本文主要是介绍性能爆炸！SXSSFWorkbook原文件上追加写入分页导出，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
使用SXSSF大数据导出，SXSSFWorkbook是用来生成海量excel数据文件，主要原理是借助临时存储空间生成excel，SXSSFWorkbook专门处理大数据，对于大型excel的创建且不会内存溢出的，就只有SXSSFWorkbook了。它的原理很简单，用硬盘空间换内存（就像hashmap用空间换时间一样）。 SXSSFWorkbook是streaming版本的XSSFWorkbook,它只会保存最新的excel rows在内存里供查看，在此之前的excel rows都会被写入到硬盘里（Windows电脑的话，是写入到C盘根目录下的temp文件夹）。被写入到硬盘里的rows是不可见的/不可访问的。只有还保存在内存里的才可以被访问到。
网上教程很多，下面是我跑出来的版本
项目依赖包及版本
<commons.compress.version>1.18</commons.compress.version>
<poi.version>4.0.1</poi.version><dependency><groupId>org.apache.poi</groupId><artifactId>poi</artifactId>
<version>${ poi.version }</version> </dependency><dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId>
<version>${ poi.version }</version></dependency>
<dependency><groupId>org.apache.commons</groupId><artifactId>commons-compress</artifactId><version>${commons.compress.version}</version></dependency>
工具类
import dbox.tbox.lang.DateUtils;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;
import org.apache.poi.xssf.streaming.SXSSFSheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.stream.Stream;/*** @Author ping* @Date 2023/12/4 17:04* excel工具类 用于service服务的导出，不使用export模式*/
public class ExcelUtil {// 读取 Excel 文件并将其映射为具体的 Java 对象public static <T> List<T> readExcel(String filePath, Class<T> clazz) throws Exception {List<T> objects = new ArrayList<>();try (FileInputStream fis = new FileInputStream(filePath);Workbook workbook = new XSSFWorkbook(fis)) {Sheet sheet = workbook.getSheetAt(0); // 选择工作表for (int i = 1; i <= sheet.getLastRowNum(); i++) {Row row = sheet.getRow(i);T obj = clazz.getDeclaredConstructor().newInstance();for (int j = 0; j < row.getLastCellNum(); j++) {Cell cell = row.getCell(j);String fieldName = sheet.getRow(0).getCell(j).getStringCellValue();Field field = clazz.getDeclaredField(fieldName);field.setAccessible(true);//跳过静态属性if (Modifier.isStatic(field.getModifiers())){continue;}//单元格为空的情况if (cell == null){continue;}if (cell.getCellType() == CellType.NUMERIC) {double numericValue = cell.getNumericCellValue();if (field.getType() == BigDecimal.class){field.set(obj, BigDecimal.valueOf(numericValue));}else if (field.getType() == Long.class){field.set(obj, (long) numericValue);}else if (field.getType() == Integer.class){field.set(obj, (int) numericValue);}else {field.set(obj, numericValue); // 设置为Double类型}} else if (cell.getCellType() == CellType.STRING) {if (field.getType() == Date.class){field.set(obj, DateUtils.strToDate(cell.getStringCellValue(),"yyyy-MM-dd HH:mm:ss"));}else if (field.getType() == String.class){field.set(obj, cell.getStringCellValue());}}}objects.add(obj);}} catch (Exception e) {e.printStackTrace();throw e;}return objects;}/*** 创建表头 MAP 格式为 filed，表头名* @param objects* @param filePath* @param titleMap* @param append* @param <T>* @throws IOException*/public static <T> void writeExcel(List<T> objects, String filePath, Map<String, String> titleMap, boolean append) throws IOException {// 确保工作簿以指定模式打开Workbook workbook;if (append) {try (FileInputStream fis = new FileInputStream(filePath)) {workbook = WorkbookFactory.create(fis);}} else {workbook = new XSSFWorkbook();}// 获取或创建SheetSheet sheet = workbook.getSheet("Sheet1");if (sheet == null) {sheet = workbook.createSheet("Sheet1");}// 创建表头List<String> titles = new ArrayList<>();titleMap.forEach((k, v) -> titles.add(v));if (!append) {Row headerRow = sheet.createRow(0);for (int i = 0; i < titles.size(); i++) {headerRow.createCell(i).setCellValue(titles.get(i));}}// 写入数据int lastRowNum = sheet.getPhysicalNumberOfRows();int currentRow = lastRowNum == 0 ? 0 : lastRowNum + 1;for (T object : objects) {Row row = sheet.createRow(currentRow++);for (String fieldName : titleMap.keySet()) {Cell cell = row.createCell(row.getLastCellNum());cell.setCellValue((String) getCellValue(object, fieldName));}}// 写入文件try (FileOutputStream outputStream = new FileOutputStream(filePath)) {workbook.write(outputStream);}}/*** 只需要列名--不创建表头* @param objects* @param filePath* @param titleList* @param append* @param <T>* @throws IOException*/public static <T> void writeExcel(List<T> objects, String filePath, List<String> titleList, boolean append) throws IOException {// 确保工作簿以指定模式打开Workbook workbook;if (append) {try (FileInputStream fis = new FileInputStream(filePath)) {workbook = WorkbookFactory.create(fis);}} else {workbook = new XSSFWorkbook();}// 获取或创建SheetSheet sheet = workbook.getSheet("Sheet1");if (sheet == null) {sheet = workbook.createSheet("Sheet1");}// 写入数据int lastRowNum = sheet.getPhysicalNumberOfRows();int currentRow = lastRowNum == 0 ? 0 : lastRowNum + 1;for (T object : objects) {Row row = sheet.createRow(currentRow++);for (String fieldName : titleList) {Cell cell = row.createCell(row.getLastCellNum());cell.setCellValue((String) getCellValue(object, fieldName));}}// 写入文件try (FileOutputStream outputStream = new FileOutputStream(filePath)) {workbook.write(outputStream);}}public static void writeExcel(List<List<String>> objects, String filePath, boolean append,List<Integer> rigthList) throws IOException {// 确保工作簿以指定模式打开Workbook workbook;if (append) {try (FileInputStream fis = new FileInputStream(filePath)) {workbook = WorkbookFactory.create(fis);}} else {workbook = new XSSFWorkbook();}// 获取或创建SheetSheet sheet = workbook.getSheet("Sheet1");if (sheet == null) {sheet = workbook.createSheet("Sheet1");}// 写入数据int lastRowNum = sheet.getPhysicalNumberOfRows();int currentRow = lastRowNum == 0 ? 0 : lastRowNum;CellStyle cellStyle = workbook.createCellStyle();cellStyle.setAlignment(HorizontalAlignment.RIGHT);cellStyle.setWrapText(true);for (List<String> objectList : objects) {Row row = sheet.createRow(currentRow++);for (int i =0;i<objectList.size();i++) {Cell cell = row.createCell(i);//右对齐if (rigthList.contains(i)){cell.setCellStyle(cellStyle);}if (objectList.get(i) == null) {cell.setCellValue("");} else {cell.setCellValue(objectList.get(i));}}}// 写入文件try (FileOutputStream outputStream = new FileOutputStream(filePath)) {workbook.write(outputStream);} finally {// 确保工作簿被关闭以释放资源if (workbook != null) {workbook.close();}}}private static <T> Object getCellValue(T object, String columnName) {// 这里业务对象有对应属性，且属性名与columnNam匹配Field field = getDeclaredField(object.getClass(), columnName);try {Object value = field.get(object);if (value instanceof Number) {return ((Number) value).doubleValue();} else if (value instanceof String) {return value;} else if (value instanceof Date){return DateUtils.dateToStr((Date)value,"yyyy-MM-dd HH:mm:ss");}return "";} catch (IllegalAccessException e) {e.printStackTrace();throw new RuntimeException(e);}}private static Field getDeclaredField(Class<?> clazz, String fieldName) {try {return clazz.getDeclaredField(fieldName);} catch (NoSuchFieldException e) {// 递归查找父类Field parentField = getDeclaredField(clazz.getSuperclass(), fieldName);if (parentField != null) {return parentField;}}return null;}public static void writeExcelBySXSSF(List<List<String>> newData,String filePath, boolean append,List<Integer> rigthList) throws IOException {if (append) {// 打开现有的Excel文件FileInputStream fis = new FileInputStream(filePath);XSSFWorkbook xssfWorkbook = new XSSFWorkbook(fis);// 创建SXSSFWorkbook实例SXSSFWorkbook sxssfWorkbook = new SXSSFWorkbook(1024);// 获取原有工作簿的工作表XSSFSheet xssfSheet = xssfWorkbook.getSheetAt(0); // 假设数据在第一个工作表SXSSFSheet sxssfSheet = sxssfWorkbook.createSheet(xssfSheet.getSheetName());// 复制原有工作表的数据和样式到SXSSFWorkbookcopySheet(xssfSheet, sxssfSheet);CellStyle cellStyle = sxssfWorkbook.createCellStyle();cellStyle.setAlignment(HorizontalAlignment.RIGHT);cellStyle.setWrapText(true);// 追加新数据到SXSSFWorkbook的工作表int rowIndex = sxssfSheet.getLastRowNum() + 1;for (List<String> row : newData) {Row sxssfRow = sxssfSheet.createRow(rowIndex++);for (int i = 0; i < row.size(); i++) {Cell cell = sxssfRow.createCell(i);cell.setCellValue(row.get(i));if (rigthList != null && rigthList.contains(i)){cell.setCellStyle(cellStyle);}}}// 将SXSSFWorkbook写入文件，覆盖原有文件FileOutputStream os = new FileOutputStream(filePath);sxssfWorkbook.write(os);os.close();// 关闭工作簿和文件输入流sxssfWorkbook.close();xssfWorkbook.close();fis.close();} else {// 如果不追加，创建新的SXSSFWorkbook并写入数据的逻辑}}private static void copySheet(XSSFSheet xssfSheet, SXSSFSheet sxssfSheet) {for (int rowIndex = 0; rowIndex <= xssfSheet.getLastRowNum(); rowIndex++) {XSSFRow xssfRow = xssfSheet.getRow(rowIndex);Row sxssfRow = sxssfSheet.createRow(rowIndex);for (int cellIndex = 0; cellIndex < xssfRow.getLastCellNum(); cellIndex++) {Cell xssfCell = xssfRow.getCell(cellIndex);Cell sxssfCell = sxssfRow.createCell(cellIndex);if (xssfCell != null) {// 复制单元格的值sxssfCell.setCellValue(xssfCell.toString());// 复制单元格的样式/*CellStyle xssfCellStyle = xssfCell.getCellStyle();if (xssfCellStyle != null) {sxssfCell.setCellStyle(xssfCellStyle);// 复制其他样式属性，如字体、边框等}*/}}}}}
以上工具类里提供的都是一次性导出的方法。那如果说需要多次导出咋整呢。说实话，支付系统里头最头痛的就是导出大数据量，性能瓶颈第一卡在数据库资源，第二卡在poi性能。
做了一系列优化后，还是觉得分页最靠谱。分页查询分页导出，于是就会有这种场景，第一次写完的excel，第二次读取后再追加写入。但我们又知道SXSSFWorkbook类是专门给写定制的，压根就没法直接读取原excel文件。只能由XSSFWorkbook类读取。所以TM实现起来真难啊。只能先读，后复制再写。给两个方法自行体会。
第一个XSSFWorkbook类追加写入，只是参考模式，具体参数自己玩
public static void writeExcel(List<List<String>> objects, String filePath, boolean append,List<Integer> rigthList) throws IOException {// 确保工作簿以指定模式打开Workbook workbook;if (append) {try (FileInputStream fis = new FileInputStream(filePath)) {workbook = WorkbookFactory.create(fis);}} else {workbook = new XSSFWorkbook();}// 获取或创建SheetSheet sheet = workbook.getSheet("Sheet1");if (sheet == null) {sheet = workbook.createSheet("Sheet1");}// 写入数据int lastRowNum = sheet.getPhysicalNumberOfRows();int currentRow = lastRowNum == 0 ? 0 : lastRowNum;CellStyle cellStyle = workbook.createCellStyle();cellStyle.setAlignment(HorizontalAlignment.RIGHT);cellStyle.setWrapText(true);for (List<String> objectList : objects) {Row row = sheet.createRow(currentRow++);for (int i =0;i<objectList.size();i++) {Cell cell = row.createCell(i);//右对齐if (rigthList.contains(i)){cell.setCellStyle(cellStyle);}if (objectList.get(i) == null) {cell.setCellValue("");} else {cell.setCellValue(objectList.get(i));}}}// 写入文件try (FileOutputStream outputStream = new FileOutputStream(filePath)) {workbook.write(outputStream);} finally {// 确保工作簿被关闭以释放资源if (workbook != null) {workbook.close();}}}private static <T> Object getCellValue(T object, String columnName) {// 这里业务对象有对应属性，且属性名与columnNam匹配Field field = getDeclaredField(object.getClass(), columnName);try {Object value = field.get(object);if (value instanceof Number) {return ((Number) value).doubleValue();} else if (value instanceof String) {return value;} else if (value instanceof Date){return DateUtils.dateToStr((Date)value,"yyyy-MM-dd HH:mm:ss");}return "";} catch (IllegalAccessException e) {e.printStackTrace();throw new RuntimeException(e);}}private static Field getDeclaredField(Class<?> clazz, String fieldName) {try {return clazz.getDeclaredField(fieldName);} catch (NoSuchFieldException e) {// 递归查找父类Field parentField = getDeclaredField(clazz.getSuperclass(), fieldName);if (parentField != null) {return parentField;}}return null;}第二个SXSSFWorkbook类追加写入
public static void writeExcelBySXSSF(List<List<String>> newData,String filePath, boolean append,List<Integer> rigthList) throws IOException {if (append) {// 打开现有的Excel文件FileInputStream fis = new FileInputStream(filePath);XSSFWorkbook xssfWorkbook = new XSSFWorkbook(fis);// 创建SXSSFWorkbook实例SXSSFWorkbook sxssfWorkbook = new SXSSFWorkbook(1024);// 获取原有工作簿的工作表XSSFSheet xssfSheet = xssfWorkbook.getSheetAt(0); // 假设数据在第一个工作表SXSSFSheet sxssfSheet = sxssfWorkbook.createSheet(xssfSheet.getSheetName());// 复制原有工作表的数据和样式到SXSSFWorkbookcopySheet(xssfSheet, sxssfSheet);CellStyle cellStyle = sxssfWorkbook.createCellStyle();cellStyle.setAlignment(HorizontalAlignment.RIGHT);cellStyle.setWrapText(true);// 追加新数据到SXSSFWorkbook的工作表int rowIndex = sxssfSheet.getLastRowNum() + 1;for (List<String> row : newData) {Row sxssfRow = sxssfSheet.createRow(rowIndex++);for (int i = 0; i < row.size(); i++) {Cell cell = sxssfRow.createCell(i);cell.setCellValue(row.get(i));if (rigthList != null && rigthList.contains(i)){cell.setCellStyle(cellStyle);}}}// 将SXSSFWorkbook写入文件，覆盖原有文件FileOutputStream os = new FileOutputStream(filePath);sxssfWorkbook.write(os);os.close();// 关闭工作簿和文件输入流sxssfWorkbook.close();xssfWorkbook.close();fis.close();} else {// 如果不追加，创建新的SXSSFWorkbook并写入数据的逻辑}}private static void copySheet(XSSFSheet xssfSheet, SXSSFSheet sxssfSheet) {for (int rowIndex = 0; rowIndex <= xssfSheet.getLastRowNum(); rowIndex++) {XSSFRow xssfRow = xssfSheet.getRow(rowIndex);Row sxssfRow = sxssfSheet.createRow(rowIndex);for (int cellIndex = 0; cellIndex < xssfRow.getLastCellNum(); cellIndex++) {Cell xssfCell = xssfRow.getCell(cellIndex);Cell sxssfCell = sxssfRow.createCell(cellIndex);if (xssfCell != null) {// 复制单元格的值sxssfCell.setCellValue(xssfCell.toString());// 复制单元格的样式/*CellStyle xssfCellStyle = xssfCell.getCellStyle();if (xssfCellStyle != null) {sxssfCell.setCellStyle(xssfCellStyle);// 复制其他样式属性，如字体、边框等}*/}}}}
以上方法都是经过系统测试的，用于记录自己遇到的问题，如果你也遇到并且有疑问欢迎留言解答。
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