server:   port: 80 spring:   datasource:     driver-class-name: com.mysql.jdbc.Driver     url: jdbc:mysql://localhost:3306/blog1?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC     username: root     password: 123456   thymeleaf:     mode: HTML   jpa:     hibernate:       ddl-auto: update     show-sql: true   

public interface UserDao extends JpaRepository<User,Long> { 
             User findByUsernameAndPassword(String username, String password); } 

@Service public class UserServiceImpl implements IUserService { 
              @Autowired     private UserDao userDao;      @Override     public User checkUser(String username, String password) { 
                 return userDao.findByUsernameAndPassword(username, MD5Util.code(password));     } }   public interfac IUserService { 
        
    User checkUser(String username,String password);
}

public class MD5Util { 
        

    /** * MD5加密类 * @param str 要加密的字符串 * @return 加密后的字符串 */
    public static String code(String str){ 
        
        try { 
        
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(str.getBytes());
            byte[]byteDigest = md.digest();
            int i;
            StringBuffer buf = new StringBuffer("");
            for (int offset = 0; offset < byteDigest.length; offset++) { 
        
                i = byteDigest[offset];
                if (i < 0)
                    i += 256;
                if (i < 16)
                    buf.append("0");
                buf.append(Integer.toHexString(i));
            }
            //32位加密
            return buf.toString();
            // 16位的加密
            //return buf.toString().substring(8, 24);
        } catch (NoSuchAlgorithmException e) { 
        
            e.printStackTrace();
            return null;
        }

    }


    public static void main(String[] args) { 
        
        System.out.println(code("1"));
    }
}

@SpringBootApplication
public class BlgApplication { 
        
    public static void main(String[] args) { 
        
        SpringApplication.run(BlgApplication.class,args);
    }
}

<?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>

    <groupId>com.zr</groupId>
    <artifactId>Day09</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <java.version>1.8</java.version>
        <!-- <thymeleaf.version>3.0.11</thymeleaf.version>-->
        <thymeleaf-layout-dialect.version>2.1.1</thymeleaf-layout-dialect.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>