在數據傳遞和遠程調用過程中，有時候調用者傳遞錯誤的數據和是調用的方法錯誤。在Web Service中，不可避免地也會出現這些異常信息，那么我們怎樣處理這些異常信息呢?本文就向大家介紹下Web Service處理異常信息方法。

1、編寫服務器端的異常類，在遠處調用中(WebService)異常類繼承RemoteException，記得要序列化下，代碼如下：

package com.hoo.exception;

import java.rmi.RemoteException;

/**

* function:定制服務器端異常信息

* @author hoojo

* @createDate Dec 17, 2010 00:00:52 AM

* @file RemoteServerException.java

* @package com.hoo.exception

* @project AxisWebService

* @blog http://blog.csdn.net/IBM_hoojo

* @email [email protected]

* @version 1.0

*/

public class RemoteServerException extends RemoteException {

private static final long serialVersionUID = 1L;

private String message;

public String getMessage() {

return message;

}

public void setMessage(String message) {

this.message = message;

}

public RemoteServerException() {

System.out.println("Remote Servier Exception ");

}

public void showMessage() {

System.out.println(this.message);

}

}

2、編寫客戶端的異常信息類，和前面遠程傳遞對象一樣。因為我們并不知道服務器端的異常信息類代碼，但是通過wsdl的xml文件的描述我們可以知道遠程異常類的基本信息：方法、方法參數、返回值等信息，下面是客戶端的異常信息類代碼：

package com.hoo.exception;

import java.rmi.RemoteException;

/**

* function:本地客戶端異常信息

* @author hoojo

* @createDate Dec 17, 2010 00:05:30 AM

* @file LocalClientException.java

* @package com.hoo.exception

* @project AxisWebService

* @blog http://blog.csdn.net/IBM_hoojo

* @email [email protected]

* @version 1.0

*/

public class LocalClientException extends RemoteException {

private static final long serialVersionUID = 3;

private String message;

public String getMessage() {

return message;

}

public void setMessage(String message) {

this.message = message;

}

public LocalClientException() {

System.out.println("Local Client Exception ");

}

public void showMessage() {

System.out.println(this.message);

}

}

內容幾乎一樣，就是類名稱不同。

3、編寫觸發異常的WebService服務器端代碼

package com.hoo.service;

import com.hoo.exception.RemoteServerException;

/**

* function:發出異常信息

* @author hoojo

* @createDate Dec 17, 2010 00:08:07 AM

* @file ThrowException.java

* @package com.hoo.service

* @project AxisWebService

* @blog http://blog.csdn.net/IBM_hoojo

* @email [email protected]

* @version 1.0

*/

public class ThrowException {

public void doException() throws RemoteServerException {

RemoteServerException rse = new RemoteServerException();

rse.setMessage("服務器端出現異常");

throw rse;

}

}

4、定制wsdd文件，發布當前WebService。

<deployment xmlns="http://xml.apache.org/axis/wsdd/" p="" <="">

xmlns:java="http://xml.apache.org/axis/wsdd/providers/java">

deserializer="org.apache.axis.encoding.ser.BeanDeserializerFactory" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>

5、用定制好的wsdd文件發布我們的WebService，依舊是命令行：

C:\SoftWare\tomcat-5.0.28\tomcat-5.0.28\webapps\AxisWebService\WEB-INF>java -Djava.ext.dirs=lib org.apache.axis.client.AdminClient -lhttp://localhost:8080/AxisWebService/services/AdminService deployException.wsdd

發布完成后，在瀏覽器中輸入：

http://localhost:8080/AxisWebService/servlet/AxisServlet

即可查看剛才發布的服務信息，但是你點擊wsdl鏈接的時候并不能看到xml的內容，那是因為服務器端拋出了異常導致的。這個不是錯誤是正常的，不過你可以在web.xml中配置異常的信息頁面。

6、編寫客戶端代碼，這里的代碼和傳遞對象的WebService也很類似

package com.hoo.client;

import java.rmi.RemoteException;

import javax.xml.namespace.QName;

import javax.xml.rpc.ServiceException;

import org.apache.axis.client.Call;

import org.apache.axis.client.Service;

import org.apache.axis.encoding.ser.BeanDeserializerFactory;

import org.apache.axis.encoding.ser.BeanSerializerFactory;

import com.hoo.exception.LocalClientException;

import com.hoo.exception.RemoteServerException;

public class TryExceptionClient {

/**

* function:捕捉服務器端異常信息的WebService的客戶端

* @author hoojo

* @createDate Dec 17, 2010 00:12:56 AM

* @param args

* @throws ServiceException

* @throws RemoteException

*/

public static void main(String[] args) {

String url = "http://localhost:8080/AxisWebService/services/ThrowException";

Service service = new Service();

try {

Call call = (Call) service.createCall();

/**

* 注冊異常類信息和序列化類

* ns:CustomException 和 wsdd 配置文件中的typeMapping中的xmlns:myNSD="ns:CustomException"的對應

* Exception 和 wsdd 配置文件中的typeMapping中的qname="myNSD:Exception"的Exception對應

*/

QName qn = new QName("ns:CustomException", "Exception");

/**

* 這里配置的LocalClientException，會將服務器端的RemoteServerException轉換成本地的異常信息LocalClientException

*/

call.registerTypeMapping(LocalClientException.class, qn,

new BeanSerializerFactory(LocalClientException.class,qn),

new BeanDeserializerFactory(LocalClientException.class, qn));

call.setOperationName(new QName(url, "doException"));

call.setTargetEndpointAddress(url);

call.invoke(new Object[]{});

} catch (RemoteServerException e) {

e.showMessage();

System.out.println("RemoteServerException:" + e.getMessage());

e.printStackTrace();

} catch (LocalClientException e) {

e.showMessage();

System.out.println("LocalClientException:" + e.getMessage());

e.printStackTrace();

} catch (RemoteException e) {

System.out.println("RemoteException:" + e.getMessage());

e.printStackTrace();

} catch (ServiceException e) {

System.out.println("ServiceException:" + e.getMessage());

e.printStackTrace();

}

}

}

看上面的registerTypeMapping和wsdd文件中的typeMapping有些相同之處吧，下面運行下上面的代碼，結果如下：

Local Client Exception

服務器端出現異常

LocalClientException:服務器端出現異常

com.hoo.exception.LocalClientException: 服務器端出現異常

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

at java.lang.Class.newInstance0(Unknown Source)

at java.lang.Class.newInstance(Unknown Source)

at org.apache.axis.encoding.ser.BeanDeserializer.(BeanDeserializer.java:104)

at org.apache.axis.encoding.ser.BeanDeserializerFactory.getGeneralPurpose(BeanDeserializerFactory.java:89)

at org.apache.axis.encoding.ser.BaseDeserializerFactory.getDeserializerAs(BaseDeserializerFactory.java:89)

at org.apache.axis.encoding.DeserializationContext.getDeserializer(DeserializationContext.java:464)

at org.apache.axis.encoding.DeserializationContext.getDeserializerForType(DeserializationContext.java:547)

at org.apache.axis.message.SOAPFaultDetailsBuilder.onStartChild(SOAPFaultDetailsBuilder.java:157)

at org.apache.axis.encoding.DeserializationContext.startElement(DeserializationContext.java:1035)

at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(Unknown Source)

at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)

at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)

at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)

at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)

at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)

at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)

at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)

at javax.xml.parsers.SAXParser.parse(Unknown Source)

at org.apache.axis.encoding.DeserializationContext.parse(DeserializationContext.java:227)

at org.apache.axis.SOAPPart.getAsSOAPEnvelope(SOAPPart.java:696)

at org.apache.axis.Message.getSOAPEnvelope(Message.java:435)

at org.apache.axis.handlers.soap.MustUnderstandChecker.invoke(MustUnderstandChecker.java:62)

at org.apache.axis.client.AxisClient.invoke(AxisClient.java:206)

at org.apache.axis.client.Call.invokeEngine(Call.java:2784)

at org.apache.axis.client.Call.invoke(Call.java:2767)

at org.apache.axis.client.Call.invoke(Call.java:2443)

at org.apache.axis.client.Call.invoke(Call.java:2366)

at org.apache.axis.client.Call.invoke(Call.java:1812)

at com.hoo.client.TryExceptionClient.main(TryExceptionClient.java:44)

服務器端控制臺會輸出：Remote Servier Exception

這是在創建異常的時候，在構造函數中輸出的。

相信小伙伴們在看完本文后，能夠掌握這些Web Service處理異常信息方法，能夠更好地處理在使用Web Service時的一些日常異常問題，得到更好的編程體驗。