aspectj

关于事务，简单来说，就是为了保证数据完整性而存在的一种工具，其主要有四大特性：原子性，一致性，隔离性和持久性。对于Spring事务，其最终还是在数据库层面实现的，而Spring只是以一种比较优雅的方式对其进行封装支持。本文首先会通过一个简单的示例来讲解Spring事务是如何使用的，然后会讲解Spring是如何解析xml中的标签，并对事务进行支持的。 1. 使用示例 关于事务最简单的示例，就是其一致性，比如在整个事务执行过程中，如果任何一个位置报错了，那么都会导致事务回滚，回滚之后数据的状态将和事务执行之前完全一致。这里我们以用户数据为例，在插入用户数据的时候，如果程序报错了，那么插入的动作就会回滚。如下是用户的实体： public class User { private long id; private String name; private int age; // getter, setter... } 如下是模拟插入用户数据的业务代码： public interface UserService { void insert(User user); } @Service @Transactional public class UserServiceImpl implements UserService { @Autowired private JdbcTemplate

I was trying to debug java application using instrumentation. The problem with current system are Hardly written any log statements Poor exception handling This made very difficult to trace root cause of broken functionality. To handle the situation I have developed tool,java agent using Instrumentation API , and I was able to inject log statements and half of the problem solved. But the next problem is to recording the Exception. I want to extend my tool record every exception thrown during the execution of the application. I tried injecting 'try-catch' block using javaassist API for methods

I have a service class implemented in Java 6 / Spring 3 that needs an annotation to restrict access by role. I have defined an annotation called RequiredPermission that has as its value attribute one or more values from an enum called OperationType: public @interface RequiredPermission { /** * One or more {@link OperationType}s that map to the permissions required * to execute this method. * * @return */ OperationType[] value();} public enum OperationType { TYPE1, TYPE2; } package com.mycompany.myservice; public interface MyService{ @RequiredPermission(OperationType.TYPE1) void myMethod(