Struts1 声明式异常

 

1、创建自定义异常，代码如下：

package com.bjpowernode.struts;

public class ErrorCodeException extends RuntimeException {

	private static final long serialVersionUID = 1L;
	private String errCode;
	private Object args[];
	public ErrorCodeException(String errCode, Object[] args) {
		this.errCode = errCode;
		this.args = args;
	}
	
	public ErrorCodeException(String errCode, Object args) {
		this(errCode,new Object[]{args});
	}
	
	public ErrorCodeException(String errCode) {
		this(errCode,null);
	}

	public String getErrCode() {
		return errCode;
	}

	public Object[] getArgs() {
		return args;
	}
	
	
	

}

 

2、创建自定义异常处理类：

 

package com.bjpowernode.struts;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.Globals;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ExceptionHandler;
import org.apache.struts.config.ExceptionConfig;
import org.apache.struts.util.ModuleException;

public class ErrorCodeExceptionHandler extends ExceptionHandler {

	public ErrorCodeExceptionHandler() {
	}
	
	
	public ActionForward execute(
	        Exception ex,
	        ExceptionConfig ae,
	        ActionMapping mapping,
	        ActionForm formInstance,
	        HttpServletRequest request,
	        HttpServletResponse response)
	        throws ServletException {

	        ActionForward forward = null;
	        ActionMessage error = null;
	        String property = null;

	        if(!(ex instanceof ErrorCodeException)){
	        	return super.execute(ex, ae, mapping, formInstance, request, response);
	        }
	        
	        // Build the forward from the exception mapping if it exists
	        // or from the form input
	        if (ae.getPath() != null) {
	            forward = new ActionForward(ae.getPath());
	        } else {
	            forward = mapping.getInputForward();
	        }

	        // Figure out the error
	        if (ex instanceof ModuleException) {
	            error = ((ModuleException) ex).getActionMessage();
	            property = ((ModuleException) ex).getProperty();
	        } else {
//	            error = new ActionMessage(ae.getKey(), ex.getMessage());
	        	ErrorCodeException ece=(ErrorCodeException) ex;
	            error = new ActionMessage(ece.getErrCode(), ece.getArgs());
	            property = error.getKey();
	        }

	        this.logException(ex);

	        // Store the exception
	        request.setAttribute(Globals.EXCEPTION_KEY, ex);
	        this.storeException(request, property, error, forward, ae.getScope());

	        return forward;

	    }

}

 

 

3、在struts-config.xml中配置一个全局的异常配置分别指向自定义异常和自定义异常处理类：

<global-exceptions>
		<exception key=""
			type="com.bjpowernode.struts.ErrorCodeException" handler="com.bjpowernode.struts.ErrorCodeExceptionHandler">
		</exception>
	</global-exceptions>

 

4、注意在service层抛出的异常种类一定要是自己定义的ErrorCodeException，代码如下：

 

package com.bjpowernode.struts;

public class UserManager {

	public void login(String username, String password) {
		if (!"admin".equals(username)) {
			throw new ErrorCodeException("login.user.not.found",new Object[]{username,username});
		}
		if (!"admin".equals(password)) {
			throw new ErrorCodeException("login.password.error");
		}
	}
}

 

这样的话，大功告成。