自定义标签2

自定义标签2

Set,Out标签的开发
if标签的开发
foreach标签的开发
select标签的开发
Set,Out标签的开发
CheckeboxTag标签的开发

1.助手类

package com.dl.jsp2;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.BodyTagSupport;

public class SetTag extends BodyTagSupport{

	private static final long serialVersionUID = 1L;

private String var;
private Object value;
public String getVar() {
	return var;
}
public void setVar(String var) {
	this.var = var;
}
public Object getValue() {
	return value;
}
public void setValue(Object value) {
	this.value = value;
}

@Override
public int doStartTag() throws JspException {
	pageContext.setAttribute(var, value);//将值存入pageContext


	return SKIP_BODY;
	}
}

package com.dl.jsp2;

import java.io.IOException;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyTagSupport;

public class OutTag extends BodyTagSupport{

	private static final long serialVersionUID = 8655118409172739205L;

private Object value;

public Object getValue() {
	return value;
}

public void setValue(Object value) {
	this.value = value;
}

@Override
public int doStartTag() throws JspException {
	JspWriter out = pageContext.getOut();
	try {
		out.print(value);//输出值
	} catch (IOException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();

		}
		return SKIP_BODY;
	}
	
}

2.配置tld文件

    set
    com.Dl.jsp2.SetTag
    JSP
    
    	var
        true
        false
    
    
    	value
        true
        true
    
  

  
    out
    com.shl.jsp2.OutTag
    JSP
    
    	value
        true
        true
    
  

if标签的开发

1.if只有test一个属性值，定义它们助手类
private boolean test;
public boolean isTest() {
	return test;
}
public void setTest(boolean test) {
	this.test = test;
}
@Override
public int doStartTag() throws JspException {
	//如果test为true，则进入doAfterBody方法，如果为false，则直接进入doEndTag方法
	return test?EVAL_BODY_INCLUDE:SKIP_BODY;
}

2.配置tld文件

 
    if
    com.dl.jsp2.IfTag
    JSP
    
    	test
        true
        true
    
  

checkbox标签

配置描述文件

 
    checkbox
    com.xy.taglib.CheckboxTag
    JSP
    
     
        textKey
        true
        true
     
     
        textVal
        true
        true
     
      
        item
        true
        true
     
     
        checkedVal
        false
        true
     
     
  

CheckeboxTag助手类

public class CheckboxTag extends BodyTagSupport {
	
	private String textKey;//传入值
	private String textVal;//显示值
	private List