Java

Knife4j

Knife4j是Java MVC框架集成Swagger生成Api文档的增强解决方案

使用方法：1.导入knife4j的maven坐标

​ 2.在配置类中加入knife4j相关配置

​ 3.设置静态资源映射，否则接口文档页面无法访问

<dependency>
            <groupId>com.gitthub.xiaoymin</groupId>
            <artifactId>knife4j-spring-boot-starter</artifactId>
            <version>3.0.2</version>
 </dependency>

在config包下的WebMvcConfiguration的配置

package com.sky.config;
import com.sky.interceptor.JwtTokenAdminInterceptor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
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.WebMvcConfigurationSupport;
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;

/**
 * 配置类，注册web层相关组件
 */
@Configuration
@Slf4j
public class WebMvcConfiguration extends WebMvcConfigurationSupport {

    @Autowired
    private JwtTokenAdminInterceptor jwtTokenAdminInterceptor;

    /**
     * 注册自定义拦截器
     *
     * @param registry
     */
    protected void addInterceptors(InterceptorRegistry registry) {
        log.info("开始注册自定义拦截器...");
        registry.addInterceptor(jwtTokenAdminInterceptor)
                .addPathPatterns("/admin/**")
                .excludePathPatterns("/admin/employee/login");
    }

    /**
     * 通过knife4j生成接口文档
     * @return
     */
    @Bean
    public Docket docket() {
        ApiInfo apiInfo = new ApiInfoBuilder()
                .title("苍穹外卖项目接口文档")
                .version("2.0")
                .description("苍穹外卖项目接口文档")
                .build();
        Docket docket = new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo)
                .select()
                .apis(RequestHandlerSelectors.basePackage("com.sky.controller")) //要扫描的包
                .paths(PathSelectors.any())
                .build();
        return docket;
    }

    /**
     * 设置静态资源映射
     * @param registry
     */
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/doc.html").addResourceLocations("classpath:/META-INF/resources/");
        registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");
    }
}

Swagger常用注解

@Api                    //用在类上，例如Controller，表示对类的说明
@ApiOperation           //用在方法上，例如Controller的方法，说明方法的用途、作用
@ApiModel               //用在类上，例如entity,DTO,VO
@ApiModelProperty       //用在属性上，描述属性信息

//示例
@ApiModel(description = "员工登录时传递的数据模型")
public class EmployeeLoginDTO implements Serializable {
    @ApiModelProperty("用户名")
    private String username;

    @ApiModelProperty("密码")
    private String password;

}

//对象属性拷贝
Employee employee = new Employee();
BeanUtils.copyProperties(employeeDTO, employee); // (原数据，拷贝后的新数据)

Redis

pom文件引入依赖

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

config包下创建 RedisConfiguration

@Configuration
public class RedisConfiguration {
    @Bean
    public RedisTemplate redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        log.info("开始创建RedisTemplate对象...");
        RedisTemplate redisTemplate = new RedisTemplate();
        // 设置RedisConnectionFactory
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        // 设置key的序列化器
        redisTemplate.setKeySerializer(new StringRedisSerializer());
       return redisTemplate;
    }
}

使用

@Autowired
private RedisTemplate redisTemplate;
 redisTemplate.opsForValue().set("SHOP_STATUS", status);
 Integer status = (Integer) redisTemplate.opsForValue().get("SHOP_STATUS");

HttpClient

<dependency>
          <groupId>org.apache.httpcomponents</groupId>
          <artifactId>httpclient</artifactId>
          <version>4.5.13</version>
      </dependency>

发送请求步骤

1.创建 HttpClient对象

2.创建Http请求对象

3.调用HttpClient的execute方法发送请求

CloseableHttpClient httpClient = HttpClients.createDefault();
 HttpGet httpGet =  new HttpGet("https://jin88.top/xianyuepro/random");  //发送GET请求
 CloseableHttpResponse response = httpClient.execute(httpGet);
 HttpEntity entity = response.getEntity();
 String body = EntityUtils.toString(entity);
 System.out.println(body+"body");
 response.close(); //关闭响应
 httpClient.close();

      CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost =  new HttpPost("https://jin88.top/xianyuepro/index/login");
        
        JSONObject jsonObject =new JSONObject();
        jsonObject.put("phone", "17356288857");
        jsonObject.put("pwd", "123456");

        StringEntity stringEntity = new StringEntity(jsonObject.toJSONString());
//        stringEntity.setContentEncoding("utf-8");
        stringEntity.setContentType("application/json");
         httpPost.setEntity(stringEntity);

        CloseableHttpResponse execute = httpClient.execute(httpPost);  //发送POST请求
        HttpEntity entity = execute.getEntity();
        String body = EntityUtils.toString(entity);
        System.out.println(body+"body");
        execute.close();
        httpClient.close();

Spring Cache

<dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-cache</artifactId>
           <version>2.7.3</version>
       </dependency>

@SpringBootApplication  //用在启动类上
@EnableTransactionManagement //开启注解方式的事务管理 用在启动类上
@EnableCaching //开启缓存功能 ************************用在启动类上

@Cacheable(cacheNames = "setmealCache", key = "#categoryId") // key = "#categoryId" // 有缓存返回缓存，没有则查询后将结果存入缓存并返回
@CachePut  // 将方法的返回值放到缓存中
@CacheEvict(cacheNames = "setmealCache",allEntries = true) //将一条或多条数据从缓存中删除
@CacheEvict(cacheNames = "setmealCache",key = "#setmealDTO.categoryId")//key: setmealCache::100

Spring Task

//导入maven坐标 spring-context （已存在）
@EnableScheduling //开启定时任务功能
//建立Task类 需要添加 @Component
@Component
@Slf4j
public class MyTask {
    @Scheduled(cron = "0/5 * * * * ?")  //定时任务 每隔5秒触发一次
    public void executeTask(){
        log.info("定时任务开始执行：{}", new Date());
    }

}

//时间加减 plusMinutes(-15) 
LocalDateTime time = LocalDateTime.now().plusMinutes(-15); // -15表示15分钟之前
LocalDateTime.now().plusMinutes(15); //15分钟之后

WebScoket

websocket包下

package com.sky.websocket;
import org.springframework.stereotype.Component;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

@Component  //WebSocket服务
@ServerEndpoint("/ws/{sid}")  //参数
public class WebSocketServer {
    private static Map<String, Session> sessionMap = new HashMap();    //存放会话对象

    @OnOpen  //连接建立成功调用的方法
    public void onOpen(Session session, @PathParam("sid") String sid) {
        System.out.println("客户端：" + sid + "建立连接");
        sessionMap.put(sid, session);
    }

 
    @OnMessage  //收到客户端消息后调用的方法
    public void onMessage(String message, @PathParam("sid") String sid) {
        System.out.println("收到来自客户端：" + sid + "的信息:" + message);
    }
     
    @OnClose  //连接关闭调用的方法
    public void onClose(@PathParam("sid") String sid) {
        System.out.println("连接断开:" + sid);
        sessionMap.remove(sid);
    }

    public void sendToAllClient(String message) {  //群发
        Collection<Session> sessions = sessionMap.values();
        for (Session session : sessions) {
            try {   //服务器向客户端发送消息
                session.getBasicRemote().sendText(message);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

 //  WebSocket配置类，用于注册WebSocket的Bean config包下
package com.sky.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * WebSocket配置类，用于注册WebSocket的Bean
 */
@Configuration
public class WebSocketConfiguration {

    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }

}