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  • 菜鸟学习Struts——简易计算器

    这是学习Struts的一个简单的例子文件结构如下:

    1配置Struts环境

    2、新建input.jspsuccess.jsperror.jsp

    input.jsp代码如下:

    <%@ page language="java" contentType="text/html; charset=GB18030"
        pageEncoding="GB18030"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=GB18030">
    <title>Insert title here</title>
    </head>
    <body>
    <h1>简易计算器</h1>
    	<hr>
    	<form action="unit/cal.action" method="post">
    		<input type="text" name="value1">
    		<select name="flag">
    			<option value="+">+</option>
    			<option value="-">-</option>
    			<option value="*">*</option>
    			<option value="/">/</option>
    		</select>
    		<input type="text" name="value2">
    		<input type="submit" value="计算">
    		
    	</form>
    
    </body>
    </html>


    3、新建com.bjpowernode.struts这个包。

    关键的是新建CalAactionForm.javaCalAction.java这两个类的时候需要继承StrutsActionFormAction这两个类如下:

    CalAactionForm.java


    代码如下:

     

    package com.bjpowernode.struts;
    
    import org.apache.struts.action.ActionForm;
    
    @SuppressWarnings("serial")
    public class CalAactionForm extends ActionForm {
    
    	private int value1;
    	
    	private String flag;
    	
    	private int value2;
    
    	public int getValue1() {
    		return value1;
    	}
    
    	public void setValue1(int value1) {
    		this.value1 = value1;
    	}
    
    	public String getFlag() {
    		return flag;
    	}
    
    	public void setFlag(String flag) {
    		this.flag = flag;
    	}
    
    	public int getValue2() {
    		return value2;
    	}
    
    	public void setValue2(int value2) {
    		this.value2 = value2;
    	}
    	
    }
    

    注意:这个类里面的属性要和input.jsp里面的表单数据一致

    ActionForm并非单单是获取页面表单的数据,它也可以获取其他的数据,比如说通过超链接传过来的数据。也就是说凡是从页面传递过来的参数都可以注入到ActionForm。就像C#里面我们写的实体类一样。

    CalAction.java

    代码如下:

    package com.bjpowernode.struts;
    
    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;
    
    public class CalAction extends Action {
    
    	@Override
    	public ActionForward execute(ActionMapping mapping, ActionForm form,
    			HttpServletRequest request, HttpServletResponse response)
    			throws Exception {
    		CalAactionForm calForm=(CalAactionForm)form;
    		
    		int value1=calForm.getValue1();
    		String flag=calForm.getFlag();
    		int value2=calForm.getValue2();
    		
    		int result=0;
    		
    		try{
    		if("+".equals(flag)){
    			result=value1+value2;
    		}else if("-".equals(flag)){
    			result=value1-value2;
    		}else if("*".equals(flag)){
    			result=value1*value2;
    		}else if("/".equals(flag)){
    			result=value1/value2;
    		}
    		request.setAttribute("result",result);
    		return	mapping.findForward("success");
    		
    		}catch(Exception e){
    			e.printStackTrace();
    			mapping.findForward("error");
    			
    		}
    		
    		
    		return mapping.findForward("error");
    	}
    
    	
    }
    


    4、配置struts-config.xml

         代码如下:

    <?xml version="1.0" encoding="ISO-8859-1" ?>
    
    <!DOCTYPE struts-config PUBLIC
              "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN"
              "http://jakarta.apache.org/struts/dtds/struts-config_1_2.dtd">
    
    <struts-config>
    	<form-beans>
    		<form-bean  name="calForm" type="com.bjpowernode.struts.CalAactionForm"/>
    	</form-beans>
    	
    	<action-mappings>
    		<action path="/unit/cal"
    				type="com.bjpowernode.struts.CalAction"
    				name="calForm"
    				scope="request"		
    		>
    			<forward name="success" path="/success.jsp"/>
    			<forward name="error" path="/error.jsp"/>
    		
    		</action>
    		
    	</action-mappings>
    
    </struts-config>
    

         注意:struts-config.xml只要更改了就要重新启动一次Tomcat

    5、配置web.xml。

    代码如下:

    <?xml version="1.0" encoding="UTF-8"?>
    <web-app version="2.4" 
    	xmlns="http://java.sun.com/xml/ns/j2ee" 
    	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    	http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
     <servlet>
        <servlet-name>action</servlet-name>
        <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
        <init-param>
          <param-name>config</param-name>
          <param-value>/WEB-INF/struts-config.xml</param-value>
        </init-param>
        <init-param>
          <param-name>debug</param-name>
          <param-value>2</param-value>
        </init-param>
        <init-param>
          <param-name>detail</param-name>
          <param-value>2</param-value>
        </init-param>
        <load-on-startup>2</load-on-startup>
      </servlet>
    
    
      <!-- Standard Action Servlet Mapping -->
      <servlet-mapping>
        <servlet-name>action</servlet-name>
        <url-pattern>*.action</url-pattern>
      </servlet-mapping>
    </web-app>
    

    6、填写success.jsperror.jsp代码。

    Success.jsp代码如下:

    <%@ page language="java" contentType="text/html; charset=GB18030"
        pageEncoding="GB18030"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=GB18030">
    <title>Insert title here</title>
    </head>
    <body>
       ${calForm.value1}
       ${calForm.flag }
       ${calForm.value2}
       =
       ${result }
    </body>
    </html>


    Error.jsp代码如下:

    <%@ page language="java" contentType="text/html; charset=GB18030"
        pageEncoding="GB18030"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=GB18030">
    <title>Insert title here</title>
    </head>
    <body>
    ${calForm.value1 }
       ${calForm.flag }
       ${calForm.value2 }
       计算失败!
    </body>
    </html>


    7index.jsp代码。

    <%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
    <%
    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>
      	<a href="input.jsp">简易计算器</a>
      </body>
    </html>
    


     

    8、效果图:


    点击计算,成功则显示:


    如果失败则:


    Meet so Meet. C plusplus I-PLUS....
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  • 原文地址:https://www.cnblogs.com/iplus/p/4490404.html
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