easyExcel导出excel的简单使用
Java解析、生成Excel比较有名的框架有Apache poi、jxl。但他们都存在一个严重的问题就是非常的耗内存，poi有一套SAX模式的API可以一定程度的解决一些内存溢出的问题，但POI还是有一些缺陷，比如07版Excel解压缩以及解压后存储都是在内存中完成的，内存消耗依然很大。easyexcel重写了poi对07版Excel的解析，能够原本一个3M的excel用POI sax依然需要100M左右内存降低到KB级别，并且再大的excel不会出现内存溢出，03版依赖POI的sax模式。在上层做了模型转换的封装，让使用者更加简单方便
easyexcel 项目git地址为: https://github.com/alibaba/easyexcel
官方使用指南见: https://github.com/alibaba/easyexcel/blob/master/quickstart.md
1：使用：
导入依赖maven依赖：
<dependency><groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>1.1.2-beta4</version>
</dependency>
2：模型映射
public class DownMonitorExcelSheet1 extends BaseRowModel {
@ExcelProperty(value = "城市",index = 0)
private String city;
@ExcelProperty(value = "项目名字",index = 1)
private String projectName;
@ExcelProperty(value = "上刊数",index = 2)
private Integer skNum;
@ExcelProperty(value = "下刊数",index = 3)
private Integer xkNum;
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getProjectName() {
return projectName;
}
public void setProjectName(String projectName) {
this.projectName = projectName;
}
public Integer getSkNum() {
return skNum;
}
public void setSkNum(Integer skNum) {
this.skNum = skNum;
}
public Integer getXkNum() {
return xkNum;
}
public void setXkNum(Integer xkNum) {
this.xkNum = xkNum;
}
}
3：service
@Override
public void excelExportDownInfo(String schemeId, String pushDate, HttpServletResponse response) throws IOException {
String fileName = String.valueOf(System.currentTimeMillis());
response.setContentType("multipart/form-data");
response.setCharacterEncoding("utf-8");
response.addHeader("Content-Disposition", "filename=" + fileName+ ".xlsx");
String sheet1Name = "下刊监测统计";
String sheet2Name = "已下刊";
String sheet3Name = "未下刊";
ExcelWriter writer = new ExcelWriter(response.getOutputStream(), ExcelTypeEnum.XLSX);
//写第一个sheet, sheet1 数据全是List<String> 无模型映射关系
Sheet sheet = new Sheet(1, 0,DownMonitorExcelSheet1.class);
sheet.setSheetName(sheet1Name);
//下刊监测统计
List<DownMonitorExcelSheet1> downMonitorExcelSheet1s = pushMonitorDao.queryDownMonitorExcelSheet1(schemeId, pushDate);
writer.write(downMonitorExcelSheet1s, sheet);
//已下刊 sheet2
// List<DownMonitorExcelSheet2> downMonitorExcelSheet2s = pushMonitorDao.queryDownMonitorExcelSheet2(schemeId, pushDate);
// Sheet sheet2 = new Sheet(2, 0, DownMonitorExcelSheet2.class);
// sheet2.setSheetName(sheet2Name);
// writer.write(downMonitorExcelSheet2s,sheet2);
//未下刊 sheet3
// List<DownMonitorExcelSheet2> downMonitorExcelSheet3 = pushMonitorDao.queryDownMonitorExcelSheet3(schemeId, pushDate);
// Sheet sheet3 = new Sheet(3, 0, DownMonitorExcelSheet2.class);
// sheet3.setSheetName(sheet3Name);
// writer.write(downMonitorExcelSheet3,sheet3);
writer.finish();
}