526互联

两种修改字节码改变函数执行方式

发布时间 2023-08-23 14:56:46作者: Geraltz'Rivia

1

示例


public ReturnType function() {

  try {
            Object[] args = new Object[]{};
            Ret beforeRet = callOnBefore(args...);

            // 返回对象
            if (beforeRet.state == 1) {
                return (ReturnType) beforeRet.respond;
            }
            // 抛出异常
            if (beforeRet.state == 2) {
                throw (Throwable) beforeRet.respond;
            }

            // 执行正常的业务逻辑
            ReturnType retValue = ...;

            Ret returnRet = callOnReturn(retValue);
            // 返回对象
            if (returnRet.state == 1) {
                return (ReturnType) returnRet.respond;
            }
            // 抛出异常
            if (returnRet.state == 2) {
                throw (Throwable) returnRet.respond;
            }
            return retValue;
        } catch (Throwable t) {
            Ret throwRet = callOnThrow(t);
            // 返回对象
            if (throwRet.state == 1) {
                return (ReturnType) throwRet.respond;
            }
            // 抛出异常
            if (throwRet.state == 2) {
                throw (Throwable) throwRet.respond;
            }
            throw t;
        }

}

2

    public Integer function() {

        callOnBefore(args...);
        
        // 业务逻辑
        returnVal
        
        callOnReturn(returnVal);
        
        return returnVal;
    }