Java后台接口开发初步实战教程

@RequestMapping(value = "register", method = RequestMethod.GET)
 @ResponseBody
 public Map<String, Object> register(@RequestParam("username") String username, @RequestParam("password") String password) {
  out.println("welcome to register,username=" + username + ";password=" + password);
  Map<String, Object> map = new HashMap<>();
  ResultBean result = onRegister(username, password);
  out.println("result==>" + result);
  map.put("code", result.getCode());
  map.put("reason", result.getReason());
  map.put("success", result.isSuccess());
  return map;
 }

private ResultBean onRegister(String username, String password) {
  ResultBean resultBean = new ResultBean();
  SqlSession session = null;
  try {
   session = sqlSessionFactory.openSession();
   LoginMapper loginMapper = session.getMapper(LoginMapper.class);
   Map<String, Object> map = new HashMap<>();
   map.put("name", username);
   map.put("password", password);
   LoginBean bean = new LoginBean();
   bean.setName(username);
   bean.setPassword(password);
   // 查询用户是否存在
   LoginBean userExist = loginMapper.findUserByName(map);
   if (userExist != null) {
    // 存在后无法注册
    resultBean.setCode("001");
    resultBean.setSuccess(false);
    resultBean.setReason("用户已存在");
   } else {
    loginMapper.addUser(bean);
    session.commit();// 重要，一定要commit，否则无法insert
    System.out.println("当前增加的用户id为：" + bean.getId());
    resultBean.setCode("200");
    resultBean.setSuccess(true);
    resultBean.setReason("注册成功");
   }
  } catch (Exception e) {
   e.printStackTrace();
   out.println("注册异常==>" + e.getMessage());
   resultBean.setCode("001");
   resultBean.setSuccess(false);
   resultBean.setReason("注册异常");
  } finally {
   session.close();
  }
  return resultBean;
 }

public interface LoginMapper {
 public LoginBean findUserByName(Map<String,Object> map) throws Exception;
 public void addUser(LoginBean bean) throws Exception;
}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">
<mapper namespace="com.xm.travel.LoginMapper">
 <select id="loadRunList" parameterType="java.util.Map" resultType="com.xm.travel.RunBean">
  select * from run
 </select>
 <select id="loginUser" parameterType="java.util.Map" resultType="com.xm.travel.LoginBean">
  select * from user where name = #{name} and password = #{password}
 </select>
 <select id="findUserByName" parameterType="java.util.Map" resultType="com.xm.travel.LoginBean">
  select * from user where name = #{name}
 </select>
 <insert id="addUser" useGeneratedKeys="true" keyProperty="id" >
  insert into user(id,name,password) values(#{id},#{name},#{password})
 </insert>
</mapper>