esffor

MVC的设计模式，存在从用户WEB页面输入和实际JavaBean属性之间的自动类型转换问题

功能需求：页面上输入“用户名，密码”，将前半部分自动映射到User类的username属性中，将后半部分自动映射到User类的password属性中

User.java

package HelloWorld;

public class User ...{
    private String username;
      private String password;
      private String[] books;
      public String[] getBooks() ...{
            return books;
        }
        public void setBooks(String[] books) ...{
            this.books = books;
        }
        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;
        }
}

 LoginAction.java

package HelloWorld;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;

public class LoginAction implements Action...{
 
 
private String tip;

  private User user;

public User getUser() ...{
    return user;
}

public void setUser(User user) ...{
    this.user = user;
}

public String execute() throws Exception...{
      if(this.getUser().getUsername().equals("admin")&&this.getUser().getPassword().equals("1234"))...{
          ActionContext.getContext().getSession().put("user", this.getUser().getUsername());
          BookService bs=new BookService();
          this.getUser().setBooks(bs.getBooks());
          this.setTip("welcome welcome");
          return SUCCESS;
      }else...{
          return ERROR;
      }
  }

public String getTip() ...{
    return tip;
}
public void setTip(String tip) ...{
    this.tip = tip;
}


  
}

LoginAction的类型转换器，实现从String到User的双向转换

package HelloWorld;

import java.util.Map;

import ognl.DefaultTypeConverter;

public class UserConverter extends DefaultTypeConverter ...{


    
          public Object convertValue(Map context, Object value, Class toType)
            ...{
                if (toType == User.class )
                ...{
                    String[] params = (String[])value;
                    User user = new User();
                    String[] userValues = params[0].split(",");
                    user.setUsername(userValues[0]);
                    user.setPassword(userValues[1]);
                    return user;

                }
                else if (toType == String.class )
                ...{
                    User user = (User) value;
                    return "<" + user.getUsername() + "," + user.getPassword() + ">";
                } 
                return null ;
            } 
    }
  

转换器配置文件（命名规则为ActionName-convrsion.proipertoes,如果是全局的，命名为xwork.conversion.properties）,局部配置文件放在和Action同一个目录下，如果是全局的配置文件，则放到WEB-INF/classes下

user=HelloWorld.UserConverter  （Action中的user对象使用UserConverter转换器）

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
 xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 <filter>
   <filter-name>struts2</filter-name>
   <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
 </filter>
 <filter-mapping>
   <filter-name>struts2</filter-name>
   <url-pattern>/*</url-pattern>
 </filter-mapping>
</web-app>

struts.xml(WEB-INF/classes下)

<?xml version="1.0" encoding="GBK" ?>
<!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
        "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
 <package name="struts" extends="struts-default">
    <action name="Login" class="HelloWorld.LoginAction">
      <result name="input">/helloworld/index.jsp</result>
      <result name="success">/helloworld/welcome.jsp</result>
     
      <result name="error">/helloworld/error.jsp</result>
    </action>
 </package>
</struts>

struts.properties (WEB-INF/classes下)

struts.custom.i18n.resources=messageResource

messageResource.properties

pass.required = \u5BC6\u7801\u5FC5\u987B\u8F93\u5165
password = \u7528\u6237\u5BC6\u7801
user.required = \u7528\u6237\u540D\u5FC5\u987B\u8F93\u5165
username = \u7528\u6237\u59D3\u540D