Java导出数据到excel分3步处理
1、构建Workbook 数据
2、设置Workbook 格式
3、导出到Excel

1、构建Workbook 数据

public static void buildData(Workbook wb, List<Person> list) {    Sheet sheetName = wb.createSheet("sheetName");        Row row = sheetName.createRow(0);    row.createCell(0).setCellValue("Id");    row.createCell(1).setCellValue("Name");    row.createCell(2).setCellValue("Age");    row.createCell(3).setCellValue("NickName");        for (int i = 0; i < list.size(); i++) {        Person person = list.get(i);        row = sheetName.createRow(i + 1);        row.createCell(0).setCellValue(person.getId());        row.createCell(1).setCellValue(person.getName());        row.createCell(2).setCellValue(person.getAge());        row.createCell(3).setCellValue(person.getNickName());    }        wb.setSheetName(0, "sheet");}

2、设置Workbook 格式

public static void buildStyle(Workbook wb) {    Sheet sheet;    Row row;    for (int s = 0; s < wb.getNumberOfSheets(); s++) {        sheet = wb.getSheetAt(s);        for (int r = sheet.getFirstRowNum(); r <= sheet.getLastRowNum(); r++) {            row = sheet.getRow(r);            for (int c = row.getFirstCellNum(); c < row.getLastCellNum(); c++) {                if (r == 0) { // 表头                    row.getCell(c).setCellStyle(ExcelStyleUtils.headerStyle(wb));                    sheet.autoSizeColumn(c);                } else { // 数据                    row.getCell(c).setCellStyle(ExcelStyleUtils.cellsStyle(wb));                    if (sheet.getColumnWidth(c) > 50 * 256) {                        sheet.setColumnWidth(c, 50 * 256);                    }                }            }        }    }}

3、导出到Excel

public static void writeExcel(Workbook workbook) throws Exception {    ExcelUtils.deleteOldExcelFile(OUT_PATH);    ExcelUtils.makeExcelFile(OUT_PATH);    FileOutputStream fileOutputStream = new FileOutputStream(genExcelName(OUT_PATH), false);    workbook.write(fileOutputStream);    fileOutputStream.close();}public static void writeExcel2(Workbook workbook) throws Exception {    ExcelUtils.deleteOldExcelFile(OUT_PATH);    ExcelUtils.makeExcelFile(OUT_PATH);    OutputStream outputStream = new FileOutputStream(genExcelName(OUT_PATH));    workbook.write(outputStream);    outputStream.close();}private static String genExcelName(String path) {    String postName = LocalDateTime.now().fORMat(DateTimeFormatter.ofPattern("yyyyMMddHHMMSS"));    return path + "/输出" + postName + ".xlsx";}public static void deleteOldExcelFile(String path) throws Exception {    File file = new File(path);    if (file.exists() && file.isDirectory()) {        FileUtils.deleteDirectory(file);    }}public static void makeExcelFile(String path) throws Exception {    File file = new File(path);    if (!file.exists()) {        boolean mkdirs = file.mkdirs();        if (!mkdirs) {            throw new IOException("mkdirs failed");        }    }}

4、UT

@Testpublic void testWriteExcel2() throws Exception {    List<Person> persons = new ArrayList<>();    persons.add(new Person(10, "John", 11, "nickName"));    persons.add(new Person(11, "John1", 11, "nickName1"));    persons.add(new Person(12, "John2", 11, "nickName2"));    persons.add(new Person(13, "John3", 11, "nickName3"));    persons.add(new Person(14, "John4", 11, "nickName4"));        XSSFWorkbook wb = new XSSFWorkbook();    buildData(wb, persons); // 构建数据        buildStyle(wb); // 设置格式    writeExcel(wb); 或 writeExcel2(wb); // 导出数据}

5、结果展示

6、核心import

import model.Person;import org.apache.commons.io.FileUtils;import org.apache.poi.hssf.usermodel.HSSFWorkbook;import org.apache.poi.openxml4j.exceptions.InvalidFormatException;import org.apache.poi.ss.usermodel.*;import org.apache.poi.xssf.usermodel.XSSFWorkbook;import java.io.*;import java.time.LocalDateTime;import java.time.format.DateTimeFormatter;

7、Maven 依赖

<dependency>    <groupId>org.apache.poigroupId>    <artifactId>poiartifactId>    <version>5.2.3version>dependency><dependency>    <groupId>org.apache.poigroupId>    <artifactId>poi-ooxmlartifactId>    <version>5.2.3version>dependency><dependency>    <groupId>commons-iogroupId>    <artifactId>commons-ioartifactId>    <version>2.11.0version>dependency><dependency>    <groupId>org.apache.logging.log4jgroupId>    <artifactId>log4j-apiartifactId>    <version>2.15.0version>dependency><dependency>    <groupId>org.apache.logging.log4jgroupId>    <artifactId>log4j-coreartifactId>    <version>2.15.0version>dependency><dependency>    <groupId>org.apache.logging.log4jgroupId>    <artifactId>log4j-slf4j-implartifactId>    <version>2.15.0version>dependency>

来源地址：https://blog.csdn.net/weixin_37646636/article/details/132039605