JSP学习笔记（2）

一.JSP的运行原理 1.JSP处理请求的过程

2.JSP翻译的详细过程

package dao;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import entity.Emp;

public class EmpDao implements Serializable {
	public List findAll(){
		//模拟查询所有的员工
		List list = new ArrayList();
		Emp e1 = new Emp();
		e1.setEmpno(1);
		e1.setEname("唐僧");
		e1.setJob("领导");
		e1.setSal(9000.0);
		list.add(e1);
		
		Emp e2 = new Emp();
		e2.setEmpno(2);
		e2.setEname("悟空");
		e2.setJob("职员");
		e2.setSal(5000.0);
		list.add(e2);
		
		Emp e3= new Emp();
		e3.setEmpno(3);
		e3.setEname("八戒");
		e3.setJob("职员");
		e3.setSal(6000.0);
		list.add(e3);
		
		return list;
	}
	public void save(Emp e){
		System.out.println("增加员工："+e.getEname());
	}
}

package entity;

import java.io.Serializable;

public class Emp implements Serializable {
	private Integer empno;
	private String ename;
	private String job;
	private Double sal;
	public Integer getEmpno() {
		return empno;
	}
	public Double getSal() {
		return sal;
	}
	public void setSal(Double sal) {
		this.sal = sal;
	}
	public void setEmpno(Integer empno) {
		this.empno = empno;
	}
	public String getEname() {
		return ename;
	}
	public void setEname(String ename) {
		this.ename = ename;
	}
	public String getJob() {
		return job;
	}
	public void setJob(String job) {
		this.job = job;
	}
	
}

	
		
		查询员工
		
			table,td {
				border:1px solid red;
			}
			table {
				border-collapse:collapse;
			}
		
	
	
		
			
				编号
				姓名
				职位
				薪资
			
			
				
					
					
					
					
				
			
		
	

 

二.开发模式

1.Model1

2.Model2

package web;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import dao.EmpDao;
import entity.Emp;

public class FindEmpServlet extends HttpServlet {

	@Override
	protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		//查询所有的员工
		EmpDao dao = new EmpDao();
		List list = dao.findAll();
		//将数据绑定导request上
		req.setAttribute("emps", list);
		//将请求转发给emp_list.jsp
		//当前：/jsp2/findEmp
		//目标：/jsp2/emp_list.jsp
		req.getRequestDispatcher("emp_list.jsp").forward(req, res);
	}
	
}

	
		
		查询员工
		
			table,td {
				border:1px solid red;
			}
			table {
				border-collapse:collapse;
			}
		
	
	
		
			
				编号
				姓名
				职位
				薪资
			
			
				
					
					
					
					
				
			
		
	

  jsp2
  
    index.html
    index.htm
    index.jsp
    default.html
    default.htm
    default.jsp
  
  
  
  	findEmp
  	web.FindEmpServlet
  
  
  	findEmp
  	/findEmp
  

JSP1

package entity;

import java.io.Serializable;

public class Course implements Serializable {
	//对象的属性
	private Integer courseId;
	private String name;
	private Integer days;
	
	//Bean属性：
	//1.去掉get/set剩下的单词，首字母小写
	//2.通过get/set方法所分析出来的属性
	public Integer getId() {
		return courseId;
	}
	public void setId(Integer courseId) {
		this.courseId = courseId;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Integer getDays() {
		return days;
	}
	public void setDays(Integer days) {
		this.days = days;
	}
	
}

package entity;

import java.io.Serializable;

public class Student implements Serializable {
	private String name;
	private Integer age;
	private String sex;
	private String[] interests;
	private Course course;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	public String[] getInterests() {
		return interests;
	}
	public void setInterests(String[] interests) {
		this.interests = interests;
	}
	public Course getCourse() {
		return course;
	}
	public void setCourse(Course course) {
		this.course = course;
	}
	
}

package web;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import entity.Course;
import entity.Student;

public class FindStudentServlet extends HttpServlet {

	@Override
	protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		//模拟查询学生
		Student s = new Student();
		s.setName("zhangsan");
		s.setAge(25);
		s.setSex("M");
		s.setInterests(new String[]{"篮球","足球","排球"});
		Course c = new Course();
		c.setId(1);
		c.setName("Java");
		c.setDays(85);
		s.setCourse(c);
		//将数据绑定到request上
		req.setAttribute("stu", s);
		//将请求转发给student.jsp
		req.getRequestDispatcher("student.jsp").forward(req, res);
		
		
	}
	
	
}

  jsp3
  
    index.html
    index.htm
    index.jsp
    default.html
    default.htm
    default.jsp
  
  
  
  	findStudent
  	web.FindStudentServlet
  
  
  	findStudent
  	/findStudent
  

	
		
		查询学生
	
	
		
		
		

			性别:
			男
			女
		
		
		

			性别:
			
				男
				女
			
		
		
		

			
				${i}
			
		
		
		

		
		
		
		
姓名:${stu.name}
		
年龄:${stu['age']}
		
课程:${stu.course.id}
		
		
性别:${requestScope.stu.sex}
		
		
年龄+3"${stu.age+3}
		
介于20-30间:${stu.age>20 && stu.age