Caused by: org.hibernate.MappingException: No Dialect mapping for JDBC type: -4

本文探讨了在使用Hibernate时遇到的MappingException异常,特别是针对JDBC类型为-4的情况,并提供了两种解决方案:一种是通过在SQL查询中使用CONVERT或CAST函数将text类型转换为varchar;另一种是通过自定义Dialect类来注册text类型。同时,介绍了如何在实际场景中应用这些方法,以避免在执行SQL查询时遇到此类异常。

错误代码:

org.springframework.orm.hibernate3.HibernateSystemException: No Dialect mapping for JDBC type: -4; nested exception is org.hibernate.MappingException: No Dialect mapping for JDBC type: -4
    at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:659)
    at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412)
    at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:377)
    at org.springframework.orm.hibernate3.HibernateTemplate.executeFind(HibernateTemplate.java:342)
    at com.hrrm.xglm.third.basic.dao.impl.GenericDaoImpl.findBySqlNoT(GenericDaoImpl.java:541)
    at com.hrrm.xglm.third.card.dao.impl.Hibernate3PageSupportDaoImpl.findBySqlNoT(Hibernate3PageSupportDaoImpl.java:90)
    at com.hrrm.gaa.task.dao.impl.TaskDaoImpl.getGuaranteeTime(TaskDaoImpl.java:518)
    at com.hrrm.gaa.task.service.impl.TaskServiceImpl.getGuaranteeTime(TaskServiceImpl.java:1626)
    at sun.reflect.GeneratedMethodAccessor156.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:107)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
    at $Proxy44.getGuaranteeTime(Unknown Source)
    at com.hrrm.gaa.info.action.TaskAction.getGuaranteeTime(TaskAction.java:1596)
    at sun.reflect.GeneratedMethodAccessor155.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:851)
    at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1253)
    at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68)
    at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethodWithDebugInfo(XWorkMethodAccessor.java:106)
    at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethod(XWorkMethodAccessor.java:90)
    at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1329)
    at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1305)
    at com.opensymphony.xwork2.ognl.accessor.CompoundRootAccessor.callMethod(CompoundRootAccessor.java:197)
    at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1329)
    at ognl.ASTMethod.getValueBody(ASTMethod.java:90)
    at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
    at ognl.SimpleNode.getValue(SimpleNode.java:258)
    at ognl.Ognl.getValue(Ognl.java:494)
    at ognl.Ognl.getValue(Ognl.java:458)
    at com.opensymphony.xwork2.ognl.OgnlUtil.getValue(OgnlUtil.java:196)
    at com.opensymphony.xwork2.ognl.OgnlValueStack.findValue(OgnlValueStack.java:229)
    at org.apache.struts2.components.Component.findValue(Component.java:248)
    at org.apache.struts2.components.Set.end(Set.java:101)
    at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)
    at org.apache.jsp.task.taskList_jsp._jspx_meth_s_005fset_005f0(taskList_jsp.java:705)
    at org.apache.jsp.task.taskList_jsp._jspx_meth_s_005fiterator_005f1(taskList_jsp.java:567)
    at org.apache.jsp.task.taskList_jsp._jspService(taskList_jsp.java:220)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
    at org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:154)
    at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
    at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:361)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:265)
    at org.apache.struts2.interceptor.TokenInterceptor.handleValidToken(TokenInterceptor.java:178)
    at org.apache.struts2.interceptor.TokenInterceptor.doIntercept(TokenInterceptor.java:144)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.hrrm.xglm.PageSupportInterceptor.intercept(PageSupportInterceptor.java:44)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:163)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:249)
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:148)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:93)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:128)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:148)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:128)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.hrrm.xglm.LoginInterceptor.intercept(LoginInterceptor.java:28)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:468)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at com.xglm.common.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:34)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Thread.java:619)
Caused by: org.hibernate.MappingException: No Dialect mapping for JDBC type: -4
    at org.hibernate.dialect.TypeNames.get(TypeNames.java:56)
    at org.hibernate.dialect.TypeNames.get(TypeNames.java:81)
    at org.hibernate.dialect.Dialect.getHibernateTypeName(Dialect.java:369)
    at org.hibernate.loader.custom.CustomLoader$Metadata.getHibernateType(CustomLoader.java:559)
    at org.hibernate.loader.custom.CustomLoader$ScalarResultColumnProcessor.performDiscovery(CustomLoader.java:485)
    at org.hibernate.loader.custom.CustomLoader.autoDiscoverTypes(CustomLoader.java:501)
    at org.hibernate.loader.Loader.getResultSet(Loader.java:1796)
    at org.hibernate.loader.Loader.doQuery(Loader.java:674)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236)
    at org.hibernate.loader.Loader.doList(Loader.java:2220)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104)
    at org.hibernate.loader.Loader.list(Loader.java:2099)
    at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:289)
    at org.hibernate.impl.SessionImpl.listCustomQuery(SessionImpl.java:1695)
    at org.hibernate.impl.AbstractSessionImpl.list(AbstractSessionImpl.java:142)
    at org.hibernate.impl.SQLQueryImpl.list(SQLQueryImpl.java:152)
    at com.hrrm.xglm.third.basic.dao.impl.GenericDaoImpl$2.doInHibernate(GenericDaoImpl.java:612)
    at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:372)
    ... 128 more

单独取sql执行之后是这样:

执行之后变成了text类型

原因:
org.hibernate.MappingException: No Dialect mapping for JDBC type: -1异常是因为hibernate不支持数据库中的text类型,就是说hibernate没有注册该类型,而我们往往要用到这个类型

解决方法一:
从sql上面的函数下手:
用CONVERT函数,将text转成varchar
例如:CONVERT(varchar(100), isnull(bz, ”))
bz是text类型变量名,isnull函数判断下是否为空
或者
用CAST函数,将text转成varchar
例如:CAST(GROUP_CONCAT(a.flightExecuteTime) AS CHAR) AS flightExecuteTime

结果看图片:
用cast执行的结果

解决方法二:(网上找的,没尝试过)

    问题原因:数据库表中有text类型的字段,而Hibernate在native查询中没有注册这个字段,因此发生这个错误。   
    解决方法:写一个类、修改hibernate配置文件。 写一个Dialect的子类,这里我 extends MySQL5Dialect类:   
    package xxx.xxx;    //xxx.xxx自己根据情况来写 import java.sql.Types;   
    import org.hibernate.dialect.MySQL5Dialect;   
    public class DialectForInkfish extends MySQL5Dialect {   
        public DialectForInkfish() {   
            super();   
            registerHibernateType(Types.LONGVARCHAR, 65535, "text");   
        }   
    }   
    修改Hibernate配置文件hibernate.cfg.xml,把  
    <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>   
    修改为:  
    <property name="dialect">com.ibm.crl.inkfish.config.DialectForInkfish</property>  
<think>我们正在处理的是 HikariCP 连接池在使用过程中出现的 JDBC 连接异常问题,具体异常为: `Caused by: org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection` 根据引用[1]中提供的配置,我们可以知道在Spring Boot中配置HikariCP连接池的方法。同时,引用[2][3][4]也提到了一些可能导致连接异常的原因,如Jar包冲突、连接提供者配置、数据库连接参数错误等。 ### 问题分析 1. **数据库连接参数错误**:如URL、用户名、密码不正确(引用[4]) 2. **连接池配置不当**:如连接超时时间、最大连接数等设置不合理(引用[1]) 3. **网络问题**:数据库服务器不可达(引用[4]中检查MySQL是否开启) 4. **Jar包冲突**:如不同版本的commons-collections包(引用[2]) 5. **连接泄漏**:应用程序未正确关闭数据库连接 6. **数据库连接超过最大限制**:数据库端的最大连接数限制 ### 解决方案 #### 1. 检查数据库连接参数 - 确保`application.properties`(或`application.yml`)中的数据库连接参数正确: ```properties spring.datasource.url=jdbc:mysql://localhost:3306/dbname?serverTimezone=GMT%2B8&characterEncoding=utf8 spring.datasource.username=root spring.datasource.password=yourpassword ``` 注意:`serverTimezone`参数对于MySQL 8.0以上版本很重要,避免时区问题。 #### 2. 优化HikariCP连接池配置 根据引用[1]的配置示例,调整以下参数(特别是超时相关参数): ```properties # 连接池类型 spring.datasource.type=com.zaxxer.hikari.HikariDataSource # 最小空闲连接数 spring.datasource.hikari.minimum-idle=5 # 最大连接池大小 spring.datasource.hikari.maximum-pool-size=20 # 连接最大存活时间(毫秒),建议小于数据库的wait_timeout spring.datasource.hikari.max-lifetime=1800000 # 30分钟 # 连接超时时间(毫秒) spring.datasource.hikari.connection-timeout=30000 # 空闲连接超时时间(毫秒) spring.datasource.hikari.idle-timeout=300000 # 5分钟 # 连接测试查询 spring.datasource.hikari.connection-test-query=SELECT 1 ``` 注意:`max-lifetime`必须小于数据库的`wait_timeout`(默认8小时),否则数据库会关闭连接而连接池还在使用。 #### 3. 检查数据库服务器状态和网络 - 确保数据库服务正在运行 - 检查网络是否通畅,使用`telnet`命令测试数据库端口(如3306)是否可达 #### 4. 解决Jar包冲突 如引用[2]所述,检查是否有冲突的Jar包(如commons-collections),使用Maven依赖树分析: ```bash mvn dependency:tree ``` 排除冲突的依赖,例如: ```xml <dependency> <groupId>group</groupId> <artifactId>artifact</artifactId> <exclusions> <exclusion> <groupId>commons-collections</groupId> <artifactId>commons-collections</artifactId> </exclusion> </exclusions> </dependency> ``` #### 5. 检查数据库连接数限制 - 查看数据库当前连接数: ```sql SHOW STATUS LIKE 'Threads_connected'; ``` - 查看最大连接数: ```sql SHOW VARIABLES LIKE 'max_connections'; ``` 如果连接数接近最大值,需要调整数据库的`max_connections`参数。 #### 6. 启用连接池监控 在Spring Boot中启用HikariCP监控,添加以下配置: ```properties # 启用Hikari连接池监控 management.endpoints.web.exposure.include=health,info,metrics management.metrics.export.prometheus.enabled=true management.endpoint.health.show-details=always ``` 通过`/actuator/health`端点可以查看数据库连接状态。 #### 7. 检查连接泄漏 在开发环境启用泄漏检测: ```properties # 检测连接泄漏(生产环境不建议开启,性能影响) spring.datasource.hikari.leak-detection-threshold=2000 # 2秒 ``` 如果连接超过指定时间未关闭,会记录警告日志。 ### 故障排查步骤 ```mermaid graph TD A[JDBC连接异常] --> B[检查数据库参数] A --> C[检查网络连通性] A --> D[检查连接池配置] A --> E[检查Jar包冲突] A --> F[检查数据库连接数] B -->|错误| G[修正参数] C -->|不可达| H[修复网络] D -->|配置不当| I[优化配置] E -->|冲突| J[排除冲突] F -->|满额| K[增大max_connections] ``` ### 常见错误场景 1. **连接超时**:`connection-timeout`设置过短,网络波动时无法建立连接 2. **连接被数据库关闭**:`max-lifetime`大于数据库`wait_timeout`,导致连接被数据库关闭而连接池还在使用 3. **连接泄漏**:程序未关闭连接,连接池中的连接耗尽 ### 参考配置模板 ```properties # 基本配置 spring.datasource.url=jdbc:mysql://localhost:3306/test?useSSL=false&serverTimezone=Asia/Shanghai spring.datasource.username=root spring.datasource.password=root # HikariCP配置 spring.datasource.hikari.connection-timeout=30000 spring.datasource.hikari.idle-timeout=600000 spring.datasource.hikari.max-lifetime=1800000 spring.datasource.hikari.maximum-pool-size=20 spring.datasource.hikari.minimum-idle=5 spring.datasource.hikari.connection-test-query=SELECT 1 ``` > **重要提示**:生产环境修改配置后务必进行压力测试,确保连接池配置合理[^1]。 §§相关问题§§ 1. HikariCP连接池的`max-lifetime`和数据库`wait_timeout`应该如何协调? 2. 如何通过Spring Boot Actuator监控HikariCP连接池状态? 3. 有哪些常见的JDBC连接泄漏排查方法? 4. 如何解决数据库连接数超过最大值的问题?</think>### HikariCP 连接池 `JDBCConnectionException` 解决方案 #### 一、核心问题定位 当出现 `org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection` 错误时,通常由以下原因导致: 1. **连接池配置错误**:超时时间、连接数等参数不合理(引用[1]) 2. **数据库连接参数错误**:URL、用户名、密码不正确(引用[4]) 3. **JAR包冲突**:如 `commons-collections` 版本冲突(引用[2]) 4. **连接泄漏**:未正确释放数据库连接 5. **网络/数据库问题**:数据库服务不可达或过载 #### 二、解决方案步骤 ```mermaid graph TD A[异常出现] --> B{检查基础配置} B -->|错误| C[修正URL/账号/密码] B -->|正确| D{检查连接池参数} D -->|异常| E[优化HikariCP配置] D -->|正常| F{检查JAR包冲突} F -->|存在| G[排除冲突依赖] F -->|无| H{检查连接泄漏} H -->|泄漏| I[添加泄漏检测] H -->|无泄漏| J[检查数据库状态] ``` ##### 1. 验证基础连接配置(首要) 在 `application.properties` 中检查: ```properties # 必检项(引用[1][4]) spring.datasource.url=jdbc:mysql://localhost:3306/真实数据库名?serverTimezone=GMT%2B8 spring.datasource.username=root # 替换实际用户名 spring.datasource.password=root # 替换实际密码 # 验证命令(需安装mysql-client) mysql -u root -p -h localhost ``` ##### 2. 优化HikariCP配置(关键) ```properties # 连接池核心配置(引用[1]) spring.datasource.hikari.connection-timeout=30000 # 连接超时(ms) spring.datasource.hikari.idle-timeout=600000 # 空闲超时(>数据库wait_timeout) spring.datasource.hikari.max-lifetime=1800000 # 连接最大生命周期 spring.datasource.hikari.maximum-pool-size=20 # 根据DB的max_connections调整 spring.datasource.hikari.leak-detection-threshold=5000 # 泄漏检测(ms) # 必须添加的心跳检测 spring.datasource.hikari.connection-test-query=SELECT 1 ``` ##### 3. 解决JAR包冲突(常见陷阱) ```xml <!-- 检查pom.xml排除冲突包(引用[2]) --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> <exclusions> <exclusion> <groupId>commons-collections</groupId> <artifactId>commons-collections</artifactId> <!-- 冲突常见包 --> </exclusion> </exclusions> </dependency> <!-- 执行依赖树检查 --> mvn dependency:tree | grep 'commons-collections' ``` > 保留单一版本的 `commons-collections`(推荐3.2.2+) ##### 4. 连接泄漏检测与修复 在开发环境启用监控: ```properties # 开启Hikari连接泄漏日志(生产环境慎用) spring.datasource.hikari.leak-detection-threshold=2000 ``` 代码修复示例: ```java // 错误示例:未关闭连接 try (Connection conn = dataSource.getConnection()) { // Java 7+自动关闭 Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery("SELECT ..."); // ... } // 此处自动调用conn.close() ``` ##### 5. 数据库端检查 ```sql -- 检查最大连接数 SHOW VARIABLES LIKE 'max_connections'; -- 检查活跃连接 SHOW STATUS LIKE 'Threads_connected'; -- 修改最大连接数(需重启) SET GLOBAL max_connections = 200; ``` #### 三、特殊场景处理 1. **SSH/老旧项目问题**(引用[3][4]) 在 `hibernate.cfg.xml` 中添加: ```xml <property name="hibernate.connection.provider_class"> org.hibernate.hikaricp.internal.HikariCPConnectionProvider </property> ``` 2. **云数据库连接问题** 添加白名单: ```sql GRANT ALL PRIVILEGES ON *.* TO 'user'@'公网IP' IDENTIFIED BY 'password'; ``` 3. **连接池初始化失败** 在启动类添加: ```java @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class}) ``` #### 四、诊断工具 1. **监控连接池状态**: ```java HikariDataSource ds = (HikariDataSource) dataSource; System.out.println("活跃连接: " + ds.getHikariPoolMXBean().getActiveConnections()); System.out.println("空闲连接: " + ds.getHikariPoolMXBean().getIdleConnections()); ``` 2. **日志配置**(查看详细错误): ```properties logging.level.com.zaxxer.hikari=DEBUG logging.level.org.hibernate.SQL=DEBUG ``` > **关键建议**:85%的此类错误由配置错误或连接泄漏引起,优先检查连接字符串和连接池超时参数[^1][^4]。生产环境修改后务必进行压力测试!
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值