android - 从 android 调用 web 服务的示例应用程序返回错误 "Unfortunately,MyTest has stopped"

Question

我有一个代码，可以调用 www,tempuri.org 提供的网络服务。当我尝试运行该应用程序时，该应用程序意外停止并显示消息 - “不幸的是，MyTest 已停止”。这是我的 java 文件 -

主要 Activity .java :-

package com.example.mytest;


import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapPrimitive;
import org.ksoap2.serialization.SoapSerializationEnvelope;

import org.ksoap2.transport.HttpTransportSE;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {
    public static final String SOAP_ACTION = "http://tempuri.org/CelciusToFarenheit";
    public static final String METHOD_NAME = "CelciusToFarenheit";
    public static final String NAMESPACE= "http://tempuri.org/";
    public static final String URL = "http://www.w3schools.com/webservices/tempconvert.asmx";
    TextView tv;
    SoapEnvelope se;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv= (TextView) findViewById(R.id.TextView01);

        SoapObject Request=new SoapObject(NAMESPACE,METHOD_NAME);
        Request.addProperty("Celcius","32");
        SoapSerializationEnvelope sse = new SoapSerializationEnvelope (se.VER11);
        sse.dotNet=true;
        sse.setOutputSoapObject(Request);
        HttpTransportSE abt = new HttpTransportSE(URL);
        try
        {
            abt.call(SOAP_ACTION,se);
              SoapObject resultString=(SoapObject)sse.getResponse();   
              String resultData=resultString.getProperty(0).toString();

            tv.setText("Status :"+resultString);
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }





    }

    @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;
    }

}

activity_main.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=".MainActivity" >

    <TextView
        android:id="@+id/TextView01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>

logcat如下——

08-10 01:35:10.421: E/AndroidRuntime(1077): FATAL EXCEPTION: main
08-10 01:35:10.421: E/AndroidRuntime(1077): java.lang.NoClassDefFoundError: org.ksoap2.serialization.SoapObject
08-10 01:35:10.421: E/AndroidRuntime(1077):     at com.example.mytest.MainActivity.onCreate(MainActivity.java:30)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.app.Activity.performCreate(Activity.java:5133)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.os.Looper.loop(Looper.java:137)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at android.app.ActivityThread.main(ActivityThread.java:5103)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at java.lang.reflect.Method.invokeNative(Native Method)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at java.lang.reflect.Method.invoke(Method.java:525)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
08-10 01:35:10.421: E/AndroidRuntime(1077):     at dalvik.system.NativeStart.main(Native Method)

我刚开始使用 android 开发 Web 服务。你能建议我如何处理吗？

Answer 1

像这样使用:

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" >

<Button
    android:id="@+id/web_service"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_marginLeft="112dp"
    android:layout_marginTop="146dp"
    android:text="Web Service" />

<TextView
    android:id="@+id/fetch"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="TextView" />

  </RelativeLayout>

Activity :

  public class MainActivity extends Activity {

Button web_service;
TextView fetch_service;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    fetch_service = (TextView) findViewById(R.id.fetch);
    web_service = (Button) findViewById(R.id.web_service);
    web_service.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            myasynctask MAT = new myasynctask();
            MAT.execute();
        }
    });
}

class myasynctask extends AsyncTask<String, Void, String> {

    String str;
    private static final String SOAP_ACTION = "http://tempuri.org/CelsiusToFahrenheit";
    private static final String METHOD_NAME = "CelsiusToFahrenheit";
    private static final String NAMESPACE = "http://tempuri.org/";
    private static final String URL = "http://www.w3schools.com/webservices/tempconvert.asmx";

    @Override
    protected String doInBackground(String... params) {
        SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
        request.addProperty("Celsius", "32");

        SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(
                SoapEnvelope.VER11);
        envelope.dotNet = true;
        envelope.setOutputSoapObject(request);

        HttpTransportSE ht = new HttpTransportSE(URL);

        try {
            ht.call(SOAP_ACTION, envelope);
            final SoapPrimitive response = (SoapPrimitive) envelope
                    .getResponse();
            str = response.toString();

        } catch (Exception e) {
            e.printStackTrace();

        }
        Log.d("WebRespone", str);
        return str;
    }

    @Override
    public void onPostExecute(String result) {
        // TODO Auto-generated method stub
        Toast.makeText(MainActivity.this, result, Toast.LENGTH_LONG).show();
        fetch_service.setText(result);
        super.onPostExecute(result);
    }

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
    }

}
    }

list :在您的 list 中添加以下内容

 <uses-permission android:name="android.permission.INTERNET"/>

输出:

希望对您有所帮助。