java导出Excel文档，使用POI方式
首先引入依赖
org.apache.poi
poi
4.1.0
org.apache.poi
poi-ooxml
4.1.0
下面是工具类，供参考使用
package cn.stylefeng.guns.core.util;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.streaming.SXSSFSheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.IOException;
import java.io.OutputStream;
import java.math.BigDecimal;
import java.util.List;
import java.util.Map;
/**
* excel导出工具
*
* @author hexm
* @date 2019/9/5 9:29
*/
public class ExcelExportUtil {
//sheet各个列的表头
private String[] headList;
//各个列的元素key值
private String[] headKey;
//sheet需要填充的数据信息
private List> data;
//工作表名称
private String sheetName;
//字体大小
private short fontSize = 12;
//字体加粗
private boolean bold = false;
//标题与内容的字体
private String font = HSSFFont.FONT_ARIAL;
//内容颜色
private short color = Font.COLOR_NORMAL;
//内容背景色
private Short backgroundColor;
//标题字体大小
private short titleFontSize = 13;
//标题粗体
private boolean titleBold = true;
//标题颜色
private short titleColor = Font.COLOR_NORMAL;
//标题背景色
private Short titleBackgroundColor;
private ExcelExportUtil() {
}
public static ExcelExportUtil of(String sheetName, String[] headList, String[] headKey, List> data) {
ExcelExportUtil util = new ExcelExportUtil();
util.sheetName = sheetName;
util.headList = headList;
util.headKey = headKey;
util.data = data;
return util;
}
/**
* 分段性写入Xlsx格式Excel文档到流中
* 适合大量数据导出使用
* 在内存中保留{@see rowAccessWindowSize}行，超出行将之前写入的数据写到磁盘临时文件中（C:\Users\Administrator\AppData\Local\Temp）
* @param os
* @param rowAccessWindowSize rowAccessWindowsize必须大于0或小于-1
*/
public void writeXlsxTo(OutputStream os,int rowAccessWindowSize) {
//创建HSSFWorkbook对象(excel的文档对象)
SXSSFWorkbook wb = new SXSSFWorkbook(rowAccessWindowSize);
//建立新的sheet对象（excel的表单）
SXSSFSheet sheet = wb.createSheet(sheetName);
//创建表头
createHead(wb, sheet);
//跟踪所有列以调整大小
sheet.trackAllColumnsForAutoSizing();
//创建表体
createRow(wb, sheet);
try {
wb.write(os);
//删除临时文件
wb.dispose();
wb.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 一次性写入Xlsx格式Excel文档到流中。数据将保留到内存中
*
* @param os
*/
public void writeXlsxTo(OutputStream os) {
//创建HSSFWorkbook对象(excel的文档对象)
XSSFWorkbook wb = new XSSFWorkbook();
//建立新的sheet对象（excel的表单）
XSSFSheet sheet = wb.createSheet(sheetName);
//创建表头
createHead(wb, sheet);
//创建表体
createRow(wb, sheet);
try {
wb.write(os);
wb.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 一次性写入Xls格式Excel文档到流中
*
* @param os
*/
public void writeXlsTo(OutputStream os) {
//创建HSSFWorkbook对象(excel的文档对象)
HSSFWorkbook wb = new HSSFWorkbook();
//建立新的sheet对象（excel的表单）
HSSFSheet sheet = wb.createSheet(sheetName);
//创建表头
createHead(wb, sheet);
//创建表体
createRow(wb, sheet);
try {
wb.write(os);
wb.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 创建表头
*
* @param sheet
*/
private void createHead(Workbook wb, Sheet sheet) {
//在sheet里创建第一行，参数为行索引(excel的行)，可以是0～65535之间的任何一个
Row headRow = sheet.createRow(0);
// 1.生成表头字体对象
Font headFont = wb.createFont();
headFont.setFontHeightInPoints(this.titleFontSize);
headFont.setFontName(this.font);
headFont.setBold(this.titleBold);
headFont.setColor(this.titleColor);
// 2.生成样式对象
CellStyle headStyle = wb.createCellStyle();
headStyle.setFont(headFont); // 调用字体样式对象
headStyle.setWrapText(true); // 是否自动换行
if (titleBackgroundColor != null){
headStyle.setFillForegroundColor(titleBackgroundColor);
headStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
}
headStyle.setAlignment(HorizontalAlignment.CENTER);//设置居中样式
headStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
for (int i = 0; i < headList.length; i++) {
//创建单元格（excel的单元格，参数为列索引，可以是0～255之间的任何一个
Cell cell = headRow.createCell(i);
// 3.单元格应用样式
cell.setCellStyle(headStyle);
//设置单元格内容
cell.setCellValue(headList[i]);
}
}
/**
* 创建表体
*
* @param wb
* @param sheet
*/
private void createRow(Workbook wb, Sheet sheet) {
// 1.生成表数据字体对象
Font font = wb.createFont();
font.setFontHeightInPoints(this.fontSize);
font.setFontName(this.font);
font.setBold(bold);
font.setColor(this.color);
// 2.生成样式对象
CellStyle rowStyle = wb.createCellStyle();
rowStyle.setFont(font); // 调用字体样式对象
rowStyle.setWrapText(true); // 是否自动换行
if (backgroundColor != null){
rowStyle.setFillForegroundColor(backgroundColor);
rowStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
}
rowStyle.setAlignment(HorizontalAlignment.CENTER);//设置居中样式
rowStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
//填充数据
for (int i = 0; i < data.size(); i++) {
//在sheet里创建第二行，参数为行索引(excel的行)，可以是0～65535之间的任何一个
Row row = sheet.createRow(i + 1);
Map rowData = data.get(i);
for (int z = 0; z < headKey.length; z++) {
//创建单元格（excel的单元格，参数为列索引，可以是0～255之间的任何一个
Cell cell = row.createCell(z);
// 3.单元格应用样式
cell.setCellStyle(rowStyle);
String value;
Object valueObject = rowData.get(headKey[z]);
if (valueObject == null) {
value = "";
} else if (valueObject instanceof String) {
//取出的数据是字符串直接赋值
value = (String) valueObject;
} else if (valueObject instanceof Integer) {
//取出的数据是Integer
value = String.valueOf(((Integer) (valueObject)).floatValue());
} else if (valueObject instanceof BigDecimal) {
//取出的数据是BigDecimal
value = String.valueOf(((BigDecimal) (valueObject)).floatValue());
} else {
value = valueObject.toString();
}
//设置单元格内容
cell.setCellValue(value);
}
}
for (int i = 0; i < headKey.length; i++) {
//宽度自适应
sheet.autoSizeColumn(i);
}
}
public ExcelExportUtil setFontSize(short fontSize) {
this.fontSize = fontSize;
return this;
}
public ExcelExportUtil setBold(boolean bold) {
this.bold = bold;
return this;
}
public ExcelExportUtil setFont(String font) {
this.font = font;
return this;
}
public ExcelExportUtil setTitleFontSize(short titleFontSize) {
this.titleFontSize = titleFontSize;
return this;
}
public ExcelExportUtil setColor(short color) {
this.color = color;
return this;
}
public ExcelExportUtil setTitleBold(boolean titleBold) {
this.titleBold = titleBold;
return this;
}
public ExcelExportUtil setTitleColor(short titleColor) {
this.titleColor = titleColor;
return this;
}
public ExcelExportUtil setBackgroundColor(short backgroundColor) {
this.backgroundColor = backgroundColor;
return this;
}
public ExcelExportUtil setTitleBackgroundColor(short titleBackgroundColor) {
this.titleBackgroundColor = titleBackgroundColor;
return this;
}
} 调用代码示例：
/**
* 导出excel
*
* @param ids
* @return
* @throws IOException
*/
@RequestMapping("/exportExcel")
public void exportExcel(String ids, HttpServletResponse response) throws IOException {
if (StringUtils.isNotEmpty(ids)) {
List idList = Arrays.stream(ids.split(",")).map(Integer::parseInt).collect(Collectors.toList());
String[] head = {"title1", "title2"};
String[] keys = {"key1", "key2"};
List> data = service.findList(idList);
OutputStream os = response.getOutputStream();
//不缓存
response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
response.setHeader("Pragma", "no-cache");
response.setHeader("Expires", "0");
//内容标识
response.setContentType("application/vnd.ms-excel");
String name = String.format("%s(总计-%s).xlsx", DateUtil.getDateFormat(DateUtil.SQL_FORMAT), data.size());
//下载/另存为时，展示
response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(name, "UTF-8"));
//需要先设置响应头，然后再写入数据流，不然格式上会有问题
ExcelExportUtil.of("清单", head, keys, data)
.setTitleBackgroundColor(HSSFColor.HSSFColorPredefined.GREY_25_PERCENT.getIndex())//设置标题背景灰度25%
.writeXlsxTo(os,1000);//将数据写入到流中,始终保持内存最大1000条数据，防止内存溢出
os.flush();
os.close();
}
} 代码仅供参考，如果业务需支持复杂度更高的，需要自定义修改工具
贴上效果图，不然老是觉得自己没有说服力！
