学习SpringMVC(十五)之CRUD操作

Posted 2020-07-13 奔跑着的国风

使用SpringMVC完成相应的CRUD操作，静态数据来模仿从数据库中取数据。

下面从创建的类说起，一共定义了5个类，分类是DepartmentDao，EmployeeDao，Department，Employee，EmployeeHandler

代码如下：

package com.cgf.springmvc.crud.dao;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.cgf.springmvc.crud.entities.Department;
import com.cgf.springmvc.crud.entities.Employee;

@Repository
public class EmployeeDao {

	private static Map<Integer, Employee> employees = null;
	
	@Autowired
	private DepartmentDao departmentDao;
	
	static{
		employees = new HashMap<Integer, Employee>();

		employees.put(1001, new Employee(1001, "E-AA", "[email protected]", 1, new Department(101, "D-AA")));
		employees.put(1002, new Employee(1002, "E-BB", "[email protected]", 1, new Department(102, "D-BB")));
		employees.put(1003, new Employee(1003, "E-CC", "[email protected]", 0, new Department(103, "D-CC")));
		employees.put(1004, new Employee(1004, "E-DD", "[email protected]", 0, new Department(104, "D-DD")));
		employees.put(1005, new Employee(1005, "E-EE", "[email protected]", 1, new Department(105, "D-EE")));
	}
	
	private static Integer initId = 1006;
	
	public void save(Employee employee){
		if(employee.getId() == null){
			employee.setId(initId++);
		}
		
		employee.setDepartment(departmentDao.getDepartment(employee.getDepartment().getId()));
		employees.put(employee.getId(), employee);
	}
	
	public Collection<Employee> getAll(){
		return employees.values();
	}
	
	public Employee get(Integer id){
		return employees.get(id);
	}
	
	public void delete(Integer id){
		employees.remove(id);
	}
}

package com.cgf.springmvc.crud.dao;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.springframework.stereotype.Repository;

import com.cgf.springmvc.crud.entities.Department;

@Repository
public class DepartmentDao {

	private static Map<Integer, Department> departments = null;
	
	static{
		departments = new HashMap<Integer, Department>();
		
		departments.put(101, new Department(101, "D-AA"));
		departments.put(102, new Department(102, "D-BB"));
		departments.put(103, new Department(103, "D-CC"));
		departments.put(104, new Department(104, "D-DD"));
		departments.put(105, new Department(105, "D-EE"));
	}
	
	public Collection<Department> getDepartments(){
		return departments.values();
	}
	
	public Department getDepartment(Integer id){
		return departments.get(id);
	}
	
}

package com.cgf.springmvc.crud.entities;

public class Department {

	private Integer id;
	private String departmentName;

	public Department() {
		// TODO Auto-generated constructor stub
	}
	
	public Department(int i, String string) {
		this.id = i;
		this.departmentName = string;
	}

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getDepartmentName() {
		return departmentName;
	}

	public void setDepartmentName(String departmentName) {
		this.departmentName = departmentName;
	}

	@Override
	public String toString() {
		return "Department [id=" + id + ", departmentName=" + departmentName
				+ "]";
	}
	
}

package com.cgf.springmvc.crud.entities;

import java.util.Date;

import javax.validation.constraints.NotNull;

import org.hibernate.validator.constraints.Email;
import org.hibernate.validator.constraints.NotEmpty;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.format.annotation.NumberFormat;

public class Employee {

	private Integer id;
	
	@NotNull
	private String lastName;

	@Email
	private String email;
	//1 male, 0 female
	private Integer gender;
	
	private Department department;
	
	
	@DateTimeFormat(pattern="yyyy-MM-dd")
	private Date birth;
	
	@NumberFormat(pattern="#,###,###.#")
	private Float salary;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getLastName() {
		return lastName;
	}

	public void setLastName(String lastName) {
		this.lastName = lastName;
	}

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public Integer getGender() {
		return gender;
	}

	public void setGender(Integer gender) {
		this.gender = gender;
	}

	public Department getDepartment() {
		return department;
	}

	public void setDepartment(Department department) {
		this.department = department;
	}

	public Date getBirth() {
		return birth;
	}

	public void setBirth(Date birth) {
		this.birth = birth;
	}

	public Float getSalary() {
		return salary;
	}

	public void setSalary(Float salary) {
		this.salary = salary;
	}

	@Override
	public String toString() {
		return "Employee [id=" + id + ", lastName=" + lastName + ", email="
				+ email + ", gender=" + gender + ", department=" + department
				+ ", birth=" + birth + ", salary=" + salary + "]";
	}

	public Employee(Integer id, String lastName, String email, Integer gender,
			Department department) {
		super();
		this.id = id;
		this.lastName = lastName;
		this.email = email;
		this.gender = gender;
		this.department = department;
	}

	public Employee() {
		// TODO Auto-generated constructor stub
	}
}

package com.cgf.springmvc.crud.handlers;

import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import com.cgf.springmvc.crud.dao.DepartmentDao;
import com.cgf.springmvc.crud.dao.EmployeeDao;
import com.cgf.springmvc.crud.entities.Employee;

@RequestMapping(value="/springmvc")
@Controller
public class EmployeeHandler {
	
	@Autowired
	private EmployeeDao employeeDao;
	
	@Autowired
	private DepartmentDao departmentDao;
	
	@RequestMapping(value="/list")
	public String emps(Map<String,Object> map){
		map.put("emplists", employeeDao.getAll());
		return "list";
	}
	
	@RequestMapping(value="/addUi",method=RequestMethod.GET)
	public String empsAddUI(Map<String,Object> map){
		map.put("department", departmentDao.getDepartments());
		map.put("employee", new Employee());
		return "input";
	}
	
	@RequestMapping(value="/add",method=RequestMethod.POST)
	public String empsAdd(Employee employee,Map<String,Object> map){
		employeeDao.save(employee);
		//map.put("emplists", employeeDao.getAll());
		return "redirect:list";
	}
	
	@RequestMapping(value="/delete/{id}",method=RequestMethod.DELETE)
	public String empsDelete(@PathVariable("id")Integer id,Map<String,Object> map){
		employeeDao.delete(id);
		map.put("emplists", employeeDao.getAll());
		return "list";
	}
	
	@RequestMapping(value="/EditUi/{id}",method=RequestMethod.GET)
	public String empsEditUI(@PathVariable("id")Integer id,Map<String,Object> map){
		map.put("department", departmentDao.getDepartments());
		map.put("employee", employeeDao.get(id));
		return "input";
	}
	
	@ModelAttribute
	public void emps(@RequestParam(value="id",required=false)Integer id,Map<String,Object> map){
		if(id!=null){
			map.put("employee", employeeDao.get(id));
		}
		
	}
	
	@RequestMapping(value="/add",method=RequestMethod.PUT)
	public String empsEdit(Employee employee,Map<String,Object> map){
		employeeDao.save(employee);
		map.put("emplists", employeeDao.getAll());
		return "list";
	}


}

在index.jsp中：首页用来显示所有的员工，是个GET请求

<h2>SpringMVC CRUD</h2>
   <a href="springmvc/list">显示所有员工信息</a>

在input.jsp中;该页面有两个用处，一个是对添加员工进行操作（post请求），另一个用来对员工信息的修改（put请求）

 <form:form action="springmvc/add" method="POST" modelAttribute="employee">
    	<c:if test="${employee.id==null }">
    	LastName:<form:input path="lastName"/> <br>
    	</c:if>
    	<c:if test="${employee.id!=null }">
    		<form:hidden path="id"/>
    		<input type="hidden" name="_method" value="PUT">
    	</c:if>
    	Email:<form:input path="email"/>
    	<form:errors path="email"></form:errors><br>
    	<%
    		Map<String,String> genders=new HashMap();
    		genders.put("1", "Male");
    		genders.put("0","Female");
    		request.setAttribute("genders", genders);
    	 %>
    	Gender:<form:radiobuttons path="gender" items="${genders }"/><br>
    	Department:<form:select path="department.id" 
    		items="${department}" itemLabel="departmentName" itemValue="id"></form:select>
    	<input type="submit" value="Submit" />
    </form:form>

在list.jsp中：显示所有员工信息，在DELETE操作中，将GET请求，通过JQUERY完成转化为DELETE请求

<span style="font-family:SimSun;"><span style="font-size:18px;"><%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'list.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->
	<script type="text/javascript" src="scripts/jquery-1.9.1.min.js"></script>
	<script type="text/javascript">
		$(function(){
			$(".delete").click(function(){
				var href=$(this).attr("href");
				$("form").attr("action",href).submit();
				return false;
			});
		})	

	</script>
  </head>
  
  <body>
  
  <form action="" method="post">
  <input type="hidden" name="_method" value="DELETE">
  </form>
  
   <c:if test="${empty requestScope.emplists }">
    		没有任何员工信息
    </c:if>
    
    <c:if test="${!empty requestScope.emplists }">
    		<table border="1">
    			<tr>
    				<th>ID</th>
    				<th>LastName</th>
    				<th>Email</th>
    				<th>Gender</th>
    				<th>Department</th>
    				<th>Edit</th>
    				<th>Delete</th>
    			</tr>
    			
    			<c:forEach items="${requestScope.emplists}" var="emps">
    				<tr>
    					<td>${emps.id }</td>
    					<td>${emps.lastName}</td>
    					<td>${emps.email }</td>
    					<td>${emps.gender==0 ? 'Female':'male'}</td>
    					<td>${emps.department.departmentName }</td>
    					<td><a href="springmvc/EditUi/${emps.id}">Edit</a></td>
    					<td><a class="delete" href="springmvc/delete/${emps.id}">Delete</a></td>
    				</tr>
    			</c:forEach>
    		</table>
    </c:if>
    <a href="springmvc/addUi">添加员工信息</a>
  </body>
</html></span>
</span>

注意：

对静态资源的处理，需要在spring.xml文件中配置<mvc:default-servlet-handler/>default-servlet-handler将在 SpringMVC 上下文中定义一个 DefaultServletHttpRequestHandler,它会对进入DispatcherServlet的请求进行筛查, 如果发现是没有经过映射的请求, 就将该请求交由WEB应用服务器默认的Servlet 处理. 如果不是静态资源的请求,才由 DispatcherServlet 继续处理