1. DynaActionForm
（1）爲什麼用動態表單
如果用ActionForm，每個頁面的表單都要寫一個ActionForm，每當表單修改時ActionForm都要修改和重新編譯
DynaActionForm直接在配置文件中配置，不用編碼，便於修改
（2）使用DynaActionForm的方法：
* 在struts-config.xml的<form-beans>標籤中添加：
<form-bean name="DynaForm" type="org.apache.struts.action.DynaActionForm" dynamic="true">
<form-property name="userName" type="java.lang.String" />
</form-bean>
* <action>的 name="DynaForm"
* 在Action中如果要訪問DynaActionForm
String userName = ( String )( ( DynaActionForm )form ).get( "userName" );
因爲DynaActionForm是用map實現
2. 定製化Action -- DispatchAction
（1）應用場合：不同頁面，相同表單，執行不同的方法
（2）使用方法：
* 寫一個類繼承DispatchAction, 爲每個需要的服務寫一個方法
* 不用重寫 execute(), 因爲DispatchAction提供execute()
（3）例子：
* 在resource file 中添加：
account=account no.
amt=amount
submit.deposit=deposit
submit.withdraw=withdraw
* 寫兩個jsp頁面
//dispatch_dp.jsp
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<html:errors/>
<html:form action="/dpwd.do?method=deposit">
<bean:message key="account"/>
<html:text property="account" size="16" maxlength="16"/><br>
<bean:message key="amt" />
<html:text property="amount" size="16" maxlength="16"/><br>
<html:submit property="submit" value="deposit"/>
</html:form>
//dispatch_wd.jsp
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<html:errors/>
<html:form action="/dpwd.do?method=withdraw">
<bean:message key="account"/>
<html:text property="account" size="16" maxlength="16"/><br>
<bean:message key="amt" />
<html:text property="amount" size="16" maxlength="16"/><br>
<html:submit property="submit" value="withdraw"/>
</html:form>
* 在struts-config.xml配置<form-bean>
<form-bean name="DorWForm" type="org.apache.struts.validator.DynaValidatorForm" dynamic="true">
<form-property name="account" type="java.lang.String" />
<form-property name="amount" type="java.lang.String" />
</form-bean>
* 寫Action
//AccountAction
package hello;
import javax.servlet.*;
import javax.servlet.http.*;
import org.apache.struts.action.*;
import org.apache.struts.actions.*;
import org.apache.struts.util.*;
public final class AccountAction extends DispatchAction{
public ActionForward deposit( ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response ) throws Exception {
request.setAttribute( "method", "deposit" );
return mapping.findForward( "accountok" );
}
public ActionForward withdraw( ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response ) throws Exception {
request.setAttribute( "method", "withdraw" );
return mapping.findForward( "accountok" );
}
}
* 在struts-config.xml配置<action>
<action path = "/dpwd"
type = "hello.AccountAction"
name = "DorWForm"
scope = "request"
validate = "false"
input = "/dispatch_dp.jsp"
parameter="method"
>
<forward name="accountok" path="/accountok.jsp" />
</action>
* 寫accountok.jsp
method :<%= request.getAttribute( "method" ) %>
<br>
<h1>ok</h1>
3. 定製化Action -- LookupDispatchAction
（1）應用場合：同一個表單，多個同名submit
（2）使用方法：
* 寫一個類繼承LookupDispatchAction, 爲每個需要的服務寫一個方法
* 重寫getKeyMethodMap(), map key resource file 中定義的key, map value 是方法名
LookupDispatchAction 是根據submit value去resource file 中找到key, 然後到 map 中找到方法
（3）例子：
* 寫dorw.jsp
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<html:html locale="true">
<head>
<title>
<bean:message key="title"/>
</title>
<html:base/>
</head>
<body>
<html:errors/>
<html:form action="/dow.do" focus="userName">
<bean:message key="account"/>
<html:text property="account" size="16" maxlength="16"/><br>
<bean:message key="amt" />
<html:text property="amount" size="16" maxlength="16"/><br>
<html:submit property="action"><bean:message key="submit.deposit"/></html:submit>
<html:submit property="action"><bean:message key="submit.withdraw"/></html:submit>
</html:form>
</body>
</html:html>
* 寫Action
//DepositOrWithdrawAction
package hello;
import javax.servlet.*;
import javax.servlet.http.*;
import org.apache.struts.action.*;
import org.apache.struts.actions.*;
import org.apache.struts.util.*;
import java.util.*;
import java.io.*;
public final class DepositOrWithdrawAction extends
（1）爲什麼用動態表單
如果用ActionForm，每個頁面的表單都要寫一個ActionForm，每當表單修改時ActionForm都要修改和重新編譯
DynaActionForm直接在配置文件中配置，不用編碼，便於修改
（2）使用DynaActionForm的方法：
* 在struts-config.xml的<form-beans>標籤中添加：
<form-bean name="DynaForm" type="org.apache.struts.action.DynaActionForm" dynamic="true">
<form-property name="userName" type="java.lang.String" />
</form-bean>
* <action>的 name="DynaForm"
* 在Action中如果要訪問DynaActionForm
String userName = ( String )( ( DynaActionForm )form ).get( "userName" );
因爲DynaActionForm是用map實現
2. 定製化Action -- DispatchAction
（1）應用場合：不同頁面，相同表單，執行不同的方法
（2）使用方法：
* 寫一個類繼承DispatchAction, 爲每個需要的服務寫一個方法
* 不用重寫 execute(), 因爲DispatchAction提供execute()
（3）例子：
* 在resource file 中添加：
account=account no.
amt=amount
submit.deposit=deposit
submit.withdraw=withdraw
* 寫兩個jsp頁面
//dispatch_dp.jsp
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<html:errors/>
<html:form action="/dpwd.do?method=deposit">
<bean:message key="account"/>
<html:text property="account" size="16" maxlength="16"/><br>
<bean:message key="amt" />
<html:text property="amount" size="16" maxlength="16"/><br>
<html:submit property="submit" value="deposit"/>
</html:form>
//dispatch_wd.jsp
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<html:errors/>
<html:form action="/dpwd.do?method=withdraw">
<bean:message key="account"/>
<html:text property="account" size="16" maxlength="16"/><br>
<bean:message key="amt" />
<html:text property="amount" size="16" maxlength="16"/><br>
<html:submit property="submit" value="withdraw"/>
</html:form>
* 在struts-config.xml配置<form-bean>
<form-bean name="DorWForm" type="org.apache.struts.validator.DynaValidatorForm" dynamic="true">
<form-property name="account" type="java.lang.String" />
<form-property name="amount" type="java.lang.String" />
</form-bean>
* 寫Action
//AccountAction
package hello;
import javax.servlet.*;
import javax.servlet.http.*;
import org.apache.struts.action.*;
import org.apache.struts.actions.*;
import org.apache.struts.util.*;
public final class AccountAction extends DispatchAction{
public ActionForward deposit( ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response ) throws Exception {
request.setAttribute( "method", "deposit" );
return mapping.findForward( "accountok" );
}
public ActionForward withdraw( ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response ) throws Exception {
request.setAttribute( "method", "withdraw" );
return mapping.findForward( "accountok" );
}
}
* 在struts-config.xml配置<action>
<action path = "/dpwd"
type = "hello.AccountAction"
name = "DorWForm"
scope = "request"
validate = "false"
input = "/dispatch_dp.jsp"
parameter="method"
>
<forward name="accountok" path="/accountok.jsp" />
</action>
* 寫accountok.jsp
method :<%= request.getAttribute( "method" ) %>
<br>
<h1>ok</h1>
3. 定製化Action -- LookupDispatchAction
（1）應用場合：同一個表單，多個同名submit
（2）使用方法：
* 寫一個類繼承LookupDispatchAction, 爲每個需要的服務寫一個方法
* 重寫getKeyMethodMap(), map key resource file 中定義的key, map value 是方法名
LookupDispatchAction 是根據submit value去resource file 中找到key, 然後到 map 中找到方法
（3）例子：
* 寫dorw.jsp
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<html:html locale="true">
<head>
<title>
<bean:message key="title"/>
</title>
<html:base/>
</head>
<body>
<html:errors/>
<html:form action="/dow.do" focus="userName">
<bean:message key="account"/>
<html:text property="account" size="16" maxlength="16"/><br>
<bean:message key="amt" />
<html:text property="amount" size="16" maxlength="16"/><br>
<html:submit property="action"><bean:message key="submit.deposit"/></html:submit>
<html:submit property="action"><bean:message key="submit.withdraw"/></html:submit>
</html:form>
</body>
</html:html>
* 寫Action
//DepositOrWithdrawAction
package hello;
import javax.servlet.*;
import javax.servlet.http.*;
import org.apache.struts.action.*;
import org.apache.struts.actions.*;
import org.apache.struts.util.*;
import java.util.*;
import java.io.*;
public final class DepositOrWithdrawAction extends