用AOP实现业务service的重新调用(二) 博客分类： spring springaopinterceptorStaleConnectionExceptionSQL0901

 承接 用AOP实现业务service的重新调用(一),我们继续......

 

service重试的落地实现

       方案A: web业务系统里面有很多action,很多service,如果直接从每个调用service的点入手的话,修改点会很多,而且代码会大量冗余,实现代码并不复杂

 

try{
    //service调用
} catch(UncategorizedSQLException e) { 
    if(retry) {
        //service调用
    }
}

 

 

       方案B: 因为我们使用了spring,所以自然会想到AOP,通过拦截器来拦截service方法的调用,一旦发生UncategorizedSQLException,就重试一次service方法的调用.直接上代码:

 

import java.lang.reflect.Method;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.framework.ReflectiveMethodInvocation;
import org.springframework.dao.DataIntegrityViolationException;

public class ServiceRetryAdvice implements MethodInterceptor {
	
	private static ThreadLocal<Integer> retryNum = new ThreadLocal<Integer>() {  
        public Integer initialValue() {  
            return 0;  
        }  
    };

	public Object invoke(MethodInvocation invocation) throws Throwable {
				
		Object returnObject = null;
		try{
			returnObject = invocation.proceed();
		} catch(DataIntegrityViolationException e) {
			
			if (retryNum.get() == 0){
				retryNum.set(1);

				ReflectiveMethodInvocation refInvocation = (ReflectiveMethodInvocation)invocation;
				Object proxy = refInvocation.getProxy();
				Method method = refInvocation.getMethod();
				Object[] args = refInvocation.getArguments();
				
				returnObject = method.invoke(proxy, args);
			} else {
				throw e;
			}
		} finally {
			retryNum.remove();
		}
		return returnObject;
	}
}

 

关于代码的详细说明以及各种需要考虑到的方方面面,请参照

 

用AOP实现业务service的重新调用(三)