POI 读取 Excel 文件

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
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;


public class ReadExcel {
    private POIFSFileSystem pois ;
    private HSSFWorkbook  workBook;
    private HSSFSheet  sheet;
    private HSSFRow  row;
    private HSSFCell cell;
    List<String> RegionList = new ArrayList<String>();
    Map<String, String> unitMap = new HashMap<String, String>(); //存放集合 <region,unit>1:1
    Map<String, List<String>> deptMap = new HashMap<String, List<String>>(); //存放集合 <unit,dept>1:n
    /**
     * sheetName
     * @param os
     * @param sheetCount
     * @return
     * @throws Exception
     */
    public List readExcelSheetName(InputStream os,int sheetCount) throws Exception{        
        pois =  new POIFSFileSystem(os);
        workBook = new HSSFWorkbook(pois);
        for(int i=0;i<sheetCount;i++){
            sheet = workBook.getSheetAt(i);            
            String sheetName = sheet.getSheetName();        
//            System.out.println("sheetName:"+sheetName);
            RegionList.add(sheetName);    
            List plist = readCell(sheet,sheetName);    
            File f = new File("F://person.txt");
            OutputStream osa = new FileOutputStream(f);        
            System.out.println(plist.size() + " 总数");
            for(int j = 0 ;j<plist.size();j++){
                Person per = (Person) plist.get(j);
                StringBuffer sb = new StringBuffer();
                sb.append("region:"+per.getCity()+"           "+"unit:"+per.getUnit()+"            "+"dept:"+per.getDept()+"         "+"name:"+per.getName());
                sb.append("              "+"tel:"+per.getTel()+"            "+"phone:"+per.getPhone());
                sb.append("\r\n");
                osa.write(sb.toString().getBytes());
            }
            osa.close();
        }        
        return RegionList;
    }    
    
    /**
     * 一个sheet上的相关信心
     * @param sheet
     * @return
     */
    public List readCell(HSSFSheet sheet,String sheetName){
        List Personlist = new ArrayList();        
        String dept = "";
        String unit = "";
        int rowcount = 0;        
        for (Iterator iterator = sheet.iterator(); iterator.hasNext();) {
            Person person = new Person();        
            HSSFRow rows = (HSSFRow) iterator.next(); //获得每个sheet的行数
            if(rowcount == 0 ){ //有特殊的特殊处理，第一行标题
                cell = rows.getCell(1);
                String title = cell.getStringCellValue();
//                System.out.println("一标题："+title.trim());
            }else if(rowcount ==1 ){ //第二行，单位名称
                cell = rows.getCell(0);
                String unitCell = cell.getStringCellValue();
                unit =  unitCell.replace("单位名称：", "");
                unitMap.put(sheetName, unit);//
            }else{
                for(int i = 0;i<rows.getPhysicalNumberOfCells();i++){  //获得每行的cell个数
                    cell = rows.getCell(i);            
                    if(rowcount == 2){ //第三行标题栏
//                        switch (i){
//                        case 1 :
//                            String b1 = cell.getStringCellValue();    
//                            System.out.println("三标题："+b1);    
//                            break;
//                        case 2 :
//                            String b2 = cell.getStringCellValue();
//                            System.out.println("三标题："+b2);    
//                            break;
//                        case 3:
//                            String b3 = cell.getStringCellValue();
//                            System.out.println("三标题："+b3);    
//                            break;
//                        case 4:
//                            String b4 = cell.getStringCellValue();
//                            System.out.println("三标题："+b4);    
//                            break;
//                        }
                    }else{
                        if(cell != null){                    
                            if(i == 0 && formateCell(cell) != null&& !"".equals(formateCell(cell).trim())){ //第一个单元格有合并的部分
                                System.out.println(cell.getCellType()+"+++++"+cell.getStringCellValue().trim());
                                dept = cell.getStringCellValue();
                                dept = dept.replaceAll("\n", "").replace(" ","");
                                List deplist = deptMap.get("unit");
                                if(deplist == null ){
                                    deplist = new ArrayList<String>();
                                    deplist.add(dept);
                                }                                
                                deptMap.put(unit, deplist);                                
                            }else{
                                switch (i){
                                case 1 :
                                    String b1 = cell.getStringCellValue();        
                                    person.setName(b1);
                                    break;
                                case 2 :
                                    String b2 = cell.getStringCellValue();
                                    person.setPosition(b2);
                                    break;
                                case 3:                                    
                                    //System.out.println("-------"+cell.getCellType());
                                    double b3 =cell.getNumericCellValue();    //默认的cell类型：0:double,1:string    
                                    person.setTel(formatDouble(b3+""));
                                    break;
                                case 4:
                                    double b4 = cell.getNumericCellValue();        
                                    person.setPhone(formatDouble(b4+""));
                                    break;
                                }
                            }
                        }
                    }
                }
                person.setCity(sheetName);
                person.setDept(dept);
                person.setUnit(unit);
                if(rowcount !=2 ){
                    Personlist.add(person);            
                }
           }
            rowcount ++;
        }
        return Personlist;
    }

    /**
     * 格式化cell里面的内容
     * @param cell
     * @return
     */
    private String formateCell(HSSFCell cell){
        String strCell = "";
        switch (cell.getCellType()){
        case HSSFCell.CELL_TYPE_STRING:
            strCell = cell.getStringCellValue();
            break;
        case HSSFCell.CELL_TYPE_NUMERIC:
            strCell = formatDouble(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;
    }
    
    private  String formatDouble(String str) {
        if (str == null || "".equals(str.trim()))
            return "";
        if (str.indexOf(".") > 0) {
            if (str.indexOf("E") > 0) {
                str = str.substring(0, str.indexOf("E")).replace(".", "");
            } else {
                str = str.substring(0, str.indexOf("."));
            }
        }
        return str;
    }

}

所需jar 

官网下载最新jar : http://poi.apache.org/