我正在尝试编写一个连接到我用java编写的服务器的Android应用程序。这是我的代码（单击按钮时调用）：
package me.nrubin29.quiz.student;
import android.app.Activity;
import android.widget.Toast;
import java.io.EOFException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
public class Connection {
private Socket socket;
private Thread reader;
private ObjectInputStream inputStream;
private ObjectOutputStream outputStream;
public void initConnection(final Activity activity, String ip, String port, String name) {
try {
Toast.makeText(activity.getApplicationContext(), "Starting connection to " + ip + ":" + Integer.parseInt(port), Toast.LENGTH_SHORT).show();
socket = new Socket(ip, Integer.parseInt(port));
Toast.makeText(activity.getApplicationContext(), "Connected!", Toast.LENGTH_SHORT).show();
outputStream = new ObjectOutputStream(socket.getOutputStream());
inputStream = new ObjectInputStream(socket.getInputStream());
outputStream.writeObject(name);
reader = new Thread(new Runnable() {
public void run() {
while (true) {
try {
Object in = inputStream.readObject();
System.out.println(in);
}
catch (EOFException e) { Toast.makeText(activity.getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show(); }
catch (Exception e) { e.printStackTrace(); }
}
}
});
reader.start();
}
catch (Exception e) { e.printStackTrace(); }
}
}
显示第一个toast（使用正确的端口和IP），但第二个toast永远不会出现。手机和电脑都连接到同一个网络，我肯定在服务器上使用正确的内部IP和端口。
很抱歉，如果这是一个不起眼的问题，我对此非常陌生。
更新
看起来 是一个错误。这是：
09-23 01:00:00.963: WARN/System.err(890): java.net.SocketException: socket failed: EACCES (Permission denied)
09-23 01:00:00.963: WARN/System.err(890): at libcore.io.IoBridge.socket(IoBridge.java:583)
09-23 01:00:00.963: WARN/System.err(890): at java.net.PlainSocketImpl.create(PlainSocketImpl.java:201)
09-23 01:00:00.972: WARN/System.err(890): at java.net.Socket.startupSocket(Socket.java:559)
09-23 01:00:00.972: WARN/System.err(890): at java.net.Socket.tryAllAddresses(Socket.java:127)
09-23 01:00:00.972: WARN/System.err(890): at java.net.Socket.<init>(Socket.java:177)
09-23 01:00:00.972: WARN/System.err(890): at java.net.Socket.<init>(Socket.java:149)
09-23 01:00:00.972: WARN/System.err(890): at me.nrubin29.quiz.student.Connection.initConnection(Connection.java:22)
09-23 01:00:00.972: WARN/System.err(890): at me.nrubin29.quiz.student.Main$1.onClick(Main.java:35)
09-23 01:00:00.983: WARN/System.err(890): at android.view.View.performClick(View.java:4204)
09-23 01:00:00.983: WARN/System.err(890): at android.view.View$PerformClick.run(View.java:17355)
09-23 01:00:00.983: WARN/System.err(890): at android.os.Handler.handleCallback(Handler.java:725)
09-23 01:00:00.983: WARN/System.err(890): at android.os.Handler.dispatchMessage(Handler.java:92)
09-23 01:00:00.983: WARN/System.err(890): at android.os.Looper.loop(Looper.java:137)
09-23 01:00:00.993: WARN/System.err(890): at android.app.ActivityThread.main(ActivityThread.java:5041)
09-23 01:00:00.993: WARN/System.err(890): at java.lang.reflect.Method.invokeNative(Native Method)
09-23 01:00:00.993: WARN/System.err(890): at java.lang.reflect.Method.invoke(Method.java:511)
09-23 01:00:00.993: WARN/System.err(890): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
09-23 01:00:01.003: WARN/System.err(890): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
09-23 01:00:01.003: WARN/System.err(890): at dalvik.system.NativeStart.main(Native Method)
09-23 01:00:01.013: WARN/System.err(890): Caused by: libcore.io.ErrnoException: socket failed: EACCES (Permission denied)
09-23 01:00:01.013: WARN/System.err(890): at libcore.io.Posix.socket(Native Method)
09-23 01:00:01.013: WARN/System.err(890): at libcore.io.BlockGuardOs.socket(BlockGuardOs.java:181)
09-23 01:00:01.023: WARN/System.err(890): at libcore.io.IoBridge.socket(IoBridge.java:568)
09-23 01:00:01.023: WARN/System.err(890): ... 18 more
更新二：
这是我的AndroidManifest.xml：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="me.nrubin29.quiz.student"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="15"/>
<uses-permission android:name="android.permission.INTERNET"/>
<application android:label="@string/app_name" android:icon="@drawable/ic_launcher" android:name=".App">
<activity android:name="Main"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>
这是另一个新错误：
09-23 01:17:00.618: WARN/System.err(1109): android.os.NetworkOnMainThreadException
09-23 01:17:00.638: WARN/System.err(1109): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
09-23 01:17:00.638: WARN/System.err(1109): at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
09-23 01:17:00.648: WARN/System.err(1109): at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
09-23 01:17:00.648: WARN/System.err(1109): at libcore.io.IoBridge.connect(IoBridge.java:112)
09-23 01:17:00.648: WARN/System.err(1109): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
09-23 01:17:00.648: WARN/System.err(1109): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
09-23 01:17:00.668: WARN/System.err(1109): at java.net.Socket.startupSocket(Socket.java:566)
09-23 01:17:00.668: WARN/System.err(1109): at java.net.Socket.tryAllAddresses(Socket.java:127)
09-23 01:17:00.668: WARN/System.err(1109): at java.net.Socket.<init>(Socket.java:177)
09-23 01:17:00.668: WARN/System.err(1109): at java.net.Socket.<init>(Socket.java:149)
09-23 01:17:00.668: WARN/System.err(1109): at me.nrubin29.quiz.student.Connection.initConnection(Connection.java:22)
09-23 01:17:00.688: WARN/System.err(1109): at me.nrubin29.quiz.student.Main$1.onClick(Main.java:35)
09-23 01:17:00.688: WARN/System.err(1109): at android.view.View.performClick(View.java:4204)
09-23 01:17:00.701: WARN/System.err(1109): at android.view.View$PerformClick.run(View.java:17355)
09-23 01:17:00.708: WARN/System.err(1109): at android.os.Handler.handleCallback(Handler.java:725)
09-23 01:17:00.708: WARN/System.err(1109): at android.os.Handler.dispatchMessage(Handler.java:92)
09-23 01:17:00.719: WARN/System.err(1109): at android.os.Looper.loop(Looper.java:137)
09-23 01:17:00.719: WARN/System.err(1109): at android.app.ActivityThread.main(ActivityThread.java:5041)
09-23 01:17:00.738: WARN/System.err(1109): at java.lang.reflect.Method.invokeNative(Native Method)
09-23 01:17:00.738: WARN/System.err(1109): at java.lang.reflect.Method.invoke(Method.java:511)
09-23 01:17:00.748: WARN/System.err(1109): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
09-23 01:17:00.748: WARN/System.err(1109): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
09-23 01:17:00.758: WARN/System.err(1109): at dalvik.system.NativeStart.main(Native Method)
09-23 01:17:00.908: INFO/Choreographer(613): Skipped 71 frames! The application may be doing too much work on its main thread.
更新3
将连接内容移动到新线程，但是当我单击完成按钮（第一个Toast没有显示）时，现在没有任何反应：
package me.nrubin29.quiz.student;
import android.app.Activity;
import android.widget.Toast;
import java.io.EOFException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
public class Connection {
private Socket socket;
private Thread reader;
private ObjectInputStream inputStream;
private ObjectOutputStream outputStream;
public void initConnection(final Activity activity, final String ip, final String port, final String name) {
new Thread(new Runnable() {
public void run() {
try {
Toast.makeText(activity.getApplicationContext(), "Starting connection to " + ip + ":" + Integer.parseInt(port), Toast.LENGTH_SHORT).show();
socket = new Socket(ip, Integer.parseInt(port));
Toast.makeText(activity.getApplicationContext(), "Connected!", Toast.LENGTH_SHORT).show();
outputStream = new ObjectOutputStream(socket.getOutputStream());
inputStream = new ObjectInputStream(socket.getInputStream());
outputStream.writeObject(name);
reader = new Thread(new Runnable() {
public void run() {
while (true) {
try {
Object in = inputStream.readObject();
System.out.println(in);
}
catch (EOFException e) { Toast.makeText(activity.getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show(); }
catch (Exception e) { e.printStackTrace(); }
}
}
});
reader.start();
}
catch (Exception e) { e.printStackTrace(); }
}
}).start();
}
}
看起来我们遇到了错误：
09-23 01:26:12.939: WARN/ActivityManager(308): Unbind failed: could not find connection for android.os.BinderProxy@40f246d0
09-23 01:26:26.028: WARN/System.err(1276): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
09-23 01:26:26.028: WARN/System.err(1276): at android.os.Handler.<init>(Handler.java:197)
09-23 01:26:26.028: WARN/System.err(1276): at android.os.Handler.<init>(Handler.java:111)
09-23 01:26:26.028: WARN/System.err(1276): at android.widget.Toast$TN.<init>(Toast.java:324)
09-23 01:26:26.059: WARN/System.err(1276): at android.widget.Toast.<init>(Toast.java:91)
09-23 01:26:26.059: WARN/System.err(1276): at android.widget.Toast.makeText(Toast.java:238)
09-23 01:26:26.059: WARN/System.err(1276): at me.nrubin29.quiz.student.Connection$1.run(Connection.java:22)
09-23 01:26:26.059: WARN/System.err(1276): at java.lang.Thread.run(Thread.java:856)
答案 0 :(得分：3)
它说＆＃34;权限被拒绝＆＃34;。您的清单文件中有<uses-permission android:name="android.permission.INTERNET"/>吗？
答案 1 :(得分：0)
此异常是因为您尝试从后台线程显示UI元素（Toast）。
您需要在UI线程中创建处理程序，然后从handler方法发布run消息。
类似这样的事情
在你的UI线程中：
final Handler handler = new Handler() {
@Override
public void handleMessage(final Message msgs) {
// Show toast here based on your Message.WHAT Parameter.
}
}
new Thread(new Runnable() {
@Override
public void run() {
handler.sendEmptyMessage(1);
}
}).start();