springboot+mybatis实现登录功能，返回json

1、新建maven项目（pom）

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <!--自己起的-->
    <groupId>com.weixinone</groupId>
    <artifactId>ssmone</artifactId>
    <version>1.0-SNAPSHOT</version>

    <!-- Inherit defaults from Spring Boot -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.BUILD-SNAPSHOT</version>
    </parent>

    <!-- Add typical dependencies for a web application -->
    <!--加入web模块-->
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--加入mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--gson-->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.2</version>
        </dependency>
    </dependencies>

    <!-- Package as an executable jar -->
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <!-- (you don't need this if you are using a .RELEASE version) -->
    <repositories>
        <repository>
            <id>spring-snapshots</id>
            <url>https://repo.spring.io/snapshot</url>
            <snapshots><enabled>true</enabled></snapshots>
        </repository>
        <repository>
            <id>spring-milestones</id>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-snapshots</id>
            <url>https://repo.spring.io/snapshot</url>
        </pluginRepository>
        <pluginRepository>
            <id>spring-milestones</id>
            <url>https://repo.spring.io/milestone</url>
        </pluginRepository>
    </pluginRepositories>
</project>

　　

2、项目架构

3.源代码

3.1 Mapperer接口

@Mapper
public interface ManMapper {
    @Select("SELECT user, password FROM man WHERE user = #{user}" +
            " AND password = #{password}")
    Man findByState(@Param("user") String username,
                    @Param("password") String password);
}

3.2 Excample类

@RestController
//为 @RequestMapping("/")下面的denglu方法添加映射
@EnableAutoConfiguration
////自动配置应用
@SpringBootApplication
public class Example{

    private final ManMapper manMapper;
//    显示调用，构造器的作用
    public Example(ManMapper manMapper) {
        this.manMapper = manMapper;
    }

    public static void main(String[] args) throws Exception {
        SpringApplication.run(Example.class, args);
    }

    @RequestMapping(value = "/denglu", method = RequestMethod.GET)
    @ResponseBody
    public String denglu(@RequestParam(value = "name", required = true) String name,
                         @RequestParam(value = "pwd", required = true) String pwd) throws Exception {

        Logger.getGlobal().info(pwd);
        Logger.getGlobal().info("结果"+this.manMapper.findByState(name, pwd));

        if (this.manMapper.findByState(name, pwd)!=null){
            String msg="登录成功";
            Gson gson = new Gson();
            return gson.toJson(msg);
        }
        else {
            String msg="登录失败";
            Gson gson = new Gson();
            return gson.toJson(msg);
        }
    }
}

3.3Man类

public  class Man implements Serializable{
    private Long id;
    private String user;
    private String password;

    public Long getId() {
        return id;
    }

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

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "Man{" +
                "id=" + id +
                ", user='" + user + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

3.4MySQL

CREATE TABLE IF NOT EXISTS man  (
  id int(11) NOT NULL AUTO_INCREMENT,
  user varchar(255) NOT NULL,
  password varchar(255) NOT NULL,
  PRIMARY KEY (id)
)CHARACTER SET utf8;
INSERT INTO man VALUES (1, 'test', '123');

4.运行