Async异步线程执行器的定义与使用

短命女 2022-11-14 14:54 159阅读 0赞

> java后台很多场景是需要异步去处理的，比如耗时比较的大的，以及当前任务关系不是很依赖的推送、发送短信、赠送卡券优惠券、打包zip等等。这个时候异步执行器会很方便。

## 1、定义多线程池 ##

启用异步注解：@EnableAsync

ExecutorConfig.java

import lombok.extern.slf4j.Slf4j;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.scheduling.annotation.EnableAsync;
    import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
    
    import java.util.concurrent.Executor;
    
    @Configuration
    @EnableAsync
    @Slf4j
    public class ExecutorConfig { 
    
        String executors = "10";//可以从配置文件中获取
    
        @Bean
        public Executor asyncServiceExecutor() { 
            log.debug("开始配置 --> asyncServiceExecutor 异步线程执行器");
            ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
            //配置核心线程数
            executor.setCorePoolSize(Integer.parseInt(executors));
            //配置最大线程数
            executor.setMaxPoolSize(Integer.parseInt(executors));
            //配置队列大小
            executor.setQueueCapacity(0);
            //配置线程池中的线程的名称前缀
            executor.setThreadNamePrefix("async-service-");
            // rejection-policy：当pool已经达到max size的时候，如何处理新任务
            // CALLER_RUNS：不在新线程中执行任务，而是有调用者所在的线程来执行
    // executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
            //执行初始化
            executor.initialize();
            return executor;
        }
    }

## 2、使用异步执行 ##

service方法中打上@Async(“asyncServiceExecutor”)注解

package com.dj.yier.service;
    
    import com.dj.admin.config.ConfigProp;
    import com.dj.yier.entity.GiftCard;
    import com.dj.yier.utils.QRCodeUtil;
    import lombok.extern.slf4j.Slf4j;
    import org.apache.commons.io.FileUtils;
    import org.apache.commons.io.IOUtils;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.scheduling.annotation.Async;
    import org.springframework.stereotype.Service;
    import org.springframework.util.CollectionUtils;
    
    import java.io.File;
    import java.io.FileOutputStream;
    import java.util.List;
    import java.util.zip.ZipEntry;
    import java.util.zip.ZipOutputStream;
    
    @Service
    @Slf4j
    public class AsynService { 
    
        @Value("${card.url}")
        private String cardUrl;
    
        private GiftCardService giftCardService;
    
        @Autowired
        private ConfigProp configProp;
    
    	/** * 异步生成图片 */
        @Async("asyncServiceExecutor")
        public void executeAsync(GiftCardService service,String batchNo) { 
            giftCardService = service;
            log.info("开始生成图片--> batchNo:" + batchNo);
            long startTime = System.currentTimeMillis();
            String subPath = "/coupon/" + batchNo + "/";
            String fileRealPath = configProp.serverUploadPath + subPath;
            String rootPath = configProp.serverUploadRoot + subPath;
            File file = new File(fileRealPath + "/createFolder.jpg");
            file.getParentFile().mkdirs();
            List<GiftCard> cardList = giftCardService.getListByBatchNo(batchNo);
            if(!CollectionUtils.isEmpty(cardList)) { 
                for (GiftCard giftCard : cardList) { 
                    String imgName = giftCard.getCardNo() + ".jpg";
                    giftCard.setCardImg(rootPath + imgName);
                    QRCodeUtil.createQRCode(new File(fileRealPath + imgName), 300, cardUrl + giftCard.getCardNo(), "FQ" + giftCard.getCardId());
                }
                giftCardService.updateBatchById(cardList);
            }
            log.info("结束生成图片 --> batchNo:{}, 总个数:{},耗时：{}ms",batchNo,cardList.size(),System.currentTimeMillis() - startTime);
        }
    
    	/** * 异步打包zip */
        @Async("asyncServiceExecutor")
        public void packageZip(Integer batchId,File filePath,File saveFile) { 
            log.debug("开始打包ZIP-->" + batchId);
            try { 
                saveFile.getParentFile().mkdirs();
                if(saveFile.exists()){ 
                    saveFile.delete();
                    saveFile.createNewFile();
                }
                FileOutputStream fos = new FileOutputStream(saveFile);
                ZipOutputStream out = new ZipOutputStream(fos);
                zip(out, filePath, "");
                out.close();
                log.info("打包ZIP已完成...");
            }catch (Exception e){ 
                e.printStackTrace();
                log.error("打包ZIP出现异常-->" + batchId);
            }
        }
    
        public static void zip(ZipOutputStream out, File sourceFile, String base) throws Exception { 
            //如果路径为目录（文件夹）
            if (sourceFile.isDirectory()) { 
                //取出文件夹中的文件（或子文件夹）
                File[] fileList = sourceFile.listFiles();
                if (fileList.length == 0) { 
                    //如果文件夹为空，则只需在目的地zip文件中写入一个目录进入点
                    System.out.println(base + "/");
                    out.putNextEntry(new ZipEntry(base + "/"));
                } else { 
                    //如果文件夹不为空，则递归调用zip，文件夹中的每一个文件（或文件夹）进行压缩
                    for (File file : fileList) { 
                        zip(out, file, base + "/" + file.getName());
                    }
                }
            } else { 
                //如果不是目录（文件夹），即为文件，则先写入目录进入点，之后将文件写入zip文件中
                out.putNextEntry(new ZipEntry(base));
                IOUtils.write(FileUtils.readFileToByteArray(sourceFile), out);
                out.flush();
            }
        }
    
    }