用poi实现excel的读写
Microsoft的Office系列产品拥有大量的用户,Word、Excel也成为办公文件的首选。在Java中,已经有很多对于Word、Excel的开源的解决方案,其中比较出色的是Apache的Jakata项目的POI子项目。该项目的官方网站是http://jakarta.apache.org/poi/。
POI包括一系列的API,它们可以操作基于MicroSoft OLE 2 Compound Document Format的各种格式文件,可以通过这些API在Java中读写Excel、Word等文件。POI是完全的Java Excel和Java Word解决方案。POI子项目包括:POIFS、HSSF、HDF、HPSF。
刚刚碰到excel的读写问题,还不熟悉阿帕奇的POI,在找写例子,先记下api的地址:http://poi.apache.org/apidocs/index.html
import java.io.BufferedInputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.text.DecimalFormat; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Arrays; import java.util.Date; import java.util.List; import org.apache.poi.hssf.usermodel.HSSFCell; import org.apache.poi.hssf.usermodel.HSSFDateUtil; import org.apache.poi.hssf.usermodel.HSSFRow; import org.apache.poi.hssf.usermodel.HSSFSheet; import org.apache.poi.hssf.usermodel.HSSFWorkbook; import org.apache.poi.poifs.filesystem.POIFSFileSystem; public class ExcelOperate { public static void main(String[] args) throws Exception { File file = new File("ExcelDemo.xls"); String[][] result = getData(file, 1); int rowLength = result.length; for(int i=0;i<rowLength;i++) { for(int j=0;j<result[i].length;j++) { System.out.print(result[i][j]+"\t\t"); } System.out.println(); } } /** * 读取Excel的内容,第一维数组存储的是一行中格列的值,二维数组存储的是多少个行 * @param file 读取数据的源Excel * @param ignoreRows 读取数据忽略的行数,比喻行头不需要读入 忽略的行数为1 * @return 读出的Excel中数据的内容 * @throws FileNotFoundException * @throws IOException */ public static String[][] getData(File file, int ignoreRows) throws FileNotFoundException, IOException { List<String[]> result = new ArrayList<String[]>(); int rowSize = 0; //建立输入流 BufferedInputStream in = new BufferedInputStream(new FileInputStream( file)); // 打开HSSFWorkbook POIFSFileSystem fs = new POIFSFileSystem(in); HSSFWorkbook wb = new HSSFWorkbook(fs); HSSFCell cell = null; //开始读取数据 for (int sheetIndex = 0; sheetIndex < wb.getNumberOfSheets(); sheetIndex++) { HSSFSheet st = wb.getSheetAt(sheetIndex); System.out.println(st); // 第一行为标题,不取 for (int rowIndex = ignoreRows; rowIndex <= st.getLastRowNum(); rowIndex++) { HSSFRow row = st.getRow(rowIndex); if (row == null) { continue; } int tempRowSize = row.getLastCellNum() + 1; if (tempRowSize > rowSize) { rowSize = tempRowSize; } String[] values = new String[rowSize]; Arrays.fill(values, ""); boolean hasValue = false; for (short columnIndex = 0; columnIndex <= row.getLastCellNum(); columnIndex++) { String value = ""; cell = row.getCell(columnIndex); if (cell != null) { switch (cell.getCellType()) { case HSSFCell.CELL_TYPE_STRING: value = cell.getStringCellValue(); break; case HSSFCell.CELL_TYPE_NUMERIC: if (HSSFDateUtil.isCellDateFormatted(cell)) { Date date = cell.getDateCellValue(); if (date != null) { value = new SimpleDateFormat("yyyy-MM-dd") .format(date); } else { value = ""; } } else { value = new DecimalFormat("0").format(cell .getNumericCellValue()); } break; case HSSFCell.CELL_TYPE_FORMULA: // 导入时如果为公式生成的数据则无值 if (!cell.getStringCellValue().equals("")) { value = cell.getStringCellValue(); } else { value = cell.getNumericCellValue() + ""; } break; case HSSFCell.CELL_TYPE_BLANK: break; case HSSFCell.CELL_TYPE_ERROR: value = ""; break; case HSSFCell.CELL_TYPE_BOOLEAN: value = (cell.getBooleanCellValue() == true ? "Y" : "N"); break; default: value = ""; } } if (columnIndex == 0 && value.trim().equals("")) { break; } values[columnIndex] = rightTrim(value); hasValue = true; } if (hasValue) { result.add(values); } } } in.close(); String[][] returnArray = new String[result.size()][rowSize]; for (int i = 0; i < returnArray.length; i++) { returnArray[i] = (String[]) result.get(i); } return returnArray; } /** * 去掉字符串右边的空格 * @param str 要处理的字符串 * @return 处理后的字符串 */ public static String rightTrim(String str) { if (str == null) { return ""; } int length = str.length(); for (int i = length - 1; i >= 0; i--) { if (str.charAt(i) != 0x20) { break; } length--; } return str.substring(0, length); } }