问题描述
因此，我找到了有关使用spring-boot和olingo创建odata服务的教程
https://www.baeldung.com/olingo
但是问题是我遇到了连接泄漏。在服务器开发方面，我并不是真正的专家，因此我很难找到泄漏发生的地方。我认为这里的2个重要源代码是我的DoeOdataJpaServiceFactory.java
package gov.doe.app;
import java.util.List;
import java.util.Map;
import javax.persistence.EntityGraph;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.FlushModeType;
import javax.persistence.LockModeType;
import javax.persistence.Query;
import javax.persistence.StoredProcedureQuery;
import javax.persistence.TypedQuery;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaDelete;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.CriteriaUpdate;
import javax.persistence.metamodel.metamodel;
import javax.servlet.http.HttpServletRequest;
import org.apache.olingo.odata2.api.processor.ODataContext;
import org.apache.olingo.odata2.jpa.processor.api.ODataJPAContext;
import org.apache.olingo.odata2.jpa.processor.api.ODataJPAServiceFactory;
import org.apache.olingo.odata2.jpa.processor.api.exception.ODataJPARuntimeException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import gov.doe.app.JerseyConfig;
/**
* ODataJPAServiceFactory implementation for our sample domain
* @author Philippe
*
*/
@Component
public class DoeODataJPAServiceFactory extends ODataJPAServiceFactory {
private static final Logger log = LoggerFactory.getLogger(DoeODataJPAServiceFactory.class);
public DoeODataJPAServiceFactory() {
// Enable detailed error messages (useful for debugging)
setDetailErrors(true);
}
/**
* This method will be called by Olingo on every request to
* initialize the ODataJPAContext that will be used.
*/
@Override
public ODataJPAContext initializeODataJPAContext() throws ODataJPARuntimeException {
log.info("[I32] >>> initializeODataJPAContext()");
ODataJPAContext ctx = getoDataJPAContext();
ODataContext octx = ctx.getoDataContext();
HttpServletRequest request = (HttpServletRequest)octx.getParameter(ODataContext.HTTP_SERVLET_REQUEST_OBJECT);
EntityManager em = (EntityManager)request.getAttribute(JerseyConfig.EntityManagerFilter.EM_REQUEST_ATTRIBUTE);
// Here we're passing the EM that was created by the EntityManagerFilter (see JerseyConfig)
ctx.setEntityManager(new EntityManagerWrapper(em));
ctx.setPersistenceUnitName("default");
// We're managing the EM's lifecycle,so we must inform Olingo that it should not
// try to manage transactions and/or persistence sessions
ctx.setContainerManaged(true);
return ctx;
}
static class EntityManagerWrapper implements EntityManager {
private EntityManager delegate;
public void persist(Object entity) {
log.info("[I68] persist: entity.class=" + entity.getClass()
.getSimpleName());
delegate.persist(entity);
// delegate.flush();
}
public <T> T merge(T entity) {
log.info("[I74] merge: entity.class=" + entity.getClass()
.getSimpleName());
return delegate.merge(entity);
}
public void remove(Object entity) {
log.info("[I78] remove: entity.class=" + entity.getClass()
.getSimpleName());
delegate.remove(entity);
}
public <T> T find(Class<T> entityClass,Object primaryKey) {
log.info("[1]find");
return delegate.find(entityClass,primaryKey);
}
public <T> T find(Class<T> entityClass,Object primaryKey,Map<String,Object> properties) {
log.info("[2]find");
return delegate.find(entityClass,primaryKey,properties);
}
public <T> T find(Class<T> entityClass,LockModeType lockMode) {
log.info("[3]find");
return delegate.find(entityClass,lockMode);
}
public <T> T find(Class<T> entityClass,LockModeType lockMode,Object> properties) {
log.info("[4]find");
return delegate.find(entityClass,lockMode,properties);
}
public <T> T getReference(Class<T> entityClass,Object primaryKey) {
log.info("[5]find");
return delegate.getReference(entityClass,primaryKey);
}
public void flush() {
log.info("[1]flush");
delegate.flush();
}
public void setFlushMode(FlushModeType flushMode) {
log.info("[1]setflushmode");
delegate.setFlushMode(flushMode);
}
public FlushModeType getFlushMode() {
log.info("[1]getflushmode");
return delegate.getFlushMode();
}
public void lock(Object entity,LockModeType lockMode) {
log.info("[1]lock");
delegate.lock(entity,lockMode);
}
public void lock(Object entity,Object> properties) {
log.info("[2]lock");
delegate.lock(entity,properties);
}
public void refresh(Object entity) {
log.info("[1]refresh");
delegate.refresh(entity);
}
public void refresh(Object entity,Object> properties) {
log.info("[2]refresh");
delegate.refresh(entity,properties);
}
public void refresh(Object entity,LockModeType lockMode) {
log.info("[3]refresh");
delegate.refresh(entity,lockMode);
}
public void refresh(Object entity,Object> properties) {
log.info("[4]refresh");
delegate.refresh(entity,properties);
}
public void clear() {
log.info("[1]clear");
delegate.clear();
}
public void detach(Object entity) {
log.info("[1]detach");
delegate.detach(entity);
}
public boolean contains(Object entity) {
log.info("[1]contains");
return delegate.contains(entity);
}
public LockModeType getLockMode(Object entity) {
log.info("[1]getlockmode");
return delegate.getLockMode(entity);
}
public void setProperty(String propertyName,Object value) {
log.info("[1]setproperty:",propertyName);
delegate.setProperty(propertyName,value);
}
public Map<String,Object> getProperties() {
log.info("[1]getproperties");
return delegate.getProperties();
}
public Query createquery(String qlString) {
log.info("[1]createquery:",qlString);
return delegate.createquery(qlString);
}
public <T> TypedQuery<T> createquery(CriteriaQuery<T> criteriaQuery) {
log.info("[2]createquery");
return delegate.createquery(criteriaQuery);
}
public Query createquery(CriteriaUpdate updateQuery) {
log.info("[3]createquery");
return delegate.createquery(updateQuery);
}
public Query createquery(CriteriaDelete deleteQuery) {
log.info("[4]createquery");
return delegate.createquery(deleteQuery);
}
public <T> TypedQuery<T> createquery(String qlString,Class<T> resultClass) {
log.info("[5]createquery");
return delegate.createquery(qlString,resultClass);
}
public Query createNamedQuery(String name) {
log.info("[1]creatnamedequery");
return delegate.createNamedQuery(name);
}
public <T> TypedQuery<T> createNamedQuery(String name,Class<T> resultClass) {
log.info("[2]creatnamedequery");
return delegate.createNamedQuery(name,resultClass);
}
public Query createNativeQuery(String sqlString) {
log.info("[1]creatnativeequery");
return delegate.createNativeQuery(sqlString);
}
public Query createNativeQuery(String sqlString,Class resultClass) {
log.info("[2]creatnativeequery");
return delegate.createNativeQuery(sqlString,resultClass);
}
public Query createNativeQuery(String sqlString,String resultSetMapping) {
log.info("[3]creatnativeequery");
return delegate.createNativeQuery(sqlString,resultSetMapping);
}
public StoredProcedureQuery createNamedStoredProcedureQuery(String name) {
log.info("[1]creatnamedstoredequery");
return delegate.createNamedStoredProcedureQuery(name);
}
public StoredProcedureQuery createStoredProcedureQuery(String procedureName) {
log.info("[1]createstoredequery");
return delegate.createStoredProcedureQuery(procedureName);
}
public StoredProcedureQuery createStoredProcedureQuery(String procedureName,Class... resultClasses) {
log.info("[2]createstoredequery");
return delegate.createStoredProcedureQuery(procedureName,resultClasses);
}
public StoredProcedureQuery createStoredProcedureQuery(String procedureName,String... resultSetMappings) {
log.info("[2]createstoredequery");
return delegate.createStoredProcedureQuery(procedureName,resultSetMappings);
}
public void joinTransaction() {
log.info("[1]jointransaction");
delegate.joinTransaction();
}
public boolean isJoinedToTransaction() {
log.info("[1]isjoinedtoransaction");
return delegate.isJoinedToTransaction();
}
public <T> T unwrap(Class<T> cls) {
log.info("[1]unwrap");
return delegate.unwrap(cls);
}
public Object getDelegate() {
log.info("[1]getdelegate");
return delegate.getDelegate();
}
public void close() {
log.info("[I229] close");
delegate.close();
}
public boolean isopen() {
boolean isOpen = delegate.isopen();
log.info("[I236] isOpen: " + isOpen);
return isOpen;
}
public EntityTransaction getTransaction() {
log.info("[I240] getTransaction()");
return delegate.getTransaction();
}
public EntityManagerFactory getEntityManagerFactory() {
return delegate.getEntityManagerFactory();
}
public CriteriaBuilder getCriteriaBuilder() {
return delegate.getCriteriaBuilder();
}
public metamodel getmetamodel() {
return delegate.getmetamodel();
}
public <T> EntityGraph<T> createEntityGraph(Class<T> roottype) {
return delegate.createEntityGraph(roottype);
}
public EntityGraph<?> createEntityGraph(String graphName) {
return delegate.createEntityGraph(graphName);
}
public EntityGraph<?> getEntityGraph(String graphName) {
return delegate.getEntityGraph(graphName);
}
public <T> List<EntityGraph<? super T>> getEntityGraphs(Class<T> entityClass) {
return delegate.getEntityGraphs(entityClass);
}
public EntityManagerWrapper(EntityManager delegate) {
this.delegate = delegate;
}
}
}
和JeresyConfig.java
package gov.doe.app;
import java.io.IOException;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.Path;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
import javax.ws.rs.container.ContainerResponseContext;
import javax.ws.rs.container.ContainerResponseFilter;
import javax.ws.rs.core.Context;
import javax.ws.rs.ext.Provider;
import org.apache.olingo.odata2.api.ODataServiceFactory;
import org.apache.olingo.odata2.core.rest.ODaTarootLocator;
import org.apache.olingo.odata2.core.rest.app.ODataApplication;
import org.glassfish.jersey.server.ResourceConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
/**
* Jersey JAX-RS configuration
* @author Philippe
*
*/
@Component
@ApplicationPath("/odata")
public class JerseyConfig extends ResourceConfig {
public JerseyConfig(DoeODataJPAServiceFactory serviceFactory,EntityManagerFactory emf) {
ODataApplication app = new ODataApplication();
app
.getClasses()
.forEach( c -> {
// Avoid using the default RootLocator,as we want
// a Spring Managed one
if ( !ODaTarootLocator.class.isAssignableFrom(c)) {
register(c);
}
});
register(new DoeRootLocator(serviceFactory));
register( new EntityManagerFilter(emf));
}
/**
* This filter handles the EntityManager transaction lifecycle.
* @author Philippe
*
*/
@Provider
public static class EntityManagerFilter implements ContainerRequestFilter,ContainerResponseFilter {
private static final Logger log = LoggerFactory.getLogger(EntityManagerFilter.class);
public static final String EM_REQUEST_ATTRIBUTE = EntityManagerFilter.class.getName() + "_ENTITY_MANAGER";
private final EntityManagerFactory emf;
@Context
private HttpServletRequest httpRequest;
public EntityManagerFilter(EntityManagerFactory emf) {
this.emf = emf;
}
@Override
public void filter(ContainerRequestContext ctx) throws IOException {
log.info("[I60] >>> filter");
EntityManager em = this.emf.createEntityManager();
httpRequest.setAttribute(EM_REQUEST_ATTRIBUTE,em);
// Start a new transaction unless we have a simple GET
try {
if (!"GET".equalsIgnoreCase(ctx.getmethod())) {
em.getTransaction()
.begin();
}
} catch (Exception e) {
//Todo: handle exception
log.info("[I68] <<< EXCEPTION");
em.close();
throw e;
}
}
@Override
public void filter(ContainerRequestContext requestContext,ContainerResponseContext responseContext) throws IOException {
log.info("[I68] <<< filter");
EntityManager em = (EntityManager) httpRequest.getAttribute(EM_REQUEST_ATTRIBUTE);
try {
if (!"GET".equalsIgnoreCase(requestContext.getmethod())) {
EntityTransaction t = em.getTransaction();
if (t.isActive()) {
if (!t.getRollbackOnly()) {
t.commit();
}
}
}
} catch (Exception e) {
//Todo: handle exception
log.info("[I68] <<< EXCEPTION");
em.close();
throw e;
}
log.info("[I68] <<< CLOSE");
em.close();
}
}
@Path("/")
public static class DoeRootLocator extends ODaTarootLocator {
private DoeODataJPAServiceFactory serviceFactory;
public DoeRootLocator(DoeODataJPAServiceFactory serviceFactory) {
this.serviceFactory = serviceFactory;
}
@Override
public ODataServiceFactory getServiceFactory() {
return this.serviceFactory;
}
}
}
其余只是模型。 据我了解，这两个负责将请求转换为odata服务。我可以看到，JerseyConfig.java中的私有类的过滤器功能之一有一个调用来关闭EntityManager，我认为这应该关闭连接。不幸的是，它似乎并没有关闭连接。这里缺少我应该实施的东西吗？当它在我们的SAP云平台服务中运行时，似乎发生了泄漏，但是当我在本地计算机上运行时，未出现问题。至少我已经使用每分钟执行一次get请求的脚本在本地计算机上运行了该脚本，但是我的应用程序在6小时后仍然可以正常工作。另一方面，当我在SAP云平台服务上运行应用程序时，所有连接都不可用的时间不到一个小时。有人可以告诉我我在这里做错了什么，以及为什么在本地运行它和在服务上运行之间的区别？是运行应用程序的区别还是代码有问题？
更新：在进一步测试中，似乎GET请求导致了泄漏，但是POST请求被关闭就好了。仍然需要测试DELETE和PUT是否会泄漏。
更新2：看来我最初的评估是错误的。我创建了更多测试，实际上问题是调用并发请求会导致一些无法获取JDBC连接，从而导致泄漏。现在的第一个问题是，当Spring Boot应该能够处理并发连接时，为什么并发连接会出现问题，而出现错误时该如何秒关闭连接？我在EntityManagerFilter中编辑了函数以捕获异常并从那里关闭连接，但是它似乎无法正常工作，而且仍然会泄漏。
解决方法
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