具体代码实现
ExportQueue队列
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
@Component
public class ExportQueue {
private final int MAX_CAPACITY = 10; // 队列最大容量
private LinkedList queue; // 用户队列
public ExportQueue(LinkedList queue) {
this.queue = new LinkedList<>();
}
public synchronized LinkedList add(ExportUser sysUser) {
while (queue.size() >= MAX_CAPACITY) {
try {
log.info("当前排队人已满,请等待");
wait();
} catch (InterruptedException e) {
e.getMessage();
}
}
queue.add(sysUser);
log.info("目前导出队列排队人数:" + queue.size());
notifyAll();
return queue;
}
public synchronized ExportUser getNextSysUser() {
while (queue.isEmpty()) {
try {
wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
ExportUser sysUser = queue.remove();
notifyAll(); //唤醒
return sysUser;
}
}
AbstractExport导出类
引入EasyExcel百万级别的导出功能
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;
@Slf4j
public abstract class AbstractExport {
public abstract void export(ExportUser sysUser) throws InterruptedException;
public void export(HttpServletResponse response, int pageSize, T t, Class k, String fileName) throws Exception {
ExcelWriter writer = null;
try {
writer = getExcelWriter(response, fileName);
//查询导出总条数
int total = this.countExport(t);
//页数
int loopCount = PageUtil.totalPage(total, pageSize);
BeanUtil.setProperty(t, "pageSize", pageSize);
for (int i = 0; i < loopCount; i++) {
//开始页
BeanUtil.setProperty(t, "pageNum", PageUtil.getStart(i + 1, pageSize));
//获取Excel导出信息
List kList = this.getExportDetail(t);
WriteSheet writeSheet = EasyExcel.writerSheet(fileName).head(k).build();
writer.write(kList, writeSheet);
}
} catch (Exception e) {
String msg = "导出" + fileName + "异常";
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");
// 这里URLEncoder.encode可以防止中文乱码 当然和easyexcel没有关系
String fileNameUtf = URLEncoder.encode(fileName, "UTF-8").replaceAll("\\+", "%20");
response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileNameUtf + ".xlsx");
return EasyExcel.write(response.getOutputStream()).build();
}
public abstract void complexFillWithTable(T t, String fileName, HttpServletResponse response);
public abstract int countExport(T t);
public abstract List getExportDetail(T t);
}
ExportImpl导出实现方法
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
@Slf4j
public class ExportImpl extends AbstractExport {
@Autowired
private ExportQueue exportQueue;
@Override
public void export(ExportUser sysUser) throws InterruptedException {
//导出
log.info("导出文件方法执行~~~~~~~~~");
// export(response,pageSize,t,k,fileName);
LinkedList queue = exportQueue.add(sysUser);
log.info("导出队列:" + queue);
//休眠时间稍微设置大点,模拟导出处理时间
Thread.sleep(20000);
//导出成功后移除当前导出用户
ExportUser nextSysUser = exportQueue.getNextSysUser();
log.info("移除后获取下一个排队的用户: " + 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;
}
}
测试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")
@Slf4j
public 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();
}
}
测试结果
通过请求测试方法,限制了我们导出队列最大限制10次,队列场长度超过10次则无法进行继续提交;
图片
第一次请求和第二次请求,间隔10秒,第一个用户导出完成后出列,下一个排队用户在队列首位,再进行导出请求排在上一个用户后面;
图片