java读取excel

package com.jjm.lht;  
 
import java.io.FileInputStream;  
import java.io.FileNotFoundException;  
import java.io.IOException;  
import java.io.InputStream;  
import java.util.Date;  
import java.util.HashMap;  
import java.util.Map;  
 
import org.apache.poi.hssf.usermodel.HSSFCell;  
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;  
 
/** 
* 操作Excel表格的功能类 
* @author：hnylj 
* @version 1.0 
*/ 
public class ExcelReader {  
    private POIFSFileSystem fs;  
    private HSSFWorkbook wb;  
    private HSSFSheet sheet;  
    private HSSFRow row;  
    /** 
     * 读取Excel表格表头的内容 
     * @param InputStream 
     * @return String 表头内容的数组 
     *  
     */ 
    public String[] readExcelTitle(InputStream is) {  
        try {  
            fs = new POIFSFileSystem(is);  
            wb = new HSSFWorkbook(fs);  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
        sheet = wb.getSheetAt(0);  
        row = sheet.getRow(0);  
        //标题总列数  
        int colNum = row.getPhysicalNumberOfCells();  
        String[] title = new String[colNum];  
        for (int i=0; i<colNum; i++) {  
            title[i] = getStringCellValue(row.getCell((short) i));  
        }  
        return title;  
    }  
      
    /** 
     * 读取Excel数据内容 
     * @param InputStream 
     * @return Map 包含单元格数据内容的Map对象 
     */ 
    public Map<Integer,String> readExcelContent(InputStream is) {  
        Map<Integer,String> content = new HashMap<Integer,String>();  
        String str = "";  
        try {  
            fs = new POIFSFileSystem(is);  
            wb = new HSSFWorkbook(fs);  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
        sheet = wb.getSheetAt(0);  
        //得到总行数  
        int rowNum = sheet.getLastRowNum();  
        row = sheet.getRow(0);  
        int colNum = row.getPhysicalNumberOfCells();  
        //正文内容应该从第二行开始,第一行为表头的标题  
        for (int i = 1; i <= rowNum; i++) {  
            row = sheet.getRow(i);  
            int j = 0;  
            while (j<colNum) {  
        //每个单元格的数据内容用"-"分割开，以后需要时用String类的replace()方法还原数据  
        //也可以将每个单元格的数据设置到一个javabean的属性中，此时需要新建一个javabean  
                str += getStringCellValue(row.getCell((short) j)).trim() + "-";  
                j ++;  
            }  
            content.put(i, str);  
            str = "";  
        }  
        return content;  
    }  
      
    /** 
     * 获取单元格数据内容为字符串类型的数据 
     * @param cell Excel单元格 
     * @return String 单元格数据内容 
     */ 
    private String getStringCellValue(HSSFCell cell) {  
        String strCell = "";  
        switch (cell.getCellType()) {  
        case HSSFCell.CELL_TYPE_STRING:  
            strCell = cell.getStringCellValue();  
            break;  
        case HSSFCell.CELL_TYPE_NUMERIC:  
            strCell = String.valueOf(cell.getNumericCellValue());  
            break;  
        case HSSFCell.CELL_TYPE_BOOLEAN:  
            strCell = String.valueOf(cell.getBooleanCellValue());  
            break;  
        case HSSFCell.CELL_TYPE_BLANK:  
            strCell = "";  
            break;  
        default:  
            strCell = "";  
            break;  
        }  
        if (strCell.equals("") || strCell == null) {  
            return "";  
        }  
        if (cell == null) {  
            return "";  
        }  
        return strCell;  
    }  
      
    /** 
     * 获取单元格数据内容为日期类型的数据 
     * @param cell Excel单元格 
     * @return String 单元格数据内容 
     */ 
    private String getDateCellValue(HSSFCell cell) {  
        String result = "";  
        try {  
            int cellType = cell.getCellType();  
            if (cellType == HSSFCell.CELL_TYPE_NUMERIC) {  
                Date date = cell.getDateCellValue();  
                result = (date.getYear() + 1900) + "-" + (date.getMonth() + 1)   
                + "-" + date.getDate();  
            } else if (cellType == HSSFCell.CELL_TYPE_STRING) {  
                String date = getStringCellValue(cell);  
                result = date.replaceAll("[年月]", "-").replace("日", "").trim();  
            } else if (cellType == HSSFCell.CELL_TYPE_BLANK) {  
                result = "";  
            }  
        } catch (Exception e) {  
            System.out.println("日期格式不正确!");  
            e.printStackTrace();  
        }  
        return result;  
    }  
      
    public static void main(String[] args) {  
        try {  
            //对读取Excel表格标题测试  
            InputStream is = new FileInputStream("D:\\test.xls");  
            ExcelReader excelReader = new ExcelReader();  
            String[] title = excelReader.readExcelTitle(is);  
            System.out.println("获得Excel表格的标题:");
            for (String s : title) {  
                System.out.print(s + " ");  
            }  
              
            //对读取Excel表格内容测试  
            InputStream is2 = new FileInputStream("D:\\test.xls");  
            Map<Integer,String> map = excelReader.readExcelContent(is2);
            System.out.println();
            System.out.println("获得Excel表格的内容:");  
            for (int i=1; i<=map.size(); i++) {  
                System.out.println(map.get(i).replace("-", " "));  
            }  
        } catch (FileNotFoundException e) {  
            System.out.println("未找到指定路径的文件!");  
            e.printStackTrace();  
        }  
    }  
} 

评论

1 楼 love_wbo 2012-06-11  

你好，我用的Eclipse编写代码的，我用了你这段代码，运行出现错误：
获得Excel表格的标题:
aaa bbb xxx sss ddd Exception in thread "main" java.lang.NullPointerException
at ExcelReader.getStringCellValue(ExcelReader.java:92)
at ExcelReader.readExcelContent(ExcelReader.java:76)
at ExcelReader.main(ExcelReader.java:157)；
你能帮忙解释一下么？
第92行代码是： case HSSFCell.CELL_TYPE_STRING:
第76行代码是： j ++;
第157行代码是： System.out.println();

我也不知道是怎么出现的错误，你知道是为什么么？谢谢！！