SpringBoot构建项目02

1. Thymeleaf模板引擎

Thymeleaf模板引擎用来渲染视图，其原理是模板+数据=文件

使用方法：

①：导入依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf </artifactId>
        </dependency>

②：在templates下创建模板文件，其默认的模板文件格式是html，注意添加命名空间！

<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>成功！</h1>
<!--使用语法th:text 将div里面的文本内容设置为 -->

<div th:text="${msg}">这是显示欢迎信息</div>
</body>
</html>

thymeleaf的表达式是作为标签中的一个属性！在渲染数据时会被替换成对应的值！

③：控制层绑定数据

    @RequestMapping("/thy")
    public String hello(Model model){
        model.addAttribute("msg", "hello world");
        return "hello";
    }

Thymeleaf的视图解析器：

自动配置类：ThymeleafAutoConfiguration

默认的前缀是classpath:/templates/,默认的后缀是.html

可以在application.yml中自定义前缀、后缀等！

spring:
  thymeleaf:
    prefix: classpath:/templates/html/
    suffix: .jsp

2. 拦截器

①：自定义拦截器继承HandlerInterceptorAdapter重写preHandle方法并交给spring管理

@Component
public class MyInterceptor extends HandlerInterceptorAdapter {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("登录拦截..." +"路径为："+request.getRequestURL());
        return super.preHandle(request, response, handler);
    }
}

②：在配置类中实现WebMvcConfigurer接口重写addInterceptors方法，注册拦截器

@SpringBootApplication
public class HelloConfig implements WebMvcConfigurer{
    @Autowired
    private MyInterceptor myInterceptor;
    public static void main(String[] args) {
        SpringApplication.run(HelloConfig.class,args);
    }

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

表示拦截所有请求，对/login放行！

3. DataSource集成

手动配置：

①：导入依赖

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.20</version>
        </dependency>
        <!-- mysql 数据库驱动. -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>

②：yml中配置相关属性

jdbc:
  username: root
  password: 112334
  url: jdbc:mysql:///test
  driverClassName: com.mysql.jdbc.Driver

③：配置类中注入值

@SpringBootApplication
public class ApplicationConfig {
    public static void main(String[] args) {
        SpringApplication.run(ApplicationConfig.class);
    }
    @ConfigurationProperties(prefix = "jdbc")
    @Bean
    public DataSource dataSource(){
        return new DruidDataSource();
    }
}

自动配置：

只需要在yml中配置

spring:
  datasource:
    url: jdbc:mysql:///test
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: 112334

4. Mybatis集成

①：导包

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>

②：搭建项目结构

domain、mappper、service、controller

③：yml中的配置

配置数据源

spring:
  datasource:
    url: jdbc:mysql:///test
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: 112334
    type: com.alibaba.druid.pool.DruidDataSource

配置mybatis扫描的配置文件

mybatis:
  mapper-locations: classpath:com/hanfengyi/mapper/*Mapper.xml

④：配置类中加上@MapperScan注解扫描mapper接口交给spring管理

@SpringBootApplication
@MapperScan("com.hanfengyi.mapper")
public class ApplicationConfig {
    public static void main(String[] args) {
        SpringApplication.run(ApplicationConfig.class);
    }
}

5. 事务继承

导入mybatis依赖

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>

在配置类中使用@EnableTransactionManagement开启事务管理器

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

在业务层开启事务

@Service
@Transactional
public class UserServiceImpl implements IUserService {
    @Autowired
    private UserMapper userMapper;
    @Transactional(readOnly = true)
    @Override
    public List<User> getAll() {
        return userMapper.selectAll();
    }
}