一、搭建 mvc 环境
新建一个 module 模块，创建 maven 工程，步骤跟以前一样，各种配置文件内容也可以拷贝修改一下即可。
二、创建实体类
新建个 bean 包，创建实体类 Employee：
package com.pingguo.rest.bean; public class Employee { private Integer id; private String lastName; private String email; //1 male, 0 female private Integer gender; 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 Employee(Integer id, String lastName, String email, Integer gender) { super(); this.id = id; this.lastName = lastName; this.email = email; this.gender = gender; } public Employee() { } }
三、准备 dao 模拟数据
新建一个 dao 包，创建 EmployeeDao 类，这里不使用数据库，直接存放一些静态数据：
@Repository public class EmployeeDao { private static Map<Integer, Employee> employees = null; static{ employees = new HashMap<Integer, Employee>(); employees.put(1001, new Employee(1001, "E-AA", "aa@163.com", 1)); employees.put(1002, new Employee(1002, "E-BB", "bb@163.com", 1)); employees.put(1003, new Employee(1003, "E-CC", "cc@163.com", 0)); employees.put(1004, new Employee(1004, "E-DD", "dd@163.com", 0)); employees.put(1005, new Employee(1005, "E-EE", "ee@163.com", 1)); } private static Integer initId = 1006; public void save(Employee employee){ if(employee.getId() == null){ employee.setId(initId++); } 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); } }
dao 中实现了几个增删改查的操作，代替与数据库的交互：
map集合employees，里存放了 5 个 Employee 对象。save()方法是保存，包含了添加操作和修改操作。getAll()是查询所有，返回的是所有 Employee 对象的 value。get()是查询单个员工信息，根据 id 。delete()是根据 id 删除数据。
四、准备控制器
controller 包下新建 EmployeeController 类：
@Controller public class EmployeeController { @Autowired private EmployeeDao employeeDao; }
接下来就可以一个个的实现功能了，大概有：
- 访问首页
- 查询全部数据
- 删除
- 跳转到添加数据页面
- 执行保存
- 跳转到更新数据页面
- 执行更新
