枚举类型数据定义和使用

1，web.xml定义一个系统的过滤器

<listener>
		<listener-class>com.zainta.pregnancy.web.listener.ServletContextLoaderListener</listener-class>
	</listener>

2，写这个filter的内容

package com.zainta.pregnancy.web.listener;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

public class ServletContextLoaderListener implements ServletContextListener {

	
	public void contextDestroyed(ServletContextEvent event) {
		ServletContext servletContext = event.getServletContext();

		// 通过WebApplicationContextUtils 得到Spring容器的实例。
		ApplicationContext application = WebApplicationContextUtils
				.getWebApplicationContext(servletContext);
		// 返回Bean的实例。
		SystemServletContextLoader systemServletContextLoader = (SystemServletContextLoader) application
				.getBean("systemServletContextLoader");
		
		
		//初始化所有的枚举类型的实体
		systemServletContextLoader.closeServletContext(servletContext);
	}

	public void contextInitialized(ServletContextEvent event) {
		ServletContext servletContext = event.getServletContext();

		// 通过WebApplicationContextUtils 得到Spring容器的实例。
		ApplicationContext application = WebApplicationContextUtils
				.getWebApplicationContext(servletContext);
		// 返回Bean的实例。
		SystemServletContextLoader systemServletContextLoader = (SystemServletContextLoader) application
				.getBean("systemServletContextLoader");
		
		//初始化
		systemServletContextLoader.initServletContext(servletContext);
		
	}

}

3，spring配置一个systemServletContextLoader的bean

<bean id="systemServletContextLoader" class="com.zainta.pregnancy.web.listener.SystemServletContextLoader">
		<property name="enumEntityPackage" value="${enumration.entity.package}"></property>
	</bean>

${enumration.entity.package}这个是系统定义枚举类型所放置的包，比方叫com.xxxx.entity.enumeration

4,这个bean所得对应的内容如下

/**
 * 
 */
package com.zainta.pregnancy.web.listener;

import java.net.URL;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Component;

import com.opensymphony.xwork2.util.ResolverUtil;

/**
 * @author Downpour
 * 
 */
@Component("systemServletContextLoader")
public class SystemServletContextLoader {

	private static final Log logger = LogFactory
			.getLog(SystemServletContextLoader.class);

	private String enumEntityPackage;

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * com.demo2do.core.web.loader.ServletContextLoader#initServletContext(javax
	 * .servlet.ServletContext)
	 */
	public void initServletContext(ServletContext servletContext) {

		if (logger.isDebugEnabled()) {
			logger.debug("Initial ServletContext for system");
		}

		// alias enum entity to servletContext
		aliasEnumEntity(servletContext);

		servletContext.setAttribute("ctx", servletContext.getContextPath());
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * com.demo2do.core.web.loader.ServletContextLoader#closeServletContext(
	 * javax.servlet.ServletContext)
	 */
	public void closeServletContext(ServletContext servletContext) {

		if (logger.isDebugEnabled()) {
			logger.debug("Destroying ServletContext for system");
		}

		servletContext.removeAttribute("enums");

		servletContext.removeAttribute("ctx");
	}

	/**
	 * Alias Enum entity under entity package
	 * 
	 * @param servletContext
	 */
	protected void aliasEnumEntity(ServletContext servletContext) {

		// first find out all the enum classes according to the entity packages
		ResolverUtil<Object> resolver = new ResolverUtil<Object>();
		resolver.find(new ResolverUtil.Test() {
			@SuppressWarnings({ "rawtypes" })
			public boolean matches(Class type) {
				return Enum.class.isAssignableFrom(type);
			}

			@Override
			public boolean matches(URL resource) {
				// TODO Auto-generated method stub
				return false;
			}

			@Override
			public boolean doesMatchClass() {
				return true;
			}

			@Override
			public boolean doesMatchResource() {
				// TODO Auto-generated method stub
				return false;
			}
		}, enumEntityPackage);

		Map<String, Object> enums = new HashMap<String, Object>();

		for (Class<?> clazz : resolver.getClasses()) {
			String key = clazz.getName().substring(
					clazz.getName().lastIndexOf(".") + 1);
			try {
				enums.put(key, clazz.getMethod("values").invoke(clazz));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

		servletContext.setAttribute("enums", enums);
	}

	public String getEnumEntityPackage() {
		return enumEntityPackage;
	}

	public void setEnumEntityPackage(String enumEntityPackage) {
		this.enumEntityPackage = enumEntityPackage;
	}

}

这个类通过配置的枚举类型所放的包，通过反射的方式拿到枚举类型
5,枚举类型的类如下

package com.zainta.pregnancy.entity.enumeration;

/**
 *@author : [e-mail]	
 *@version: 2012-10-24上午10:16:27
 *@desc:
 */
public enum FakeStatus {

	//0，非冒名
	NOTFAKED("enum.fake_status.notfaked"),
	//1，疑似
	UNSURE("enum.fake_status.unsure"),
	//2，冒名
	FAKED("enum.fake_status.faked");
	
	FakeStatus(String key) {
		this.key = key;
	}
	
	String key;

	public String getKey() {
		return key;
	}

	public void setKey(String key) {
		this.key = key;
	}

	public int getOrdinal() {
		return this.ordinal();
	}
	
}

message_zh_CN.properties配置文件如下

#enum
enum.fake_status.notfaked=非冒名
enum.fake_status.unsure=疑似
enum.fake_status.faked=冒名

6,jsp页面如使用方式
    a,<%@ taglib   prefix="fmt" uri= "http://java.sun.com/jsp/jstl/fmt" %>
<fmt:setBundle basename ="message" />这是配置枚举类型显示的文件
message_zh_CN.properties，这个要在spring配置文件预先加载
    b,使用如下
   

<select name = "">
						<option value = "">--请选择--</option>
						<c:forEach items="${enums['FakeStatus']}" var = "fakeStatus">
							<option value = "${fakeStatus}">
								<fmt:message key = "${fakeStatus.key}"></fmt:message>
							</option>
						</c:forEach>
					</select>