Handling Exception In Spring Standalone Application - spring

Question

i have created Standalone application in spring.
for exception handling i am using custom exception handler which extends SimpleMappingExceptionResolver class.
whenever exception occurs in program i want to delegate it to specific java method.
how do i do that ?
i saw lots of examples on the net, but everywhere exception handling done on .jsp page.
how i catch the exception in java method.
here is my bean config file
<bean class="com.ys.core.exception.ExceptionHandler">
<property name="exceptionMappings">
<props>
<prop key="com.ys.core.exception.MyException">ExceptionHandler</prop>
<prop key="java.lang.Exception">ExceptionHandler</prop>
<prop key="java.lang.ArithmeticException">ExceptionHandler</prop>
</props>
</property>
</bean>
<bean id="exceptionHandler" class="com.ys.core.exception.ExceptionHandler" />
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/com/ys/core/service/myservices" />
<property name="suffix" value=".java" />
</bean>
can i do like this ?
means call .java class instead of jsp file ?

Answer 1

ExceptionProcessorAspect : It's an after throwing aspect which is handling a Pointcut with annotation : ExceptionAnnotation
In side the #AfterThrowing handler, exception Processor is triggered which is based on the Command Pattern
#AfterThrowing(pointcut = "getExceptionPointcut()", throwing ="error")
public void processor(JoinPoint call,Throwable error){
if(null!=call){
MethodSignature signature = (MethodSignature) call.getSignature();
Method method = signature.getMethod();
ExceptionAnnotation myAnnotation = method.getAnnotation(ExceptionAnnotation.class);
Class<?> value = myAnnotation.value();
AbstractExceptionProcessor exceptionProcessor = (AbstractExceptionProcessor)this.exceptionMap.get(value);
exceptionProcessor.processException(error);
}
}
Other classes are the supporting components that make up an #AfterThrwoing aspect
1.ExceptionAnnotation : a base on which the pointcut is made
2.SystemException : which will be thrown from a TestExceptionClass.testEx1

Answer 2

package com.spring;
public abstract class AbstractExceptionProcessor {
public void processException(Throwable error){
System.out.println("Processed "+error);
}
}
..............................................................................
package com.spring;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.PostConstruct;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
#Component("com.spring.ExceptionProcessorAspect")
#Aspect
public class ExceptionProcessorAspect {
//#Value("#{exceptionMap}")
private Map<Class<?>,AbstractExceptionProcessor> exceptionMap;
#Autowired
#Qualifier("com.spring.SystemExceptionProcessor")
private SystemExceptionProcessor systemExceptionProcessor;
#Autowired
#Qualifier("com.spring.UnsupportedExceptionProcessor")
private UnsupportedExceptionProcessor unsupportedExceptionProcessor;
public ExceptionProcessorAspect(){
}
#PostConstruct
public void init(){
this.exceptionMap = new HashMap<Class<?>,AbstractExceptionProcessor>();
exceptionMap.put(SystemException.class, systemExceptionProcessor);
exceptionMap.put(UnsupportedException.class, unsupportedExceptionProcessor);
}
#Pointcut("#annotation(ExceptionAnnotation)")
public void getExceptionPointcut(){
}
#AfterThrowing(pointcut = "getExceptionPointcut()", throwing ="error")
public void processor(JoinPoint call,Throwable error){
if(null!=call){
MethodSignature signature = (MethodSignature) call.getSignature();
Method method = signature.getMethod();
ExceptionAnnotation myAnnotation = method.getAnnotation(ExceptionAnnotation.class);
Class<?> value = myAnnotation.value();
AbstractExceptionProcessor exceptionProcessor = (AbstractExceptionProcessor)this.exceptionMap.get(value);
exceptionProcessor.processException(error);
}
}
}
................................................................................................................................................................
package com.spring;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
#Target(ElementType.METHOD)
#Retention(RetentionPolicy.RUNTIME)
#Documented
public #interface ExceptionAnnotation {
Class<?> value();
}
................................................................................................................................................................
/**
*
*/
package com.spring;
public class SystemException extends RuntimeException {
public SystemException(String message) {
super(message);
this.message = message;
}
String message;
}
................................................................................................................................................................
package com.spring;
import org.springframework.stereotype.Component;
#Component("com.spring.SystemExceptionProcessor")
public class SystemExceptionProcessor extends AbstractExceptionProcessor {
#Override
public void processException(Throwable error) {
// TODO Auto-generated method stub
System.out.println("Processed " + error.getMessage());
}
}
................................................................................................................................................................
package com.spring;
import org.springframework.stereotype.Component;
#Component
public class TestExceptionClass {
#ExceptionAnnotation(value=SystemException.class)
public void testEx1(){
System.out.println("In SystemException Block" );
if(1==Integer.parseInt("1")){
throw new SystemException("SystemException raised");
}
System.out.println("After throws Block SystemException");
}
}
................................................................................................................................................................
/**
*
*/
package com.spring;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class BootClass {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:spring-resources/config.xml");
System.out.println("Spring context initialized.");
TestExceptionClass test = applicationContext.getBean(TestExceptionClass.class);
test.testEx1();
}
}