @Override protected String doInBackground(String... params) { try { URL url = new URL("http://192.168.0.248/?" + params[0]); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream())); StringBuilder result = new StringBuilder(); String inputLine; while ((inputLine = in.readLine()) != null) result.append(inputLine).append(" "); in.close(); connection.disconnect(); return result.toString(); } catch (IOException e) { e.printStackTrace(); } return null; } } }

2)RPi上的Apache服务器 - 非常简单的php代码:
  • 如果它是“led1 = 1”,启动Python脚本,使设备工作10秒(time.sleep(10)
  • 如果它是“led1 = 0”,只需打印一些东西
  • 如果它是“led2 = 1”,则启动另一个Python脚本,使设备无限期工作(while True: time.sleep(1)
  • 如果它是“led2 = 0”,则启动第三个停止设备的Python脚本
我的问题:我可以通过网络浏览器使用这些脚本正确控制我的设备,例如:
  • http://192.168.0.248/?led2=1将打开设备并使其工作
  • http://192.168.0.248/?led2=0将关闭设备
出于测试目的,这是针对led1的Apache2的access.log(= 1使其工作10秒,= 0只是打印一行):
192.168.0.10--[01 / Mar / 2018:10:42:01 +0100]“GET /?led1 = 1 HTTP / 1.1”200 411“ - ”“Mozilla / 5.0(Windows NT 6.1; Win64; x64)AppleWebKit /537.36(Khtml,与Gecko一样)Chrome / 64.0.3282.186 Safari / 537.36“
(它开始工作)
192.168.0.10--[01 / Mar / 2018:10:42:05 +0100]“GET /?led1 = 0 HTTP / 1.1”200 233“ - ”“Mozilla / 5.0(Windows NT 6.1; Win64; x64)AppleWebKit /537.36(KHTML,与Gecko一样)Chrome / 64.0.3282.186 Safari / 537.36“
(没有问题,在4秒后得到led1 = 0并且led1 = 1的脚本仍然可以工作几秒钟)
不幸的是,我的Android应用程序无法做到这一点。这是Apache的日志:
192.168.0.66--[01 / Mar / 2018:10:3??6:53 +0100]“GET /?led1 = 1 HTTP / 1.1”200 411“ - ”“Dalvik / 2.1.0(Linux; U; Android 8.1。 0; Nexus 5X Build / OPM3.171019.014)“
(我在5秒后做出“关闭”但......)
192.168.0.66-[01 / Mar / 2018:10:3??7:07 +0100]“GET /?led1 = 0 HTTP / 1.1”200 232“ - ”“Dalvik / 2.1.0(Linux; U; Android 8.1。 0; Nexus 5X Build / OPM3.171019.014)“
(它没有!注意差异14秒(它发射约3秒然后工作10秒)。它在led1 = 1的脚本完成其工作后收到GET)。
当脚本工作10秒(led1)时,这是一个问题,但是当脚本在无限循环(led2)中工作时是一个大问题 - 我不能破坏它直到第一个脚本停止(但它是True循环所以......)
我在第二个脚本中考虑Python的subprocess.check_call()来杀死第一个但它似乎没有帮助。
任何想法如何解决这个问题?
答案最后,我设法做到了。杀死无限循环的想法是正确的,但首先我考虑在Python脚本上做错,这是错误的。
我注意到,当本地.php站点正在加载时(由于while循环),那些GET响应没有出现在日志中,因此需要中止当前的GET。它可以用Apache的httpcomponents完成。
所以经过一些修改我的代码看起来像这样:
public class MainActivity extends AppCompatActivity {private static final String TAG = "MainActivity"; boolean flagToggle = true; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Switch switch_auto = findViewById(R.id.switch_auto); Switch switch_manual = findViewById(R.id.switch_manual); switch_auto.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { HttpGet requestOn = new HttpGet(); HttpGet requestOff = new HttpGet(); public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {if (!flagToggle) { requestOn = new HttpGet(); requestOff = new HttpGet(); flagToggle = true; }Background_get switchOn = new Background_get(requestOn); Background_get switchOff = new Background_get(requestOff); if (isChecked) { switchOn.execute("led1=1"); } else { requestOn.abort(); switchOff.execute("led1=0"); flagToggle = false; }} }); switch_manual.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { HttpGet requestOn = new HttpGet(); HttpGet requestOff = new HttpGet(); public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {if (!flagToggle) { requestOn = new HttpGet(); requestOff = new HttpGet(); flagToggle = true; }Background_get switchOn = new Background_get(requestOn); Background_get switchOff = new Background_get(requestOff); if (isChecked) { switchOn.execute("led2=1"); } else { requestOn.abort(); switchOff.execute("led2=0"); flagToggle = false; }} }); }public class Background_get extends AsyncTask< String, Void, String> {private HttpGet mRequest = new HttpGet(); public Background_get(HttpGet newRequest) { mRequest = newRequest; }public HttpGet getRequest() { return mRequest; }public void setRequest(HttpGet newRequest) { mRequest = newRequest; }@Override protected String doInBackground(String... params) { try { URI url = new URI("http://192.168.0.248/?" + params[0]); // HttpURLConnection connection = (HttpURLConnection) url.openConnection(); HttpClient httpclient = new DefaultHttpClient(); getRequest().setURI(url); HttpResponse response = httpclient.execute(getRequest()); BufferedReader in = new BufferedReader(new InputStreamReader(response.getEntity().getContent())); StringBuilder result = new StringBuilder(); String inputLine; while ((inputLine = in.readLine()) != null) result.append(inputLine).append(" "); in.close(); // response.close(); // httpclient.close(); return result.toString(); } catch (IOException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); }return null; } } }

【通过Android应用程序向Apache服务器发送请求,摆脱无限循环】值得注意的事情:
  • 对于每个切换切换,它需要单独的请求(新的HttpGet())
  • 与BackgroundGet相同(因为它是AsyncTask)
  • flagToggle有助于多次切换切换

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