excel读取工具类

package com.wujian.util;

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;

import java.io.*;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;


public class ImportExcelUtil {
	/**
	 * 读取EXCEL
	 * @param file
	 * @param firstrow 从第几行开始读取
	 * @return 读取后返回数组
	 * @throws FileNotFoundException
	 * @throws IOException
	 */
	@SuppressWarnings("deprecation")
	public static String[][] importExcel(File file, int firstrow) throws FileNotFoundException, IOException {
		List<String[]> result = new ArrayList<String[]>();
		int rowSize = 0;
		BufferedInputStream in = new BufferedInputStream(new FileInputStream(file));
		POIFSFileSystem fs = new POIFSFileSystem(in);
		HSSFWorkbook wb = new HSSFWorkbook(fs);
		HSSFCell cell = null;
		for (int sheetIndex = 0; sheetIndex < wb.getNumberOfSheets(); sheetIndex++) {
			HSSFSheet st = wb.getSheetAt(sheetIndex);
			for (int rowIndex = firstrow; 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://读取的格式为字符串
							value = cell.getStringCellValue();
							break;
						case HSSFCell.CELL_TYPE_NUMERIC://读取的格式为数组
							//如果格式为日期格式，自定义格式输出
							if (HSSFDateUtil.isCellDateFormatted(cell)) {
								Date date = cell.getDateCellValue();
								if (date != null) {
									value = new SimpleDateFormat("yyyy-MM-dd").format(date);
								} else {
									value = "";
								}
							} else {
								//如果格式为数值，自定义格式输出
								value = new DecimalFormat().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
							value = "";
							break;
							// 导入时如果为空
						case HSSFCell.CELL_TYPE_BLANK:
							break;
						case HSSFCell.CELL_TYPE_ERROR:
							value = "";
							break;
							// 导入时如果为BOOLEAN型 自定义格式输出
						case HSSFCell.CELL_TYPE_BOOLEAN:
							value = (cell.getBooleanCellValue() == true ? "Y" : "N");
							break;
						default:
							value = "";
						}
					}

					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] = result.get(i);
			}
			return returnArray;
		}
		return null;
	}

	/**
	 * 读取EXCEL
	 * @param file
	 * @param firstrow 从第几行开始读取
	 * @param sheetName 读取名称为sheetName的sheet
	 * @return 读取后返回数组
	 * @throws FileNotFoundException
	 * @throws IOException
	 */
	@SuppressWarnings("deprecation")
	public static String[][] importExcelBySheelName(File file, int firstrow,String sheetName) throws FileNotFoundException, IOException {
		List<String[]> result = new ArrayList<String[]>();
		int rowSize = 0;
		BufferedInputStream in = new BufferedInputStream(new FileInputStream(file));
		POIFSFileSystem fs = new POIFSFileSystem(in);
		HSSFWorkbook wb = new HSSFWorkbook(fs);
		HSSFCell cell = null;
		if (!StringUtil.isNullStr(sheetName)) {
			HSSFSheet st = wb.getSheet(sheetName);
			for (int rowIndex = firstrow; 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://读取的格式为字符串
								value = cell.getStringCellValue();
								break;
							case HSSFCell.CELL_TYPE_NUMERIC://读取的格式为数组
								//如果格式为日期格式，自定义格式输出
								if (HSSFDateUtil.isCellDateFormatted(cell)) {
									Date date = cell.getDateCellValue();
									if (date != null) {
										value = new SimpleDateFormat("yyyy-MM-dd").format(date);
									} else {
										value = "";
									}
								} else {
									//如果格式为数值，自定义格式输出
									value = new DecimalFormat().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
								value = "";
								break;
							// 导入时如果为空
							case HSSFCell.CELL_TYPE_BLANK:
								break;
							case HSSFCell.CELL_TYPE_ERROR:
								value = "";
								break;
							// 导入时如果为BOOLEAN型 自定义格式输出
							case HSSFCell.CELL_TYPE_BOOLEAN:
								value = (cell.getBooleanCellValue() == true ? "Y" : "N");
								break;
							default:
								value = "";
						}
					}

					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] = result.get(i);
			}
			return returnArray;
		}
		return null;
	}

	/**
	 * 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);
	}
}