1. 啟用aop
a. 在類上添加@aspect注解
b. 注入該類, 可以使用@component進行注入到spring容器中
2. 通過pointcut對象創建切入點
a. 在某個方法使用類似下面的方法進行注入
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@pointcut("execution(* com.sguess.service.iaopservice.*(..))") private void pointcut() { } |
i. 其中,execution表達式為
execution(modifiers-pattern? ret-type-pattern declaring-type-pattern? name-pattern(param-pattern)throws-pattern?)
ii. 注意, pointcut()方法名是后面切入的時候需要使用的
iii. 方法內可以什么也不寫, 寫了也調不到
iv. 也可以創建多個pointcut,例如再創建一個
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@pointcut("execution(* com.sguess.service.iaopservice.fun1(..))") private void pointcut2() { } |
這個的方法名就位pointcut2, 方法名不一樣.
b. 創建after方法,before方法
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@after(value = "pointcut()") public void doafter() { system.out.println("do aop after function 01"); } |
i. after方法是指, 在配置了的切入點被執行后, 執行該方法.
ii. value中的pointcut() 是我們前面在創建@pointcut中的方法名. 也就是說,是通過方法名和切入點進行匹配的.
iii. 這個的方法名可以隨便起.
iv. before方法同理
c. 帶return的after方法,
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@afterreturning(returning = "str", pointcut = "pointcut()") public void doafterreturning(string str) throws exception { system.out.println("return value is: " + str); } |
i. afterreturn是指在被切入的方法執行后, 獲取其返回值, 再執行該方法. 注意關鍵, 這個可以進行操作返回值.
ii. returning = "str",是指, 假設切入方法的返回的值變量名為str
doafterreturning(string str)方法的參數變量名必須和和returning保持一致, 這里也叫作str. 然后才能在方法體中使用.
iii. pointcut = "pointcut()"同樣是指前面聲明的pointcut方法名
3. 通過注解, 使用切入點
a. 監聽方法參數
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@before("execution(public int com.sguess.service.*(int, int))") public void beformethod(joinpoint point) { string methodname = point.getsignature().getname(); list<object> args = arrays.aslist(point.getargs()); system.out.println("before functionname：" + methodname + ",parametername：" + args); } @after("execution(public int com.sguess.service.*(int, int))") public void aftermethod(joinpoint point) { string methodname = point.getsignature().getname(); list<object> args = arrays.aslist(point.getargs()); system.out.println("after functionname：" + methodname + ",parametername：" + args); } |
4. 執行順序:
a.around的方法優先于before/after執行,after優先于afterreturn.
i. 代碼
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@before("execution(public int com.sguess.service.*.*(int, int))") public void beformethod(joinpoint point) { system.out.println("before function"); } @after("execution(public int com.sguess.service.*.*(int, int))") public void aftermethod(joinpoint point) { system.out.println("after function"); } @afterreturning("execution(public int com.sguess.service.*.*(int, int))") public void afterreturnmethod(joinpoint point) { system.out.println("afterreturn function"); } @afterthrowing(value = "execution(public int com.sguess.service.*.*(int, int))", throwing = "e") public void afterreturningthrowing(joinpoint point, exception e) { system.out.println("afterreturnthrowing function"); } @around("execution(public int com.sguess.service.*.*(int, int))") public object aroundmethod(proceedingjoinpoint pdj) { system.out.println("start aroundfunction"); object result = null; try { system.out.println("around process start"); result = pdj.proceed(); system.out.println("around process end"); } catch (throwable e) { system.out.println("around process exception"); } system.out.println("after around process"); return result; } } |
執行結果:
start aroundfunction
around process start
before function
around process end
after around process
after function
afterreturn function
5.小結:
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@afterreturning(returning = "str", pointcut = "pointcut()")public void doafterreturning(string str) throws exception { system.out.println("return value is: " + str);}@before("execution(public int com.sguess.service.*.*(int, int))")public void beformethod(joinpoint point) { string methodname = point.getsignature().getname(); list<object> args = arrays.aslist(point.getargs()); system.out.println("before functionname：" + methodname + ",parametername：" + args);}@after("execution(public int com.sguess.service.*.*(int, int))")public void aftermethod(joinpoint point) { string methodname = point.getsignature().getname(); list<object> args = arrays.aslist(point.getargs()); system.out.println("after functionname：" + methodname + ",parametername：" + args);}@afterthrowing(value = "execution(public int com.sguess.service.*.*(int, int))", throwing = "e")public void afterreturningthrowing(joinpoint point, exception e) { string methodname = point.getsignature().getname(); list<object> args = arrays.aslist(point.getargs()); system.out.println("afterreturningthrowing functionname：" + methodname + ",parametername：" + args + ",exception：" + e);}@around("execution(public int com.sguess.service.*.*(int, int))")public object aroundmethod(proceedingjoinpoint pdj) { system.out.println("start aroundfunction"); object result = null; try { system.out.println("around process start"); result = pdj.proceed(); system.out.println("around process end"); } catch (throwable e) { system.out.println("around process exception"); } system.out.println("after around process"); return result;} |
總結
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原文鏈接：https://blog.csdn.net/sanpic/article/details/82800017
