简单标签库功能

package cn.itcast.web.tag;

import java.io.IOException;
import java.io.StringWriter;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.JspFragment;
import javax.servlet.jsp.tagext.SimpleTagSupport;

//控制标签体内容为大写
public class SimpleTagDemo1 extends SimpleTagSupport {
    
    
    
    @Override
    public void doTag() throws JspException, IOException {
        JspFragment jf = this.getJspBody();
        StringWriter sw = new StringWriter();
        jf.invoke(sw);
        
        String content = sw.toString();
        content = content.toUpperCase();
        
        this.getJspContext().getOut().write(content);
    }

    

}