在摸索中漸漸找到了屬于自己的學(xué)習(xí)方式 learn ** in action 而且喜歡上了in action 系列的書

我的記性實(shí)在不是很好 但是我知道自己擅長(zhǎng)的是歸納和總結(jié) 加上我是完美主義者 所以到現(xiàn)在很多問題我都從根源上理解和解決了 所以in action 的學(xué)習(xí)方法是最適合我的

Struts的核心是MVC的控制層 它將模式和視圖連接起來(lái) 可以用來(lái)定義超鏈 表單和用戶動(dòng)作組件

超鏈可以這樣

< forward name ="welcome"
path ="pages/index.jsp" />

<% @tagliburi = " /tags/struts-logic " prefix = " logic " %>

< logic:redirectforward = " welcome " />

也可以

< global-forwards >
....
< forward
name ="welcome"
path ="/welcome.do" />
</ global-forwards >

< action-mappings >
< action
path ="/welcome"
type ="org.apache.struts.actions.ForwardAction"
parameter ="/pages/welcome.jsp" />
......
</ action-mappings >

通過(guò)實(shí)現(xiàn)的ActionForm來(lái)處理表單數(shù)據(jù)和完成驗(yàn)證的工作

定位和實(shí)例化ActionForm

< form-beans >
< form-bean name ="logonForm" type ="ergal.LogonForm" />
</ form-beans >

在html表單中的action 指向一個(gè)Action 用這個(gè)Action來(lái)處理數(shù)據(jù) Struts會(huì) 自動(dòng)把其看作form來(lái)處理

看例子

< struts-config >

<!-- ========================================FormBeanDefinitions -->
< form-beans >
< form-bean name ="logonForm" type ="ergal.LogonForm" />
</ form-beans >


<!-- ===================================GlobalForwardDefinitions -->
......

<!-- ===================================ActionMappingDefinitions -->
< action-mappings >
......

< action
path ="/logonSubmit"
type ="ergal.LogonAction"
name ="logonForm"
scope ="request"
validate ="true"
input ="/pages/logon.jsp" >
< forward
name ="success"
path ="/pages/welcome.jsp" />
</ action >

</ action-mappings >

</ struts-config >

html的表單交出以后 根據(jù)action屬性轉(zhuǎn)向一個(gè)url來(lái)處理 在這里就是LogonSubmit 它通過(guò)LogonAction來(lái)處理數(shù)據(jù)

強(qiáng)制把其數(shù)據(jù)作為了Form的字段數(shù)據(jù) 就像Hibernate持久化了一個(gè)POJO一樣 然后通過(guò)一定的邏輯來(lái)進(jìn)行驗(yàn)證from和想要的數(shù)據(jù)是否符合 從而實(shí)現(xiàn)了驗(yàn)證

例子

文件目錄樹

webtest
| |-- index.jsp
|
| |-- META-INF
| | |-- MANIFEST.MF
| |
| |-- pages
| | |-- logon.jsp
| | |-- struts-power.gif
| | |-- velocity-power.gif
| | |-- welcome.jsp
| |
| |-- WEB-INF
| | |-- struts-bean.tld
| | |-- struts-config.xml
| | |-- struts-html.tld
| | |-- struts-logic.tld
| | |-- struts-nested.tld
| | |-- struts-tiles.tld
| | |-- tiles-defs.xml
| | |-- validation.xml
| | |-- validator-rules.xml
| | |-- web.xml
| |
| | |classes
| | |
| | | |-- ergal
| | | | |-- Constants.class
| | | | |-- LogoffAction.class
| | | | |-- LogonAction.class
| | | | |-- LogonForm.class
| | | | |-- UserDirectory.class
| | | | |-- UserDirectoryException.class
| | | |
| | | |-- resources
| | | | |-- application.properties
| | | | |-- users.properties
| | |-- lib
......
| | |
| | |--src
| | | |-- build.xml
| | |
| | | |-- java
| | | |
| | | | |-- ergal
| | | | | |-- Constants.java
| | | | | |-- LogoffAction.java
| | | | | |-- LogonAction.java
| | | | | |-- LogonForm.java
| | | | | |-- UserDirectory.java
| | | | | |-- UserDirectoryException.java
| | | | |
| | | |-- resources
| | | | |-- application.properties
| | | | |-- users.properties

核心部分

index.jsp

<% @tagliburi = " /tags/struts-logic " prefix = " logic " %>

< logic:redirectforward = " welcome " />

直接轉(zhuǎn)向welcome.jsp

welcome.jsp

<% ... @tagliburi = " /tags/struts-bean " prefix = " bean " %>
<% ... @tagliburi = " /tags/struts-html " prefix = " html " %>
<% ... @tagliburi = " /tags/struts-logic " prefix = " logic " %>

< html >
< head >
< title > Welcome! </ title >
< html:base />
</ head >

< body >
< logic:present name ="user" >
< h3 > Welcome < bean:write name ="user" property ="username" /></ h3 >
</ logic:present >

< logic:notPresent scope ="session" name ="user" >
< h3 > Welcomeworld! </ h3 >
</ logic:notPresent >

< html:errors />

< UL >
< LI >< html:link forward ="logon" > Signin </ html:link ></ LI >
< logic:present name ="user" >
< LI >< html:link forward ="logoff" > Signout </ html:link ></ LI >
</ logic:present >
</ UL >
< img src ="struts-power.gif" alt ="Poweredbystruts" >
</ body >
</ html >

這里用了taglib 里面是個(gè)邏輯引用 定義在web.xml中

這里還用了present和notPresent 用來(lái)判別制定對(duì)象是否存在來(lái)決定是否處理內(nèi)容

logon.jsp

<% ... @tagliburi = " /tags/struts-html " prefix = " html " %>

< html >
< head >
< title > SigninPlease! </ title >
</ head >

< body >
< html:errors />
< html:form action ="logonSubmit" focus ="username" >
< table border ="0" width ="100%" >
< tr >
< th align ="right" > Username: </ th >
< td align ="left" >< html:text property ="username" /></ td >
</ tr >
< tr >
< th align ="right" > Password: </ th >
< td align ="left" >< html:password property ="password" /></ td >
</ tr >
< tr >
< td align ="right" >< html:submit /></ td >
< td align ="left" >< html:reset /></ td >
</ tr >
</ table >
</ html:form >
</ body >
</ html >

這里的action指向了logonSumit

現(xiàn)在來(lái)看struts-config.xml

<? xmlversion="1.0"encoding="ISO-8859-1" ?>

<! DOCTYPEstruts-configPUBLIC
"-//ApacheSoftwareFoundation//DTDStrutsConfiguration1.2//EN"
"http://jakarta.apache.org/struts/dtds/struts-config_1_2.dtd" >



< struts-config >

<!-- ========================================FormBeanDefinitions -->
< form-beans >
< form-bean name ="logonForm" type ="ergal.LogonForm" />
</ form-beans >


<!-- ===================================GlobalForwardDefinitions -->
< global-forwards >
< forward
name ="logoff"
path ="/logoff.do" />
< forward
name ="logon"
path ="/logon.do" />
< forward
name ="welcome"
path ="/welcome.do" />
</ global-forwards >


<!-- ===================================ActionMappingDefinitions -->
< action-mappings >
< action
path ="/welcome"
type ="org.apache.struts.actions.ForwardAction"
parameter ="/pages/welcome.jsp" />

< action
path ="/logon"
type ="org.apache.struts.actions.ForwardAction"
parameter ="/pages/logon.jsp" />

< action
path ="/logonSubmit"
type ="ergal.LogonAction"
name ="logonForm"
scope ="request"
validate ="true"
input ="/pages/logon.jsp" >
< forward
name ="success"
path ="/pages/welcome.jsp" />
</ action >

< action
path ="/logoff"
type ="ergal.LogoffAction" >
< forward
name ="success"
path ="/pages/welcome.jsp" />
</ action >
</ action-mappings >

</ struts-config >

先是給一個(gè)ActionForm命名 并制定類 然后定義全局可用的forwards 都賦予一個(gè)邏輯地址

然后action-mapping

<action
path="/logonSubmit"
type="ergal.LogonAction"
name="logonForm"
scope="request"
validate="true"
input="/pages/logon.jsp">
<forward
name="success"
path="/pages/welcome.jsp"/>
</action>

制定了actionForm和來(lái)源地址

Form很簡(jiǎn)單 就像一個(gè)POJO

LogonForm.java

package ergal;

import javax.servlet.http. * ;
import org.apache.struts.action. * ;

public class LogonForm extends ActionForm
... {
private Stringusername;
private Stringpassword;

public void setUsername(Stringusername)
... {
this .username = username;
}
public StringgetUsername()
... {
return this .username;
}

public void setPassword(Stringpassword)
... {
this .password = password;
}
public StringgetPassword()
... {
return this .password;
}

public void reset(ActionMappingmapping,HttpServletRequestrequest)
... {
setPassword( null );
setUsername( null );
}

public ActionErrorsvalidate(ActionMappingmapping,HttpServletRequestrequest)
... {

ActionErrorserrors = new ActionErrors();

if ((username == null ) || (username.length() < 1 ))
errors.add( " username " ,
new ActionError( " error.username.required " ));

if ((password == null ) || (password.length() < 1 ))
errors.add( " password " ,
new ActionError( " error.password.required " ));

return errors;

}
}

ActionForm有個(gè)基本效驗(yàn)方法

可以重寫這個(gè)方法 定制 主要用來(lái)檢驗(yàn)域是否都輸入了數(shù)據(jù)

驗(yàn)證Action

LogonAction.java

package ergal;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionError;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionServlet;


public final class LogonAction extends Action
... {
public boolean isUserLogon(Stringusername,Stringpassword) throws UserDirectoryException
... {
return UserDirectory.getInstance().isValidPassword(username,password);
}

public ActionForwardexecute(ActionMappingmapping,ActionFormform,
HttpServletRequestrequest,
HttpServletResponseresponse) throws IOException,ServletException
... {
Stringusername = ((LogonForm)form).getUsername();
Stringpassword = ((LogonForm)form).getPassword();

boolean validated = false ;
try
... {
validated = isUserLogon(username,password);
}
catch (UserDirectoryExceptione)
... {
ActionMessageserrors = new ActionMessages();
errors.add(ActionErrors.GLOBAL_ERROR, new ActionError( " error.logon.invalid " ));
saveErrors(request,errors);
return mapping.getInputForward();
}

if ( ! validated)
... {
ActionMessageserrors = new ActionMessages();
errors.add(ActionErrors.GLOBAL_ERROR, new ActionError( " error.logon.invalid " ));
saveErrors(request,errors);
return mapping.getInputForward();
}

HttpSessionsession = request.getSession();
session.setAttribute(Constants.USER_KEY,form);



StringBuffermessage = new StringBuffer( " LogonAction:User' " );
message.append(username);
message.append( " 'loggedoninsession " );
message.append(session.getId());
servlet.log(message.toString());


return (mapping.findForward(Constants.SUCCESS));

}
}

這里引用了另一個(gè)定制的一個(gè)驗(yàn)證數(shù)據(jù)的UserDirectory

UserDirectory.java

package ergal;

import java.io. * ;
import java.util. * ;

public class UserDirectory
... {
private static final StringUserDirectoryFile = " resources/users.properties " ;
private static final StringUserDirectoryHeader = " ${user}=${password} " ;

private static UserDirectoryuserDirectory = null ;

private static Propertiesp;

private UserDirectory() throws UserDirectoryException
... {

java.io.InputStreami = null ;
p = null ;
i = this .getClass().getClassLoader().getResourceAsStream(UserDirectoryFile);


if ( null == i)
... {
throw new UserDirectoryException();
}

else
... {

try
... {
p = new Properties();
p.load(i);
i.close();
}
catch (java.io.IOExceptione)
... {
p = null ;
System.out.println(e.getMessage());
throw new UserDirectoryException();
}
finally
... {
i = null ;
}
}
}

public static UserDirectorygetInstance() throws UserDirectoryException
... {

if ( null == userDirectory)
... {

userDirectory = new UserDirectory();

}

return userDirectory;

}

public StringfixId(StringuserId)
... {
return userId.toUpperCase();
}

public boolean isValidPassword(StringuserId,Stringpassword)
... {

if ( null == password) return false ;

String_userId = fixId(userId);

if ( ! isUserExist(_userId)) return false ;

return (password.equals(getPassword(_userId)));

}

public boolean isUserExist(StringuserId)
... {

if ( null == userId) return false ;


return ! ( null == p.getProperty(userId));

}



public StringgetPassword(StringuserId)
... {
return p.getProperty(userId);
}



public EnumerationgetUserIds()
... {
return p.propertyNames();
}



public void setUser(StringuserId,Stringpassword) throws UserDirectoryException
... {

// nonulls
if (( null == userId) || ( null == password))
... {
throw new UserDirectoryException();
}


try
... {

p.put(fixId(userId),password);
p.store( new FileOutputStream(UserDirectoryFile),
UserDirectoryHeader);

}

catch (IOExceptione)
... {

throw new UserDirectoryException();

}
}

}

這里用了class的getClassLoder()方法 和ClassLoader的getResourceAsStream()方法

最后返回的是一個(gè)InpuStream

java.util
類 Properties

    
      java.lang.Object
    
    
    
      java.util.Dictionary
    
    <K,V>
      
    
    
      java.util.Hashtable
    
    <
    
      Object
    
    ,
    
      Object
    
    >
          
    
    
      java.util.Properties
    
  

      public class 
      
        Properties
      
    

  

    
      Properties
    
     類表示了一個(gè)持久的屬性集。
    
      Properties
    
     可保存在流中或從流中加載。屬性列表中每個(gè)鍵及其對(duì)應(yīng)值都是一個(gè)字符串。 
  
  

    一個(gè)屬性列表可包含另一個(gè)屬性列表作為它的“默認(rèn)值”；如果未能在原有的屬性列表中搜索到屬性鍵，則搜索第二個(gè)屬性列表。 
  
  

    因?yàn)?
    
      Properties
    
     繼承于 
    
      Hashtable
    
    ，所以可對(duì) 
    
      Properties
    
     對(duì)象應(yīng)用 
    
      put
    
     和 
    
      putAll
    
     方法。但強(qiáng)烈反對(duì)使用這兩個(gè)方法，因?yàn)樗鼈冊(cè)试S調(diào)用方插入其鍵或值不是 
    
      Strings
    
     的項(xiàng)。相反，應(yīng)該使用 
    
      setProperty
    
     方法。如果在“有危險(xiǎn)”的 
    
      Properties
    
     對(duì)象（即包含非 
    
      String
    
     的鍵或值）上調(diào)用 
    
      store
    
     或 
    
      save
    
     方法，則該調(diào)用將失敗。 
  
  

    
    
  
  

    
      
        load
      
    
     和 
    
      
        store
      
    
     方法按下面所指定的、簡(jiǎn)單的面向行的格式加載和存儲(chǔ)屬性。此格式使用 ISO 8859-1 字符編碼。可以使用 
    
      Unicode 轉(zhuǎn)義符
    
    來(lái)編寫此編碼中無(wú)法直接表示的字符；轉(zhuǎn)義序列中只允許單個(gè) 'u' 字符。可使用 native2ascii 工具對(duì)屬性文件和其他字符編碼進(jìn)行相互轉(zhuǎn)換。 
  
  

  
  

    
      
        loadFromXML(InputStream)
      
    
     和 
    
      
        storeToXML(OutputStream, String, String)
      
    
     方法按簡(jiǎn)單的 XML 格式加載和存儲(chǔ)屬性。默認(rèn)使用 UTF-8 字符編碼，但如果需要，可以指定某種特定的編碼。XML 屬性文檔具有以下 DOCTYPE 聲明： 
  
  
     <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
 
  
  

    注意，導(dǎo)入或?qū)С鰧傩詴r(shí)
    
      不
    
     訪問系統(tǒng) URI (http://java.sun.com/dtd/properties.dtd)；該系統(tǒng) URI 僅作為一個(gè)惟一標(biāo)識(shí) DTD 的字符串： 
  
  
        <?xml version="1.0" encoding="UTF-8"?>

    <!-- DTD for properties -->

    <!ELEMENT properties ( comment?, entry* ) >

    <!ATTLIST properties version CDATA #FIXED "1.0">

    <!ELEMENT comment (#PCDATA) >

    <!ELEMENT entry (#PCDATA) >

    <!ATTLIST entry key CDATA #REQUIRED>
 重要的方法
  
  
  

    

      

        

          
            
              String
            
          
        
        

          
            
              
                getProperty
              
            
            (
            
              String
            
            key)
          
          

          用指定的鍵在此屬性列表中搜索屬性。
        
      
      

        

          
            
              String
            
          
        
        

          
            
              
                getProperty
              
            
            (
            
              String
            
            key, 
            
              String
            
            defaultValue)
          
          

          用指定的鍵在屬性列表中搜索屬性。
        
      
    
  
  
  

    

      

        

          
            void
          
        
        

          
            
              
                load
              
            
            (
            
              InputStream
            
            inStream)
          
          

          從輸入流中讀取屬性列表（鍵和元素對(duì)）。
        
      
    
  
  
  

    

      

        

          
            void
          
        
        

          
            
              
                store
              
            
            (
            
              OutputStream
            
            out, 
            
              String
            
            comments)
          
          

          以適合使用 
          
            
              load
            
          
           方法加載到 
          
            Properties
          
           表中的格式，將此 
          
            Properties
          
           表中的屬性列表（鍵和元素對(duì)）寫入輸出流。
        
      
    
  
  

  
  

    

      

        

          
            
              Enumeration
            
            <?>
          
        
        

          
            
              
                propertyNames
              
            
            ()
          
          

          返回屬性列表中所有鍵的枚舉，如果在主屬性列表中未找到同名的鍵，則包括默認(rèn)屬性列表中不同的鍵。
        
      
    
  
  

    這里用到了load方法從InputStream中加載流 然后用getProperty()方法
  
  

    該類展示了如何從property文件中讀取 鍵值 并和傳值進(jìn)行比較
  
  

  
  

    
      Action 1 理解Struts