CXF之五（异常处理）

     在CXF中默认的异常处理是无法满足开发需求，经常需要把异常信息转换为JSON或者XML格式，返回给客户的，这样就只能自定义异常处理了。

    在对外提供接口的时候，如果出现异常，一般会通过JSON或XML将异常码及异常信息反回给客户，这在CXF中也很容易实现。

第一步：编写自己的异常处理类 InvokeFaultExceptionMapper 

@Provider
public class InvokeFaultExceptionMapper implements ExceptionMapper {

	public Response toResponse(Throwable ex) {
		 StackTraceElement[] trace = new StackTraceElement[1];
	        trace[0] = ex.getStackTrace()[0];
	        ex.setStackTrace(trace);
	        ResponseBuilder rb = Response.status(Response.Status.INTERNAL_SERVER_ERROR);
	        rb.type("application/json;charset=UTF-8");
	        rb.entity(ex);
	        rb.language(Locale.SIMPLIFIED_CHINESE);
	        Response r = rb.build();
	        return r;
	}

}

第二部：加载InvokeFaultExceptionMapper

<jaxrs:server id="expGateway" address="/expGateway">
		<jaxrs:inInterceptors>
		   <ref bean="inMessageInterceptor"/>
		</jaxrs:inInterceptors>
		<jaxrs:outInterceptors>
		    <ref bean="outMessageInterceptor"/>
		</jaxrs:outInterceptors>
		<jaxrs:serviceBeans>
			<ref bean="expGatewayImpl" />
		</jaxrs:serviceBeans>
		<jaxrs:extensionMappings>
			<entry key="json" value="application/json" />
			<entry key="xml" value="application/xml" />
		</jaxrs:extensionMappings>
		<jaxrs:languageMappings>
			<entry key="en" value="en-gb" />
		</jaxrs:languageMappings>
		<jaxrs:providers>
            <bean class="org.codehaus.jackson.jaxrs.JacksonJsonProvider"/>
            <bean class="com.pml.service.outer.InvokeFaultExceptionMapper"/>
        </jaxrs:providers>
	</jaxrs:server>

第三步：测试

   在你的接口中跑出异常试一试，结果如下

{"operate":null,"errCode":0,"errSubCode":"err.001","cause":null,"message":"ID值异常！","localizedMessage":"ID值异常！","stackTrace":[{"className":"com.pml.service.outer.ExpGatewayImpl","fileName":"ExpGatewayImpl.java","lineNumber":59,"methodName":"getUser","nativeMethod":false}]}

 

二、在深入些

         看到上面异常返回的接口，发现很多一部分内容是无用，真正想给客户端只有     errCode":0,"errSubCode":"err.001“ ,"message":"ID值异常！"这部分内容。那我们对异常返回的内容进行过滤一下：

  第一步：修改InvokeFaultExceptionMapper.java

@Provider
public class InvokeFaultExceptionMapper implements ExceptionMapper {

	public Response toResponse(Throwable ex) {
		 StackTraceElement[] trace = new StackTraceElement[1];
	        trace[0] = ex.getStackTrace()[0];
	        ex.setStackTrace(trace);
	        ResponseBuilder rb = Response.status(Response.Status.INTERNAL_SERVER_ERROR);
	        rb.type("application/json;charset=UTF-8");
	        if (ex instanceof ServiceException) {//自定义的异常类
	        	ServiceException e = (ServiceException) ex;
	        	ServiceExceptionEntity entity=new ServiceExceptionEntity(e.getErrCode(),e.getErrSubCode(),e.getMessage());
			    rb.entity(entity);
	        }else{
	        	rb.entity(ex);
	        }
	        rb.language(Locale.SIMPLIFIED_CHINESE);
	        Response r = rb.build();
	        return r;
	}

}

 其实增加了下面这部分代码

    

if (ex instanceof ServiceException) {//自定义的异常类
   ServiceException e = (ServiceException) ex;
   ServiceExceptionEntity entity=new ServiceExceptionEntity(e.getErrCode(),e.getErrSubCode(),e.getMessage());
    rb.entity(entity);
}else{
   rb.entity(ex);
 }

    多了对自定义异常的类型判断，如果是ServiceException异常，则进行处理，非ServiceException则进行走原路。（ServiceException是系统的自定义异常类，有三个属性（int errCode,String errSubCode,String message））

 

  添加的代码中了ServiceExceptionEntity类，该类的代码如下

public class ServiceExceptionEntity implements Serializable {
	/**
	 * 注释内容
	 */
	private static final long serialVersionUID = 1L;

	public ServiceExceptionEntity(){}
	
	public ServiceExceptionEntity(int errCode, String errSubCode, String message) {
		super();
		this.errCode = errCode;
		this.errSubCode = errSubCode;
		this.message = message;
	}
	
	/*错误码，默认为0*/
	private int errCode;
	
	/*错误子码，自定义该值*/
	private String errSubCode;
	
	private String message;

	public int getErrCode() {
		return errCode;
	}

	public void setErrCode(int errCode) {
		this.errCode = errCode;
	}

	public String getErrSubCode() {
		return errSubCode;
	}

	public void setErrSubCode(String errSubCode) {
		this.errSubCode = errSubCode;
	}

	public String getMessage() {
		return message;
	}

	public void setMessage(String message) {
		this.message = message;
	}
}

   

第二步：再在代码中抛出ServiceException异常，看下返回给客户端的代码是否为下面的几项

{"errCode":0,"errSubCode":"err.001","message":"ID值异常！","localizedMessage":"ID值异常！"}

添加的代码只对自定义的ServiceExceptino异常进行了处理，当然你还可以更多的异常处理。