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
com.alibaba easyexcel {latestVersion}姬朋飞（玉霄）
读07版小于1000行数据返回List<List>
List<Object> data = EasyExcelFactory.read(inputStream, new Sheet(1, 0));
读07版小于1000行数据返回List<? extend BaseRowModel>
List<Object> data = EasyExcelFactory.read(inputStream, new Sheet(2, 1,JavaModel.class));
读07版大于1000行数据返回List<List>
ExcelListener excelListener = new ExcelListener();
EasyExcelFactory.readBySax(inputStream, new Sheet(1, 1), excelListener);
读07版大于1000行数据返回List<? extend BaseRowModel>
ExcelListener excelListener = new ExcelListener();
EasyExcelFactory.readBySax(inputStream, new Sheet(2, 1,JavaModel.class), excelListener);
读03版方法同上
测试代码地址：https://github.com/alibaba/easyexcel/blob/master/src/test/java/com/alibaba/easyexcel/test/WriteTest.java 没有模板
ExcelWriter writer = EasyExcelFactory.getWriter(out);
//写第一个sheet, sheet1 数据全是List<String> 无模型映射关系
Sheet sheet1 = new Sheet(1, 3);
sheet1.setSheetName("第一个sheet");
//设置列宽 设置每列的宽度
Map columnWidth = new HashMap();
columnWidth.put(0,10000);columnWidth.put(1,40000);columnWidth.put(2,10000);columnWidth.put(3,10000);
sheet1.setColumnWidthMap(columnWidth);
sheet1.setHead(createTestListStringHead());
//or 设置自适应宽度
//sheet1.setAutoWidth(Boolean.TRUE);
writer.write1(createTestListObject(), sheet1);
//写第二个sheet sheet2 模型上打有表头的注解，合并单元格
Sheet sheet2 = new Sheet(2, 3, JavaModel1.class, "第二个sheet", null);
sheet2.setTableStyle(createTableStyle());
writer.write(createTestListJavaMode(), sheet2);
//写第三个sheet包含多个table情况
Sheet sheet3 = new Sheet(3, 0);
sheet3.setSheetName("第三个sheet");
Table table1 = new Table(1);
table1.setHead(createTestListStringHead());
writer.write1(createTestListObject(), sheet3, table1);
//写sheet2 模型上打有表头的注解
Table table2 = new Table(2);
table2.setTableStyle(createTableStyle());
table2.setClazz(JavaModel1.class);
writer.write(createTestListJavaMode(), sheet3, table2);
//关闭资源
writer.finish();
out.close();
有模板
OutputStream out = new FileOutputStream("/Users/jipengfei/2007.xlsx");
ExcelWriter writer = EasyExcelFactory.getWriterWithTemp(inputStream,out,ExcelTypeEnum.XLSX,true);
//写第一个sheet, sheet1 数据全是List<String> 无模型映射关系
Sheet sheet1 = new Sheet(1, 3);
sheet1.setSheetName("第一个sheet");
//设置列宽 设置每列的宽度
Map columnWidth = new HashMap();
columnWidth.put(0,10000);columnWidth.put(1,40000);columnWidth.put(2,10000);columnWidth.put(3,10000);
sheet1.setColumnWidthMap(columnWidth);
sheet1.setHead(createTestListStringHead());
//or 设置自适应宽度
//sheet1.setAutoWidth(Boolean.TRUE);
writer.write1(createTestListObject(), sheet1);
//写第二个sheet sheet2 模型上打有表头的注解，合并单元格
Sheet sheet2 = new Sheet(2, 3, JavaModel1.class, "第二个sheet", null);
sheet2.setTableStyle(createTableStyle());
writer.write(createTestListJavaMode(), sheet2);
//写第三个sheet包含多个table情况
Sheet sheet3 = new Sheet(3, 0);
sheet3.setSheetName("第三个sheet");
Table table1 = new Table(1);
table1.setHead(createTestListStringHead());
writer.write1(createTestListObject(), sheet3, table1);
//写sheet2 模型上打有表头的注解
Table table2 = new Table(2);
table2.setTableStyle(createTableStyle());
table2.setClazz(JavaModel1.class);
writer.write(createTestListJavaMode(), sheet3, table2);
//关闭资源
writer.finish();
out.close();
public class Down {
@GetMapping("/a.htm")
public void cooperation(HttpServletRequest request, HttpServletResponse response) {
ServletOutputStream out = response.getOutputStream();
ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX, true);
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);
writer.finish();
response.setContentType("multipart/form-data");
response.setCharacterEncoding("utf-8");
response.setHeader("Content-disposition", "attachment;filename="+fileName+".xlsx");
out.flush();
}
}
}
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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 或者加微信：18042000709
