spring @Cacheable使用SpEL异常：org.springframework.expression.spel.SpelParseException: Unexpected token. Expected 'identifier' but was 'lcurly({)'

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  • 分类: JAVA

springboot结合redis做缓存，在@Cacheable中使用如下SpEL时报错。

@Cacheable(cacheNames = ENTERPRISE_CACHE_KEY, key = "#{T(com.emax.common.RestApiSignUtil).foo(#root.args[0])}")

异常：

org.springframework.expression.spel.SpelParseException: Expression [#{T(com.emax.common.RestApiSignUtil).foo(#root.args[0])}] @1: EL1043E: Unexpected token. Expected 'identifier' but was 'lcurly({)'

异常stacktrace信息：

org.springframework.expression.spel.SpelParseException: Expression [#{T(com.emax.common.RestApiSignUtil).foo(#root.args[0])}] @1: EL1043E: Unexpected token. Expected 'identifier' but was 'lcurly({)' at org.springframework.expression.spel.standard.InternalSpelExpressionParser.internalException(InternalSpelExpressionParser.java: 1044 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatToken(InternalSpelExpressionParser.java: 926 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.maybeEatFunctionOrVar(InternalSpelExpressionParser.java: 423 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatStartNode(InternalSpelExpressionParser.java: 512 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatPrimaryExpression(InternalSpelExpressionParser.java: 351 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatUnaryExpression(InternalSpelExpressionParser.java: 345 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatPowerIncDecExpression(InternalSpelExpressionParser.java: 304 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatProductExpression(InternalSpelExpressionParser.java: 282 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatSumExpression(InternalSpelExpressionParser.java: 264 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatRelationalExpression(InternalSpelExpressionParser.java: 218 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatLogicalAndExpression(InternalSpelExpressionParser.java: 205 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatLogicalOrExpression(InternalSpelExpressionParser.java: 192 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.eatExpression(InternalSpelExpressionParser.java: 153 )

    at org.springframework.expression.spel.standard.InternalSpelExpressionParser.doParseExpression(InternalSpelExpressionParser.java: 131 )

    at org.springframework.expression.spel.standard.SpelExpressionParser.doParseExpression(SpelExpressionParser.java: 61 )

    at org.springframework.expression.spel.standard.SpelExpressionParser.doParseExpression(SpelExpressionParser.java: 33 )

    at org.springframework.expression.common.TemplateAwareExpressionParser.parseExpression(TemplateAwareExpressionParser.java: 52 )

    at org.springframework.expression.common.TemplateAwareExpressionParser.parseExpression(TemplateAwareExpressionParser.java: 43 )

    at org.springframework.context.expression.CachedExpressionEvaluator.getExpression(CachedExpressionEvaluator.java: 88 )

    at org.springframework.cache.interceptor.CacheOperationExpressionEvaluator.key(CacheOperationExpressionEvaluator.java: 104 )

    at org.springframework.cache.interceptor.CacheAspectSupport$CacheOperationContext.generateKey(CacheAspectSupport.java: 778 )

    at org.springframework.cache.interceptor.CacheAspectSupport.generateKey(CacheAspectSupport.java: 575 )

    at org.springframework.cache.interceptor.CacheAspectSupport.findCachedItem(CacheAspectSupport.java: 518 )

    at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java: 401 )

    at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java: 345 )

    at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java: 61 )

    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java: 186 )

    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java: 688 )

    at com.emax.MyService$$EnhancerBySpringCGLIB$$4de73e25.getEnterpriseByEntId( <generated> )

    at com.emax.MyServiceTest.getEnterpriseByEntId(MyServiceTest.java: 21)

View Code

 

identifier、lcurly都是什么？一脸懵逼。
顺着stacktrace点进去看源码，才确定lcurly表示左大括号“{”。看来不能用“{”。下面是正确答案：

@Cacheable(cacheNames = ENTERPRISE_CACHE_KEY, key = "T(com.emax.common.RestApiSignUtil).foo(#root.args[0])")

 

在SpEL中可以调用类的方法，足见SpEL的强大！


扩展：@Cacheable中SpEL的用法列举

// 下面方式可以同时设置两个缓存； 取参数可以用#param形式
@Cacheable(cacheNames = {ENTERPRISE_CACHE_KEY, "test-another-key"}, key = "#enterpriseId eq 0 ? 0: #enterpriseId")
public Result baseEnterpriseByEntId(Long enterpriseId) {...}

-------------------------------------------------

// #root代表的是spring-context-***.jar中的CacheExpressionRootObject，该类里有Object[] args属性及其getter方法。
@Cacheable(cacheNames = ENTERPRISE_CACHE_KEY, key = "#root.args[0]<=0? 0 : #root.args[0]")
public Result getEnterpriseByEntId1(Long enterpriseId) {...}

-------------------------------------------------

// SpEL中调用外部类函数
@Cacheable(cacheNames = ENTERPRISE_CACHE_KEY, key = "T(com.emax.common.MyUtil).foo(#root.args[0])")
public Result getEnterpriseByEntId(Long enterpriseId) {...}

// SpEL中调用外部类函数--- 设置缓存key常用的套路：当缓存key包含一个对象时，则做md5
@Cacheable(cacheNames = ENTERPRISE_CACHE_KEY, key = "T(com.emax.common.Md5Util).sign(T(com.alibaba.fastjson.JSON).toJSONString(#root.args[0]))")
public Result getEnterpriseByEntId2(UserAccountVo userAccountVo, Long enterpriseId) {...}

标签: Java

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