一.POI簡介
Jakarta POI 是apache的子項(xiàng)目,目標(biāo)是處理ole2對(duì)象。它提供了一組操縱Windows文檔的Java API
目前比較成熟的是HSSF接口,處理MS Excel(97-2002)對(duì)象。它不象我們僅僅是用csv生成的沒有格式的可以由Excel轉(zhuǎn)換的東西,而是真正的Excel對(duì)象,你可以控制一些屬性如sheet,cell等等。
二.HSSF概況
HSSF 是Horrible SpreadSheet Format的縮寫,也即“討厭的電子表格格式”。也許HSSF的名字有點(diǎn)滑稽,就本質(zhì)而言它是一個(gè)非常嚴(yán)肅、正規(guī)的API。通過HSSF,你可以用純Java代碼來讀取、寫入、修改Excel文件。
HSSF 為讀取操作提供了兩類API:usermodel和eventusermodel,即“用戶模型”和“事件-用戶模型”。前者很好理解,后者比較抽象,但操作效率要高得多。
三.開始編碼
1 . 準(zhǔn)備工作
要求:JDK 1.4+POI開發(fā)包
可以到 http://www.apache.org/dyn/closer.cgi/jakarta/poi/ 最新的POI工具包
2 . EXCEL 結(jié)構(gòu)
HSSFWorkbook excell 文檔對(duì)象介紹
HSSFSheet excell的表單
HSSFRow excell的行
HSSFCell excell的格子單元
HSSFFont excell字體
HSSFName 名稱
HSSFDataFormat 日期格式
在poi1.7中才有以下2項(xiàng):
HSSFHeader sheet頭
HSSFFooter sheet尾
和這個(gè)樣式
HSSFCellStyle cell樣式
輔助操作包括
HSSFDateUtil 日期
HSSFPrintSetup 打印
HSSFErrorConstants 錯(cuò)誤信息表
3 .具體用法實(shí)例 (采用 usermodel )
如何讀Excel
讀取Excel文件時(shí),首先生成一個(gè)POIFSFileSystem對(duì)象,由POIFSFileSystem對(duì)象構(gòu)造一個(gè)HSSFWorkbook,該HSSFWorkbook對(duì)象就代表了Excel文檔。下面代碼讀取上面生成的Excel文件寫入的消息字串:
代碼
POIFSFileSystem fs=newPOIFSFileSystem(new FileInputStream("d:\test.xls"));
HSSFWorkbook wb = new HSSFWorkbook(fs);
} catch (IOException e) {
e.printStackTrace();
}
HSSFSheet sheet = wb.getSheetAt(0);
HSSFRow row = sheet.getRow(0);
HSSFCell cell = row.getCell((short) 0);
String msg = cell.getStringCellValue();
POIFSFileSystem fs=newPOIFSFileSystem(new FileInputStream("d:\test.xls"));
HSSFWorkbook wb = new HSSFWorkbook(fs);
} catch (IOException e) {
e.printStackTrace();
}
HSSFSheet sheet = wb.getSheetAt(0);
HSSFRow row = sheet.getRow(0);
HSSFCell cell = row.getCell((short) 0);
String msg = cell.getStringCellValue();
如何寫excel,
將excel的第一個(gè)表單第一行的第一個(gè)單元格的值寫成“a test”。
代碼
POIFSFileSystem fs =new POIFSFileSystem(new FileInputStream("workbook.xls"));
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFSheet sheet = wb.getSheetAt(0);
HSSFRow row = sheet.getRow(0);
HSSFCell cell = row.getCell((short)0);
cell.setCellValue("a test");
// Write the output to a file
FileOutputStream fileOut = new FileOutputStream("workbook.xls");
wb.write(fileOut);
fileOut.close();
4 . 可參考文檔
POI 主頁:http://jakarta.apache.org/poi/,
初學(xué)者如何快速上手使用POI HSSF
http://jakarta.apache.org/poi/hssf/quick-guide.html 。
代碼例子 http://blog.java-cn.com/user1/6749/archives/2005/18347.html
里面有很多例子代碼,可以很方便上手。
POI的中級(jí)應(yīng)該用
1、遍歷workbook
代碼
// load源文件
POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(filePath));
HSSFWorkbook wb = new HSSFWorkbook(fs);
for (int i = 0; i < wb.getNumberOfSheets(); i++) {
HSSFSheet sheet = wb.getSheetAt(i);
for (int i = sheet.getFirstRowNum(); i < sheet.getLastRowNum(); i ++) {
HSSFRow row = sheet.getRow(i);
if (row != null) {
。。。操作}
}
}
// 目標(biāo)文件
FileOutputStream fos = new FileOutputStream(objectPath);
//寫文件
swb.write(fos);
fos.close();
2、得到列和單元格
代碼
HSSFRow row = sheet.getRow(i);
HSSFCell cell = row.getCell((short) j);
3、設(shè)置sheet名稱和單元格內(nèi)容為中文
代碼
wb.setSheetName(n, "中文",HSSFCell.ENCODING_UTF_16);
cell.setEncoding((short) 1);
cell.setCellValue("中文");
4、單元格內(nèi)容未公式或數(shù)值,可以這樣讀寫
代碼
cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);
cell.getNumericCellValue()
5、設(shè)置列寬、行高
代碼
sheet.setColumnWidth((short)column,(short)width);
row.setHeight((short)height);
6、添加區(qū)域,合并單元格
代碼
Region region = new Region((short)rowFrom,(short)columnFrom,(short)rowTo,(short)columnTo);
sheet.addMergedRegion(region);
//得到所有區(qū)域
sheet.getNumMergedRegions()
7、常用方法
根據(jù)單元格不同屬性返回字符串?dāng)?shù)值
代碼
public String getCellStringValue(HSSFCell cell) {
String cellValue = "";
switch (cell.getCellType()) {
case HSSFCell.CELL_TYPE_STRING:
cellValue = cell.getStringCellValue();
if(cellValue.trim().equals("")||cellValue.trim().length()<=0)
cellValue=" ";
break;
case HSSFCell.CELL_TYPE_NUMERIC:
cellValue = String.valueOf(cell.getNumericCellValue());
break;
case HSSFCell.CELL_TYPE_FORMULA:
cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);
cellValue = String.valueOf(cell.getNumericCellValue());
break;
case HSSFCell.CELL_TYPE_BLANK:
cellValue=" ";
break;
case HSSFCell.CELL_TYPE_BOOLEAN:
break;
case HSSFCell.CELL_TYPE_ERROR:
break;
default:
break;
}
return cellValue;
}
8、常用單元格邊框格式
虛線HSSFCellStyle.BORDER_DOTTED
實(shí)線HSSFCellStyle.BORDER_THIN
代碼
public static HSSFCellStyle getCellStyle(short type)
{
HSSFWorkbook wb = new HSSFWorkbook();
HSSFCellStyle style = wb.createCellStyle();
style.setBorderBottom(type);//下邊框
style.setBorderLeft(type);//左邊框
style.setBorderRight(type);//右邊框
style.setBorderTop(type);//上邊框
return style;
}
9、設(shè)置字體和內(nèi)容位置
代碼
HSSFFont f = wb.createFont();
f.setFontHeightInPoints((short) 11);//字號(hào)
f.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);//加粗
style.setFont(f);
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);//左右居中
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);//上下居中
style.setRotation(short rotation);//單元格內(nèi)容的旋轉(zhuǎn)的角度
HSSFDataFormat df = wb.createDataFormat();
style1.setDataFormat(df.getFormat("0.00%"));//設(shè)置單元格數(shù)據(jù)格式
cell.setCellFormula(string);//給單元格設(shè)公式
style.setRotation(short rotation);//單元格內(nèi)容的旋轉(zhuǎn)的角度
cell.setCellStyle(style);
10、插入圖片
論壇里看到的
代碼
//先把讀進(jìn)來的圖片放到一個(gè)ByteArrayOutputStream中,以便產(chǎn)生ByteArray
ByteArrayOutputStream byteArrayOut = new ByteArrayOutputStream();
BufferedImage bufferImg = ImageIO.read(new File("ok.jpg"));
ImageIO.write(bufferImg,"jpg",byteArrayOut);
//讀進(jìn)一個(gè)excel模版
FileInputStream fos = new FileInputStream(filePathName+"/stencil.xlt");
fs = new POIFSFileSystem(fos);
//創(chuàng)建一個(gè)工作薄
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFSheet sheet = wb.getSheetAt(0);
HSSFPatriarch patriarch = sheet.createDrawingPatriarch();
HSSFClientAnchor anchor = new HSSFClientAnchor(0,0,1023,255,(short) 0,0,(short)10,10);
patriarch.createPicture(anchor , wb.addPicture(byteArrayOut.toByteArray(),HSSFWorkbook.PICTURE_TYPE_JPEG));
11、設(shè)置列自動(dòng)換行
HSSFCellStyle cellStyle = workbook.createCellStyle();
cellStyle.setWrapText(true);
sheet.setDefaultColumnStyle((short)0, cellStyle);
設(shè)置列的寬度
sheet.setColumnWidth((short)0,(short)9000);
sheet.setDefaultColumnStyle((short)0, cellStyle);
與
sheet.setDefaultColumnWidth((short)70);沖突
只會(huì)換行 不會(huì)設(shè)置列寬
單元格拷貝示例:
package testpoi;
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/**
* 將某SHEET頁中的某幾行復(fù)制到某SHEET頁的某幾行中。抱括被合并了的單元格。
*/
public class RowCopy {
/**
* @param args
* @throws IOException
* @throws FileNotFoundException
*/
@SuppressWarnings("deprecation")
public static void main(String[] args) {
try {
POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(
"d:\\exlsample.xls"));
HSSFWorkbook wb = new HSSFWorkbook(fs);
// source為源sheet 頁,target為目標(biāo)sheet頁
copyRows(wb, "source", "target", 5, 6, 20);
FileOutputStream fileOut = new FileOutputStream("d:\\exlsample.xls");
wb.write(fileOut);
fileOut.flush();
fileOut.close();
System.out.println("Operation finished");
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* @param wb HSSFWorkbook
* @param pSourceSheetName 源sheet頁名稱
* @param pTargetSheetName 目標(biāo)sheet頁名稱
* @param pStartRow 源sheet頁中的起始行
* @param pEndRow 源sheet頁中的結(jié)束行
* @param pPosition 目標(biāo)sheet頁中的開始行
*/
public static void copyRows(HSSFWorkbook wb, String pSourceSheetName,
String pTargetSheetName, int intStartRow, int intEndRow, int intPosition) {
// EXECL中的行是從1開始的,而POI中是從0開始的,所以這里要減1.
int pStartRow = intStartRow - 1;
int pEndRow = intEndRow - 1;
int pPosition = intPosition - 1;
HSSFRow sourceRow = null;
HSSFRow targetRow = null;
HSSFCell sourceCell = null;
HSSFCell targetCell = null;
HSSFSheet sourceSheet = null;
HSSFSheet targetSheet = null;
Region region = null;
int cType;
int i;
int j;
int targetRowFrom;
int targetRowTo;
if ((pStartRow == -1) || (pEndRow == -1)) {
return;
}
sourceSheet = wb.getSheet(pSourceSheetName);
targetSheet = wb.getSheet(pTargetSheetName);
System.out.println(sourceSheet.getNumMergedRegions());
// 拷貝合并的單元格
for (i = 0; i < sourceSheet.getNumMergedRegions(); i++) {
region = sourceSheet.getMergedRegionAt(i);
if ((region.getRowFrom() >= pStartRow)
&& (region.getRowTo() <= pEndRow)) {
targetRowFrom = region.getRowFrom() - pStartRow + pPosition;
targetRowTo = region.getRowTo() - pStartRow + pPosition;
region.setRowFrom(targetRowFrom);
region.setRowTo(targetRowTo);
targetSheet.addMergedRegion(region);
}
}
// 設(shè)置列寬
for (i = pStartRow; i <= pEndRow; i++) {
sourceRow = sourceSheet.getRow(i);
if (sourceRow != null) {
for (j = sourceRow.getLastCellNum(); j > sourceRow
.getFirstCellNum(); j--) {
targetSheet
.setColumnWidth(j, sourceSheet.getColumnWidth(j));
targetSheet.setColumnHidden(j, false);
}
break;
}
}
// 拷貝行并填充數(shù)據(jù)
for (; i <= pEndRow; i++) {
sourceRow = sourceSheet.getRow(i);
if (sourceRow == null) {
continue;
}
targetRow = targetSheet.createRow(i - pStartRow + pPosition);
targetRow.setHeight(sourceRow.getHeight());
for (j = sourceRow.getFirstCellNum(); j < sourceRow
.getPhysicalNumberOfCells(); j++) {
sourceCell = sourceRow.getCell(j);
if (sourceCell == null) {
continue;
}
targetCell = targetRow.createCell(j);
targetCell.setCellStyle(sourceCell.getCellStyle());
cType = sourceCell.getCellType();
targetCell.setCellType(cType);
switch (cType) {
case HSSFCell.CELL_TYPE_BOOLEAN:
targetCell.setCellValue(sourceCell.getBooleanCellValue());
System.out.println("--------TYPE_BOOLEAN:"
+ targetCell.getBooleanCellValue());
break;
case HSSFCell.CELL_TYPE_ERROR:
targetCell
.setCellErrorValue(sourceCell.getErrorCellValue());
System.out.println("--------TYPE_ERROR:"
+ targetCell.getErrorCellValue());
break;
case HSSFCell.CELL_TYPE_FORMULA:
// parseFormula這個(gè)函數(shù)的用途在后面說明
targetCell.setCellFormula(parseFormula(sourceCell
.getCellFormula()));
System.out.println("--------TYPE_FORMULA:"
+ targetCell.getCellFormula());
break;
case HSSFCell.CELL_TYPE_NUMERIC:
targetCell.setCellValue(sourceCell.getNumericCellValue());
System.out.println("--------TYPE_NUMERIC:"
+ targetCell.getNumericCellValue());
break;
case HSSFCell.CELL_TYPE_STRING:
targetCell
.setCellValue(sourceCell.getRichStringCellValue());
System.out.println("--------TYPE_STRING:" + i
+ targetCell.getRichStringCellValue());
break;
}
}
}
}
/**
* POI對(duì)Excel公式的支持是相當(dāng)好的,但是有一個(gè)問題,如果公式里面的函數(shù)不帶參數(shù),比如now()或today(),
* 那么你通過getCellFormula()取出來的值就是now(ATTR(semiVolatile))和today(ATTR(semiVolatile)),
* 這樣的值寫入Excel是會(huì)出錯(cuò)的,這也是我上面copyRow的函數(shù)在寫入公式前要調(diào)用parseFormula的原因,
* parseFormula這個(gè)函數(shù)的功能很簡單,就是把ATTR(semiVolatile)刪掉。
* @param pPOIFormula
* @return
*/
private static String parseFormula(String pPOIFormula) {
final String cstReplaceString = "ATTR(semiVolatile)"; //$NON-NLS-1$
StringBuffer result = null;
int index;
result = new StringBuffer();
index = pPOIFormula.indexOf(cstReplaceString);
if (index >= 0) {
result.append(pPOIFormula.substring(0, index));
result.append(pPOIFormula.substring(index
+ cstReplaceString.length()));
} else {
result.append(pPOIFormula);
}
return result.toString();
}
}
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