用Eclipse开发Struts实例－G

发布时间：2019-09-02 07:40:41编辑：auto阅读（1473）

    十、建立读取留言信息的Action类

    1、建立GuestBook的JavaBean类
    package com.meixin.beans;

    public class Guestbook
    {
      private int id;

      private String name;

      private String email;

      private String url;

      private String content;

      private String title;
        
      private String time;

      public String getTime()
      {
        return time;
      }

      public void setTime(String time)
      {
        this.time = time;
      }

      //id是主键，不提供set方法
      public int getId()
      {
        return id;
      }

      public String getName()
      {
        return name;
      }

      public void setName(String name)
      {
        this.name = name;
      }

      public String getEmail()
      {
        return email;
      }

      public void setEmail(String email)
      {
        this.email = email;
      }

      public String getUrl()
      {
        return url;
      }

      public void setUrl(String url)
      {
        this.url = url;
      }

      public String getContent()
      {
        return content;
      }

      public void setContent(String content)
      {
        this.content = content;
      }

      public String getTitle()
      {
        return title;
      }

      public void setTitle(String title)
      {
        this.title = title;
      }

    }
    2、读取留言的Action类
    package com.meixin.struts.action;

    import java.sql.SQLException;
    import java.util.List;

    import javax.naming.Context;
    import javax.naming.InitialContext;
    import javax.naming.NamingException;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import javax.sql.DataSource;

    import org.apache.commons.dbutils.QueryRunner;
    import org.apache.commons.dbutils.handlers.BeanListHandler;
    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.meixin.beans.Guestbook;

    public class ReadAction extends Action
    {
      public ActionForward execute(ActionMapping mapping, ActionForm form,
          HttpServletRequest request, HttpServletResponse response)
      {
        // 读取留言的SQL语句，以id降序排列，后发的留言先显示
        String sql = "select * from guestbook order by id desc";
        try
        {
          // 建立上下文对象，初始化
          Context context = new InitialContext();
          // 获取数据源，在Tomcat中的context.xml中设置的数据源名字要一样
          DataSource ds = (DataSource) context
              .lookup("java:/comp/env/jdbc/mssqlds");
          // 获取数据库的连接
          // ds.getConnection();
          // 用QueryRunner封装数据源，这个类完成了许多数据库的操作
          QueryRunner qr = new QueryRunner(ds);
              /**
            * 执行SQL语句，获取留言记录,这里将返回的每一个元素保存在Guestbook当中
            * 得到一个List，将来我们对List进行操作时的对象，就是一个Guestbook 类型的对象
            */
          List list = (List) qr.query(sql, new BeanListHandler(
              Guestbook.class));

          for(int i = 0;i<list.size();i++)
          {
            System.out.println(((Guestbook)list.get(i)).getName());
          }
          // 用request.setAttribute()将结果传入到JSP页面中
          request.setAttribute("list", list);
        }
        catch (NamingException e)
        {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
        catch (SQLException e)
        {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
        
        //转向forward值为guestbook.display对应的页面
        return mapping.findForward("guestbook.display");
      }
    }

     

    十一、建立display.jsp文件
    <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
    <%
      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>显示留言</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>
        <!-- 用c:forEach循环输出在Action中setAttribute()方法传来的list中的值 -->
        <c:forEach items="${requestScope.list }"
          var="article">
          <c:out value="${article.id}"></c:out>
          <c:out value="${article.name}"></c:out>
          <c:out value="${article.email}"></c:out>
          <c:out value="${article.url}"></c:out>
          <c:out value="${article.title}"></c:out>
          <c:out value="${article.content}"></c:out>
          <c:out value="${article.time}"></c:out>
          <br>
          <br>
        </c:forEach>
        <br>
      </body>
    </html>
    十二、读取留言的结果

     

    十三、在保存留言后自动进入读取留言页面

    1、建立forward

    2、struts-config.xml内容如下

     

    已在struts-config.xml加入了以下代码
    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN" "http://struts.apache.org/dtds/struts-config_1_3.dtd">

    <struts-config>
      <form-beans>
        <form-bean name="inputForm"
          type="org.apache.struts.validator.DynaValidatorForm">
          <form-property name="title" type="java.lang.String" />
          <form-property name="content" type="java.lang.String" />
          <form-property name="url" type="java.lang.String" />
          <form-property name="email" type="java.lang.String" />
          <form-property name="name" type="java.lang.String" />
        </form-bean>

      </form-beans>

      <global-exceptions />
      <global-forwards>
        <forward name="guestbook.display" path="/form/display.jsp" />
        <forward name="guestbook.read" path="/read.do" redirect="true" />

      </global-forwards>

      <action-mappings>
        <action attribute="inputForm" input="/form/input.jsp"
          name="inputForm" path="/input" scope="request"
          type="com.meixin.struts.action.InputAction" />
        <action name="readForm" path="/read"
          type="com.meixin.struts.action.ReadAction" />

      </action-mappings>

      <message-resources
        parameter="com.meixin.struts.ApplicationResources" />
      <!-- 加入Struts的一个插件,对表单进行验证,这里只能手动添加 -->
      <plug-in className="org.apache.struts.validator.ValidatorPlugIn">
        <set-property property="pathnames"
          value="/org/apache/struts/validator/validator-rules.xml,/WEB-INF/validations.xml" />
      </plug-in>
    </struts-config>

     

    3、修改InputAction.java文件

     

    //保存后自动转向到读取留言页面
    return mapping.findForward("guestbook.read");

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