Java 执行openjpa查询的性能
我有一个带有cxf 3.0.1框架和openjpa 2.3.0的rest web应用程序。web.xml文件:Java 执行openjpa查询的性能,java,performance,jpa,openjpa,Java,Performance,Jpa,Openjpa,我有一个带有cxf 3.0.1框架和openjpa 2.3.0的rest web应用程序。web.xml文件: <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.su
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name>Mobile app rest services</display-name>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>WEB-INF/cxf-servlet.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>CXFServlet</servlet-name>
<servlet-class>org.apache.cxf.transport.servlet.CXFServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>CXFServlet</servlet-name>
<url-pattern>/services/*</url-pattern>
</servlet-mapping>
</web-app>
[164毫秒]花费的时间vs执行查询时间:824毫秒
这是一个连接大约4个表的本机查询。
我自己管理entityManager生命周期—在请求开始时创建,在请求结束时结束
/**
* Enables the derived classes to execute read only operation using the entityManager
*
* @param <T>
* @param operation
* @return
*/
protected <T> T executeNonTransactionOperation(SimpleOperation<T> operation) {
try {
EntityManager entityManager = PersistenceHelper.getEntityManager();
T result = operation.execute(entityManager);
return result;
} catch (Exception e) {
//TODO: throw our custom exception?
throw e;
} finally {
PersistenceHelper.closeEntityManager();
}
}
/**
* Enables the derived classes to execute operation (inside transaction) using the entityManager
*
* @param <T>
* @param operation
* @return
*/
protected <T> T executeTransactionOperation(SimpleOperation<T> operation) {
try {
EntityManager entityManager = PersistenceHelper.getEntityManager();
PersistenceHelper.beginTransaction();
T result = operation.execute(entityManager);
PersistenceHelper.commit();
return result;
} catch (Exception e) {
PersistenceHelper.rollback();
//TODO: throw our custom exception?
throw e;
} finally {
PersistenceHelper.closeEntityManager();
}
}
/**
*使派生类能够使用entityManager执行只读操作
*
*@param
*@param操作
*@返回
*/
受保护的T ExecuteOnTransaction操作(SimpleOperation操作){
试一试{
EntityManager EntityManager=PersistenceHelper.getEntityManager();
T result=operation.execute(entityManager);
返回结果;
}捕获(例外e){
//TODO:抛出自定义异常?
投掷e;
}最后{
PersistenceHelper.closeEntityManager();
}
}
/**
*使派生类能够使用entityManager执行操作(内部事务)
*
*@param
*@param操作
*@返回
*/
受保护的T executeTransactionOperation(SimpleOperation操作){
试一试{
EntityManager EntityManager=PersistenceHelper.getEntityManager();
PersistenceHelper.beginTransaction();
T result=operation.execute(entityManager);
PersistenceHelper.commit();
返回结果;
}捕获(例外e){
PersistenceHelper.rollback();
//TODO:抛出自定义异常?
投掷e;
}最后{
PersistenceHelper.closeEntityManager();
}
}
如果openjpa声明它执行得那么快,为什么会有这样的差异呢?问题在于,您正在测量两种不同的东西。
164 ms
是数据库执行查询所花费的时间。我怀疑您测量的824 ms
是查询执行+实体对象实例化。如果这与MySQL有关,请向我们展示查询。如果不相关,请删除标记。是的,你是对的,我考虑过,但似乎实例化java对象的时间太长了。这是相当长的时间,因此值得深入研究。我再次怀疑,您可能不仅仅是在度量对象实例化/结果集处理。最好的办法是连接一个分析器,看看时间花在哪里。
2333 thePU TRACE [qtp1769466090-14] openjpa.jdbc.SQL - <t 2143135982, conn 1825478533> [164 ms] spent
2015-06-15[INFO]xz.orm.dao.impl.util.PerfMeasureUtil stop: :: exec query time: 824ms
/**
* Enables the derived classes to execute read only operation using the entityManager
*
* @param <T>
* @param operation
* @return
*/
protected <T> T executeNonTransactionOperation(SimpleOperation<T> operation) {
try {
EntityManager entityManager = PersistenceHelper.getEntityManager();
T result = operation.execute(entityManager);
return result;
} catch (Exception e) {
//TODO: throw our custom exception?
throw e;
} finally {
PersistenceHelper.closeEntityManager();
}
}
/**
* Enables the derived classes to execute operation (inside transaction) using the entityManager
*
* @param <T>
* @param operation
* @return
*/
protected <T> T executeTransactionOperation(SimpleOperation<T> operation) {
try {
EntityManager entityManager = PersistenceHelper.getEntityManager();
PersistenceHelper.beginTransaction();
T result = operation.execute(entityManager);
PersistenceHelper.commit();
return result;
} catch (Exception e) {
PersistenceHelper.rollback();
//TODO: throw our custom exception?
throw e;
} finally {
PersistenceHelper.closeEntityManager();
}
}