JSTL 自定义Function函数标签

1.首先编写类,注意:类里面的变量与方法必须是static的;

  如:

public class TestFunction {

	private static ProductInfoManager productInfoManager = (ProductInfoManager) Platform.getInstance().getBean("productInfoManager");

	public static List getLastDataByType(int type, int lastSize) {
		return productInfoManager.getLastDataByType(type, lastSize);
	}

	public static Boolean isLogin() {
		Customer customer = (Customer) ServletActionContext.getRequest().getSession().getAttribute(SessionUser.Customer_Session_User_Key);
		if (null == customer) {
			return false;
		}
		return true;
	}

 2.定义dtd文件;

  如:

<?xml version="1.0" encoding="UTF-8" ?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
	version="2.0">

	<tlib-version>1.0</tlib-version>
	<short-name>my</short-name>
	<uri>http://www.myproject.com/my/functions</uri>

	<function>
		<name>getLastDataByType</name>
		<function-class>com.myproject.app.util.TestFunction</function-class>
		<function-signature>java.util.List getLastDataByType(int,int)</function-signature>
	</function>
	<function>
		<name>isLogin</name>
		<function-class>com.myproject.app.util.TestFunction</function-class>
		<function-signature>boolean isLogin()</function-signature>
	</function>

</taglib>

 

3.JSP引入;

  如:

 <%@ taglib uri="http://www.myproject.com/my/functions" prefix="my"%>

 

4.使用;

 如:${my:isLogin()};

     ${my:getLastDataByType(2,5)}