包阅导读总结
1. `ExportQueue`、`EasyExcel`、`导出`、`队列`、`AbstractExport`
2. 本文主要介绍了一个使用`ExportQueue`队列解决多人同时导出`Excel`可能导致服务器崩溃的问题,并结合`EasyExcel`实现导出功能,还包括了相关的抽象类和实现类,目前部分功能未完善,如文件表设计、oss文件上传等,且未考虑高并发场景。
3.
– 项目配置
– `ExportQueue`类:定义最大容量,实现添加和获取队列元素的方法,处理队列满和空的情况。
– 导出功能
– `AbstractExport`抽象类:定义导出相关的方法,如`export`、获取`ExcelWriter`、复杂填充表格等,还有计数和获取导出详情的抽象方法。
– `ExportImpl`实现类:继承`AbstractExport`,实现具体的`export`方法和其他方法。
– 测试部分
– `ExportController`类:创建新线程进行导出操作。
– 后续考虑
– 未实现导出文件表设计、`oss`文件上传、用户文件下载,未考虑高并发场景,提出`Redis`队列也可实现,仅提供思路。
思维导图:
文章地址:https://mp.weixin.qq.com/s/HodQWYhumvlZjWFkiPhU8w
文章来源:mp.weixin.qq.com
作者:Lxlxxx
发布时间:2024/7/24 11:07
语言:中文
总字数:1607字
预计阅读时间:7分钟
评分:89分
标签:导出优化,服务器性能,队列管理,异步处理,Java
以下为原文内容
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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;
private LinkedList<ExportUser> queue;
public ExportQueue(LinkedList<ExportUser> queue) {
this.queue = new LinkedList<>();
}
public synchronized LinkedList<ExportUser> 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();
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<T, K> {
public abstract void export(ExportUser sysUser) throws InterruptedException;
public void export(HttpServletResponse response, int pageSize, T t, Class<K> k, String fileName) throws Exception {
ExcelWriter writer = null;
try {
writer = getExcelWriter(response, fileName);
int total = this.countExport(t);
int loopCount = PageUtil.totalPage(total, pageSize);
BeanUtil.setProperty(t, "pageSize", pageSize);
for (int i = 0; i < loopCount; i++) {
BeanUtil.setProperty(t, "pageNum", PageUtil.getStart(i + 1, pageSize));
List<K> 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");
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<K> 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 {
log.info("导出文件方法执行~~~~~~~~~");
LinkedList<ExportUser> queue = exportQueue.add(sysUser);
log.info("导出队列:" + queue);
Thread.sleep(20000);
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。
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,在进行导出请求排在上一个用户后面。
其余的还未实现,导出文件的表的设计、oss文件上传、用户导出文件下载,还有高并发的场景下会不会出现什么问题,这些都还没有太考虑进去;实现的方式应该挺多的,Redis的队列应该也是可以的,这里仅仅提供一个实现思路。