jsp页面自定义标签

自定义标签

新建maven项目taglib

maven pom.xml

<dependencies>
     <dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
			<version>3.0.1</version>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>javax.servlet.jsp</groupId>
			<artifactId>jsp-api</artifactId>
			<version>2.2</version>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>jstl</artifactId>
			<version>1.2</version>
		</dependency>
  </dependencies>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://java.sun.com/xml/ns/javaee" xmlns:jsp="http://java.sun.com/xml/ns/javaee/jsp"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
	version="3.0">
	<display-name></display-name>

    <servlet>
      <servlet-name>baseServlet</servlet-name>
      <servlet-class>com.lyncc.common.base.servlet.BaseServlet</servlet-class>
    </servlet>
    <servlet-mapping>
      <servlet-name>baseServlet</servlet-name>
      <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

BaseServlet.java

public class BaseServlet extends HttpServlet{

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	private List<String> ls = null;
	
	private List<User> users = null; 
	
	@Override
	public void init() throws ServletException {
		super.init();
	}
	
	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {
		ls = new ArrayList<String>();
		ls.add("Lyncc");
		ls.add("Smile");
		ls.add("Ted");
		ls.add("Moon");
		req.setAttribute("ls", ls);
		
		users = new ArrayList<User>();
		User u1 = new User("Lyncc", "123456", true);
		User u2 = new User("Smile", "123456", true);
		User u3 = new User("Ted", "123456", false);
		User u4 = new User("Moon", "123456", true);
		User u5 = new User("Th000", "123456", false);
		User u6 = new User("Infi", "123456", false);
		users.add(u4);
		users.add(u3);
		users.add(u2);
		users.add(u1);
		users.add(u5);
		users.add(u6);
		req.setAttribute("ls2", users);
		req.getRequestDispatcher("WEB-INF/view/first.jsp").forward(req,resp);
	}
	
	@Override
	public void destroy() {
		super.destroy();
	}
}

User.java

public class User {
	
	private String username;
	
	private String password;
	
	private boolean isVisible;

	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;
	}

	public boolean isVisible() {
		return isVisible;
	}

	public void setVisible(boolean isVisible) {
		this.isVisible = isVisible;
	}

	public User(String username, String password, boolean isVisible) {
		this.username = username;
		this.password = password;
		this.isVisible = isVisible;
	}
	
}

first.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@taglib prefix="o" uri="/WEB-INF/tld/original.tld" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>test</title>
</head>
<body>
<c:forEach items="${ls}" var="str">
  ${o:formatSpecial(str)}<br>
</c:forEach>
<c:forEach items="${o:showVisible(ls2)}" var="u">
  ${u.username}=====${u.password}=====${u.visible}<br>
</c:forEach>
</body>
</html>

original.tld

<?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/web-jsptaglibrary_2_0.xsd"
 version="2.0">
  <tlib-version>2.0</tlib-version>
  <function>
    <name>formatSpecial</name>
    <function-class>com.lyncc.common.taglib.util.OpenTaglibFunctions</function-class>
    <function-signature>java.lang.String formatSpecial(java.lang.String)</function-signature>
  </function>
  
  <function>
    <name>showVisible</name>
    <function-class>com.lyncc.common.taglib.util.OpenTaglibFunctions</function-class>
    <function-signature>java.util.List showVisible(java.util.List)</function-signature>
  </function>
  
</taglib>

OpenTaglibFunctions.java

public class OpenTaglibFunctions {
	
	public static final String formatSpecial(String str){
		return str+"war3 player";
	}
	
	public static final List<User> showVisible(List<User> u){
		if(null==u||u.size()==0)return u;
		int size = u.size()-1;
		for(int i = size;i>=0;i--){
			if(!u.get(i).isVisible())u.remove(i);
		}
		return u;
	}

}

访问http://localhost:8080/taglib/ 可以看见效果，记录一下，有时候挺方便的~

jsp页面自定义标签

猜你喜欢