1 <dependency>
 2       <groupId>org.apache.poi</groupId>
 3       <artifactId>poi</artifactId>
 4       <version>4.1.0</version>
 5   </dependency>
 6   <!-- poi2007相应依赖坐标 -->
 7   <dependency>
 8       <groupId>org.apache.poi</groupId>
 9       <artifactId>poi-ooxml</artifactId>
10       <version>4.1.0</version>
11   </dependency>
12   <dependency>
13       <groupId>org.apache.poi</groupId>
14       <artifactId>poi-ooxml-schemas</artifactId>
15       <version>4.1.0</version>
16   </dependency>

public class App {public static void main(String[] args) {//1.创建工作簿Workbook wb = new XSSFWorkbook();//2007版//2.创建sheetSheet sheet = wb.createSheet("test");//3文件流try (FileOutputStream fos = new FileOutputStream("E:\\poi\\test.xlsx")) {wb.write(fos);} catch (IOException e) {e.printStackTrace();}}
}

 1 /**
 2  * Demo2设置单元格样式
 3  */
 4 public class Demo2 {
 5     public static void main(String[] args) {
 6         //1.创建工作簿
 7         Workbook wb = new XSSFWorkbook();//2007版
 8         //2.创建sheet
 9         Sheet sheet = wb.createSheet("test");
10         //创建行对象，参数：索引从0开始
11         Row row = sheet.createRow(2);
12         //创建单元格对象，索引从0开始
13         Cell cell = row.createCell(2);
14         cell.setCellValue("才高八斗");
15
16         //样式处理
17         //创建样式对象
18         CellStyle style = wb.createCellStyle();
19         style.setBorderTop(BorderStyle.THIN);//上边框
20         style.setBorderRight(BorderStyle.THIN);//右边框
21         style.setBorderBottom(BorderStyle.THIN);//下边框
22         style.setBorderLeft(BorderStyle.THIN);//左边框
23
24         //创建字体对象
25         Font font = wb.createFont();
26         font.setFontName("华文行楷");
27         font.setFontHeightInPoints((short) 28);//设置字号
28         style.setFont(font);
29
30         //行高和列宽
31         row.setHeightInPoints(50);//设置行高
32         sheet.setColumnWidth(2, 31 * 256);//第三列，设置列宽需要乘以256
33
34         //设置水平居中
35         style.setAlignment(HorizontalAlignment.CENTER);
36         //设置垂直居中
37         style.setVerticalAlignment(VerticalAlignment.CENTER);
38
39         //向单元格设置样式
40         cell.setCellStyle(style);
41
42         //3文件流
43         try (FileOutputStream fos = new FileOutputStream("E:\\poi\\test3.xlsx")) {
44             wb.write(fos);
45         } catch (IOException e) {
46             e.printStackTrace();
47         }
48
49     }
50 }

 1 /**
 2  * Demo3在Excel中添加图片
 3  */
 4 public class Demo1 {
 5     public static void main(String[] args) throws IOException {
 6         //1.创建工作簿
 7         Workbook wb = new XSSFWorkbook();//2007版
 8         //2.创建sheet
 9         Sheet sheet = wb.createSheet("test");
10
11         //------------------------------------------------------------
12         //1.读取图片流
13         FileInputStream fis = new FileInputStream("E:\\poi\\merry.jpg");
14
15         //2.转化二进制数组
16         byte[] bytes = IOUtils.toByteArray(fis);
17         fis.read(bytes);
18         //3.向poi内存中添加一张图片，返回图片在图片集合中的索引
19         int index = ((XSSFWorkbook) wb).addPicture(bytes, Workbook.PICTURE_TYPE_JPEG);
20         //4.绘制图片工具类
21         CreationHelper helper = wb.getCreationHelper();
22         //5.创建一个绘图对象
23         Drawing<?> drawing = sheet.createDrawingPatriarch();
24         //6.创建锚点，设置图片坐标
25         ClientAnchor anchor = helper.createClientAnchor();
26         //设置图片起始位置
27         anchor.setRow1(1);
28         anchor.setCol1(1);
29         设置图片结束位置
30         anchor.setRow2(15);
31         anchor.setCol2(15);
32         //7.绘制图片
33         Picture picture = drawing.createPicture(anchor, index);//图片位置，图片的索引
34 //        picture.resize();//自适应渲染图片
35         //------------------------------------------------------------
36         //3文件流
37         try (FileOutputStream fos = new FileOutputStream("E:\\poi\\test4.xlsx")) {
38             wb.write(fos);
39         } catch (IOException e) {
40             e.printStackTrace();
41         }
42
43     }
44 }

/*** Demo4读取Excel并解析* sheet.getLastRowNum():获取最后一行的索引值* row.getLastCellNum():获取最后一个单元格的号码*/
public class Demo4 {public static void main(String[] args) throws IOException {//1.根据Excel文件创建工作簿Workbook wb = new XSSFWorkbook("E:\\poi\\demo2.xlsx");//2.获取SheetSheet sheet = wb.getSheetAt(0);//3.获取sheet中的每一行和每一个单元格for (int rowNum = 0; rowNum <= sheet.getLastRowNum(); rowNum++) {Row row = sheet.getRow(rowNum);//根据索引获取每一行if (row == null){continue;}StringBuilder sb = new StringBuilder();for (int cellNum = 0; cellNum < row.getLastCellNum(); cellNum++) {//根据索引获取每一个单元格Cell cell = row.getCell(cellNum);if(cell == null){continue;}//获取每一个单元格的内容Object value = getCellValue(cell);sb.append(value).append("-");}System.out.println(sb.toString());}}private static Object getCellValue(Cell cell) {//1.获取单元格的属性类型CellType cellType = cell.getCellType();//2.根据单元格的类型获取时间Object value = null;switch (cellType) {case NUMERIC:if (DateUtil.isCellDateFormatted(cell)) {//日期格式value = cell.getDateCellValue();} else {value = cell.getNumericCellValue();}break;case STRING:value = cell.getStringCellValue();break;case BOOLEAN:value = cell.getBooleanCellValue();break;case FORMULA://公式类型value = cell.getCellFormula();break;default:break;}return value;}
}