SpringMVC使用restful实现员工列表的查询
1、配置web.xml文件:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0">
<!-- The front controller of this Spring Web application,
responsible for handling all application requests -->
<servlet>
<servlet-name>springDispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 配置SpringMVC配置文件的位置和名称 -->
<!-- 实际上也可以使用默认的配置文件:/WEB-INF/<servlet-name>-servlet.xml -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- Map all requests to the DispatcherServlet for handling -->
<servlet-mapping>
<servlet-name>springDispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!-- 可以把POST请求转为为DELETE或者POST请求 -->
<filter>
<filter-name>HiddenHttpMethodFilter</filter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>HiddenHttpMethodFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>

2、配置springmvc.xml文件:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd">
<!-- 配置自动扫描的包 -->
<context:component-scan base-package="com.gwolf.springmvc">
</context:component-scan>
<!-- 配置视图解析器,如何把handler方法返回值解析为实际的物理视图 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<mvc:annotation-driven></mvc:annotation-driven>
</beans>

3、新建一个jsp页面list.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<c:if test="${empty requestScope.employees }">
没有任何员工信息.
</c:if>
<c:if test="${!empty requestScope.employees }">
<table border="1" cellpadding="10" cellspacing="0">
<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="${requestScope.employees }" var="emp">
<tr>
<td>${emp.id }</td>
<td>${emp.lastName }</td>
<td>${emp.email }</td>
<td>${emp.gender == 0 ? 'Female' : 'Male' }</td>
<td>${emp.department.departmentName }</td>
<td><a href="emp/${emp.id}">Edit</a></td>
<td><a class="delete" href="emp/${emp.id}">Del</a></td>
</tr>
</c:forEach>
</table>
</c:if>
</body>
</html>

4、DepartmentDao层代码如下:
package com.gwolf.springmvc.dao;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.springframework.stereotype.Repository;
import com.gwolf.springmvc.domain.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);
}
}

5、EmployeeDao代码实现如下:
package com.gwolf.springmvc.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.gwolf.springmvc.domain.Department;
import com.gwolf.springmvc.domain.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", "aa@163.com", 1, new Department(101, "D-AA")));
employees.put(1002, new Employee(1002, "E-BB", "bb@163.com", 1, new Department(102, "D-BB")));
employees.put(1003, new Employee(1003, "E-CC", "cc@163.com", 0, new Department(103, "D-CC")));
employees.put(1004, new Employee(1004, "E-DD", "dd@163.com", 0, new Department(104, "D-DD")));
employees.put(1005, new Employee(1005, "E-EE", "ee@163.com", 1, new Department(105, "D-EE")));
}
private static Integer initId = 1006;
public Collection<Employee> getAll(){
return employees.values();
}
public void delete(Integer id){
employees.remove(id);
}
}


6、控制层代码实现如下:
package com.gwolf.springmvc.handlers;
import java.util.Map;
import javax.validation.Valid;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.validation.Errors;
import org.springframework.validation.FieldError;
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.gwolf.springmvc.dao.DepartmentDao;
import com.gwolf.springmvc.dao.EmployeeDao;
import com.gwolf.springmvc.domain.Employee;
@Controller
public class EmployeeHandler {
@Autowired
private EmployeeDao employeeDao;
@Autowired
private DepartmentDao departmentDao;
@RequestMapping("/emps")
public String list(Map<String, Object> map){
map.put("employees", employeeDao.getAll());
return "list";
}
}

7、启动tomcat服务器,查看程序执行结果:
