displaybysextag.java

struts自定义标签示例

package tags;

import java.util.ArrayList;

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

import po.Student;
import dao.StudentDao;
//通过性别属性来显示学生：建立一个JavaBean风格的属性

public class DisplayBySexTag extends TagSupport{

	private String sex;
	
	public DisplayBySexTag(){
		System.out.println("DisplayAllTag构造函数");
	}
	
	public int doStartTag() throws JspException {
		// 系统开始运行这个标签时自动调用
		System.out.println("doStartTag");		
		return this.SKIP_BODY;//空体标签不要对体求值
	}
	
	public int doEndTag() throws JspException {
		//系统结束运行这个标签时自动调用
		System.out.println("doEndTag");
		StudentDao studentDao = new StudentDao();
		ArrayList stus = studentDao.queryStuBySex(sex);
		//显示成为表格
		JspWriter out = pageContext.getOut();//得到out
		//pageContext.getRequest();得到request
		//pageContext.getResponse();得到response
		//pageContext.getSession();得到session
		//pageContext.getServletContext();得到application
		try{
			out.println("<table bgColor=yellow>");
			out.println("<tr>");
			out.println("<td>学号</td>");
			out.println("<td>姓名</td>");
			out.println("<td>性别</td>");
			out.println("<td>出生年月</td>");
			out.println("<td>家庭住址</td>");
			out.println("</tr>");
			for(int i=0;i<stus.size();i++){
				Student stu = (Student)stus.get(i);
				out.println("<tr>");
				out.println("<td>"+stu.getStuId()+"</td>");
				out.println("<td>"+stu.getStuName()+"</td>");
				out.println("<td>"+stu.getStuSex()+"</td>");
				out.println("<td>"+stu.getStuBir()+"</td>");
				out.println("<td>"+stu.getStuAdd()+"</td>");
				out.println("</tr>");
			}			
			out.println("</table>");
		}catch(Exception ex){ex.printStackTrace();}

		
		return this.EVAL_PAGE;//让标签后面的Jsp继续执行
	}

	public String getSex() {
		return sex;
	}

	public void setSex(String sex) {
		this.sex = sex;
	}



}