想了解Spring-data-redis@Cacheablejava.lang.ClassCastException：无法将java.util.HashMap强制转换为java.lang.String
想了解Spring-data-redis @Cacheable java.lang.ClassCastException：无法将java.util.HashMap强制转换为java.lang.String的新动态吗？本文将为您提供详细的信息，此外，我们还将为您介绍关于ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]、AsyncTask：ClassCastException：java.lang.Object []无法转换为java.lang.String []、ClassCastException：java.math.BigInteger在连接MySQL时无法强制转换为java.lang.Long、ClassCastException：不能在连接到MySQL时将java.math.BigInteger强制转换为java.lang.Long的新知识。
本文目录一览：- Spring-data-redis @Cacheable java.lang.ClassCastException：无法将java.util.HashMap强制转换为java.lang.String
- ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]
- AsyncTask：ClassCastException：java.lang.Object []无法转换为java.lang.String []
- ClassCastException：java.math.BigInteger在连接MySQL时无法强制转换为java.lang.Long
- ClassCastException：不能在连接到MySQL时将java.math.BigInteger强制转换为java.lang.Long
Spring-data-redis @Cacheable java.lang.ClassCastException：无法将java.util.HashMap强制转换为java.lang.String
我想用spring-data-redis在spring
boot应用程序中缓存数据。但是它总是说强制转换异常。我用了一段时间搜索但没有任何想法。请帮帮我。谢谢，任何建议都很棒！
这是我的RedisConfiguation：
@Configuration@EnableCachingpublic class RedisConfiguration extends CachingConfigurerSupport {@Value("${spring.redis.host}")private String host;@Value("${spring.redis.port}")private String port;@Value("${spring.redis.expire}")private String expire;@Value("${spring.redis.database}")private String databaseIndex;@Value("${spring.redis.password}")private String password;@Beanpublic KeyGenerator keyGenerator() { return new KeyGenerator() { public Object generate(Object target, Method method, Object... params) { if (params.length == 0) { return "reids_" + method.getName(); } if (params.length == 1) { Object param = params[0]; if (param != null && !param.getClass().isArray()) { return "reids_" + method.getName() + "_" + param; } } return "reids_" + method.getName() + " [" + StringUtils.arrayToCommaDelimitedString(params) + "]"; } };}@Beanpublic CacheManager cacheManager(RedisTemplate redisTemplate) { RedisCacheManager redisCacheManager = new RedisCacheManager(redisTemplate); redisCacheManager.setDefaultExpiration(Integer.parseInt(expire)); redisTemplate.setHashValueSerializer(new StringRedisSerializer()); redisTemplate.setKeySerializer(new StringRedisSerializer()); redisTemplate.setValueSerializer(new StringRedisSerializer()); redisTemplate.setHashKeySerializer(new StringRedisSerializer()); return redisCacheManager;}@Bean(name = "redisTemplate")public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) { RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>(); redisTemplate.setConnectionFactory(factory); redisTemplate.setValueSerializer(new RedisSerializer<Object>() { @Override public byte[] serialize(Object object) throws SerializationException { if (object == null) { return new byte[0]; } if (!(object instanceof Serializable)) { throw new IllegalArgumentException("RedisSerializer.serialize requires a Serializable payload " + "but received an object of type [" + object.getClass().getName() + "]"); } return SerializationUtils.serialize((Serializable) object); } @Override public Object deserialize(byte[] bytes) throws SerializationException { if (bytes == null || bytes.length == 0) { return null; } return SerializationUtils.deserialize(bytes); } }); redisTemplate.afterPropertiesSet(); return redisTemplate;}@Beanpublic JedisConnectionFactory redisConnectionFactory() { JedisConnectionFactory redisConnectionFactory = new JedisConnectionFactory(); // Defaults redisConnectionFactory.setHostName(host); redisConnectionFactory.setPort(Integer.parseInt(port)); redisConnectionFactory.setDatabase(Integer.parseInt(databaseIndex)); redisConnectionFactory.setPassword(password); return redisConnectionFactory;}}我在Controller中使用它：
@Cacheable(value = "helloRedisCache",keyGenerator = "keyGenerator")@RequestMapping(value = "/Discovery/redisCache", method = RequestMethod.GET)public Map helloRedisCache() { return new HashMap();}我有例外：
java.lang.ClassCastException: java.util.HashMap cannot be cast to java.lang.Stringat org.springframework.data.redis.serializer.StringRedisSerializer.serialize(StringRedisSerializer.java:32) ~[spring-data-redis-1.7.3.RELEASE.jar:na]at org.springframework.data.redis.cache.RedisCache$CacheValueAccessor.convertToBytesIfNecessary(RedisCache.java:375) ~[spring-data-redis-1.7.3.RELEASE.jar:na]at org.springframework.data.redis.cache.RedisCache$BinaryRedisCacheElement.<init>(RedisCache.java:408) ~[spring-data-redis-1.7.3.RELEASE.jar:na]at org.springframework.data.redis.cache.RedisCache.put(RedisCache.java:173) ~[spring-data-redis-1.7.3.RELEASE.jar:na]at org.springframework.data.redis.cache.RedisCache.put(RedisCache.java:157) ~[spring-data-redis-1.7.3.RELEASE.jar:na]at org.springframework.cache.interceptor.AbstractCacheInvoker.doPut(AbstractCacheInvoker.java:85) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.cache.interceptor.CacheAspectSupport$CachePutRequest.apply(CacheAspectSupport.java:780) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:428) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:327) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:61) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:655) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]at com.senthink.www.rest.DiscoveryRestController$$EnhancerBySpringCGLIB$$df010633.helloRedisCache(<generated>) ~[na:na]at sun.reflect.GeneratedMethodAccessor539.invoke(Unknown Source) ~[na:na]at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java) ~[na:1.8.0_101]at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at com.senthink.www.filter.MyCORSFilter.doFilter(MyCORSFilter.java:37) ~[classes/:na]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:105) ~[spring-boot-actuator-1.4.1.RELEASE.jar:1.4.1.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:317) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:115) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:169) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at com.senthink.www.security.JwtAuthenticationTokenFilter.doFilterInternal(JwtAuthenticationTokenFilter.java:74) ~[classes/:na]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:121) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:66) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:214) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:177) ~[spring-security-web-4.1.3.RELEASE.jar:4.1.3.RELEASE]at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:89) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:107) ~[spring-boot-actuator-1.4.1.RELEASE.jar:1.4.1.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:108) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410) [tomcat-embed-core-8.5.5.jar:8.5.5]at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.5.jar:8.5.5]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_101]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_101]at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.5.jar:8.5.5]at java.lang.Thread.run(Thread.java:745) [na:1.8.0_101]答案1
小编典典当存储哈希对象时，redis将与Jackson2JsonRedisSerializer一起使用，可用于绑定到类型化的bean或未类型化的实例。
redisTemplate.setHashValueSerializer(new Jackson2JsonRedisSerializer<>(Object.class));![ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]](http://www.gvkun.com/zb_users/upload/2025/02/02e7eea5-c630-4771-a095-f15f613905de1739878495175.jpg "ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]")
ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]
错误堆栈：
java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]
at android.support.v4.util.SimpleArrayMap.allocArrays(SourceFile:183)
at android.support.v4.util.SimpleArrayMap.put(SourceFile:437)
错误原因：
由于SimpleArrayMap 里面使用了一个静态变量的缓存，mBaseCache,
static Object[] mBaseCache;
该变量默认有两个数据，第1个元素是一个object[]，用于存放上次的缓存的mBaseCache
第二个元素是int[]，用于存在hash。具体赋值代码可以看下面
synchronized (ArrayMap.class) {
if (mBaseCacheSize < CACHE_SIZE) {
array[0] = mBaseCache;
array[1] = hashes;
for (int i=(size<<1)-1; i>=2; i--) {
array[i] = null;
}
mBaseCache = array;
mBaseCacheSize++;
if (DEBUG) Log.d(TAG, "Storing 1x cache " + array
+ " now have " + mBaseCacheSize + " entries");
}
}
使用该数组的地方在：
SimpleArrayMap 的allocArrays 方法里
synchronized (ArrayMap.class) {
if (mBaseCache != null) {
final Object[] array = mBaseCache;
mArray = array;
mBaseCache = (Object[])array[0];
mHashes = (int[])array[1];
array[0] = array[1] = null;
mBaseCacheSize--;
if (DEBUG) Log.d(TAG, "Retrieving 1x cache " + mHashes
+ " now have " + mBaseCacheSize + " entries");
return;
}
}
下面这段代码是有风险的，如果mBaseCache 在多线程被修改了，就会把ClassCastException 异常。
mBaseCache = (Object[])array[0];
解决方法：
如果项目某个地方报这个错误，请把这个地方的ArrayMap替换成 HasMap. HasMap 多线程不会崩溃，虽然，他不是特别完好的支持。不需要把项目中所有的地方都替换掉，没有必要。单独线程，ArrayMap 完全没有问题。
错误复现：这个复现起来超级麻烦，我花了一周的时间，才找到复现的漏洞，分享给大家：
/**
* 复现该问题 用了四个线程
* java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]
* at android.support.v4.util.SimpleArrayMap.allocArrays(SimpleArrayMap.java:157)
* at android.support.v4.util.SimpleArrayMap.put(SimpleArrayMap.java:399)
* at com.example.fragment.MainFragment$14.run(MainFragment.java:280)
* 1.首先 线程1 执行到put 方法的
* mArray[index<<1] = key;
* mArray[(index<<1)+1] = value;
* mSize++;
* return null;
* 最上面这个位置 目的是让这个数组不再是空的
*
* 2.执行线程2 也执行到
* mArray[index<<1] = key;
* mArray[(index<<1)+1] = value;
* mSize++;
* return null;
* 最上面这个位置 目的是让这个put 的东西，放在第0个位置，因为put里面会生成index，
* 让两个线程都放到index 是0 的位置
*
* 3.把线程1执行完，这样数据里面已经放进去一个数据了
*
* 4.执行线程3 到removeAt 方法的 freeArrays 的 mBaseCache = array; 之前
* public V removeAt(int index) {
* final Object old = mArray[(index << 1) + 1];
* if (mSize <= 1) {
* // Now empty.
* if (DEBUG) Log.d(TAG, "remove: shrink from " + mHashes.length + " to 0");
* freeArrays(mHashes, mArray, mSize);
*
* mBaseCache = array;----------- freeArrays
*
* 这个的目的是调用freeArray 方法，让当前的map释放当前的数组。这样就可以生成mBaseCache了
*
* 5.把线程2 执行完
* 这样就会把mBaseCache 赋值的数组，重新赋值
*
* 6.把线程3执行完
* ok，现在mBaseCache已经被污染了
*
* 7.执行线程4
*
*/
private void CMETestCastException() {
final ArrayMap testArrayMap = new ArrayMap();
final ArrayMap testArrayMap2 = new ArrayMap();
new Thread("线程1"){
@Override
public void run() {
super.run();
testArrayMap.put("2324","fffff");
}
}.start();
new Thread("线程2"){
@Override
public void run() {
super.run();
testArrayMap.put("test","string");
}
}.start();
new Thread("线程3"){
@Override
public void run() {
super.run();
testArrayMap.removeAt(0);
}
}.start();
new Thread("线程4"){
@Override
public void run() {
super.run();
testArrayMap2.put("aaa","string");
}
}.start();
}
复现这个问题的时候，关键是把mBaseCache 污染掉。这里四个线程的话，需要调试，调试步骤就是上面我注释的。
总结：
如果当前的map 会有多个线程访问，请使用HasMap. 该问题，google 并没有解决。在高版本上，直接扔CME ConcurrentModificationException.
![AsyncTask：ClassCastException：java.lang.Object []无法转换为java.lang.String []](http://www.gvkun.com/zb_users/upload/2025/02/af2a76e8-8866-466b-90d2-b56b18c070d11739878497097.jpg "AsyncTask：ClassCastException：java.lang.Object []无法转换为java.lang.String []")
AsyncTask：ClassCastException：java.lang.Object []无法转换为java.lang.String []
在我的应用程序中，我为gcm ccs（xmpp）运行这些代码，并且代码显示以下错误执行时发生错误doinbackground.excute()
这是代码：
sendTask = new AsyncTask<String, String, String>() { protected String doInBackground(String... title) { Bundle data = new Bundle(); data.putString("ACTION", action); data.putString("CLIENT_MESSAGE", "Hello GCM CCS XMPP!"); String id = Integer.toString(ccsMsgId.incrementAndGet()); try { Log.d("RegisterActivity", "messageid: " + id); gcm.send(SENDER_ID + "@gcm.googleapis.com", id, data); Log.d("RegisterActivity", "After gcm.send successful."); } catch (IOException e) { Log.d("RegisterActivity", "Exception: " + e); e.printStackTrace(); } return "Sent message."; } protected void onPostExecute(String result) { sendTask = null; // tosat about the success in return }};sendTask.execute(null, null, null);答案1
小编典典您如何sendTask申报？我想它是简单的AsyncTask sendTask;，如果是这样，请将其更改为：
AsyncTask<String, String, String> sendTask;此异常的原因与以下代码中发生的原因类似：
Object arr1[] = new Object[] {null,null,null};String arr2[] = (String[])arr1; // here java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.String;Java中的VarArgs是作为数组实现的，因此，当您AsyncTask<String, String,String>将sendTask声明为as时，编译器将doInBackground使用with进行调用newString[]{null,null,null}，但是当您将AsyncTaskthen 声明为then
时，则将doInBackground使用with进行调用new Object[]{null,null,null}。
由于类型擦除，编译器将添加隐藏的隐式强制类型从Object[]到String[]。这是为了允许以下代码正常工作：
AsyncTask sendTask = ...; Object[] arg = new String[]{null,null,null}; sendTask.execute(arg);
ClassCastException：java.math.BigInteger在连接MySQL时无法强制转换为java.lang.Long
连接到MySQL时,出现错误(见下文).
单击here以获取代码
我得到这个输出：
run:
Now connecting to databse...
java.sql.sqlException: java.lang.classCastException: java.math.BigInteger cannot be cast to java.lang.Long
java.sql.sqlException: java.lang.classCastException: java.math.BigInteger cannot be cast to java.lang.Long
at com.@R_301_5163@.jdbc.sqlError.createsqlException(sqlError.java:1074)
at com.@R_301_5163@.jdbc.sqlError.createsqlException(sqlError.java:988)
at com.@R_301_5163@.jdbc.sqlError.createsqlException(sqlError.java:974)
at com.@R_301_5163@.jdbc.sqlError.createsqlException(sqlError.java:919)
at com.@R_301_5163@.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1062)
at com.@R_301_5163@.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3556)
at com.@R_301_5163@.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2513)
at com.@R_301_5163@.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2283)
at com.@R_301_5163@.jdbc.ConnectionImpl.301_5163@.jdbc.JDBC4Connection.java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.@R_301_5163@.jdbc.Util.handleNewInstance(Util.java:411)
at com.@R_301_5163@.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:404)
at com.@R_301_5163@.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:317)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at dbms_basic.Dbms_Basic.main(Dbms_Basic.java:28)
Caused by: java.lang.classCastException: java.math.BigInteger cannot be cast to java.lang.Long
at com.@R_301_5163@.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1007)
... 15 more
BUILD SUCCESSFUL (total time: 0 seconds)
我怎么解决这个问题？
最佳答案
您的错误清楚地表明无法进行转换,因为java.math.BigInteger类实例不是java.lang.Long类的实例.
现在出现的问题是谁在什么级别进行转换,当我们要求JDBC驱动程序建立连接时,它在场景之后做了很多工作,然后才真正给我们提供了正确的连接工作对象.
您的@R_301_5163@版本与您的mysql-connector.jar版本相结合似乎存在问题.尝试使用较新版本的@R_301_5163@ Connector / J(有关最新版本,请参阅https://dev.mysql.com/downloads/connector/j/),例如,如果您使用的是旧版本,请升级到5.1.47或8.0.12.
ClassCastException：不能在连接到MySQL时将java.math.BigInteger强制转换为java.lang.Long
连接到MySQL时，出现错误（见下文）。
点击此处获取代码
我得到以下输出：
run:Now connecting to databse...java.sql.SQLException: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Longjava.sql.SQLException: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919) at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1062) at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3556) at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2513) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2283) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:822) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at com.mysql.jdbc.Util.handleNewInstance(Util.java:411) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:404) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:317) at java.sql.DriverManager.getConnection(DriverManager.java:664) at java.sql.DriverManager.getConnection(DriverManager.java:247) at dbms_basic.Dbms_Basic.main(Dbms_Basic.java:28)Caused by: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1007) ... 15 moreBUILD SUCCESSFUL (total time: 0 seconds)我该如何解决？
答案1
小编典典您的错误明确指出无法进行强制转换，因为java.math.BigInteger类实例不是java.lang.Long类的实例。
现在出现了一个问题，即谁在哪个级别上进行强制转换，当我们要求JDBC驱动程序进行连接时，它实际上在幕后进行了大量工作，然后才真正给我们适当的连接工作对象。
您的MySQL版本与mysql-connector.jar版本组合似乎出现了问题。尝试使用更高版本的MySQL Connector /
J（有关最新版本，请参见https://dev.mysql.com/downloads/connector/j/），例如，如果使用的是旧版本，请升级到5.1.47或8.0.12版。
关于Spring-data-redis @Cacheable java.lang.ClassCastException：无法将java.util.HashMap强制转换为java.lang.String的问题我们已经讲解完毕，感谢您的阅读，如果还想了解更多关于ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]、AsyncTask：ClassCastException：java.lang.Object []无法转换为java.lang.String []、ClassCastException：java.math.BigInteger在连接MySQL时无法强制转换为java.lang.Long、ClassCastException：不能在连接到MySQL时将java.math.BigInteger强制转换为java.lang.Long等相关内容，可以在本站寻找。
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