Java导出大批量数据(文件格式篇xls,xlsx,csv)

根据最近写出的导出方法打算在文章中记录总结下学习心得

java导出我准备分为三篇文章介绍
分批查询导出篇https://blog.csdn.net/weixin_56567361/article/details/126647979异步多线程导出篇https://blog.csdn.net/weixin_56567361/article/details/126718950?spm=1001.2014.3001.5501

Java导出excel文件我分为了xls,xlsx,csv三个文件格式

首先介绍下三种文件格式的优劣

xls文件	xlsx文件	csv文件
最大65536行 256列	最大1048576行 16384列	纯文本文件无行数上线但无法编辑表头,表内容样式
占用空间大占用空间小	运算速度相比xls快些	占用空间小导出后打开很迅速
		wps,,excel,均可打开(最多显示一千万条数据,推荐notepad等其他文本编辑软件打开)

导出少量数据需要表头样式的(例如mysql中基础数据) 采用xlsx文件导出

导出大量数据无表头样式要求(例如clickhouse中历史数据) 采用csv文件导出

xlxs文件导出

csv文件导出

xlxs文件导出

导出效果如图可自定义多级表头格式颜色等这里展示基础的单表头导出

首先pom加上以下导出匀以poi4.1.2版本测试

<!-- excel工具 -->
<dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId><version>4.1.2</version>
</dependency>

xls导出则把方法中出现的XSSF改为HSSF

建议使用SXSSFWorkbook

从POI 3.8版本开始提供了一种基于XSSF的低内存占用的SXSSF方式对于大型excel文件的创建一个关键问题就是要确保不会内存溢出其实就算生成很小的excel（比如几Mb）它用掉的内存是远大于excel文件实际的size的如果单元格还有各种格式（比如，加粗，背景标红之类的）那它占用的内存就更多了对于大型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hash map用空间换时间一样）

controller层

    @GetMapping("/export")public void export(HttpServletResponse response, 对象 对象名) throws Exception {List<对象> list = Service.getList(对象名);//表头String[] title = new String[]{"测试1", "测试2","测试3"};List<String[]> rows = new ArrayList<>();String[] row = null;//表数据for (对象 名: list) {row = new String[]{名.getTest1(),名.getTest2(),名.getTest3()};rows.add(row);}//xlsx文件导出SXSSFWorkbook workbook = PoiUtils.exportExcelSXSSF(title, rows);response.setContentType("application/vnd.ms-excel");response.setHeader("Content-Disposition", "attachment;fileName=" + URLEncoder.encode("导出表.xlsx", "utf-8"));response.flushBuffer();workbook.write(response.getOutputStream());//处理工作表在磁盘上产生的临时文件workbook.dispose();}

PoiUtils

/*** 低占用内存xlsx文件导出** @param title* @param rows* @return*/public static SXSSFWorkbook exportExcelSXSSF(String[] title, List<String[]> rows) {//这样表示SXSSFWorkbook只会保留100条数据在内存中，其它的数据都会写到磁盘里，这样的话占用的内存就会很少SXSSFWorkbook workbook = new SXSSFWorkbook(100);// 生成一个表格SXSSFSheet sheet = workbook.createSheet();//设置表头白字黑底居中Font font = workbook.createFont();//设置字体颜色font.setColor(HSSFColor.HSSFColorPredefined.WHITE.getIndex());font.setFontName("宋体");//设置表头边框CellStyle headerStyle = workbook.createCellStyle();headerStyle.setBorderBottom(BorderStyle.HAIR);headerStyle.setBorderLeft(BorderStyle.HAIR);headerStyle.setBorderRight(BorderStyle.HAIR);headerStyle.setBorderTop(BorderStyle.HAIR);// 创建一个居中格式headerStyle.setAlignment(HorizontalAlignment.CENTER);headerStyle.setVerticalAlignment(VerticalAlignment.CENTER);//五十度灰headerStyle.setFillForegroundColor(HSSFColor.HSSFColorPredefined.GREY_50_PERCENT.getIndex());headerStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);headerStyle.setFont(font);Font contentFont = workbook.createFont();contentFont.setFontName("宋体");contentFont.setFontHeightInPoints((short) 10);//设置表内容边框CellStyle bodyStyle = workbook.createCellStyle();bodyStyle.setBorderBottom(BorderStyle.HAIR);bodyStyle.setBorderLeft(BorderStyle.HAIR);bodyStyle.setBorderRight(BorderStyle.HAIR);bodyStyle.setBorderTop(BorderStyle.HAIR);// 创建一个居中格式bodyStyle.setAlignment(HorizontalAlignment.CENTER);bodyStyle.setVerticalAlignment(VerticalAlignment.CENTER);bodyStyle.setFont(contentFont);// 设置表格默认列宽度为15个字节sheet.setDefaultColumnWidth((short) 18);sheet.setColumnWidth(title.length - 1, (int) ((40 + 0.72) * 256));// 循环字段名数组，创建标题行SXSSFRow row = sheet.createRow(0);for (int j = 0; j < title.length; j++) {// 创建列SXSSFCell cell = row.createCell(j);// 设置单元类型为Stringcell.setCellType(CellType.STRING);cell.setCellValue(title[j]);cell.setCellStyle(headerStyle);}for (int i = 0; i < rows.size(); i++) {// 因为第一行已经用于创建标题行，故从第二行开始创建row = sheet.createRow(i + 1);// 如果是第一行就让其为标题行String[] rowData = rows.get(i);//每一行的数据recyclingCellSXSSF(rowData, row, bodyStyle);}return workbook;}private static void recyclingCellSXSSF(String[] rowData, SXSSFRow row, CellStyle bodyStyle) {for (int j = 0; j < rowData.length; j++) {// 创建列SXSSFCell cell = row.createCell(j);cell.setCellType(CellType.STRING);cell.setCellValue(rowData[j]);cell.setCellStyle(bodyStyle);}}

不需要表头样式可注掉

前端我使用的若依框架这里也展示下代码

index.vue

     /** 导出按钮操作 */handleExport() {const queryParams = this.queryParamsthis.$confirm('是否确认导出所有信息?', '警告', {confirmButtonText: '确定',cancelButtonText: '取消',type: 'warning'}).then(() => {this.exportDataFan(queryParams)})},async exportDataFan(params) {try {const res = await exportChineseParsing(params)this.downLoad('导出表.xlsx', res)} catch (e) {console.log(e)}},downLoad(filename, content) {//filename 文件名，content 下载的内容var aLink = document.createElement('a')var blob = new Blob([content], {type: 'application/x-xls'})var evt = new Event('click')aLink.download = filenameaLink.href = URL.createObjectURL(blob)aLink.click()URL.revokeObjectURL(blob)},

js文件

//导出
export function export(query) {return request({url: '/路径名/路径名/export',method: 'get',params: query,responseType: 'blob'//设置响应数据类型为 blob。这句话很重要！！！})
}

csv文件导出

controller层(导出参数也是需要表头,表数据只用替换下面导出方法)

    @GetMapping("/export")public void export(HttpServletResponse response, 对象 对象名) throws Exception {List<对象> list = Service.getList(对象名);//表头String[] title = new String[]{"测试1", "测试2","测试3"};List<String[]> rows = new ArrayList<>();String[] row = null;//表数据for (对象 名: list) {row = new String[]{名.getTest1(),名.getTest2(),名.getTest3()};rows.add(row);}//创建临时csv文件File tempFile = PoiUtils.createTempFile(rows, title);//输出csv流文件，提供给浏览器下载PoiUtils.outCsvStream(response, tempFile);//删除临时文件PoiUtils.deleteFile(tempFile);}

PoiUtils

    /*** 创建临时的csv文件** @return* @throws IOException*/public static File createTempFile(List<String[]> datas, String[] headers) throws IOException {File tempFile = File.createTempFile("vehicle", ".csv");CsvWriter csvWriter = new CsvWriter(tempFile.getCanonicalPath(), ',', StandardCharsets.UTF_8);// 写表头csvWriter.writeRecord(headers);for (String[] data : datas) {//这里如果数据不是String类型，请进行转换for (String datum : data) {csvWriter.write(datum, true);}csvWriter.endRecord();}csvWriter.close();return tempFile;}/*** 普通csv文件传浏览器** @param response* @param tempFile* @throws IOException*/public static void outCsvStream(HttpServletResponse response, File tempFile) throws IOException {java.io.OutputStream out = response.getOutputStream();byte[] b = new byte[10240];java.io.File fileLoad = new java.io.File(tempFile.getCanonicalPath());response.reset();response.setContentType("application/csv");response.setHeader("content-disposition", "attachment; filename=" + URLEncoder.encode("export.csv", "UTF-8"));java.io.FileInputStream in = new java.io.FileInputStream(fileLoad);int n;//为了保证excel打开csv不出现中文乱码out.write(new byte[]{(byte) 0xEF, (byte) 0xBB, (byte) 0xBF});while ((n = in.read(b)) != -1) {//每次写入out1024字节out.write(b, 0, n);}in.close();out.close();}/*** 删除文件** @param file* @return*/public static boolean deleteFile(File file) {// 如果文件路径所对应的文件存在，并且是一个文件，则直接删除if (file.exists() && file.isFile()) {return file.delete();} else {return false;}}

CsvWriter(代码略长)

package com.hnxr.scada.utils;import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;
import java.nio.charset.Charset;public class CsvWriter {private PrintWriter outputStream;private String fileName;private boolean firstColumn;private boolean useCustomRecordDelimiter;private Charset charset;private UserSettings userSettings;private boolean initialized;private boolean closed;public static final int ESCAPE_MODE_DOUBLED = 1;public static final int ESCAPE_MODE_BACKSLASH = 2;public CsvWriter(String var1, char var2, Charset var3) {this.outputStream = null;this.fileName = null;this.firstColumn = true;this.useCustomRecordDelimiter = false;this.charset = null;this.userSettings = new UserSettings();this.initialized = false;this.closed = false;if (var1 == null) {throw new IllegalArgumentException("Parameter fileName can not be null.");} else if (var3 == null) {throw new IllegalArgumentException("Parameter charset can not be null.");} else {this.fileName = var1;this.userSettings.Delimiter = var2;this.charset = var3;}}public CsvWriter(String var1) {this(var1, ',', Charset.forName("ISO-8859-1"));}public CsvWriter(Writer var1, char var2) {this.outputStream = null;this.fileName = null;this.firstColumn = true;this.useCustomRecordDelimiter = false;this.charset = null;this.userSettings = new UserSettings();this.initialized = false;this.closed = false;if (var1 == null) {throw new IllegalArgumentException("Parameter outputStream can not be null.");} else {this.outputStream = new PrintWriter(var1);this.userSettings.Delimiter = var2;this.initialized = true;}}public CsvWriter(OutputStream var1, char var2, Charset var3) {this(new OutputStreamWriter(var1, var3), var2);}public char getDelimiter() {return this.userSettings.Delimiter;}public void setDelimiter(char var1) {this.userSettings.Delimiter = var1;}public char getRecordDelimiter() {return this.userSettings.RecordDelimiter;}public void setRecordDelimiter(char var1) {this.useCustomRecordDelimiter = true;this.userSettings.RecordDelimiter = var1;}public char getTextQualifier() {return this.userSettings.TextQualifier;}public void setTextQualifier(char var1) {this.userSettings.TextQualifier = var1;}public boolean getUseTextQualifier() {return this.userSettings.UseTextQualifier;}public void setUseTextQualifier(boolean var1) {this.userSettings.UseTextQualifier = var1;}public int getEscapeMode() {return this.userSettings.EscapeMode;}public void setEscapeMode(int var1) {this.userSettings.EscapeMode = var1;}public void setComment(char var1) {this.userSettings.Comment = var1;}public char getComment() {return this.userSettings.Comment;}public boolean getForceQualifier() {return this.userSettings.ForceQualifier;}public void setForceQualifier(boolean var1) {this.userSettings.ForceQualifier = var1;}public void write(String var1, boolean var2) throws IOException {this.checkClosed();this.checkInit();if (var1 == null) {var1 = "";}if (!this.firstColumn) {this.outputStream.write(this.userSettings.Delimiter);}//默认falseboolean var3 = this.userSettings.ForceQualifier;if (!var2 && var1.length() > 0) {var1 = var1.trim();}if (!var3 && this.userSettings.UseTextQualifier && (var1.indexOf(this.userSettings.TextQualifier) > -1 || var1.indexOf(this.userSettings.Delimiter) > -1 || !this.useCustomRecordDelimiter && (var1.indexOf(10) > -1 || var1.indexOf(13) > -1) || this.useCustomRecordDelimiter && var1.indexOf(this.userSettings.RecordDelimiter) > -1 || this.firstColumn && var1.length() > 0 && var1.charAt(0) == this.userSettings.Comment || this.firstColumn && var1.length() == 0)) {var3 = true;}if (this.userSettings.UseTextQualifier && !var3 && var1.length() > 0 && var2) {char var4 = var1.charAt(0);if (var4 == ' ' || var4 == '\t') {var3 = true;}if (!var3 && var1.length() > 1) {char var5 = var1.charAt(var1.length() - 1);if (var5 == ' ' || var5 == '\t') {var3 = true;}}}if (var3) {this.outputStream.write(this.userSettings.TextQualifier);if (this.userSettings.EscapeMode == 2) {var1 = replace(var1, "\\", "\\\\");var1 = replace(var1, "" + this.userSettings.TextQualifier, "\\" + this.userSettings.TextQualifier);} else {var1 = replace(var1, "" + this.userSettings.TextQualifier, "" + this.userSettings.TextQualifier + this.userSettings.TextQualifier);}} else if (this.userSettings.EscapeMode == 2) {var1 = replace(var1, "\\", "\\\\");var1 = replace(var1, "" + this.userSettings.Delimiter, "\\" + this.userSettings.Delimiter);if (this.useCustomRecordDelimiter) {var1 = replace(var1, "" + this.userSettings.RecordDelimiter, "\\" + this.userSettings.RecordDelimiter);} else {var1 = replace(var1, "\r", "\\\r");var1 = replace(var1, "\n", "\\\n");}if (this.firstColumn && var1.length() > 0 && var1.charAt(0) == this.userSettings.Comment) {if (var1.length() > 1) {var1 = "\\" + this.userSettings.Comment + var1.substring(1);} else {var1 = "\\" + this.userSettings.Comment;}}}this.outputStream.write(var1);if (var3) {this.outputStream.write(this.userSettings.TextQualifier);}this.firstColumn = false;}public void write(String var1) throws IOException {this.write(var1, false);}public void writeComment(String var1) throws IOException {this.checkClosed();this.checkInit();this.outputStream.write(this.userSettings.Comment);this.outputStream.write(var1);if (this.useCustomRecordDelimiter) {this.outputStream.write(this.userSettings.RecordDelimiter);} else {this.outputStream.println();}this.firstColumn = true;}public void writeRecord(String[] var1, boolean var2) throws IOException {if (var1 != null && var1.length > 0) {for(int var3 = 0; var3 < var1.length; ++var3) {this.write(var1[var3], var2);}this.endRecord();}}public void writeRecord(String[] var1) throws IOException {this.writeRecord(var1, false);}public void endRecord() throws IOException {this.checkClosed();this.checkInit();if (this.useCustomRecordDelimiter) {this.outputStream.write(this.userSettings.RecordDelimiter);} else {this.outputStream.println();}this.firstColumn = true;}private void checkInit() throws IOException {if (!this.initialized) {if (this.fileName != null) {this.outputStream = new PrintWriter(new OutputStreamWriter(new FileOutputStream(this.fileName), this.charset));}this.initialized = true;}}public void flush() {this.outputStream.flush();}public void close() {if (!this.closed) {this.close(true);this.closed = true;}}private void close(boolean var1) {if (!this.closed) {if (var1) {this.charset = null;}try {if (this.initialized) {this.outputStream.close();}} catch (Exception var3) {}this.outputStream = null;this.closed = true;}}private void checkClosed() throws IOException {if (this.closed) {throw new IOException("This instance of the CsvWriter class has already been closed.");}}protected void finalize() {this.close(false);}public static String replace(String var0, String var1, String var2) {int var3 = var1.length();int var4 = var0.indexOf(var1);if (var4 <= -1) {return var0;} else {StringBuffer var5 = new StringBuffer();int var6;for(var6 = 0; var4 != -1; var4 = var0.indexOf(var1, var6)) {var5.append(var0.substring(var6, var4));var5.append(var2);var6 = var4 + var3;}var5.append(var0.substring(var6));return var5.toString();}}public class UserSettings {public char TextQualifier = '"';public boolean UseTextQualifier = true;public char Delimiter = ',';public char RecordDelimiter = 0;public char Comment = '#';public int EscapeMode = 1;public boolean ForceQualifier = false;public UserSettings() {}}private class Letters {public static final char LF = '\n';public static final char CR = '\r';public static final char QUOTE = '"';public static final char COMMA = ',';public static final char SPACE = ' ';public static final char TAB = '\t';public static final char POUND = '#';public static final char BACKSLASH = '\\';public static final char NULL = '\u0000';private Letters() {}}
}

前端代码

index.vue

    //导出exportFile() {let params = Object.assign({}, this.form)this.$confirm('是否确认导出文件?', '警告', {confirmButtonText: '确定',cancelButtonText: '取消',type: 'warning'}).then(() => {this.exportDataFan(params)})},async exportDataFan(params) {try {const res = await exportData(params)this.downLoad('导出文件.csv', res)} catch (e) {console.log(e)}},downLoad(filename, content) {//filename 文件名，content 下载的内容console.log(filename)console.log(content)var aLink = document.createElement('a')var blob = new Blob([content], {// type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' //文件类型type: 'application/x-xls'//type: 'text/csv,charset=UTF-8'})console.log(blob)var evt = new Event('click')aLink.download = filenameaLink.href = URL.createObjectURL(blob)aLink.click()URL.revokeObjectURL(blob)}

js文件

//导出
export function exportData(query){return request({url:'/地址/地址/export',method:'get',params:query,responseType: 'blob'})
}

到此三种导出方法已经介绍完成大家根据需求调整代码

有遇到什么问题可以留言告诉我哦欢迎评论区讨论