使用反射在外部JAR / CLASS上调用包含Hibernate事务的方法(Java EE)
Posted
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了使用反射在外部JAR / CLASS上调用包含Hibernate事务的方法(Java EE)相关的知识,希望对你有一定的参考价值。
美好的一天!我有问题使hibernate在外部jar上工作,这个jar通过我的EJB反射加载。截至目前,我已经尝试了三个选项,但这些都没有,只是给了我错误。
以下是我尝试过的代码片段。我还在每个选项中添加了对哪一行发生错误的注释。
选项1.将会话从EJB传递到外部JAR THRU HashMap / Map
我的会话Bean类
public Object processRequest(Map parameters) {
String runnerClass = (String) parameters.get("runnerClass");
String value = (String) parameters.get("value");
String jarPath = "csys.runner.jar";
Object returnObj = null;
try {
parameters.put("sessionEjb", getSession());
File f = new File(jarPath);
URLClassLoader urlClassLoader = new URLClassLoader(new URL[]{f.toURL()},
System.class.getClassLoader());
Class c = urlClassLoader.loadClass(runnerClass);
Method m = c.getMethod("performService", new Class[]{String.class, Map.class});
returnObj = m.invoke(c.newInstance(), new Object[]{value, parameters});
} catch (MalformedURLException | ClassNotFoundException | NoSuchMethodException | SecurityException | InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException ex) {
Logger.getLogger(CSysSessionBean.class.getName()).log(Level.SEVERE, null, ex);
throw new RuntimeException(ex);
}
return returnObj;
}
外部JAR方法
public Object performService(String value, Map<Object, Object> parameters) {
this.session = (Session) parameters.get("sessionEjb"); // ERROR IN THIS PART ClassCastException
return null;
它给了我这个错误。
java.lang.ClassCastException: org.hibernate.internal.SessionImpl cannot be cast to org.hibernate.Session
选项2.通过方法的参数将会话从EJB传递到外部JAR我的会话Bean类
public Object processRequest(Map parameters) {
String runnerClass = (String) parameters.get("runnerClass");
String value = (String) parameters.get("value");
String jarPath = "csys.runner.jar";
Object returnObj = null;
try {
File f = new File(jarPath);
URLClassLoader urlClassLoader = new URLClassLoader(new URL[]{f.toURL()},
System.class.getClassLoader());
Class c = urlClassLoader.loadClass(runnerClass);
Method m = c.getMethod("performService", new Class[]{String.class, Map.class, org.hibernate.Session.class}); //ERROR IN THIS PART NoSuchMethodException
returnObj = m.invoke(c.newInstance(), new Object[]{value, parameters, getSession()});
} catch (MalformedURLException | ClassNotFoundException | NoSuchMethodException | SecurityException | InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException ex) {
Logger.getLogger(CSysSessionBean.class.getName()).log(Level.SEVERE, null, ex);
throw new RuntimeException(ex);
}
return returnObj;
}
外部JAR方法
public Object performService(String value, Map<Object, Object> parameters, org.hibernate.Session session) {
this.session = session;
return null;
}
现在它抛出了这个错误。
java.lang.NoSuchMethodException: csys.server.main.runner.ProjectRunner.performService(java.lang.String, java.util.Map, org.hibernate.Session)
选项3.在外部JAR中创建会话
我的会话Bean类
public Object processRequest(Map parameters) {
String runnerClass = (String) parameters.get("runnerClass");
String value = (String) parameters.get("value");
String jarPath = "csys.runner.jar";
String configPath = "D:/config/hibernate.cfg.xml";
Object returnObj = null;
try {
File f = new File(jarPath);
URLClassLoader urlClassLoader = new URLClassLoader(new URL[]{f.toURL()},
System.class.getClassLoader());
Class c = urlClassLoader.loadClass(runnerClass);
Method m = c.getMethod("performService", new Class[]{String.class, Map.class, String.class});
returnObj = m.invoke(c.newInstance(), new Object[]{value, parameters, configPath});
} catch (MalformedURLException | ClassNotFoundException | NoSuchMethodException | SecurityException | InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException ex) {
Logger.getLogger(CSysSessionBean.class.getName()).log(Level.SEVERE, null, ex);
throw new RuntimeException(ex);
}
return returnObj;
}
外部JAR方法
public Object performService(String value, Map<Object, Object> parameters, String configPath) {
Configuration configuration = new Configuration();
configuration.configure(new File(configpath)); //ERROR IN THIS PART, COULD NOT PARSE CONFIGURATION
SessionFactory sessionFactory = configuration.buildSessionFactory();
this.session = sessionFactory.openSession();
return null;
}
现在它又引发了另一个错误。
org.hibernate.HibernateException: Could not parse configuration: D:confighibernate.cfg.xml
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2163)
at org.hibernate.cfg.Configuration.configure(Configuration.java:2133)
Caused by: org.dom4j.DocumentException: org.dom4j.DocumentFactory cannot be cast to org.dom4j.DocumentFactory Nested exception: org.dom4j.DocumentFactory cannot be cast to org.dom4j.DocumentFactory
请注意,在我的EJB项目中执行hibernate事务运行良好,它只是从外部jar执行给我错误。
答案
找到了解决方案。问题出在我的ClassLoader上。
System.class.getClassLoader()
应该
this.getClass().getClassLoader()
以上是关于使用反射在外部JAR / CLASS上调用包含Hibernate事务的方法(Java EE)的主要内容,如果未能解决你的问题,请参考以下文章