父标签：ChooseTag

package tagTest;import javax.servlet.jsp.JspException;import javax.servlet.jsp.tagext.SimpleTagSupport;import java.io.IOException;public class ChooseTag extends SimpleTagSupport {    private boolean flag = true;    public boolean isFlag() {        return flag;    }    public void setFlag(boolean flag) {        this.flag = flag;    }    @Override    public void doTag() throws JspException, IOException {        getJspBody().invoke(null);    }}

　　子标签1：WhenTag

package tagTest;import javax.servlet.jsp.JspException;import javax.servlet.jsp.tagext.SimpleTagSupport;import java.io.IOException;public class WhenTag extends SimpleTagSupport {    private boolean test;    public boolean isTest() {        return test;    }    public void setTest(boolean test) {        this.test = test;    }    @Override    public void doTag() throws JspException, IOException {        if(test){            ChooseTag chooseTag = (ChooseTag) getParent();            boolean flag = chooseTag.isFlag();            if(flag){                getJspBody().invoke(null);                chooseTag.setFlag(false);            }        }    }}

　　子标签2：OtherwiseTag

package tagTest;import javax.servlet.jsp.JspException;import javax.servlet.jsp.tagext.SimpleTagSupport;import java.io.IOException;public class OtherwiseTag extends SimpleTagSupport {    @Override    public void doTag() throws JspException, IOException {        ChooseTag chooseTag = (ChooseTag)getParent();        boolean flag = chooseTag.isFlag();        if(flag){            getJspBody().invoke(null);        }    }}

　　配置tld文件

             
      
       choose
              
      
       tagTest.ChooseTag
              
      
       scriptless
          
         
             
      
       when
              
      
       tagTest.WhenTag
              
      
       scriptless
              
                  
       
        test
                   
       
        true
                   
       
        true
               
          
         
             
      
       otherwise
              
      
       tagTest.OtherwiseTag
              
      
       scriptless
          
     

　　编写jsp文件

     
      ${cust.id} -- ${cust.name}
      
     
         
      
       大学毕业
          
      
       高中毕业
          
      
       高中以下