Apache POI是Apache软件基金会的开放源码函式库，POI提供API给Java程序对Microsoft Office格式档案读和写的功能。pdf框架之IText的使用，参见我的博客：Java三方—->pdf框架之IText的使用。今天我们开始POI中Excel部分的学习。

POI框架的简单实例

我们通过案例来学习POI，项目结构如下：

一、 创建工作薄

@Test

public void createExcel() throws Exception {

// 建立xls文件，只需要引入poi-3.14-20160307.jar

Workbook wb1 = new HSSFWorkbook();

FileOutputStream fileOut = new FileOutputStream("excel/workbook.xls");

wb1.write(fileOut);

fileOut.close();

wb1.close();

// 需要额外引入poi-ooxml-3.14-20160307.jar， xmlbeans-2.6.0.jar， poi-ooxml-schemas-3.14-20160307.jar

Workbook wb2 = new XSSFWorkbook();

FileOutputStream fileOut2 = new FileOutputStream("excel/workbook.xlsx");

wb2.write(fileOut2);

fileOut2.close();

wb2.close();

}

二、 创建工作表

@Test

public void createExce2() throws Exception {

Workbook wb = new HSSFWorkbook();

wb.createSheet("new sheet");

wb.createSheet("second sheet");

String safeName = WorkbookUtil.createSafeSheetName("[O'Brien's sales*?]s"); // returns " O'Brien's sales "

wb.createSheet(safeName);

FileOutputStream fileOut = new FileOutputStream("excel/workbook1.xls");

wb.write(fileOut);

fileOut.close();

wb.close();

}

注意: sheet name is Excel must not exceed 31 characters and must not contain any of the any of the following characters:

0x0000

0x0003

colon (:)

backslash (\)

asterisk (*)

question mark (?)

forward slash (/)

opening square bracket ([)

closing square bracket (])

You can use org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)} for a safe way to create valid names, this utility replaces invalid characters with a space (‘ ‘)

三、 创建单元格

@Test

public void createExce3() throws Exception {

Workbook wb = new HSSFWorkbook();

CreationHelper createHelper = wb.getCreationHelper();

Sheet sheet = wb.createSheet("new sheet");

// Create a row and put some cells in it. Rows are 0 based.

Row row = sheet.createRow((short) 0);

// Create a cell and put a value in it.

Cell cell = row.createCell(0);

cell.setCellValue(1);

// Or do it on one line.

row.createCell(1).setCellValue(1.2);

row.createCell(2).setCellValue(createHelper.createRichTextString("This is a string"));

row.createCell(3).setCellValue(true);

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("excel/workbook2.xls");

wb.write(fileOut);

fileOut.close();

wb.close();

}

四、 创建时间单元格

@Test

public void createExce4() throws Exception {

Workbook wb = new HSSFWorkbook();

CreationHelper createHelper = wb.getCreationHelper();

Sheet sheet = wb.createSheet("new sheet");

// Create a row and put some cells in it. Rows are 0 based.

Row row = sheet.createRow(0);

// Create a cell and put a date value in it. The first cell is not

// styled

// as a date.

Cell cell = row.createCell(0);

cell.setCellValue(new Date());

// we style the second cell as a date (and time). It is important to

// create a new cell style from the workbook otherwise you can end up

// modifying the built in style and effecting not only this cell but

// other cells.

CellStyle cellStyle = wb.createCellStyle();

cellStyle.setDataFormat(createHelper.createDataFormat().getFormat("m/d/yy h:mm"));

cell = row.createCell(1);

cell.setCellValue(new Date());

cell.setCellStyle(cellStyle);

// you can also set date as java.util.Calendar

cell = row.createCell(2);

cell.setCellValue(Calendar.getInstance());

cell.setCellStyle(cellStyle);

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("excel/workbook3.xls");

wb.write(fileOut);

fileOut.close();

wb.close();

}

五、 不同类型的单元格

@Test

public void createExce5() throws Exception {

Workbook wb = new HSSFWorkbook();

Sheet sheet = wb.createSheet("new sheet");

Row row = sheet.createRow((short) 2);

row.createCell(0).setCellValue(1.1);

row.createCell(1).setCellValue(new Date());

row.createCell(2).setCellValue(Calendar.getInstance());

row.createCell(3).setCellValue("a string");

row.createCell(4).setCellValue(true);

row.createCell(5).setCellType(Cell.CELL_TYPE_ERROR);

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("excel/workbook4.xls");

wb.write(fileOut);

fileOut.close();

wb.close();

}

六、 边框的使用

@Test

public void createExce6() throws Exception {

Workbook wb = new HSSFWorkbook();

Sheet sheet = wb.createSheet("new sheet");

Row row = sheet.createRow(1);

// Create a cell and put a value in it.

Cell cell = row.createCell(1);

cell.setCellValue(4);

// Style the cell with borders all around.

CellStyle style = wb.createCellStyle();

style.setBorderBottom(CellStyle.BORDER_THIN);

style.setBottomBorderColor(IndexedColors.BLACK.getIndex());

style.setBorderLeft(CellStyle.BORDER_THIN);

style.setLeftBorderColor(IndexedColors.GREEN.getIndex());

style.setBorderRight(CellStyle.BORDER_THIN);

style.setRightBorderColor(IndexedColors.BLUE.getIndex());

style.setBorderTop(CellStyle.BORDER_MEDIUM_DASHED);

style.setTopBorderColor(IndexedColors.BLACK.getIndex());

cell.setCellStyle(style);

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("excel/workbook5.xls");

wb.write(fileOut);

fileOut.close();

wb.close();

}

七、合并单元格

@Test

public void createExce7() throws Exception {

Workbook wb = new HSSFWorkbook();

Sheet sheet = wb.createSheet("new sheet");

Row row = sheet.createRow((short) 1);

Cell cell = row.createCell((short) 1);

cell.setCellValue("This is a test of merging");

sheet.addMergedRegion(new CellRangeAddress(1, // first row (0-based)

1, // last row (0-based)

1, // first column (0-based)

2 // last column (0-based)

));

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("excel/workbook6.xls");

wb.write(fileOut);

fileOut.close();

wb.close();

}

八、 字体的设置

@Test

public void createExce8() throws Exception {

Workbook wb = new HSSFWorkbook();

Sheet sheet = wb.createSheet("new sheet");

// Create a row and put some cells in it. Rows are 0 based.

Row row = sheet.createRow(1);

// Create a new font and alter it.

Font font = wb.createFont();

font.setFontHeightInPoints((short) 24);

font.setFontName("Courier New");

font.setItalic(true);

font.setStrikeout(true);

// Fonts are set into a style so create a new one to use.

CellStyle style = wb.createCellStyle();

style.setFont(font);

// Create a cell and put a value in it.

Cell cell = row.createCell(1);

cell.setCellValue("This is a test of fonts");

cell.setCellStyle(style);

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("excel/workbook7.xls");

wb.write(fileOut);

fileOut.close();

wb.close();

}

九、 读或重写工作表

@Test

public void createExce9() throws Exception {

InputStream inp = new FileInputStream("excel/workbook4.xls");

Workbook wb = WorkbookFactory.create(inp);

Sheet sheet = wb.getSheetAt(0);

Row row = sheet.getRow(2);

Cell cell = row.getCell(3);

if (cell == null)

cell = row.createCell(3);

cell.setCellType(Cell.CELL_TYPE_STRING);

cell.setCellValue("a test");

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("excel/workbook8.xls");

wb.write(fileOut);

fileOut.close();

}

十、 单元格换行

@Test

public void createExce10() throws Exception {

Workbook wb = new XSSFWorkbook(); // or new HSSFWorkbook();

Sheet sheet = wb.createSheet();

Row row = sheet.createRow(2);

Cell cell = row.createCell(2);

cell.setCellValue("Use \n with word wrap on to create a new line");

// to enable newlines you need set a cell styles with wrap=true

CellStyle cs = wb.createCellStyle();

cs.setWrapText(true);

cell.setCellStyle(cs);

// increase row height to accomodate two lines of text

row.setHeightInPoints((2 * sheet.getDefaultRowHeightInPoints()));

// adjust column width to fit the content

sheet.autoSizeColumn((short) 2);

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("excel/workbook9.xlsx");

wb.write(fileOut);

fileOut.close();

wb.close();

}

友情链接

https://www.cnblogs.com/huhx/tag/java/default.html