Spring Boot项目构建

步骤

（1）初始化

（2）配置

（3）项目依赖

（4）存放位置

（5）测试

新建ControllerServlet

@Controller
public class UserController {
    @ResponseBody
    @RequestMapping("/user/login")
    public String userLogin(){
        return "user login...";
    }
}

启动项目

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

注：

项目结构

Web项目依赖

项目配置

基本配置

application.properties

# 服务器配置
server.port=5000
server.servlet.context-path=/app

多环境配置

示例如下

application.properties

# 服务器配置
spring.profiles.active=dev

组件赋值

@ConfigurationProperties

示例代码

@Component
@ConfigurationProperties(prefix = "db")
@Data
public class User {
    private String username;
    private String password;
}

属性配置文件

# 用户信息
db.username=zs
db.password=123456

测试

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        ApplicationContext app = SpringApplication.run(Application.class, args);
        User user = (User) app.getBean("user");
        System.out.println(user.getUsername());
    }
}

在Spring容器初始化完成之后，如果想要进行一些操作，就可以实现ComnandLineRunner或ApplicationRunner接口。会自动执行run方法

示例代码

@Component
@ConfigurationProperties(prefix = "db")
@Data
public class User implements CommandLineRunner {
    private String username;
    private String password;
    @Override
    public void run(String... args) throws Exception {
        System.out.println("Spring容器初始化完成...");
    }
}

控制台

Servlet

示例代码

AdminServlet

public class AdminServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.getWriter().println("admin模块...");
    }
}

注册成为容器中的组件

@Configuration
public class WebApplicationConfig {
    @Bean
    public ServletRegistrationBean servletRegist(){
        ServletRegistrationBean bean = new ServletRegistrationBean();
        bean.setServlet(new AdminServlet());
        bean.addUrlMappings("/admin");
        return bean;
    }
}

过滤器

自定义过滤器

public class SetCharsetEncodingFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        // 统一编码设置
        servletRequest.setCharacterEncoding("utf8");
        servletResponse.setCharacterEncoding("utf8");
        servletResponse.setContentType("text/html;charset=utf8");
        // 放行请求
        filterChain.doFilter(servletRequest, servletResponse);
    }
    @Override
    public void destroy() {
    }
}

注册为容器中的组件

@Component
public class WebApplicationConfig {
    @Bean
    public FilterRegistrationBean charsetFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new SetCharsetEncodingFilter());
        bean.addUrlPatterns("/*");
        return bean;
    }
}

拦截器

自定义拦截器

public class PermissionInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 请求拦截
        HttpSession session = request.getSession();
        if(session.getAttribute("username") == null){
            // 未登录, 给用户提示
            response.getWriter().println("请登录...");
            return false;
        }else{
            return true;
        }
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    }
}

注册拦截器

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        PermissionInterceptor permissionInterceptor = new PermissionInterceptor();
        registry.addInterceptor(permissionInterceptor)
            .addPathPatterns("/user/**")
            .excludePathPatterns("/user/login");
    }
}

集成Mybatis框架

数据库配置

# 数据库配置
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=123456

方式一

dao层代理对象

@Mapper
public interface UserDao {
    User selectUserByUserNameAndPassword(String username, String password);
}

方式二

组件扫描器

@SpringBootApplication
@MapperScan(basePackages = "com.cskaoyan.demo.dao")
public class Application {
    public static void main(String[] args){
        SpringApplication.run(Application.class, args);
    }
}

开启日志

# Mybatis开启日志
mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl

事务

注解方式

开启事务

@EnableTransactionManagement

@SpringBootApplication
@MapperScan(basePackages = "com.cskaoyan.demo.dao")
@EnableTransactionManagement
public class Application {
    public static void main(String[] args){
        SpringApplication.run(Application.class, args);
    }
}

给需要添加事务的方法添加注解

@Transactional

示例代码

@Transactional
@Override
public int insertUser(String username, String password) {
    int res = userDao.insertUser(username, password);
    // 模拟操作异常
    int a = 1 / 0;
    return res;
}