前言

業務關系定義

分別是用戶、導出隊列、導出執行方法

• ExportQueue： 維護一條定長隊列，可以獲取隊列里前后排隊的用戶，提供查詢，隊列如果已經滿了，其余的人需要進行等待
• User信息： 排隊執行導出方法對應用戶；
• Export類： 定義導出方法，異步執行，用戶可以通過導出頁面查看、下載，導出的文件；

圖片95a28資訊網——每日最新資訊28at.com

具體代碼實現

ExportQueue隊列

package com.example.system.config;import com.example.system.api.domain.ExportUser;import lombok.extern.slf4j.Slf4j;import org.springframework.stereotype.Component;import java.util.LinkedList;@Slf4j@Componentpublic class ExportQueue {    private final int MAX_CAPACITY = 10; // 隊列最大容量    private LinkedList<ExportUser> queue; // 用戶隊列    public ExportQueue(LinkedList<ExportUser> queue) {        this.queue = new LinkedList<>();    }    /**     * 排隊隊列添加     * @param sysUser     */    public synchronized LinkedList<ExportUser> add(ExportUser sysUser) {        while (queue.size() >= MAX_CAPACITY) {            try {                log.info("當前排隊人已滿，請等待");                wait();            } catch (InterruptedException e) {                e.getMessage();            }        }        queue.add(sysUser);        log.info("目前導出隊列排隊人數：" + queue.size());        notifyAll();        return queue;    }    /**     * 獲取排隊隊列下一個人     * @return     */    public synchronized ExportUser getNextSysUser() {        while (queue.isEmpty()) {            try {                wait();            } catch (InterruptedException e) {                e.printStackTrace();            }        }        ExportUser sysUser = queue.remove();        notifyAll(); //喚醒        return sysUser;    }}

AbstractExport導出類

引入EasyExcel百萬級別的導出功能95a28資訊網——每日最新資訊28at.com

package com.example.system.config;import cn.hutool.core.bean.BeanUtil;import cn.hutool.core.util.PageUtil;import com.alibaba.excel.EasyExcel;import com.alibaba.excel.ExcelWriter;import com.alibaba.excel.write.metadata.WriteSheet;import com.example.system.api.domain.ExportUser;import lombok.extern.slf4j.Slf4j;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.net.URLEncoder;import java.util.List;@Slf4jpublic abstract class AbstractExport<T, K> {    public abstract void export(ExportUser sysUser) throws InterruptedException;    /**     * 導出     *     * @param response 輸出流     * @param pageSize 每頁大小     * @param t        導出條件     * @param k        Excel內容實體類     * @param fileName 文件名稱     */    public void export(HttpServletResponse response, int pageSize, T t, Class<K> k, String fileName) throws Exception {        ExcelWriter writer = null;        try {            writer = getExcelWriter(response, fileName);            //查詢導出總條數            int total = this.countExport(t);            //頁數            int loopCount = PageUtil.totalPage(total, pageSize);            BeanUtil.setProperty(t, "pageSize", pageSize);            for (int i = 0; i < loopCount; i++) {                //開始頁                BeanUtil.setProperty(t, "pageNum", PageUtil.getStart(i + 1, pageSize));                //獲取Excel導出信息                List<K> kList = this.getExportDetail(t);                WriteSheet writeSheet = EasyExcel.writerSheet(fileName).head(k).build();                writer.write(kList, writeSheet);            }        } catch (Exception e) {            String msg = "導出" + fileName + "異常";            log.error(msg, e);            throw new Exception(msg + e);        } finally {            if (writer != null) {                writer.finish();            }        }    }    public com.alibaba.excel.ExcelWriter getExcelWriter(HttpServletResponse response, String fileName) throws IOException {        response.setContentType("application/vnd.ms-excel");        response.setCharacterEncoding("utf-8");        // 這里URLEncoder.encode可以防止中文亂碼 當然和easyexcel沒有關系        String fileNameUtf = URLEncoder.encode(fileName, "UTF-8").replaceAll("http://+", "%20");        response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileNameUtf + ".xlsx");        return EasyExcel.write(response.getOutputStream()).build();    }    /**     * （模版導出）     *     * @param t     * @param fileName     * @param response     */    public abstract void complexFillWithTable(T t, String fileName, HttpServletResponse response);    /**     * 查詢導出總條數     *     * @param t     * @return     */    public abstract int countExport(T t);    /**     * 查詢導出數據     *     * @param t     * @return     */    public abstract List<K> getExportDetail(T t);}

ExportImpl導出實現方法

package com.example.system.service.impl;import com.alibaba.excel.ExcelWriter;import com.example.system.api.domain.ExportUser;import com.example.system.config.AbstractExport;import com.example.system.config.ExportQueue;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.util.LinkedList;import java.util.List;@Service@Slf4jpublic class ExportImpl extends AbstractExport {    @Autowired    private ExportQueue exportQueue;    @Override    public void export(ExportUser sysUser) throws InterruptedException {        //導出        log.info("導出文件方法執行～～～～～～～～～");//        export(response,pageSize,t,k,fileName);        LinkedList<ExportUser> queue = exportQueue.add(sysUser);        log.info("導出隊列：" + queue);        //休眠時間稍微設置大點，模擬導出處理時間        Thread.sleep(20000);        //導出成功后移除當前導出用戶        ExportUser nextSysUser = exportQueue.getNextSysUser();        log.info("移除后獲取下一個排隊的用戶: " + nextSysUser.getUserName());    }    @Override    public void export(HttpServletResponse response, int pageSize, Object o, Class k, String fileName) throws Exception {        super.export(response, pageSize, o, k, fileName);    }    @Override    public ExcelWriter getExcelWriter(HttpServletResponse response, String fileName) throws IOException {        return super.getExcelWriter(response, fileName);    }    @Override    public void complexFillWithTable(Object o, String fileName, HttpServletResponse response) {    }    @Override    public int countExport(Object o) {        return 0;    }    @Override    public List getExportDetail(Object o) {        return null;    }}

測試controller

package com.example.system.controller;import com.example.system.api.domain.ExportUser;import com.example.system.api.domain.SysUser;import com.example.system.service.impl.ExportImpl;import lombok.SneakyThrows;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.PostMapping;import org.springframework.web.bind.annotation.RequestBody;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;@RestController@RequestMapping("/export")@Slf4jpublic class ExportController {    @Autowired    private ExportImpl export;    @PostMapping("/exportFile")    public void exportFile() {            new Thread(new Runnable() {                @SneakyThrows                @Override                public void run() {                    Thread thread1 = Thread.currentThread();                    ExportUser sysUser =new ExportUser();                    sysUser.setUserName(thread1.getName());                    export.export(sysUser);                }            }).start();        }}

測試結果

通過請求測試方法，限制了我們導出隊列最大限制10次，隊列場長度超過10次則無法進行繼續提交；95a28資訊網——每日最新資訊28at.com

圖片95a28資訊網——每日最新資訊28at.com

第一次請求和第二次請求，間隔10秒，第一個用戶導出完成后出列，下一個排隊用戶在隊列首位，再進行導出請求排在上一個用戶后面；95a28資訊網——每日最新資訊28at.com

圖片95a28資訊網——每日最新資訊28at.com

總結

95a28資訊網——每日最新資訊28at.com

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