祝大家新年快乐：）
我正在使用Arduino Uno和Android应用程序进行一个家庭自动化项目，它可以通过我的TP-Link路由器进行通信。
我有一个java.io.IOException:连接上的流意外结束一旦我向Arduino发送了一个查询，我就无法解决它。
01-01 16:51:47.771 10592-11256/com.projects.mahmoudmahdi.etherdroid E/EtherDroid: java.io.IOException: unexpected end of stream on Connection{192.168.1.215:80, proxy=DIRECT@ hostAddress=192.168.1.215 cipherSuite=none protocol=http/1.1} (recycle count=0)
at com.android.okhttp.internal.http.HttpConnection.readResponse(HttpConnection.java:210)
at com.android.okhttp.internal.http.HttpTransport.readResponseHeaders(HttpTransport.java:80)
at com.android.okhttp.internal.http.HttpEngine.readNetworkResponse(HttpEngine.java:904)
at com.android.okhttp.internal.http.HttpEngine.readResponse(HttpEngine.java:788)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:443)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:388)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:501)
at com.projects.mahmoudmahdi.etherdroid.MainActivity$commandArduino.doInBackground(MainActivity.java:50)
at com.projects.mahmoudmahdi.etherdroid.MainActivity$commandArduino.doInBackground(MainActivity.java:31)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.io.EOFException: n not found: size=0 content=...
at com.android.okhttp.okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:200)
at com.android.okhttp.internal.http.HttpConnection.readHeaders(HttpConnection.java:220)
at com.android.okhttp.internal.http.HttpConnection.readResponse(HttpConnection.java:199)
at com.android.okhttp.internal.http.HttpTransport.readResponseHeaders(HttpTransport.java:80)
at com.android.okhttp.internal.http.HttpEngine.readNetworkResponse(HttpEngine.java:904)
at com.android.okhttp.internal.http.HttpEngine.readResponse(HttpEngine.java:788)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:443)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:388)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:501)
at com.projects.mahmoudmahdi.etherdroid.MainActivity$commandArduino.doInBackground(MainActivity.java:50)
at com.projects.mahmoudmahdi.etherdroid.MainActivity$commandArduino.doInBackground(MainActivity.java:31)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
我的Arduino素描：
#include <UIPEthernet.h>
int relay = 2;
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
byte ip[] = { 192, 168, 1, 215 }; // ip in lan (that's what you need to use in your browser. (F("192.168.1.200"))
byte gateway[] = { 192, 168, 1, 10 }; // internet access via router
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
EthernetServer server(80); //server port
String readString;
void setup() {
// Open serial communications and wait for port to open:
Serial.begin(9600);
pinMode(relay, OUTPUT);
// start the Ethernet connection and the server:
Ethernet.begin(mac, ip, gateway, subnet);
server.begin();
Serial.print(F("server is at "));
Serial.println(Ethernet.localIP());
}
void loop() {
// Create a client connection
EthernetClient client = server.available();
if (client) {
//clearing string for next read
readString = "";
while (client.connected()) {
if (client.available()) {
char c = client.read();
//read char by char HTTP request
if (readString.length() < 100) {
//store characters to string
readString += c;
Serial.print(c);
}
//if HTTP request has ended
if (c == 'n') {
Serial.println(readString); //print to serial monitor for debuging
client.println("HTTP/1.1 200 OK"); //send new page
client.println("Content-Type: text/html");
//stopping client
client.stop();
//controls the Arduino if you press the buttons
if (readString.indexOf("?relay1on") > 0) {
digitalWrite(relay, LOW);
Serial.println("relay is on");
}
if (readString.indexOf("?relay1off") > 0) {
digitalWrite(relay, HIGH);
Serial.println("relay is off");
}
}
}
}
}
}
我的Android代码：
package com.projects.mahmoudmahdi.etherdroid;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import java.net.HttpURLConnection;
import java.net.URL;
public class MainActivity extends AppCompatActivity implements OnClickListener {
private class commandArduino extends AsyncTask<URL, Void, Integer> {
@Override
protected Integer doInBackground(URL... url) {
int response = 0;
if (isNetworkAvailable()) {
// params comes from the execute() call: params[0] is the url.
try {
HttpURLConnection urlConnection = (HttpURLConnection) url[0].openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
switch (urlConnection.getResponseCode()) {
case HttpURLConnection.HTTP_OK:
Log.d("RESPONSE", "**OK**");
break; // fine, go on
case HttpURLConnection.HTTP_GATEWAY_TIMEOUT:
Log.d("RESPONSE", "**gateway timeout**");
break;// retry
case HttpURLConnection.HTTP_UNAVAILABLE:
Log.d("RESPONSE", "**unavailable**");
break;// retry, server is unstable
default:
Log.d("RESPONSE", "**unknown response code**.");
break; // abort
}
urlConnection.disconnect();
Log.d("RESPONSE", "Aborting download of dataset.");
} catch (Exception e) {
Log.e("EtherDroid", "STACKTRACE");
Log.e("EtherDroid", Log.getStackTraceString(e));
}
}
return response;
}
}
static boolean relay1 = false;
commandArduino cmdAdn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button Relay1 = (Button) findViewById(R.id.relay1);
Relay1.setOnClickListener(this);
}
private boolean isNetworkAvailable() {
boolean available = false;
/** Getting the system's connectivity service */
ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
/** Getting active network interface to get the network's status */
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isAvailable())
available = true;
/** Returning the status of the network */
return available;
}
public void onClick(View thisView) {
cmdAdn = new commandArduino();
switch (thisView.getId()) {
case R.id.relay1:
if (!relay1) {
relay1 = true;
try {
cmdAdn.execute(new URL("http://192.168.1.215/?relay1on"));
} catch (Exception e) {
e.printStackTrace();
}
Toast.makeText(getApplicationContext(), "relay1 on", Toast.LENGTH_SHORT).show();
} else {
relay1 = false;
try {
cmdAdn.execute(new URL("http://192.168.1.215/?relay1off"));
} catch (Exception e) {
e.printStackTrace();
}
Toast.makeText(getApplicationContext(), "relay1 off", Toast.LENGTH_SHORT).show();
}
break;
}
}
}
一般来说，您缺少：
- 在响应中发送数据
- 为套接字在关闭前发送数据提供时间
- 关闭连接前读取Android的响应
更详细地说，确保在建立连接后发送一些数据：
client.println("HTTP/1.1 200 OK"); //send new page
client.println("Content-Type: text/html");
client.println("Connection: close"); // the connection will be closed after completion of the response
client.println();
client.println("<!DOCTYPE HTML>");
client.println("<html>");
client.println("</html>");
// Give it time to close
delay(1);
client.close();
参考：https://www.arduino.cc/en/Tutorial/WebServer，这是完整的示例：
void loop() {
// listen for incoming clients
EthernetClient client = server.available();
if (client) {
Serial.println("new client");
// an http request ends with a blank line
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) {
char c = client.read(); // NOTE: You're missing this in your code
Serial.write(c);
// if you've gotten to the end of the line (received a newline
// character) and the line is blank, the http request has ended,
// so you can send a reply
if (c == 'n' && currentLineIsBlank) {
// send a standard http response header
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Connection: close"); // the connection will be closed after completion of the response
client.println("Refresh: 5"); // refresh the page automatically every 5 sec
client.println();
client.println("<!DOCTYPE HTML>");
client.println("<html>");
// output the value of each analog input pin
for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
int sensorReading = analogRead(analogChannel);
client.print("analog input ");
client.print(analogChannel);
client.print(" is ");
client.print(sensorReading);
client.println("<br />");
}
client.println("</html>");
break;
}
if (c == 'n') {
// you're starting a new line
currentLineIsBlank = true;
} else if (c != 'r') {
// you've gotten a character on the current line
currentLineIsBlank = false;
}
}
}
// give the web browser time to receive the data
delay(1);
// close the connection:
client.stop();
Serial.println("client disconnected");
Ethernet.maintain();
}
}
此外，考虑使用json而不是html作为Arduino的响应。要做到这一点，您需要更改：
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: application/json");
client.println("Connection: close");
client.println();
client.println("{"status":"ok"}"); // Or whatever you want to change