1.控制JSP页面某一部分内容是否执行
public void doTag()
this.getJspBody().invoke(null);执行
空白，不执行
2.控制JSP页面内容重复执行
1 package cn.itcast.web.simpletag; 2 ?3 import java.io.IOException; 4 ?5 import javax.servlet.jsp.JspException; 6 import javax.servlet.jsp.tagext.JspFragment; 7 import javax.servlet.jsp.tagext.SimpleTagSupport; 8 ?9 public class SimpleTagDemo2 extends SimpleTagSupport {10 11 ????@Override12 ????public void doTag() throws JspException, IOException {13 ????????// TODO Auto-generated method stub14 ????????JspFragment jf = this.getJspBody();15 16 ????????for (int i = 0; i < 10; i++) {17 ????????????jf.invoke(null);18 ????????}19 ????}20 21 }3.修改JSP页面内容输出
1 package cn.itcast.web.simpletag; 2 ?3 import java.io.IOException; 4 import java.io.StringWriter; 5 ?6 import javax.servlet.jsp.JspContext; 7 import javax.servlet.jsp.JspException; 8 import javax.servlet.jsp.tagext.JspFragment; 9 import javax.servlet.jsp.tagext.SimpleTagSupport;10 11 public class SimpleTagDemo3 extends SimpleTagSupport {12 13 ????@Override14 ????public void doTag() throws JspException, IOException {15 ????????// TODO Auto-generated method stub16 17 ????????JspFragment jf = this.getJspBody();18 ????????StringWriter sw = new StringWriter();19 ????????jf.invoke(sw);20 21 ????????String content = sw.getBuffer().toString();22 23 ????????content = content.toUpperCase();24 25 ????????JspContext pageContent = this.getJspContext();26 ????????pageContent.getOut().write(content);27 ????}28 29 }4.控制标签余下的JSP不执行
1 package cn.itcast.web.simpletag; 2 ?3 import java.io.IOException; 4 ?5 import javax.servlet.jsp.JspException; 6 import javax.servlet.jsp.SkipPageException; 7 import javax.servlet.jsp.tagext.SimpleTagSupport; 8 ?9 public class SimpleTagDemo4 extends SimpleTagSupport {10 11 ????@Override12 ????public void doTag() throws JspException, IOException {13 ????????// TODO Auto-generated method stub14 ????????throw new SkipPageException();15 ????}16 17 }开发带属性的标签
要想让一个自定义标签具有属性，通常需要完成两个任务：
在标签处理器中编写每个属性对应的setter方法
1 package cn.itcast.web.simpletag; 2 ?3 import java.io.IOException; 4 ?5 import javax.servlet.jsp.JspException; 6 import javax.servlet.jsp.tagext.SimpleTagSupport; 7 ?8 public class SimpleTagDemo5 extends SimpleTagSupport { 9 10 ????private int count;11 12 ????public void setCount(int count) {13 ????????this.count = count;14 ????}15 16 ????@Override17 ????public void doTag() throws JspException, IOException {18 ????????// TODO Auto-generated method stub19 20 ????????for (int i = 0; i < count; i++) {21 ????????????this.getJspBody().invoke(null);22 ????????}23 ????}24 25 }在tld文件中描述标签的属性
1 ????<tag> 2 ????????<name>demo5</name> 3 ????????<tag-class>cn.itcast.web.simpletag.SimpleTagDemo5</tag-class> 4 ????????<body-content>scriptless</body-content> 5 ????????<attribute> 6 ????????????<name>count</name> 7 ????????????<required>true</required> 8 ????????????<rtexprvalue>true</rtexprvalue> 9 ????????</attribute>10 ????</tag>
wewe
JSP 简单标签extends SimpleTagSupport
原文地址：https://www.cnblogs.com/denggelin/p/8159826.html