Spring缓存密钥生成器

Question

我刚刚开始研究 Spring 缓存。

我的服务方式是……

@Override
@Cacheable(value="profile", **key**="personId" )
public String cpuService2(Long personId, String personAddress){
    return "CachedMessage";
}

没有 key 子句，不会抛出异常，并假设两个参数都自动生成用于缓存 但关键是，当我调用此方法时，会抛出异常...

Exception in thread "main" org.springframework.expression.spel.SpelEvaluationException: EL1008E:(pos 0): Field or property 'personId' cannot be found on object of type 'org.springframework.cache.interceptor.CacheExpressionRootObject'
        at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:246)
        at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:112)
        at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:107)
        at org.springframework.expression.spel.ast.OpGT.getValueInternal(OpGT.java:37)
        at org.springframework.expression.spel.ast.OpGT.getValueInternal(OpGT.java:29)
        at org.springframework.expression.spel.ast.SpelNodeImpl.getTypedValue(SpelNodeImpl.java:102)
        at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:98)
        at org.springframework.cache.interceptor.ExpressionEvaluator.condition(ExpressionEvaluator.java:99)
        at org.springframework.cache.interceptor.CacheAspectSupport$CacheOperationContext.isConditionPassing(CacheAspectSupport.java:462)
        at org.springframework.cache.interceptor.CacheAspectSupport$CacheOperationContext.isConditionPassing(CacheAspectSupport.java:456)
        at org.springframework.cache.interceptor.CacheAspectSupport.inspectCacheables(CacheAspectSupport.java:292)
        at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:199)
        at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:66)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
        at $Proxy5.cpuService3(Unknown Source)
        at pack100_cache.pack020CacheKey.TestSimpleBean.main(TestSimpleBean.java:34)

搜索了文档但没有任何线索。希望有人能解决这个问题。

Answer 1

personId 前面缺少#

@Override
@Cacheable(value="profile", key="#personId" )
public String cpuService2(Long personId, String personAddress){
    return "CachedMessage";
}

caching abstraction chapter 有许多您正在尝试做的事情的示例。

Answer 2

当事情变得更复杂时，在容易理解用于生成密钥的算法时，SpEL 可能不是理想的解决方案。 您可以考虑使用 Java 生成密钥：

@Component
public class FooGenerator implements KeyGenerator {
    @Override
    public Object generate(Object target, Method method, Object... params) {
        String param = "";

        if (params.length == 2) {
            if (params[0] instanceof String) {
                param = (String) params[0];

        String key = "FooKeyEquatesTo" + param;
        return key;
}

然后你可以在你需要的地方连接这个密钥生成器：

@Cacheable(value = "nameofmycachearea", keyGenerator="fooGenerator")