一个简单的struts的例子

index.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>测试ActionForm</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>
      <h1>测试ActionForm</h1>
      <hr>
      <li>测试动态ActionForm</li><br>
      <form action="dyanactionform.do" method="post">
          姓名：<input type="text" name="username"><br>
           年龄：<input type="text" name="age"><br>
           <input type="submit" value="提交">    
      </form>  
      <p>
      <li>测试struts上传文件</li><br>
      <form action="upload.do" method="post" enctype="multipart/form-data">
          标题：<input type="text" name="title"><br>
          文件：<input type="file" name="myfile"><br>
          <input type="submit" value="提交">
      </form>
      <p>
      <li>空字段测试</li><br>
      <form action="blankfield.do" method="post">
          姓名：<input type="text" name="username"><br>
          <input type="submit" value="提交">
      </form>
       <p>
       <li>测试ActionForm类型转换器</li><br>
       <form action="typeconvert.do" method="post">
           intValue:<input type="text" name="intValue"><br>
           doubleValue:<input type="text" name="doubleValue"><br>
           booleanValue:<input type="text" name="booleanValue"><br>
           java.sql.Date:<input type="text" name="sqlDate"><br>
           java.util.Date:<input type="text" name="utilDate"><br>
           <input type="submit" value="提交">
       </form>
  </body>
</html>

配置文件

struts-config.xml

代码 
<?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="dynaForm" type="org.apache.struts.action.DynaActionForm">
            <form-property name="username" type="java.lang.String"/>
            <form-property name="age" type="java.lang.Integer"/>
        </form-bean>
        
        <form-bean name="uploadForm" type="com.bjsxt.struts.UploadActionForm"/>
        
        <form-bean name="blankFieldForm" type="com.bjsxt.struts.BlankFieldActionForm"/>
        
        <form-bean name="typeconvertForm" type="com.bjsxt.struts.TypeConvertActionForm"/>
    </form-beans>
    
    <action-mappings>
        <action path="/dyanactionform"
                type="com.bjsxt.struts.DynaActionFormTestAction"
                name="dynaForm"
                scope="request"
        >
            <forward name="success" path="/dyna_actionform.jsp"/>
        </action>
        
        <action path="/upload"
                type="com.bjsxt.struts.UploadTestAction"
                name="uploadForm"
                scope="request"
        >
            <forward name="success" path="/upload_success.jsp"/>
        </action>
        
        <action path="/blankfield"
                type="com.bjsxt.struts.BlankFieldTestAction"
                name="blankFieldForm"
                scope="request"        
        >
            <forward name="success" path="/blankfield_success.jsp"/>
        </action>
        
        <action path="/typeconvert"
                type="com.bjsxt.struts.TypeConvertTestAction"
                name="typeconvertForm"
                scope="request"
        >
            <forward name="success" path="/typeconvert_success.jsp"/>    
        </action>
    </action-mappings>
    
    <controller maxFileSize="10M"/>
    
    <plug-in className="com.bjsxt.struts.UtilDateConverterInitWithPlugin"/>
</struts-config>

1、AtionForm

代码 
package com.bjsxt.struts;

import org.apache.struts.action.ActionForm;

/**
 * 测试空字段
 * @author Administrator
 *
 */
public class BlankFieldActionForm extends ActionForm {

    private String username;
    
    private String password;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}
代码 
package com.bjsxt.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;

/**
 * 测试空字段
 * @author Administrator
 *
 */
public class BlankFieldTestAction extends Action {

    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        return mapping.findForward("success");
    }

}
代码 
<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<%@ page import="com.bjsxt.struts.*" %>    
<!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>
    <%
        BlankFieldActionForm form = (BlankFieldActionForm)request.getAttribute("blankFieldForm");
     %>
    <li>jsp脚本</li><br>
    姓名：<%=form.getUsername() %><br>
    密码:<%=form.getPassword() %><br>
    <p>
    <li>el表达式</li><br>
    姓名：${blankFieldForm.username }<br>
    密码:${blankFieldForm.password }<br>
</body>
</html>

业务逻辑类

DynaActionFormTestAction.java

代码 
package com.bjsxt.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;
import org.apache.struts.action.DynaActionForm;

/**
 * 测试动态ActionForm
 * @author Administrator
 *
 */
public class DynaActionFormTestAction extends Action {

    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        DynaActionForm daf = (DynaActionForm)form;
        String username = (String)daf.get("username");
        Integer age = (Integer)daf.get("age");
        System.out.println("username=" + username);
        System.out.println("age=" + age);
        return mapping.findForward("success");
    }

}

成功的返回页面

dyna_actionform.jsp

代码 
<%@ 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>
    用户名称：${dynaForm.map.username }<br>
    年龄：${dynaForm.map.age }<br>
</body>
</html>

 2、struts上传文件

代码 
package com.bjsxt.struts;

import org.apache.struts.action.ActionForm;
import org.apache.struts.upload.FormFile;

/**
 * 上传ActionForm
 * @author Administrator
 *
 */
public class UploadActionForm extends ActionForm {

    private String title;
    
    //必须采用FormFile
    private FormFile myfile;

    public String getTitle() {
        return title;
    }

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

    public FormFile getMyfile() {
        return myfile;
    }

    public void setMyfile(FormFile myfile) {
        this.myfile = myfile;
    }
}
代码 
package com.bjsxt.struts;

import java.io.FileOutputStream;

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 org.apache.struts.upload.FormFile;

/**
 * 上传Action
 * @author Administrator
 *
 */
public class UploadTestAction extends Action {

    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        UploadActionForm uaf = (UploadActionForm)form;
        System.out.println("title" + uaf.getTitle());
        FormFile myFile = uaf.getMyfile();
        if (myFile != null) {
            System.out.println("fileName=" + myFile.getFileName());
            
            FileOutputStream fos = new FileOutputStream("c:\\" + myFile.getFileName());
            fos.write(myFile.getFileData());
            fos.flush();
            fos.close();
        }
        return mapping.findForward("success");
    }

}

成功返回页面

upload_success.jsp

代码 
<%@ 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>
    标题：${uploadForm.title}<br>
    文件名：${uploadForm.myfile.fileName  }<br>
</body>
</html>

3、类型转换

代码 
package com.bjsxt.struts;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.apache.commons.beanutils.Converter;

/**
 * java.util.Date类型转换器
 * @author Administrator
 *
 */
public class UtilDateConverter implements Converter {

    public Object convert(Class type, Object value) {
        System.out.println("UtilDateConverter.value=" + value);
        if (value == null) {
            return value;
        }
        if (value instanceof Date) {
            return value;
        }
        Date d = null;
        if (value instanceof String) {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
            try {
                d = sdf.parse((String)value);
            } catch (ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return d;
    }

}
代码 
package com.bjsxt.struts;

import java.util.Date;

import javax.servlet.ServletException;

import org.apache.commons.beanutils.ConvertUtils;
import org.apache.struts.action.ActionServlet;
import org.apache.struts.action.PlugIn;
import org.apache.struts.config.ModuleConfig;

public class UtilDateConverterInitWithPlugin implements PlugIn {

    public void destroy() {
    }

    public void init(ActionServlet servlet, ModuleConfig config)
            throws ServletException {
        System.out.println("UtilDateConverterInitWithPlugin.init()");
        ConvertUtils.register(new UtilDateConverter(), Date.class);
    }
}
代码 
package com.bjsxt.struts;

import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;

import org.apache.commons.beanutils.ConvertUtils;

/**
 * 注册java.util.date转换器
 * @author Administrator
 *
 */
public class UtilDateConverterInitWithServlet extends HttpServlet {

    @Override
    public void init() throws ServletException {
        System.out.println("UtilDateConverterInitWithServlet.init()");
        ConvertUtils.register(new UtilDateConverter(), Date.class);
    }

}

成功返回页面

typeconvert_success.jsp

代码 
<%@ 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>
    intValue:${typeconvertForm.intValue }<br>
    doubleValue:${typeconvertForm.doubleValue }<br>
    booleanValue:${typeconvertForm.booleanValue }<br>
    java.sql.dateValue:${typeconvertForm.sqlDate }<br>
    java.util.utilValue:${typeconvertForm.utilDate }<br>
</body>
</html>

 讲解

1、动态ActionForm
 动态ActionForm是为了避免标准ActionForm膨胀而设计的，使用动态ActionForm可以获得标准
 ActionForm的所有功能
 * 在struts-config.xml文件中定义动态ActionForm,如：
 <form-beans>
  <form-bean name="dynaForm" type="org.apache.struts.action.DynaActionForm">
   <form-property name="username" type="java.lang.String" />
   <form-property name="age" type="java.lang.Integer"/>
  </form-bean>
 </form-beans>
 *在Action中使用动态ActionForm，参见DynaActionFormTestAction.java
  DynaActionForm daf = (DynaActionForm)form;
  String username = (String)daf.get("username");
  Integer age = (Integer)daf.get("age");
  
 动态ActionForm其实是把页面中的html元素的名字和值放到了map中，所以通过get方法可以取出相应的值
 动态ActionForm采用EL表达式的输出方式，${dynabean.map.prop}, 参见：dyna_actionform.jsp
 动态Action的验证，通常使用动态验证框架validator

2、采用struts上传文件
 * 页面的配置，如：
  <form action="upload.do" method="post" enctype="multipart/form-data">
    标题：<input type="text" name="title"><br>
    文件：<input type="file" name="myfile"><br>
    <input type="submit" value="提交">
   </form>
  * ActionForm中使用FormFile来接收上传的文件，参见：UploadActionForm.java
  * 在Action中调用FormFile取得上传文件数据，采用流输出，即完成上传，参见：UploadTestAction.java
  * 采用<controller/>标签配置上传参数，如：<controller maxFileSize="10M"/>
  
3、空字段测试
 * 在表单中没有input输入域，jsp脚本接收到的值为null，el表达式接收到的值为空串
 * 如果表单中的值，没有输入，那么jsp脚本和el表达式接收到的值都为空串
 
4、测试ActionForm类型的自动转换
 * boolean:yes,1,on,true都会转换成True类型，而且忽略大小写，其他情况转换成false
 * Date类型的转换：
  * 如果是java.sql.Date，页面日期的格式必须为yyyy-mm-dd，才可以转换
  * 如果是java.util.Date,默认情况下struts无法转换

 * 自定义转换器的实现步骤
  * 实现converter接口，实现convert方法
  * 将实现的conerter注册，通常情况采用servlet注册
  * 采用servlet注册需要注意标签的配置,<load-on-startup>10</load-on-startup>(也可以采用struts plugin注册)
  
Struts对ActionForm的自动搜集过程：
  * 将页面数据放到map中，其中map中的key为页面中的名称，map中的value为页面中的value值
  * 调用BeanUtils.setProperties方法，将map中的值逐个设置到ActionForm实例上，对于ActionForm中的每个属性
    根据类型调用相应的Converter，然后调用相应的convert方法，将相应的字符串转换成ActionForm中指定的类型
   
可以通过BeanUtils.copyProperties(目标对象，源对象)方法进行对象值的复制。

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原文地址：https://www.cnblogs.com/linzheng/p/1903421.html