com.opensymphony.xwork.interceptor
Class ExceptionMappingInterceptor
java.lang.Object
 com.opensymphony.xwork.interceptor.ExceptionMappingInterceptor
- All Implemented Interfaces:
- Interceptor, Serializable
public class ExceptionMappingInterceptor - extends Object
- implements Interceptor
This interceptor forms the core functionality of the exception handling feature. Exception handling allows you to map
an exception to a result code, just as if the action returned a result code instead of throwing an unexpected
exception. When an exception is encountered, it is wrapped with an ExceptionHolder and pushed on the stack,
providing easy access to the exception from within your result.
Note: While you can configure exception mapping in your configuration file at any point, the configuration
will not have any effect if this interceptor is not in the interceptor stack for your actions. It is recommended that
you make this interceptor the first interceptor on the stack, ensuring that it has full access to catch any
exception, even those caused by other interceptors.
Interceptor parameters:
- logEnabled (optional) - Should exceptions also be logged? (boolean true|false)
- logLevel (optional) - what log level should we use (
trace, debug, info, warn, error, fatal)? - defaut is debug
- logCategory (optional) - If provided we would use this category (eg.
com.mycompany.app).
Default is to use com.opensymphony.xwork.interceptor.ExceptionMappingInterceptor.
The parameters above enables us to log all thrown exceptions with stacktace in our own logfile,
and present a friendly webpage (with no stacktrace) to the end user.
Extending the interceptor:
If you want to add custom handling for publishing the Exception, you may override
publishException(com.opensymphony.xwork.ActionInvocation, ExceptionHolder). The default implementation
pushes the given ExceptionHolder on value stack. A custom implementation could add additional logging etc.
Example code:
<xwork>
<include file="webwork-default.xml"/>
<package name="default" extends="webwork-default">
<global-results>
<result name="success" type="freemarker">error.ftl</result>
</global-results>
<global-exception-mappings>
<exception-mapping exception="java.lang.Exception" result="error"/>
</global-exception-mappings>
<action name="test">
<interceptor-ref name="exception"/>
<interceptor-ref name="basicStack"/>
<exception-mapping exception="com.acme.CustomException" result="custom_error"/>
<result name="custom_error">custom_error.ftl</result>
<result name="success" type="freemarker">test.ftl</result>
</action>
</package>
</xwork>
This second example will also log the exceptions using our own category
com.mycompany.app.unhandled at WARN level.
<xwork>
<include file="webwork-default.xml"/>
<package name="something" extends="webwork-default">
<interceptors>
<interceptor-stack name="exceptionmapping-stack">
<interceptor-ref name="exception">
<param name="logEnabled">true</param>
<param name="logCategory">com.mycompany.app.unhandled</param>
<param name="logLevel">WARN</param>
</interceptor-ref>
<interceptor-ref name="i18n"/>
<interceptor-ref name="static-params"/>
<interceptor-ref name="params"/>
<interceptor-ref name="validation">
<param name="excludeMethods">input,back,cancel,browse</param>
</interceptor-ref>
</interceptor-stack>
</interceptors>
<default-interceptor-ref name="exceptionmapping-stack"/>
<global-results>
<result name="unhandledException">/unhandled-exception.jsp</result>
</global-results>
<global-exception-mappings>
<exception-mapping exception="java.lang.Exception" result="unhandledException"/>
</global-exception-mappings>
<action name="exceptionDemo" class="com.opensymphony.webwork.showcase.exceptionmapping.ExceptionMappingAction">
<exception-mapping exception="com.opensymphony.webwork.showcase.exceptionmapping.ExceptionMappingException"
result="damm"/>
<result name="input">index.jsp</result>
<result name="success">success.jsp</result>
<result name="damm">damm.jsp</result>
</action>
</package>
</xwork>
- Author:
- Matthew E. Porter (matthew dot porter at metissian dot com), Claus Ibsen
- See Also:
- Serialized Form
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
log
protected static final org.apache.commons.logging.Log log
categoryLogger
protected org.apache.commons.logging.Log categoryLogger
logEnabled
protected boolean logEnabled
logCategory
protected String logCategory
logLevel
protected String logLevel
ExceptionMappingInterceptor
public ExceptionMappingInterceptor()
isLogEnabled
public boolean isLogEnabled()
setLogEnabled
public void setLogEnabled(boolean logEnabled)
getLogCategory
public String getLogCategory()
setLogCategory
public void setLogCategory(String logCatgory)
getLogLevel
public String getLogLevel()
setLogLevel
public void setLogLevel(String logLevel)
destroy
public void destroy()
- Description copied from interface:
Interceptor
- Called to let an interceptor clean up any resources it has allocated.
- Specified by:
destroy in interface Interceptor
init
public void init()
- Description copied from interface:
Interceptor
- Called after an interceptor is created, but before any requests are processed using
intercept , giving
the Interceptor a chance to initialize any needed resources.
- Specified by:
init in interface Interceptor
intercept
public String intercept(ActionInvocation invocation)
throws Exception
- Description copied from interface:
Interceptor
- Allows the Interceptor to do some processing on the request before and/or after the rest of the processing of the
request by the
ActionInvocation or to short-circuit the processing and just return a String return code.
- Specified by:
intercept in interface Interceptor
- Returns:
- the return code, either returned from
ActionInvocation.invoke(), or from the interceptor itself.
- Throws:
Exception - any system-level error, as defined in Action.execute().
handleLogging
protected void handleLogging(Exception e)
- Handles the logging of the exception.
- Parameters:
e - the exception to log.
doLog
protected void doLog(org.apache.commons.logging.Log logger,
Exception e)
- Performs the actual logging.
- Parameters:
logger - the provided logger to use.e - the exception to log.
getDepth
public int getDepth(String exceptionMapping,
Throwable t)
- Return the depth to the superclass matching. 0 means ex matches exactly. Returns -1 if there's no match.
Otherwise, returns depth. Lowest depth wins.
- Parameters:
exceptionMapping - the mapping classnamet - the cause
- Returns:
- the depth, if not found -1 is returned.
publishException
protected void publishException(ActionInvocation invocation,
ExceptionHolder exceptionHolder)
- Default implementation to handle ExceptionHolder publishing. Pushes given ExceptionHolder on the stack.
Subclasses may override this to customize publishing.
- Parameters:
invocation - The invocation to publish Exception for.exceptionHolder - The exceptionHolder wrapping the Exception to publish.
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