使用標籤一定要注意加上jar包，為jstl.jar 和standard.jar就是了

在WEB-INF下建立一個myTag.tld 用xml檔案格式建立

myTag.tld

HelloSimpleTag.java

package cn.limbo.tags;

import javax.servlet.jsp.JspContext;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.JspFragment;
import javax.servlet.jsp.tagext.JspTag;
import javax.servlet.jsp.tagext.SimpleTag;
import java.io.IOException;

/**
 * Created by Limbo on 2016/9/21.
 */
public class HelloSimpleTag implements SimpleTag{

    private PageContext pageContext;
    @Override
    //執行標籤的功能
    public void doTag() throws JspException, IOException {
        String name = pageContext.getRequest().getParameter("name");
        pageContext.getOut().print("hello " + name);
    }

    @Override
    public void setParent(JspTag jspTag) {

    }

    @Override
    public JspTag getParent() {

        return null;
    }


    //設定pageContext
    @Override
    public void setJspContext(JspContext jspContext) {
        this.pageContext = (PageContext) jspContext;
    }

    @Override
    public void setJspBody(JspFragment jspFragment) {

    }
}