自定义标记无法正常工作

Question

我创建了一个自定义标记，通过它我创建了一个锚标记。代码工作正常，但问题是它是三次创建锚标记。我不明白为什么会这样。 这是java代码

package test;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.SimpleTagSupport;

import java.io.*;


public class ImageTag extends SimpleTagSupport {

    private String url = "";
    private boolean bOpenNewWindow= false;
    private String label= "";
    private boolean close = false;
    private String className = "";
    private String title = "";
    private boolean relAttribute = false;   

    public boolean isRelAttribute() {
        return relAttribute;
    }

    public void setRelAttribute(boolean relAttribute) {
        this.relAttribute = relAttribute;
    }
    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getClassName() {
        return className;
    }

    public void setClassName(String className) {
        this.className = className;
    }

    public boolean isClose() {
        return close;
    }

    public void setClose(boolean close) {
        this.close = close;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }



    public boolean isbOpenNewWindow() {
        return bOpenNewWindow;
    }

    public void setbOpenNewWindow(boolean bOpenNewWindow) {
        this.bOpenNewWindow = bOpenNewWindow;
    }

    public String getLabel() {
        return label;
    }

    public void setLabel(String label) {
        this.label = label;
    }


    public void doTag() throws JspException {

        PageContext pageContext = (PageContext) getJspContext();
        JspWriter out = pageContext.getOut();
        StringWriter sw = new StringWriter();
        Boolean isInternalUrl = getUrl().startsWith("/")?true:false;


        //Boolean isContainHtml = getUrl().endsWith("html")?true:false;

        try {

            StringBuffer resultURL = new StringBuffer();


            if(!getUrl().equals(""))
            {


                    resultURL.append("<a href="+ url);

                //this is internal URL and not poiniting to dam so need to append .html
                if(isInternalUrl  )
                {                   
                    resultURL.append(".html\"");                        
                }
                // for appending classname 
                if( !getClassName().equals(""))
                {
                    resultURL.append(" class=\""+ getClassName() +"\"");
                }
                // for appending Title attribute
                if( !getTitle().equals(""))
                {
                    resultURL.append(" title=\""+ getTitle() +"\"");
                }

                // for open link in new window
                if(isbOpenNewWindow())
                {
                    resultURL.append(" target=_blank");
                }
                if(isRelAttribute())
                {
                    resultURL.append(" rel = nofollow");
                }

                resultURL.append(">");
                // Label of link
                if(!getLabel().equals(""))
                {
                    resultURL.append(getLabel());
                }               


                getJspBody().invoke(sw);
                resultURL.append(sw.toString());
                out.println(resultURL);


            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }  


    }
}

这里是tld文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN" "http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>

    <tlib-version>1.0</tlib-version>
    <jsp-version>2.0</jsp-version>
    <short-name>testing</short-name>
    <uri>http://www.tomcat-demo.com/testing</uri>
    <description>This is a demonstration tag library</description>

    <tag>
        <name>link</name>
        <tag-class>test.ImageTag</tag-class>
         <body-content>scriptless</body-content>
        <description>This tag is for displaying url</description>
        <attribute>
            <name>url</name>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>

        <attribute>
            <name>bOpenNewWindow</name>
            <required>false</required>
            <rtexprvalue>false</rtexprvalue>
            <type>boolean</type>
        </attribute>
        <attribute>
            <name>label</name>
            <required>false</required>
            <rtexprvalue>false</rtexprvalue>
        </attribute>
        <attribute>
            <name>className</name>
            <required>false</required>
            <rtexprvalue>false</rtexprvalue>
        </attribute>
        <attribute>
            <name>title</name>
            <required>false</required>
            <rtexprvalue>false</rtexprvalue>
        </attribute>
        <attribute>
            <name>relAttribute</name>
            <required>false</required>
            <rtexprvalue>false</rtexprvalue>
        </attribute>

    </tag>

</taglib>

这里是jsp文件

<%@ page contentType="text/html; charset=ISO-8859-1"%>
<%@ taglib prefix="mytest" uri="http://www.tomcat-demo.com/testing"%>

<%
String name = "testttt";
pageContext.setAttribute("test" ,name);
%>
<div>
    <span>
        <mytest:link url="http://www.google.com"  bOpenNewWindow="true" className="play" title="title of link" relAttribute = "true"  >
            <div class="hello">${test} </div>
        </mytest:link>
    </span>         
</div>

这是我检查元素时的屏幕截图  

有没有人对此有所了解

Answer 1

您可以更改下面的代码

原始代码

getJspBody().invoke(sw);
resultURL.append(sw.toString());
out.println(resultURL);

更新的代码

getJspBody().invoke(sw);
//resultURL.append(sw.toString());
//out.println(resultURL);
getJspContext().getOut().write(resultURL.toString());