springboot入门

java.boot

主程序

1
2
3
4
5
6
7
8
9
10
11
12
13
package cn.sdadgz.boot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

controller

注解：

1
2
3
4
@RestController		// 无页面
@Controller		// 页面
@RequestMapping("[路径]")
@ResponseBody // 无页面

config

手动添加bean

1
2
3
4
5
6
7
8
9
@Configuration
public class MyConfig(){
    
    @Bean // 方法名做组件id，对象里面放值
    public User user01(){
        return new User("张三",18);
    }
    
}

自定义

拦截器config
1
2
3
4
5
6
7
8
9
10
11
@Configuration
public class adminWebConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginInterceptor())
                .addPathPatterns("/**")
//                此时静态资源也被拦截，网站访问静态资源也会出现登录
                .excludePathPatterns("/","/login","/css/**","/fonts/**","/images/**","/js/**");

    }
}

矩阵变量|converter

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
//矩阵变量生效用
@Bean
public WebMvcConfigurer webMvcConfigurer(){
    return  new WebMvcConfigurer() {
        @Override
        public void configurePathMatch(PathMatchConfigurer configurer) {
            UrlPathHelper urlPathHelper  = new UrlPathHelper();
            urlPathHelper.setRemoveSemicolonContent(false);
            configurer.setUrlPathHelper(urlPathHelper);
        }
        //重写这个extend方法，在数据类型中额外添加自己定义的数据
        @Override
        public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
           converters.add(new GuiguconventerMessage());
        }
    };
}

converter 提交数据时

1660233269866

messageConverter 返回数据时

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
public class GuiguconventerMessage implements HttpMessageConverter<Person> {
    @Override
    public boolean canRead(Class<?> aClass, MediaType mediaType) {
        return false;//不让被注释识别
    }

    @Override
    public boolean canWrite(Class<?> aClass, MediaType mediaType) {
        return true;
    }

    @Override
    public List<MediaType> getSupportedMediaTypes() {
        return MediaType.parseMediaTypes("application/x-guigu");
    }

    @Override
    public Person read(Class<? extends Person> aClass, HttpInputMessage httpInputMessage) throws IOException, HttpMessageNotReadableException {
        return null;
    }

    @Override
    public void write(Person person, MediaType mediaType, HttpOutputMessage httpOutputMessage) throws IOException, HttpMessageNotWritableException {
        //规定数据类型
        String data  =  person.getName()+";"+person.getPassword()+";"+person.getAge();
        OutputStream body = httpOutputMessage.getBody();
        //将类型保存
        body.write(data.getBytes());
    }
}

@Configuration

  • proxyBeanMethods = false // 默认true，其他组件不依赖它时用false更快

@Import({})

  • {User.class,Pet.class} // 自动创建组件

@ConditionalOnBean(name = “[tom]”) // tom存在时创建组件，省略其他条件装配

@ImportResource(“classpath:beans.xml”) // 导入xml装配

@EnableConfigurationProperties(User.class) // 自动装配配置文件

pojo

注解：

@Component // 组件

@ConfigurationPeroperties(Prefix = “[mycar]”) // 配置文件自动装配

拦截器旧

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
package com.atguigu.springboot.demo2.interceptor;
//登录拦截器

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class LoginInterceptor implements HandlerInterceptor {
//    执行之前
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        HttpSession session = request.getSession();
        Object loginuser = session.getAttribute("loginuser");
        if(loginuser != null){
            return  true;
        }else {
            session.setAttribute("msg","请先登录");
//            response.sendRedirect("/login");
            request.getRequestDispatcher("/").forward(request,response);
            //弹幕：因为前端页面是获取request域中数据，而重定向只能放session数据，为了不改变前端代码，所以这里改为请求转发
            return  false;

        }
    }
//执行之后
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
    }
//页面渲染
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }
}

文件上传

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
@Controller
public class FormTestController {
    @GetMapping("/form_layouts")
    public String formLayout(){
        return "form/form_layouts";
    }


    @PostMapping("/upload")
    public String uploadForm(
            @RequestParam("email") String email,
            @RequestParam("username") String username,
            @RequestParam("headerImg")MultipartFile headerImg,
            @RequestParam("photos") MultipartFile [] photos
//            自动封装
            ){
//        获取文件测试
        System.out.println("email:"+email+"username:"+username+"headering:"+headerImg.getSize()+"photos:"+photos.length);
//      保存文件
        if(!headerImg.isEmpty()){
            try {
//                获取文件名
                String originalFilename = headerImg.getOriginalFilename();
                headerImg.transferTo(new File("D:/cache/"+originalFilename));
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
//        保存一组图片
        if (photos.length>0){
            for (MultipartFile photo : photos) {
                if(!photo.isEmpty()){
                    String originalFilename = photo.getOriginalFilename();
                    try {
                        photo.transferTo(new File("D:/cache/"+originalFilename));
                    } catch (IOException e) {
                        throw new RuntimeException(e);
                    }
                }
            }
        }

        return "main";
    }
}

resources

application.properties|application.yaml

springboot配置文件 官网

开启页面表单的Rest功能

1
2
3
4
5
spring:
  mvc:
    hiddenmethod:
      filter:
        enabled: true   #开启页面表单的Rest功能

开启请求参数内容协商模式

1
2
3
4
5
spring:
	mvc:
        contentnegotiation:
          favor-parameter: true  #开启请求参数内容协商模式

pom

导入JDBC

导入boot

1
2
3
4
5
6
7
8
9
10
11
12
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.7.2</version>
</parent>

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

yaml和properties自动提示

1
2
3
4
5
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-configuration-processor</artifactId>
    <optional>true</optional>
</dependency>

maven打包jar

1
2
3
4
5
6
7
8
9
10
11
12
<!--打包jar-->

<packaging>jar</packaging>

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

maven重写boot配置

1
2
3
4
5
6
7
8
9
10
<properties>
	<mysql.version>5.1.43</mysql.version>
</properties>

<dependecies>
	<dependency>
    	<groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
</dependecies>

springboot+mybatis

导入pom

1
2
3
4
5
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.4</version>
</dependency>

配置文件properties|yaml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
# 配置mybatis规则
mybatis:
  config-location: classpath:mybatis/mybatis-config.xml  #全局配置文件位置
  mapper-locations: classpath:mybatis/mapper/*.xml  #sql映射文件位置

# 或

# 配置mybatis规则
mybatis:
#  config-location: classpath:mybatis/mybatis-config.xml
  mapper-locations: classpath:mybatis/mapper/*.xml
  configuration:
    map-underscore-to-camel-case: true # 开启驼峰命名法
    
# 可以不写全局；配置文件，所有全局配置文件的配置都放在configuration配置项中即可

mapper

注解

  • @Mapper

我不会，长大后再学习

原生组件注入(Servlet,Filters,Listeners)

尚硅谷65p mybatisPlus下次从这p开始看，草，这会不看了

SpringBoot2核心技术与响应式编程 · 语雀 (yuque.com)