Question

我的Web服务应该返回一个整数，但每次运行代码时都会出现NullPointerException错误。任何想法或帮助将非常感激

这是我的代码：

public class CGCountTest extends Activity {

    TextView testTV;

    private static final String NAMESPACE = "http://passport-america.com/webservices/";
    private static final String URL = "http://localhost:11746/Service1.asmx";
    private static final String SOAP_ACTION = "http://www.passport-america.com/webservices/getCGCount";
    private static final String METHOD_NAME = "getCGCount";

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

          SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
            SoapSerializationEnvelope envelope =
                new SoapSerializationEnvelope(SoapEnvelope.VER11);
                envelope.dotNet = true;
                envelope.setOutputSoapObject(request);
                HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);

                try {
                    androidHttpTransport.call(SOAP_ACTION, envelope);
                    java.lang.Integer result = (Integer)envelope.getResponse();
                    TextView testTV = (TextView)findViewById(R.id.testTV);
                    result.toString();
                    testTV.setText(result);
                }
                catch(Exception e)
                {
                    testTV.setText(e.getMessage());
                }
    }

这是logcat

06-02 15:13:36.557: WARN/dalvikvm(326): threadid=3: thread exiting with uncaught exception (group=0x4001aa28)
06-02 15:13:36.557: ERROR/AndroidRuntime(326): Uncaught handler: thread main exiting due to uncaught exception
06-02 15:13:36.876: ERROR/AndroidRuntime(326): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.pa.passammain/com.pa.passammain.CGCountTest}: java.lang.NullPointerException
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2417)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.app.ActivityThread.access$2100(ActivityThread.java:116)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.os.Handler.dispatchMessage(Handler.java:99)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.os.Looper.loop(Looper.java:123)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.app.ActivityThread.main(ActivityThread.java:4203)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at java.lang.reflect.Method.invokeNative(Native Method)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at java.lang.reflect.Method.invoke(Method.java:521)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at dalvik.system.NativeStart.main(Native Method)
06-02 15:13:36.876: ERROR/AndroidRuntime(326): Caused by: java.lang.NullPointerException
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at com.pa.passammain.CGCountTest.onCreate(CGCountTest.java:46)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
06-02 15:13:36.876: ERROR/AndroidRuntime(326):     ... 11 more

我认为我的网址字符串可能是问题，但我尝试使用我的网络没有运气

Answer 1

这不是您的URL字符串（可能不是正确，但它是一个有效的字符串），您正在使用的一个函数调用将null作为输入参数之一。最有可能的原因是，您尝试执行返回null的操作，然后在另一个方法调用中使用该值。

我不知道你在代码的第326行有什么，但是我打赌其中一个对象是null，所以我先开始检查它。

如果你想粘贴第326行，我将能够进一步提供帮助。

Answer 2

我已经处理过类似的情况，下面的代码正在运行，没有任何错误。

        String NAMESPACE = "http://tempuri.org/";
        String METHOD_NAME = "getOutletCount";
        String SOAP_ACTION = "http://tempuri.org/getOutletCount";
        String URL = "http://10.20.10.80/dinotawebsrv/GetDataWebService.asmx";

        SoapObject Request = new SoapObject(NAMESPACE, METHOD_NAME);

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

        AndroidHttpTransport androidHttpTransport = new AndroidHttpTransport(
                URL);

        androidHttpTransport.call(SOAP_ACTION, envelope);
        System.out.println("web service call completed......");
        SoapPrimitive response = (SoapPrimitive) envelope.getResponse();

        return Integer.parseInt(response.toString());

尝试调试它，检查是否得到任何响应结果，我认为你不能直接将响应转换为Integer。祝你好运..

尝试使用kSoap方法Android连接到Web服务时出现NullPointerException

2 个答案: