这是我的 BaseDao.java 类
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import java.io.Serializable;
public abstract class BaseDAO<E extends Serializable, K extends Serializable> {
protected final Logger LOGGER = LoggerFactory.getLogger(this.getClass());
private final Class<E> entityType;
private final Class<K> keyType;
@Autowired
private EntityManagerFactory emf;
public BaseDAO(final Class<E> entityType, final Class<K> keyType) {
this.entityType = entityType;
this.keyType = keyType;
}
//<editor-fold desc="BaseDAO properties">
protected Class<E> getEntityType() {
return this.entityType;
}
protected Class<K> getKeyType() {
return this.keyType;
}
protected EntityManager em() {
return emf.createEntityManager();
}
protected CriteriaBuilder cb() {
return emf.createEntityManager().getCriteriaBuilder();
}
}
StudentDao .java
import demo.eaze.school.common.api.entity.StudentEntity;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import javax.persistence.TypedQuery;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import java.util.List;
@Repository
public class StudentDao extends BaseDAO<StudentEntity, Integer> {
public StudentDao() {
super(StudentEntity.class, Integer.class);
}
@Transactional(readOnly = true)
public List<StudentEntity> findStudentSearchData() {
CriteriaQuery<StudentEntity> query = cb().createQuery(StudentEntity.class);
Root<StudentEntity> from = query.from(StudentEntity.class);
CriteriaQuery<StudentEntity> select = query.select(from);
TypedQuery<StudentEntity> studentEntityTypedQuery = em().createQuery(select).setMaxResults(50);
return studentEntityTypedQuery.getResultList();
}
}
当我同时点击10次API时，我开始获得异常
16:04:27.172 [HikariPool-1 housekeeper] DEBUG com.zaxxer.hikari.pool.HikariPool - HikariPool-1 - Pool stats (total=10, active=10, idle=0, waiting=3)
16:04:36.330 [HikariPool-2 housekeeper] DEBUG com.zaxxer.hikari.pool.HikariPool - HikariPool-2 - Pool stats (total=10, active=0, idle=10, waiting=0)
16:04:36.361 [HikariPool-3 housekeeper] DEBUG com.zaxxer.hikari.pool.HikariPool - HikariPool-3 - Pool stats (total=10, active=0, idle=10, waiting=0)
DEBUG com.zaxxer.hikari.pool.HikariPool - HikariPool-1 - Timeout failure stats (total=10, active=10, idle=0, waiting=2)
16:04:44.907 [reactor-http-nio-3] DEBUG org.hibernate.engine.jdbc.spi.SqlExceptionHelper - Unable to acquire JDBC Connection [n/a]
java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30014ms.
at com.zaxxer.hikari.pool.HikariPool.createTimeoutException(HikariPool.java:669)
at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:183)
at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:148)
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:100)
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)
at org.hibernate.internal.NonContextualJdbcConnectionAccess.obtainConnection(NonContextualJdbcConnectionAccess.java:35)
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:106)
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:136)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.connection(StatementPreparerImpl.java:47)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:145)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:171)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:147)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1985)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1915)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1893)
at org.hibernate.loader.Loader.doQuery(Loader.java:938)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341)
at org.hibernate.loader.Loader.doList(Loader.java:2692)
at org.hibernate.loader.Loader.doList(Loader.java:2675)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2507)
at org.hibernate.loader.Loader.list(Loader.java:2502)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:502)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:392)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1490)
at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1445)
at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1414)
at org.hibernate.query.Query.getResultList(Query.java:146)
at org.hibernate.query.criteria.internal.compile.CriteriaQueryTypeQueryAdapter.getResultList(CriteriaQueryTypeQueryAdapter.java:72)
at demo.eaze.school.common.api.dao.StudentDao.findStudentSearchData(StudentDao.java:26)
at demo.eaze.school.common.api.dao.StudentDao$$FastClassBySpringCGLIB$$9548950c.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:746)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688)
at demo.eaze.school.common.api.dao.StudentDao$$EnhancerBySpringCGLIB$$3f35fe59.findStudentSearchData(<generated>)
at demo.eaze.school.controller.StudentController.students(StudentController.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
注意：
另一方面，如果我使用Spring的内部JpaReository界面，我没有遇到这个问题。
import demo.eaze.school.common.api.entity.StudentEntity;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import java.util.List;
import java.util.Optional;
@Repository
public interface StudentRepository extends JpaRepository<StudentEntity, Long> {
List<StudentEntity> findByEmail(String username);
Optional<StudentEntity> findByAdmissionNo(String admissionNumber);
}
所以我的问题是我如何摆脱异常，哪个部分需要配置好以及这是什么原因。