1
Я новичок в Struts и hibernate. Теперь я делаю это, следуя учебному пособию, чтобы интегрировать стойки и спящий режим и получить нулевой указатель Exception. Ошибка я получаюstruts 2 интеграция с hibernate 3 исключение пустой указателя
Sep 24, 2013 12:25:54 AM com.sun.faces.config.ConfigureListener contextInitialized
INFO: Initializing Sun's JavaServer Faces implementation (1.2_03-20070706-NIGHTLY) for context '/BookShop'
url isnull
log4j:WARN No appenders could be found for logger (org.hibernate.type.BasicTypeRegistry).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
null
<Sep 24, 2013 12:27:01 AM IST> <Error> <org.apache.struts2.dispatcher.Dispatcher> <BEA-000000> <Exception occurred during processing request: null
java.lang.NullPointerException
at com.author.action.AuthorAction.listAuthor(AuthorAction.java:71)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
Truncated. see log file for complete stacktrace
>
Структура каталогов:
Действие Файл AuthorAction.java:
package com.author.action;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.apache.struts2.ServletActionContext;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import com.author.listener.HibernateListener;
import com.author.model.Author;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
@SuppressWarnings({ "serial", "unchecked" })
public class AuthorAction extends ActionSupport implements ModelDriven{
Author author = new Author();
List<Author> authorList = new ArrayList<Author>();
public String execute() throws Exception {
return SUCCESS;
}
public Object getModel() {
return author;
}
public List<Author> getAuthorList() {
return authorList;
}
public void setAuthorList(List<Author> authorList) {
this.authorList = authorList;
}
//save customer
public String addAuthor() throws Exception{
//get hibernate session from the servlet context
SessionFactory sessionFactory =
(SessionFactory) ServletActionContext.getServletContext()
.getAttribute(HibernateListener.KEY_NAME);
Session session = sessionFactory.openSession();
//save it
author.setCreatedDate(new Date());
session.beginTransaction();
System.out.println("the value which is to be saved is"+author);
session.save(author);
session.getTransaction().commit();
//reload the customer list
authorList = null;
authorList = session.createQuery("from author").list();
System.out.println(" the author list is"+authorList);
return SUCCESS;
}
//list all customers
public String listAuthor() throws Exception{
//get hibernate session from the servlet context
SessionFactory sessionFactory =
(SessionFactory) ServletActionContext.getServletContext()
.getAttribute(HibernateListener.KEY_NAME);
Session session = sessionFactory.openSession();
authorList = session.createQuery("from author").list();
return SUCCESS;
}
}
Hibernate слушатель файла:
package com.author.listener;
import java.net.URL;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateListener implements ServletContextListener{
private Configuration config;
private SessionFactory factory;
private String path = "src/resources/hibernate.cfg.xml";
@SuppressWarnings("unchecked")
private static Class clazz = HibernateListener.class;
public static final String KEY_NAME = clazz.getName();
public void contextDestroyed(ServletContextEvent event) {
//
}
public void contextInitialized(ServletContextEvent event) {
try {
URL url = HibernateListener.class.getResource(path);
System.out.println("url is"+url);
config = new Configuration().configure(url);
factory = config.buildSessionFactory();
//save the Hibernate session factory into serlvet context
event.getServletContext().setAttribute(KEY_NAME, factory);
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
}
Моя модель файла Author.java:
package com.author.model;
import java.util.Date;
public class Author{
private Long customerId;
private String name;
private String address;
private Date createdDate;
public Long getCustomerId() {
return customerId;
}
public void setCustomerId(Long customerId) {
this.customerId = customerId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public Date getCreatedDate() {
return createdDate;
}
public void setCreatedDate(Date createdDate) {
this.createdDate = createdDate;
}
}
hibernate.cfg.xml:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.bytecode.use_reflection_optimizer">false</property>
<property name="hibernate.connection.password">root</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/bookshop</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<property name="use_sql_comments">false</property>
<mapping resource="com/author/hibernate/Author.hbm.xml" />
</session-factory>
</hibernate-configuration>
Hibernate Mapping файл Author.hbm.xml:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.mkyong.customer.model.Customer"
table="customer" catalog="mkyong">
<id name="customerId" type="java.lang.Long">
<column name="CUSTOMER_ID" />
<generator class="identity" />
</id>
<property name="name" type="string">
<column name="NAME" length="45" not-null="true" />
</property>
<property name="address" type="string">
<column name="ADDRESS" not-null="true" />
</property>
<property name="createdDate" type="timestamp">
<column name="CREATED_DATE" length="19" not-null="true" />
</property>
</class>
</hibernate-mapping>
JSP файла Author.jsp:
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
</head>
<body>
<h1>Struts 2 + Hibernate integration example</h1>
<h2>Add Customer</h2>
<s:form action="addAuthorAction" >
<s:textfield name="name" label="Name" value="" />
<s:textarea name="address" label="Address" value="" cols="50" rows="5" />
<s:submit />
</s:form>
<h2>All Customers</h2>
<s:if test="authorList.size() > 0">
<table border="1px" cellpadding="8px">
<tr>
<th>Customer Id</th>
<th>Name</th>
<th>Address</th>
<th>Created Date</th>
</tr>
<s:iterator value="authorList" status="userStatus">
<tr>
<td><s:property value="customerId" /></td>
<td><s:property value="name" /></td>
<td><s:property value="address" /></td>
<td><s:date name="createdDate" format="dd/MM/yyyy" /></td>
</tr>
</s:iterator>
</table>
</s:if>
<br/>
<br/>
</body>
</html>
struts.xml:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.devMode" value="false" />
<package name="default" namespace="/" extends="struts-default">
<action name="addAuthorAction"
class="com.author.action.AuthorAction" method="addAuthor" >
<result name="success">pages/Author.jsp</result>
</action>
<action name="listAuthorAction"
class="com.author.action.AuthorAction" method="listAuthor" >
<result name="success">pages/Author.jsp</result>
</action>
</package>
</struts>
web.xml:
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Bookshop</display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>com.author.listener.HibernateListener
</listener-class>
</listener>
</web-app>