java - Android 应用程序作为 Web 服务的客户端

Question

这个问题已经有答案了:

已关闭 10 年前。

Possible Duplicate:
Android HttpClient : NetworkOnMainThreadException

我在创建一个 Android 应用程序时遇到了麻烦，该应用程序应该是 Web 服务的客户端
我已经用java(eclipse)创建了。
这确实很基本，但仍然不起作用..

网络服务类:

package com.ws;

public class Converter {

    public Converter () {
    }

    public String sayHello(String name) {
        return "Hello " + name + "!"; 
    }
}

Android 应用程序中的类:(我为此使用了 this 教程)

package MyConverter.Android;

import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class access extends Activity {

    private String METHOD_NAME = "";
    // our webservice method name
    private String NAMESPACE = "http://ws.com";
    // Here package name in webservice with reverse order.
    private String SOAP_ACTION = NAMESPACE + METHOD_NAME;
    // NAMESPACE + method name
    // private static final String URL =
    private static final String URL = "http://my-ip:8080/ConverterWebSrvice/services/Converter";

    // you must use ipaddress here, don’t use Hostname or localhost

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.access);

        Button b2 = (Button) findViewById(R.id.button2);
        b2.setOnClickListener(new OnClickListener(){ 
            public void onClick(View v){      
                ws();
            }});
        }

    public void ws() {
        String name = "Dan";

        METHOD_NAME = "sayHello";
        try {
            SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
            request.addProperty("name", name);
            SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(
                    SoapEnvelope.VER11);
            envelope.dotNet = true;
            envelope.setOutputSoapObject(request);
            HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
            androidHttpTransport.call(SOAP_ACTION, envelope);
            Object result = envelope.getResponse();
            ((TextView) findViewById(R.id.textView1)).setText(name
                    + " Longitude is : " + result.toString());

        } catch (Exception E) {
            E.printStackTrace();
            ((TextView) findViewById(R.id.textView1)).setText("ERROR:"
                    + E.getClass().getName() + ":" + E.getMessage());
        }
    }
}

这就是我运行整个过程的方式:
1.我为 Converter 项目执行“Run as > run on server”
2.我为应用程序项目执行“Run as > android application”

模拟器运行，当我按下按钮时，我收到了“不幸的是”消息。
在 LogCat(在 Eclipse 中)中，我看到以下消息:

10-19 22:29:41.250: W/System.err(643): android.os.NetworkOnMainThreadException
10-19 22:29:41.260: W/System.err(643):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
10-19 22:29:41.270: W/System.err(643):  at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
10-19 22:29:41.270: W/System.err(643):  at libcore.io.IoBridge.connectErrno(IoBridge.java:144)
10-19 22:29:41.270: W/System.err(643):  at libcore.io.IoBridge.connect(IoBridge.java:112)
10-19 22:29:41.270: W/System.err(643):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
10-19 22:29:41.280: W/System.err(643):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
10-19 22:29:41.280: W/System.err(643):  at java.net.Socket.connect(Socket.java:842)
10-19 22:29:41.290: W/System.err(643):  at libcore.net.http.HttpConnection.<init>(HttpConnection.java:76)
10-19 22:29:41.290: W/System.err(643):  at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
10-19 22:29:41.300: W/System.err(643):  at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:341)
10-19 22:29:41.300: W/System.err(643):  at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
10-19 22:29:41.300: W/System.err(643):  at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
10-19 22:29:41.300: W/System.err(643):  at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:315)
10-19 22:29:41.310: W/System.err(643):  at libcore.net.http.HttpEngine.connect(HttpEngine.java:310)
10-19 22:29:41.310: W/System.err(643):  at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
10-19 22:29:41.320: W/System.err(643):  at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239)
10-19 22:29:41.320: W/System.err(643):  at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:80)
10-19 22:29:41.320: W/System.err(643):  at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:188)
10-19 22:29:41.330: W/System.err(643):  at org.ksoap2.transport.ServiceConnectionSE.openOutputStream(ServiceConnectionSE.java:109)
10-19 22:29:41.330: W/System.err(643):  at org.ksoap2.transport.HttpTransportSE.call(HttpTransportSE.java:157)
10-19 22:29:41.350: W/System.err(643):  at org.ksoap2.transport.HttpTransportSE.call(HttpTransportSE.java:96)
10-19 22:29:41.350: W/System.err(643):  at MyConverter.Android.access.ws(access.java:53)
10-19 22:29:41.350: W/System.err(643):  at MyConverter.Android.access$1.onClick(access.java:37)
10-19 22:29:41.360: W/System.err(643):  at android.view.View.performClick(View.java:4084)
10-19 22:29:41.360: W/System.err(643):  at android.view.View$PerformClick.run(View.java:16966)
10-19 22:29:41.370: W/System.err(643):  at android.os.Handler.handleCallback(Handler.java:615)
10-19 22:29:41.380: W/System.err(643):  at android.os.Handler.dispatchMessage(Handler.java:92)
10-19 22:29:41.390: W/System.err(643):  at android.os.Looper.loop(Looper.java:137)
10-19 22:29:41.390: W/System.err(643):  at android.app.ActivityThread.main(ActivityThread.java:4745)
10-19 22:29:41.402: W/System.err(643):  at java.lang.reflect.Method.invokeNative(Native Method)
10-19 22:29:41.402: W/System.err(643):  at java.lang.reflect.Method.invoke(Method.java:511)
10-19 22:29:41.410: W/System.err(643):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-19 22:29:41.410: W/System.err(643):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-19 22:29:41.410: W/System.err(643):  at dalvik.system.NativeStart.main(Native Method)
10-19 22:29:41.420: D/AndroidRuntime(643): Shutting down VM
10-19 22:29:41.420: W/dalvikvm(643): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
10-19 22:29:41.450: E/AndroidRuntime(643): FATAL EXCEPTION: main
10-19 22:29:41.450: E/AndroidRuntime(643): java.lang.NullPointerException
10-19 22:29:41.450: E/AndroidRuntime(643):  at MyConverter.Android.access.ws(access.java:60)
10-19 22:29:41.450: E/AndroidRuntime(643):  at MyConverter.Android.access$1.onClick(access.java:37)
10-19 22:29:41.450: E/AndroidRuntime(643):  at android.view.View.performClick(View.java:4084)
10-19 22:29:41.450: E/AndroidRuntime(643):  at android.view.View$PerformClick.run(View.java:16966)
10-19 22:29:41.450: E/AndroidRuntime(643):  at android.os.Handler.handleCallback(Handler.java:615)
10-19 22:29:41.450: E/AndroidRuntime(643):  at android.os.Handler.dispatchMessage(Handler.java:92)
10-19 22:29:41.450: E/AndroidRuntime(643):  at android.os.Looper.loop(Looper.java:137)
10-19 22:29:41.450: E/AndroidRuntime(643):  at android.app.ActivityThread.main(ActivityThread.java:4745)
10-19 22:29:41.450: E/AndroidRuntime(643):  at java.lang.reflect.Method.invokeNative(Native Method)
10-19 22:29:41.450: E/AndroidRuntime(643):  at java.lang.reflect.Method.invoke(Method.java:511)
10-19 22:29:41.450: E/AndroidRuntime(643):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-19 22:29:41.450: E/AndroidRuntime(643):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-19 22:29:41.450: E/AndroidRuntime(643):  at dalvik.system.NativeStart.main(Native Method)
10-19 22:29:44.060: I/Process(643): Sending signal. PID: 643 SIG: 9

如有任何帮助，我们将不胜感激!

Answer 1

最基本的问题是您试图在 UI 线程上进行网络访问，这在 Android 中是不允许的。您可能应该查找 AsyncTask 的文档，并使用它来进行网络连接。

本教程似乎与您的问题密切相关: http://www.vogella.com/articles/AndroidPerformance/article.html