SpringBoot进阶使用
参考自 4.Web开发进阶.pptx[1]
静态资源访问
默认将静态资源放到src/main/resources/static目录下，这种情况直接通过ip:port/静态资源名称即可访问(默认做了映射)
也可以在application.properties中通过spring.web.resources.static-locations进行设置
例如[2]，spring.web.resources.static-locations=/images/**，则必须在原路径前加上images
编译后resources下面的文件，都会放到target/classes下
文件上传
传文件时，(对前端来说)表单的enctype属性，必须由默认的application/x-www-form-urlencoded，改为multipart/form-data，这样编码方式就会变化
`spring.servlet.multipart.max-file-size=10MB`[3]
src/main/java/com/example/helloworld/controller/FileUploadController.java[4]
package com.example.helloworld.controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.util.Date;
@RestController
public class FileUploadController {
@PostMapping("/upload")
// 上面这行等价于 @RequestMapping(value = "/upload", method = RequestMethod.POST)
public String up(String nickname, MultipartFile photo, HttpServletRequest request) throws IOException {
System.out.println(nickname);
// 获取图片的原始名称
System.out.println(photo.getOriginalFilename());
// 取文件类型
System.out.println(photo.getContentType());
// HttpServletRequest 获取web服务器的路径(可动态获取)
String path = request.getServletContext().getRealPath("/upload/");
System.out.println(path);
saveFile(photo, path);
return "上传成功";
}
//
public void saveFile(MultipartFile photo, String path) throws IOException {
// 判断存储的目录是否存在，如果不存在则创建
File dir = new File(path);
if (!dir.exists()) {
// 创建目录
dir.mkdir();
}
// 调试时可以把这个路径写死
File file = new File(path + photo.getOriginalFilename());
photo.transferTo(file);
}
}
拦截器
就是一个中间件..
和gin的middleware完全一样
先定义一个普通的java类，一般以Interceptor结尾，代表是一个拦截器。需要继承系统的拦截器类，可以重写父类里的方法
父类基本没做啥事，空的方法实现
下面重写其中的方法
src/main/java/com/example/helloworld/interceptor/LoginInterceptor.java[5]
package com.example.helloworld.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("LoginInterceptor拦截！！！");
return true;
}
}
src/main/java/com/example/helloworld/config/WebConfig.java[6]
配置只拦截/user
package com.example.helloworld.config;
import com.example.helloworld.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class WebConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/user/**");
}
}
5.构建RESTful服务.pptx[7]
Spring Boot实现RESTful API
PUT和PATCH咋精确区分？ ...前几年用过PUT，而PATCH我印象里从来没用过。。
没啥太大意思，还有主张一律用POST的
src/main/java/com/example/helloworld/controller/UserController.java[8]:
package com.example.helloworld.controller;
import com.example.helloworld.entity.User;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.*;
@RestController
public class UserController {
@ApiOperation("获取用户")
@GetMapping("/user/{id}")
public String getUserById(@PathVariable int id) { // 想拿到路径上的动态参数，需要加@PathVariable 注解
System.out.println(id);
return "根据ID获取用户信息";
}
@PostMapping("/user")
public String save(User user) {
return "添加用户";
}
@PutMapping("/user")
public String update(User user) {
return "更新用户";
}
@DeleteMapping("/user/{id}")
public String deleteById(@PathVariable int id) {
System.out.println(id);
return "根据ID删除用户";
}
}
使用Swagger生成Web API文档
pom.xml[9]:
<dependency>
<groupId>io.springfoxgroupId>
<artifactId>springfox-swagger2artifactId>
<version>2.9.2version>
dependency>
<dependency>
<groupId>io.springfoxgroupId>
<artifactId>springfox-swagger-uiartifactId>
<version>2.9.2version>
dependency>
除了添加依赖，还需要加一个配置类
src/main/java/com/example/helloworld/config/SwaggerConfig.java[10]:
package com.example.helloworld.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
@Configuration // 告诉Spring容器，这个类是一个配置类(SB的配置类，都需要加上@Configuration这个注解)
@EnableSwagger2 // 启用Swagger2功能
public class SwaggerConfig {
/**
* 配置Swagger2相关的bean
*/
@Bean
public Docket createRestApi() {
return new Docket(DocumentationType.SWAGGER_2)
.apiInfo(apiInfo()) // 调用了一个自定义方法(改改标题啥的~)
.select()
.apis(RequestHandlerSelectors.basePackage("com"))// com包下所有API都交给Swagger2管理
.paths(PathSelectors.any()).build();
}
/**
* 此处主要是API文档页面显示信息
*/
private ApiInfo apiInfo() {
return new ApiInfoBuilder()
.title("爽哥提示：演示项目API") // 标题
.description("爽哥提示：演示项目") // 描述
.version("1.0") // 版本
.build();
}
}
可以访问http://localhost:8080/swagger-ui.html[11]
读的项目里的控制器，展开可以看到每个控制器里都有什么方法
可以通过如下注解，在页面添加注释
例如@ApiOperation("获取用户")
还可以在页面直接进行调试
参考资料
[1]4.Web开发进阶.pptx: https://github.com/cuishuang/springboot-vue/blob/main/%E8%AF%BE%E4%BB%B6/4.Web%E5%BC%80%E5%8F%91%E8%BF%9B%E9%98%B6.pptx
[2]例如: https://github.com/cuishuang/springboot-vue/blob/main/SpringBoot%E4%BB%A3%E7%A0%81/helloworld/src/main/resources/application.properties#L5
[3]spring.servlet.multipart.max-file-size=10MB: https://github.com/cuishuang/springboot-vue/blob/main/SpringBoot%E4%BB%A3%E7%A0%81/helloworld/src/main/resources/application.properties#L3
src/main/java/com/example/helloworld/controller/FileUploadController.java: https://github.com/cuishuang/springboot-vue/blob/main/SpringBoot%E4%BB%A3%E7%A0%81/helloworld/src/main/java/com/example/helloworld/controller/FileUploadController.java
[5]src/main/java/com/example/helloworld/interceptor/LoginInterceptor.java: https://github.com/cuishuang/springboot-vue/blob/main/SpringBoot%E4%BB%A3%E7%A0%81/helloworld/src/main/java/com/example/helloworld/interceptor/LoginInterceptor.java
[6]src/main/java/com/example/helloworld/config/WebConfig.java: https://github.com/cuishuang/springboot-vue/blob/main/SpringBoot%E4%BB%A3%E7%A0%81/helloworld/src/main/java/com/example/helloworld/config/WebConfig.java
[7]5.构建RESTful服务.pptx: https://github.com/cuishuang/springboot-vue/blob/main/%E8%AF%BE%E4%BB%B6/5.%E6%9E%84%E5%BB%BARESTful%E6%9C%8D%E5%8A%A1.pptx
[8]src/main/java/com/example/helloworld/controller/UserController.java: https://github.com/cuishuang/springboot-vue/blob/main/SpringBoot%E4%BB%A3%E7%A0%81/helloworld/src/main/java/com/example/helloworld/controller/UserController.java
[9]pom.xml: https://github.com/cuishuang/springboot-vue/blob/main/SpringBoot%E4%BB%A3%E7%A0%81/helloworld/pom.xml#L37
[10]src/main/java/com/example/helloworld/config/SwaggerConfig.java: https://github.com/cuishuang/springboot-vue/blob/main/SpringBoot%E4%BB%A3%E7%A0%81/helloworld/src/main/java/com/example/helloworld/config/SwaggerConfig.java
[11]http://localhost:8080/swagger-ui.html: http://localhost:8080/swagger-ui.html
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