springboot快速创建项目框架

一、项目框架准备

1.1 新建maven空项目，并在pom中引入依赖

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.12.RELEASE</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!-- web启动器 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--jdbc连接及其启动器 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.48</version>
        </dependency>
        <!--tk.mybatis及mybatis启动器 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.1.5</version>
        </dependency>
        <!--thymeleaf启动器 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
    </dependencies>

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

1.2 准备mysql数据表

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(255) NOT NULL,
  `password` varchar(255) NOT NULL,
  `birthday` date DEFAULT NULL,
  `address` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4;
INSERT INTO `user` VALUES ('1', '张三', '12345', '2020-01-16', '许昌市');
INSERT INTO `user` VALUES ('2', '李四', '54321', '2020-01-01', '河南省许昌市');

二、实现数据的展示

2.1 新建启动入口并测试

在java文件夹中新建 MyApplication.java 文件，作为程序的启动入口。

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

在resources文件夹中新建application.yml文件，配置端口和数据库连接

server:
  port: 7001
spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mydb
    username: root
    password: fanbao0713

新建controller --> UserController.java 文件，并启动测试：http://localhost:7001/user/hello

@Controller
@RequestMapping("user")
public class UserController {
    @GetMapping("hello")
    public String hello(){
        return "Hello World!";
    }
}

2.2 数据库连接配置

新建 pojo --> User.java 文件：

@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String username;
    private String password;
    private Date birthday;
    private String address;

    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

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

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

在 application.yml 文件中，新增mybatis关联

mybatis:
  type-aliases-package: com.springbootdemo.pojo

在 mapper --> UserMapper.java 文件：

@Mapper
public interface UserMapper extends tk.mybatis.mapper.common.Mapper<User> {
}

在 service --> UserService.java 文件，由于tk.mybati不是spring官方插件，“userMapper”会报错，可以忽略：

@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;

    public User selectById(Long id){
        return this.userMapper.selectByPrimaryKey(id);
    }

    public List<User> selectAll(){
        return userMapper.selectAll();
    }
}

在 controller --> UserController.java 文件中，展示接口，并进行测试：http://localhost:7001/user/findAll

@RestController
@RequestMapping("user")
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping("{id}")
    public User selectById(@PathVariable("id") Long id){
        return this.userService.selectById(id);
    }

    @GetMapping("findAll")
    public Map<String, Object> findAll(){
        Map<String, Object> map = new HashMap<>();
        map.put("用户列表", userService.selectAll());
        return map;
    }
}

三、静态资源访问及拦截器

3.1 访问静态资源

在 resources 文件夹中新增static中，并加入目录中，static中的各类资源可以直接访问：http://localhost:7001/js/common.js

3.2 拦截器设置

在 interceptors --> UserInterceptor中，首先我们定义一个拦截器：

@Component
public class UserInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle/前置拦截器 method is running!");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle/运行拦截器 method is running!");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("postHandle/后置拦截器 method is running!");
    }
}

新建 config --> MvcConfig.java 中，定义配置类，注册拦截器：

@Configuration
public class MvcConfig implements WebMvcConfigurer {
    @Autowired
    private HandlerInterceptor handlerInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(handlerInterceptor).addPathPatterns("/**");
    }
}