我正在尝试在android中创建一个与Java桌面服务器通信的应用程序（消息和文件），为此我使用了套接字编程。我在网上找到了代码。当我尝试运行显示客户端的android客户端时，应用程序中没有错误。我输入了一个字符串，然后单击显示“不幸的是，应用程序已停止工作”的提交按钮，这是我的源代码：
JAVA服务器编码：
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
public class Main {
private static ServerSocket serverSocket;
private static Socket clientSocket;
private static InputStreamReader inputStreamReader;
private static BufferedReader bufferedReader;
private static String message;
public Main(){}
public static void main(String[] args) {
try {
serverSocket = new ServerSocket(7575); //Server socket
} catch (IOException e) {
System.out.println("Could not listen on port: 7575");
}
System.out.println("Server started. Listening to the port 7575");
while (true) {
try {
clientSocket = serverSocket.accept(); //accept the client connection
inputStreamReader = new InputStreamReader(clientSocket.getInputStream());
bufferedReader = new BufferedReader(inputStreamReader); //get the client message
message = bufferedReader.readLine();
System.out.println(message);
inputStreamReader.close();
clientSocket.close();
} catch (IOException ex) {
System.out.println("Problem in message reading");
}
}
}
}
Android编码
activity_simple_client.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".SimpleClientActivity" >
<EditText
android:id="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="83dp"
android:ems="10"
android:hint="@string/clientmsg" >
<requestFocus />
</EditText>
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/editText1"
android:layout_centerHorizontal="true"
android:layout_marginBottom="46dp"
android:text="@string/instrut"
android:textAppearance="?android:attr/textAppearanceLarge" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/editText1"
android:layout_centerHorizontal="true"
android:layout_marginTop="34dp"
android:text="@string/send" />
</RelativeLayout>
SimpleClientActivity.java
package com.andro.SimpleClient;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class SimpleClientActivity extends Activity {
private Socket client;
private PrintWriter printwriter;
private EditText textField;
private Button button;
private String messsage;
public SimpleClientActivity(){}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_simple_client);
textField = (EditText) findViewById(R.id.editText1); //reference to the text field
button = (Button) findViewById(R.id.button1); //reference to the send button
//Button press event listener
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
messsage = textField.getText().toString(); //get the text message on the text field
textField.setText(""); //Reset the text field to blank
try {
client = new Socket("localhost", 7575); //connect to server
printwriter = new PrintWriter(client.getOutputStream(),true);
printwriter.write(messsage); //write the message to output stream
printwriter.flush();
printwriter.close();
client.close(); //closing the connection
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
}
SimpleClient清单
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.andro.SimpleClient"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.andro.SimpleClient.SimpleClientActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
我需要在Eclipse中修改任何设置吗？任何人都可以帮助我吗？提前致谢
我的LOCCAT文件
01-25 00:51:42.035: W/System.err(920): java.net.SocketException: socket failed: EACCES (Permission denied)
01-25 00:51:42.035: W/System.err(920): at libcore.io.IoBridge.socket(IoBridge.java:576)
01-25 00:51:42.095: W/System.err(920): at java.net.PlainSocketImpl.create(PlainSocketImpl.java:201)
01-25 00:51:42.095: W/System.err(920): at java.net.Socket.startupSocket(Socket.java:560)
01-25 00:51:42.105: W/System.err(920): at java.net.Socket.tryAllAddresses(Socket.java:128)
01-25 00:51:42.105: W/System.err(920): at java.net.Socket.<init>(Socket.java:178)
01-25 00:51:42.105: W/System.err(920): at java.net.Socket.<init>(Socket.java:150)
01-25 00:51:42.105: W/System.err(920): at com.android.homeapp.Sendstring.run(Sendstring.java:17)
01-25 00:51:42.105: W/System.err(920): at java.lang.Thread.run(Thread.java:841)
01-25 00:51:42.105: W/System.err(920): Caused by: libcore.io.ErrnoException: socket failed: EACCES (Permission denied)
01-25 00:51:42.105: W/System.err(920): at libcore.io.Posix.socket(Native Method)
01-25 00:51:42.105: W/System.err(920): at libcore.io.BlockGuardOs.socket(BlockGuardOs.java:181)
01-25 00:51:42.125: W/System.err(920): at libcore.io.IoBridge.socket(IoBridge.java:561)
I changed my Mainactivity.java as follows but it still display "Application has Stopped" and in my logcat "MainThread doing too much of work"
MainActivity.java
package com.andro.asynctask;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.EditText;
import android.widget.Button;
import android.view.*;
public class MainActivity extends Activity {
private String mMsg;
private Socket client;
private PrintWriter writer;
private Asyncclass ac;
private EditText txt;
//private Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txt=(EditText)findViewById(R.id.editText1);
//btn=(Button)findViewById(R.id.button1);
}
class Asyncclass extends AsyncTask<String,Void, String>
{
public Asyncclass(String msg)
{
mMsg=msg;
}
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
try
{
hardtask();
}
catch(IOException i)
{
i.printStackTrace();
}
return null;
}
public void hardtask() throws IOException,UnknownHostException
{
client=new Socket("localhost", 7575);
writer=new PrintWriter(client.getOutputStream(),true);
writer.write(mMsg);
writer.flush();
writer.close();
}
}
public void OnClick(View view)
{
mMsg=txt.getText().toString();
ac=new Asyncclass(mMsg);
ac.execute();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
您正在尝试在主线程上进行网络通信，这在Android 4.0+上是不允许的。要解决崩溃，只需将您的代码移到另一个Thread（例如，您应该看一下AsyncTask）。
您可以执行以下操作：
private class SendMessage implements Runnable {
private String mMsg;
public SendMessage(String msg) {
mMsg = msg;
}
public void run() {
try {
client = new Socket("localhost", 7575); //connect to server
printwriter = new PrintWriter(client.getOutputStream(),true);
printwriter.write(messsage); //write the message to output stream
printwriter.flush();
printwriter.close();
client.close(); //closing the connection
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
然后更改onClick为：
public void onClick(View v) {
messsage = textField.getText().toString(); //get the text message on the text field
textField.setText(""); //Reset the text field to blank
new Thread(new SendMessage(message)).start(); // start a new thread to make the communication in the background
}
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