jsp自定义标签

1.定义处理类

 

import java.io.IOException;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;
import org.apache.commons.lang.StringUtils;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import com.etool.modules.curd.service.CurdService;

public class OutputTag extends TagSupport{

        //接收2个参数
	private String target;
	private String fieldName;
	
	@Override
	public int doStartTag() throws JspException {
		
		String result="";
		
		
		JspWriter out = this.pageContext.getOut();
		ServletContext servletContext = pageContext.getServletContext();
		
		//逻辑
		
		try
		{	
				out.print(result);
		}catch(IOException e)
		{
			e.printStackTrace();
		}
		
		return super.doStartTag();
	}

	public String getTarget() {
		return target;
	}

	public void setTarget(String target) {
		this.target = target;
	}

	public String getFieldName() {
		return fieldName;
	}

	public void setFieldName(String fieldName) {
		this.fieldName = fieldName;
	}
}

 

 

2.编辑tld文件，在WEB-INF\my-tag.tld

 

<?xml version="1.0" encoding="UTF-8"?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
	version="2.0">

	<description>/</description>
	<display-name>My Tag Library</display-name>
	<tlib-version>1.0</tlib-version>
	<short-name>m</short-name>
	<uri>/my-tags</uri>

	<tag>
		<name>out</name>
		<tag-class>com.etool.commons.tag.OutputTag</tag-class>
		<body-content>JSP</body-content>
		<attribute>
			<name>target</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
			<type>String</type>
		</attribute>
		<attribute>
			<name>fieldName</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
			<type>String</type>
		</attribute>
	</tag>
	
</taglib>

 

 

3.配置web.xml

 

	<jsp-config>
		<taglib>
			<taglib-uri>/my-tags</taglib-uri>
			<taglib-location>/WEB-INF/my-tags.tld</taglib-location>
		</taglib>
	</jsp-config>

 

4.使用前

<%@ taglib uri="/my-tags" prefix="m" %>

 

这个uri和web.xml中的<taglib-uri>的值一样

 

5.使用

<m:out target="${target}" fieldName="${item.name}"></m:out> 

 

在eclipse会有提示