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
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>{latestVersion}</version>
</dependency>
姬朋飞(玉霄)
public void noModelMultipleSheet() {
InputStream inputStream = getInputStream("2007NoModelMultipleSheet.xlsx");
try {
ExcelReader reader = new ExcelReader(inputStream, ExcelTypeEnum.XLSX, null,
new AnalysisEventListener<List<String>>() {
@Override
public void invoke(List<String> object, AnalysisContext context) {
System.out.println(
"当前sheet:" + context.getCurrentSheet().getSheetNo() + " 当前行:" + context.getCurrentRowNum()
+ " data:" + object);
}
@Override
public void doAfterAllAnalysed(AnalysisContext context) {
}
});
reader.read();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
@Test
public void test1() throws FileNotFoundException {
OutputStream out = new FileOutputStream("/Users/jipengfei/78.xlsx");
try {
ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX);
//写第一个sheet, sheet1 数据全是List<String> 无模型映射关系
Sheet sheet1 = new Sheet(1, 0,ExcelPropertyIndexModel.class);
writer.write(getData(), sheet1);
writer.finish();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
package com.alibaba.china.pte.web.seller.dingtalk.rpc;
import java.io.IOException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List;
import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;
import com.alibaba.excel.ExcelWriter; import com.alibaba.excel.metadata.Sheet; import com.alibaba.excel.support.ExcelTypeEnum;
import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController;
/**
-
@author jipengfei
-
@date 2018/05/25 */ @RequestMapping("/api/dingtalk") @RestController public class Down {
@GetMapping("/a.htm") public void cooperation(HttpServletRequest request, HttpServletResponse response) { ServletOutputStream out = null; try { out = response.getOutputStream(); } catch (IOException e) { e.printStackTrace(); } ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX, true); try {
String fileName = new String(("UserInfo " + new SimpleDateFormat("yyyy-MM-dd").format(new Date())) .getBytes(), "UTF-8"); Sheet sheet1 = new Sheet(1, 0); sheet1.setSheetName("第一个sheet"); writer.write0(getListString(), sheet1); response.setContentType("multipart/form-data"); response.setCharacterEncoding("utf-8"); response.setHeader("Content-disposition", "attachment;filename="+fileName+".xlsx"); out.flush(); } catch (Exception e) { e.printStackTrace(); }finally { writer.finish(); try { out.close(); } catch (IOException e) { e.printStackTrace(); } }
}
private List<List> getListString() { List list = new ArrayList(); list.add("ooo1"); list.add("ooo2"); list.add("ooo3"); list.add("ooo4"); List list1 = new ArrayList(); list1.add("ooo1"); list1.add("ooo2"); list1.add("ooo3"); list1.add("ooo4"); List<List> ll = new ArrayList<List>(); ll.add(list); ll.add(list1); return ll; }
}
有问题阿里同事可以通过钉钉找到我,阿里外同学可以通过git留言。其他技术非技术相关的也欢迎一起探讨。
阿里巴巴新零售事业部--诚招JAVA资深开发、技术专家。有意向可以微信联系,简历可以发我邮箱jipengfei.jpf@alibaba-inc.com 可以走内推流程