Java开发网 - [实战＋疑问]一个Struts+Hibernate的例子

Topic: [实战＋疑问]一个Struts+Hibernate的例子

1.[实战＋疑问]一个Struts+Hibernate的例子

Posted by: seaboy
Posted on: 2004-09-01 10:32

介绍：很简单的一个功能，添加一段内容到数据库，
浏览添加的内容。
添加页面：input.jsp
浏览页面：list.jsp

数据库结构：

CREATE TABLE book (
  id int(11) NOT NULL auto_increment,
  name varchar(50) NOT NULL default '',
  PRIMARY KEY  (id)
) TYPE=MyISAM;

目录结构如下：


├─src
│  │  hibernate.cfg.xml
│  │
│  └─com
│      └─book
│          ├─hibernate
│          │      AbstractBook.java
│          │      Book.hbm.xml
│          │      Book.java
│          │      BookService.java
│          │      SessionFactory.java
│          │
│          └─struts
│              │  ApplicationResources.properties
│              │
│              ├─action
│              │      InputAction.java
│              │
│              └─form
│                      InputForm.java
│
└─WebRoot
    │  inc.jsp
    │  list.jsp
    │
    ├─form
    │      input.jsp
    │
    ├─META-INF
    │      MANIFEST.MF
    │
    └─WEB-INF
        │  .struts-config.mex
        │  struts-bean.tld
        │  struts-config.xml
        │  struts-html.tld
        │  struts-logic.tld
        │  struts-nested.tld
        │  struts-template.tld
        │  struts-tiles.tld
        │  validator-rules.xml
        │  web.xml
        │
        ├─classes
        │  │  hibernate.cfg.xml
        │  │
        │  └─com
        │      └─book
        │          ├─hibernate
        │          └─struts
        │              ├─action
        │              └─form
        └─lib
                ant-1.5.3.jar
                ant-optional-1.5.3.jar
                c3p0-0.8.4.5.jar
                cglib-full-2.0.1.jar
                commons-beanutils.jar
                commons-collections-2.1.jar
                commons-collections.jar
                commons-dbcp-1.1.jar
                commons-digester.jar
                commons-fileupload.jar
                commons-lang-1.0.1.jar
                commons-lang.jar
                commons-logging-1.0.3.jar
                commons-logging.jar
                commons-pool-1.1.jar
                commons-validator.jar
                concurrent-1.3.2.jar
                connector.jar
                dom4j-1.4.jar
                ehcache-0.7.jar
                hibernate2.jar
                jaas.jar
                jakarta-oro.jar
                jboss-cache.jar
                jboss-common.jar
                jboss-jmx.jar
                jboss-system.jar
                jcs-1.0-dev.jar
                jdbc2_0-stdext.jar
                jgroups-2.2.1.jar
                jta.jar
                junit-3.8.1.jar
                log4j-1.2.8.jar
                odmg-3.0.jar
                oscache-2.0.jar
                proxool-0.8.3.jar
                struts-legacy.jar
                struts.jar
                swarmcache-1.0rc2.jar
                xalan-2.4.0.jar
                xerces-2.4.0.jar
                xml-apis.jar

下面是相关代码：

2.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]

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Posted by: seaboy
Posted on: 2004-09-01 10:34

inc.jsp


<%@ page language="java"  contentType="text/html; charset=utf-8"%>
<%@taglib uri="/tags/struts-bean" prefix="bean" %>
<%@taglib uri="/tags/struts-html" prefix="html" %>
<%@taglib uri="/tags/struts-logic" prefix="logic" %>

/form/input.jsp


<%@ include file="../inc.jsp" %>

<html> 
[$nbsp][$nbsp]<head>
[$nbsp][$nbsp][$nbsp][$nbsp]<title>JSP for inputForm form</title>
[$nbsp][$nbsp]</head>
[$nbsp][$nbsp]<body>
[$nbsp][$nbsp][$nbsp][$nbsp]<html:form action="/input">
[$nbsp][$nbsp][$nbsp][$nbsp][$nbsp][$nbsp]name : <html:text property="name"/><html:errors property="name"/></br>
[$nbsp][$nbsp][$nbsp][$nbsp][$nbsp][$nbsp]<html:submit/><html:cancel/>
[$nbsp][$nbsp][$nbsp][$nbsp]</html:form>
[$nbsp][$nbsp][$nbsp][$nbsp]
[$nbsp][$nbsp]</body>
</html>

list.jsp



<%@ include file="inc.jsp"%>

<%@ page import="com.book.hibernate.*" %>
<%@ page import="java.util.*" %>

<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
  </head>
  
  <body>
    This is my JSP page. <br>
   <%
      /*
       * This code will generate a list of objects from the
       * database and place a reference to this list in the
       * request object.
       *
       */
      List bookList = BookService.getInstance().getBookList();
      request.setAttribute("book", bookList);
   %>

   <p>List of vips in <code>Vipdata</code> table of database <code>Vipinfo</code>.</p>
   <table border=1>
   <logic:iterate id="element" name="book" scope="request" type="com.book.hibernate.Book" >
   <tr>
      <td><bean:write name="element" property="name" /></td> 
   </tr>
   </logic:iterate>
   </table>
<html:link href="input.do">input</html:link>
  </body>
</html>

3.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]

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Posted by: seaboy
Posted on: 2004-09-01 10:35

/com/book/struts/action
InputAction.java

package com.book.struts.action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.book.struts.form.InputForm;
import com.book.hibernate.*;/** 

public class InputAction extends Action {

    // --------------------------------------------------------- Instance Variables

    // --------------------------------------------------------- Methods

    /** 
     * Method execute
     * @param mapping
     * @param form
     * @param request
     * @param response
     * @return ActionForward
     */
    public ActionForward execute(
        ActionMapping mapping,
        ActionForm form,
        HttpServletRequest request,
        HttpServletResponse response) {
        InputForm inputForm = (InputForm) form;
        
        Book book = new Book();
        if(inputForm.getName()!=null){
            book.setName(inputForm.getName());
            BookService.getInstance().addBook(book);
            
        }
        return mapping.findForward("list");
        //throw new UnsupportedOperationException(
        //    "Generated method 'execute(...)' not implemented.");
    }

}

com/book/struts/form
InputForm.java


class package com.book.struts.form;

import org.apache.struts.action.ActionForm;

public class InputForm extends ActionForm {

    /** name property */
    private String name;

    /** 
     * Returns the name.
     * @return String
     */
    public String getName() {
        return name;
    }

    /** 
     * Set the name.
     * @param name The name to set
     */
    public void setName(String name) {
        this.name = name;
    }

}

4.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]

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Posted by: seaboy
Posted on: 2004-09-01 10:37

AbstractBook.java


package com.book.hibernate;

import java.io.Serializable;

public abstract class AbstractBook 
    implements Serializable
{

    /** The value of the simple id property. */
    private java.lang.Integer id;

    /** The value of the simple name property. */
    private java.lang.String name;

    /**
     * Simple constructor of AbstractBook instances.
     */
    public AbstractBook()
    {
    }
    public AbstractBook(java.lang.Integer id)
    {
        this.setId(id);
    }
    
    
    /**
     * Return the value of the id column.
     * @return java.lang.Integer
     */
    public java.lang.Integer getId()
    {
        return this.id;
    }

    /**
     * Set the value of the id column.
     * @param id
     */
    public void setId(java.lang.Integer id)
    {
        this.id = id;
    }

    /**
     * Return the value of the name column.
     * @return java.lang.String
     */
    public java.lang.String getName()
    {
        return this.name;
    }

    /**
     * Set the value of the name column.
     * @param name
     */
    public void setName(java.lang.String name)
    {
        this.name = name;
    }
}

Book.java


// Book.java
package com.book.hibernate;

import java.io.Serializable;

/**
 * A class that represents a row in the 'book' table. 
 * This class may be customized as it is never re-generated 
 * after being created.
 */
public class Book
    extends AbstractBook
    implements Serializable
{
    /**
     * Simple constructor of Book instances.
     */
    public Book()
    {
    }
    public Book(java.lang.Integer id)
    {
        super(id);
    }

    /* Add customized code below */

}

Book.hbm.xml


<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
                            "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
                            "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping package="com.book.hibernate">

  <class name="Book" table="book">
    <id name="id" column="id">
      <generator class="increment" />
    </id>

    <property name="name" column="name" type="java.lang.String"
      not-null="true" />
  </class>

</hibernate-mapping>

5.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]

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Posted by: seaboy
Posted on: 2004-09-01 10:39

SessionFactory.java


package com.book.hibernate;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Session;
import net.sf.hibernate.cfg.Configuration;

/**
 * Configures and provides access to Hibernate sessions, tied to the
 * current thread of execution.  Follows the Thread Local Session
 * pattern, see {@link http://hibernate.org/42.html}.
 */
public class SessionFactory {

    /** 
     * Location of hibernate.cfg.xml file.
     * NOTICE: Location should be on the classpath as Hibernate uses
     * #resourceAsStream style lookup for its configuration file. That
     * is place the config file in a Java package - the default location
     * is the default Java package.<br><br>
     * Examples: <br>
     * <code>CONFIG_FILE_LOCATION = "/hibernate.conf.xml". 
     * CONFIG_FILE_LOCATION = "/com/foo/bar/myhiberstuff.conf.xml".</code> 
     */
    private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";

    /** Holds a single instance of Session */
    private static final ThreadLocal threadLocal = new ThreadLocal();

    /** The single instance of hibernate configuration */
    private static final Configuration cfg = new Configuration();

    /** The single instance of hibernate SessionFactory */
    private static net.sf.hibernate.SessionFactory sessionFactory;

    /**
     * Returns the ThreadLocal Session instance.  Lazy initialize
     * the <code>SessionFactory</code> if needed.
     *
     *  @return Session
     *  @throws HibernateException
     */
    public static Session currentSession() throws HibernateException {
        Session session = (Session) threadLocal.get();

        if (session == null) {
            if (sessionFactory == null) {
                try {
                    cfg.configure(CONFIG_FILE_LOCATION);
                    sessionFactory = cfg.buildSessionFactory();
                }
                catch (Exception e) {
                    System.err.println("%%%% Error Creating SessionFactory %%%%");
                    e.printStackTrace();
                }
            }
            session = sessionFactory.openSession();
            threadLocal.set(session);
        }

        return session;
    }

    /**
     *  Close the single hibernate session instance.
     *
     *  @throws HibernateException
     */
    public static void closeSession() throws HibernateException {
        Session session = (Session) threadLocal.get();
        threadLocal.set(null);

        if (session != null) {
            session.close();
        }
    }

    /**
     * Default constructor.
     */
    private SessionFactory() {
    }

}

BookService.java


package com.book.hibernate;

import java.util.List;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.ObjectNotFoundException;
import net.sf.hibernate.Query;
import net.sf.hibernate.Session;
import com.book.hibernate.Book;

/**
 * @author Administrator
 * 
 * TODO To change the template for this generated type comment go to Window -
 * Preferences - Java - Code Style - Code Templates
 */
public class BookService {

    private static BookService instance = null;

    private BookService() {

    }
    /**
     * 
     * @return
     */
    public static synchronized BookService getInstance() {
        if (instance == null) {
            instance = new BookService();
        }
        return instance;
    }
    /**
     * 
     * @param id
     * @return
     */
    public Book getBook(Long id) {
        Session session = null;
        try {
            session = SessionFactory.currentSession();
            return (Book) session.load(Book.class, id);
        } catch (ObjectNotFoundException onfe) {
            return null;
        } catch (HibernateException e) {
            System.err.println("Hibernate Exception" + e.getMessage());
            throw new RuntimeException();
        } finally {
            if (session != null) {
                try {
                    session.close();
                } catch (HibernateException e) {
                    System.err.println("Hibernate Exception" + e.getMessage());
                    throw new RuntimeException(e);
                }
            }
        }
    }

    public void updateBook(Book book) {
        /*
         * Use the ConnectionFactory to retrieve an open Hibernate Session.
         *  
         */

        Session session = null;
        try {
            session = SessionFactory.currentSession();
            /*
             * Update the state of the item using the Hibernate session's update
             * method.
             * 
             * Call the flush method to ensure that the object in saved.
             *  
             */
            session.update(book);
            session.flush();
        } catch (HibernateException e) {
            System.err.println("Hibernate Exception" + e.getMessage());
            throw new RuntimeException(e);
        }
        /*
         * Regardless of whether the above processing resulted in an Exception
         * or proceeded normally, we want to close the Hibernate session. When
         * closing the session, we must allow for the possibility of a Hibernate
         * Exception.
         *  
         */
        finally {
            if (session != null) {
                try {
                    session.close();
                } catch (HibernateException e) {
                    System.err.println("Hibernate Exception" + e.getMessage());
                    throw new RuntimeException(e);
                }

            }
        }

    }

    public List getBookList() {
        /*
         * Use the ConnectionFactory to retrieve an open Hibernate Session.
         *  
         */
        Session session = null;

        try {
            session = SessionFactory.currentSession();
            /*
             * Build HQL (Hibernate Query Language) query to retrieve a list of
             * all the items currently stored by Hibernate.
             */
            Query query = session
                    .createQuery("select Book from com.book.hibernate.Book Book order by Book.id");
            return query.list();

        } catch (HibernateException e) {
            System.err.println("Hibernate Exception" + e.getMessage());
            throw new RuntimeException(e);
        }
        /*
         * Regardless of whether the above processing resulted in an Exception
         * or proceeded normally, we want to close the Hibernate session. When
         * closing the session, we must allow for the possibility of a Hibernate
         * Exception.
         *  
         */
        finally {
            if (session != null) {
                try {
                    session.close();
                } catch (HibernateException e) {
                    System.err.println("Hibernate Exception" + e.getMessage());
                    throw new RuntimeException(e);
                }

            }
        }
    }

    /**
     * addItem() inserts new <code>Item</code> into the database through
     * Hibernate.
     * 
     * @param item
     *            A new <code>Item</code> to be added.
     */
    public void addBook(Book data) {

        Session session = null;

        try {
            session = SessionFactory.currentSession();
            session.save(data);
            session.flush();
        } catch (HibernateException e) {
            System.err.println("Hibernate Exception" + e.getMessage());
            throw new RuntimeException(e);
        }
        /*
         * Regardless of whether the above processing resulted in an Exception
         * or proceeded normally, we want to close the Hibernate session. When
         * closing the session, we must allow for the possibility of a Hibernate
         * Exception.
         *  
         */
        finally {
            if (session != null) {
                try {

                    session.close();
                } catch (HibernateException e) {
                    System.err.println("Hibernate Exception" + e.getMessage());
                    throw new RuntimeException(e);
                }

            }
        }

    }
}

6.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]

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Posted by: seaboy
Posted on: 2004-09-01 10:43

很多内容都是参照别人的例子写的。

感觉没什么错，
但是部署到tomcat,就是报错，刚刚接触，
想用个简单的例子实践一下，但是老失败。实在是受打击。

还请高手看看。哪里有问题。谢谢

提交input之后，tomcat提示：


type Exception report

message 

description The server encountered an internal error () that prevented it from fulfilling this request.

exception 

javax.servlet.ServletException
  org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:545)
  org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:486)
  org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
  org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
  org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

root cause 

java.lang.NullPointerException
  com.book.hibernate.SessionFactory.currentSession(SessionFactory.java:56)
  com.book.hibernate.BookService.addBook(BookService.java:162)
  com.book.struts.action.InputAction.execute(InputAction.java:46)
  org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
  org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
  org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
  org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

看来好像是SessionFactory出问题了，我看别人也差不多是这种模式写的呢。实在想不出什么问题。
单独试验Struts or Hibernate,好像问题不多，但是一结合起来。问题太多。
即使是个很简单的例子，都问题很多。真是....
Black Eye

7.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]

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Posted by: seaboy
Posted on: 2004-09-01 10:47

SessionFactory 好像并不能建立session???

现在数据库有数据，浏览list,也报错，

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:372)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

root cause

java.lang.NullPointerException
  com.book.hibernate.SessionFactory.currentSession(SessionFactory.java:56)
  com.book.hibernate.BookService.getBookList(BookService.java:117)
  org.apache.jsp.list_jsp._jspService(list_jsp.java:117)
  org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

8.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]	Copy to clipboard
Posted by: hua123456 Posted on: 2004-09-15 17:43 关注中..

9.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]	Copy to clipboard
Posted by: ming500 Posted on: 2004-09-15 18:10 好

10.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]	Copy to clipboard
Posted by: cyfboy Posted on: 2004-10-12 14:55 关注中！！

11.Re:[实战＋疑问]一个Struts+Hibernate的例子 [Re: seaboy]	Copy to clipboard
Posted by: LostParadise Posted on: 2004-10-14 12:55 我只是花了2分钟看了一下，不一定准确。 session = SessionFactory.currentSession()；如果在没有初始化session之前就运行到这里，一定会出现java.lang.NullPointerException的。所以要确保先创建了一个Seesion先。具体你查查hibernate的教程吧。