「小程序JAVA实战」小程序登录与后端联调（36）

重新温习下用户的注册的方式，开发一个用户登录的spring boot接口。源码：https://github.com/limingios/wxProgram.git 中的wx-springboot 和 No.15

service 类的开发

UserService.java

··· java

package com.idig8.service;

import com.idig8.pojo.Users;

public interface UserService {

/**
 * 判断用户名是否存在
 * @param username
 * @return
 */
public boolean queryUsernameIsExist(String username);

/**
 * 保存用户
 * @param user
 * @return
 */
public void saveUser(Users user);

/**
 * 查询用户对象
 * @param username
 * @return
 */
public Users queryUserIsExist(Users user);

}

···

UserServiceImpl.java

> Sid 是注入的id的生成工具，Example queryExample = new Example(Users.class);

和 Criteria criteria = queryExample.createCriteria(); 都是一种套路，就是查询套路，大家可以看看

https://baike.baidu.com/item/criteria/5354117

··· java

package com.idig8.service;

import org.n3r.idworker.Sid;

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

import org.springframework.boot.autoconfigure.security.SecurityProperties.User;

import org.springframework.stereotype.Service;

import org.springframework.transaction.annotation.Propagation;

import org.springframework.transaction.annotation.Transactional;

import com.idig8.mapper.UsersMapper;

import com.idig8.pojo.Users;

import com.idig8.utils.MD5Utils;

import tk.mybatis.mapper.entity.Example;

import tk.mybatis.mapper.entity.Example.Criteria;

@Service

public class UserServiceImpl implements UserService {

@Autowired
private UsersMapper usersMapper;

@Autowired
private Sid sid;

@Transactional(propagation =Propagation.SUPPORTS)
@Override
public boolean queryUsernameIsExist(String username) {
    Users user = new Users();
    user.setUsername(username);
    Users result = usersMapper.selectOne(user);
    return result==null? false:true;
}

@Transactional(propagation =Propagation.REQUIRED)
@Override
public void saveUser(Users user) {
    String userId =sid.nextShort();
    user.setId(userId);
    usersMapper.insert(user);
}

@Transactional(propagation =Propagation.SUPPORTS)
@Override
public Users queryUserIsExist(Users user) {
    Example queryExample = new Example(Users.class);
    Criteria criteria = queryExample.createCriteria();
    criteria.andEqualTo("username",user.getUsername());
    try {
        criteria.andEqualTo("password",MD5Utils.getMD5Str(user.getPassword()));
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    Users userOne =  usersMapper.selectOneByExample(queryExample);
    return userOne;
}

}

### controller 类的开发
RegistLoginController.java
>增加了登录方法。
``` java

package com.idig8.controller;

import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import com.idig8.pojo.Users;
import com.idig8.service.UserService;
import com.idig8.utils.JSONResult;
import com.idig8.utils.MD5Utils;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;

@RestController
@Api(value="用户注册登录的接口",tags={"注册和登录的controller"})
public class RegistLoginController {

    @Autowired
    private UserService userService;


    @ApiOperation(value="用户注册",notes="用户注册的接口")
    @PostMapping("/regist")
    public JSONResult regist(@RequestBody Users user) {
        //1.判断用户名和密码不能为空
        if(StringUtils.isBlank(user.getUsername())||StringUtils.isBlank(user.getPassword())) {
            return JSONResult.errorMsg("用户名或密码不能为空");
        }

        //2.判断用户名是否存在
        boolean usernameIsExist = userService.queryUsernameIsExist(user.getUsername());
        if(!usernameIsExist) {
            user.setNickname(user.getUsername());
            try {
                user.setPassword(MD5Utils.getMD5Str(user.getPassword()));
            } catch (Exception e) {

                return JSONResult.errorMsg(e.getMessage());
            }
            user.setFollowCounts(0);
            user.setReceiveLikeCounts(0);
            user.setFansCounts(0);
            userService.saveUser(user);
        }else {
            return JSONResult.errorMsg("用户名或已经存在，请更换在试试！");
        }

        //防止密码返回被获取到
        user.setPassword("");
        return JSONResult.ok(user);
    }

    @ApiOperation(value="用户登录",notes="用户登录的接口")
    @PostMapping("/login")
    public JSONResult login(@RequestBody Users user) {
        //1.判断用户名和密码不能为空
        if(StringUtils.isBlank(user.getUsername())||StringUtils.isBlank(user.getPassword())) {
            return JSONResult.errorMsg("用户名或密码不能为空");
        }

        //2.判断用户名是否存在
        Users userObject = userService.queryUserIsExist(user);

        if(userObject==null){
            return JSONResult.errorMsg("用户名或密码不存在！");
        }

        //防止密码返回被获取到
        user.setPassword("");
        return JSONResult.ok(userObject);
    }
}
</code></pre>

<h3>wx前端部分的开发</h3>

<img src="https://upload-images.jianshu.io/upload_images/11223715-e2151b8653637425.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240" alt="" />

``` userLogin.wxml


  
            
   
     
            
   
     账号

        <view class="line"></view>

        <!--密码-->
        <view class="inputView">
            <image class="keyImage" src="../../resource/images/password.png"></image>
            <label class="loginLabel">密码</label>
            <input name="password" maxlength="10" type="text" class="inputText" password="{{true}}" placeholder="请输入密码"/>
        </view>

        <!--按钮-->
        <view>
            <button class="loginBtn" type="primary" form-type='submit'>登陆</button>
        </view>

        <view>
            <button class="goLoginBtn" type="warn" bindtap="goRegisterPage">返回注册</button>
        </view>
    </form>
</view>

``` javascript
const app = getApp()

Page({
  data: {

  },

  doLogin: function (e) {
    var formObject = e.detail.value;
    var username = formObject.username;
    var password = formObject.password;

    // 简单验证
    if (username.length == 0 || password.length == 0) {
      wx.showToast({
        title: '用户名或密码不能为空',
        icon: 'none',
        duration: 3000
      })
    } else {
      wx.request({
        url: app.serverUrl + "/login",
        method: "POST",
        data: {
          username: username,
          password: password
        },
        header: {
          'content-type': 'application/json' // 默认值
        },
        success: function (res) {
          console.log(res.data);
          var status = res.data.status;
          if (status == 200) {
            wx.showToast({
              title: "用户登陆成功~！",
              icon: 'none',
              duration: 3000
            })
            app.userinfo = res.data.data;
          } else if (status == 500) {
            wx.showToast({
              title: res.data.msg,
              icon: 'none',
              duration: 3000
            })
          }
        }
      })
    }
  },
  goLoginPage: function (e) {
    console.log("跳转到注册");
  }
})