poi 导入/导出 工具类

package com.holy.util;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class ExcelExporterOrImp {
    /**
     * 导出数据
     * @param os
     * @param data
     * @throws IOException
     */
    public static void exportToExcel(OutputStream os, List<List<String>> data) throws IOException {
        HSSFWorkbook wb=null;
        try {
            wb = new HSSFWorkbook();
            HSSFSheet sheet = wb.createSheet("Data");

            for (int r = 0 ; r < data.size() ; r++) {
                HSSFRow row = sheet.createRow(r);
                
                List<String> cols = data.get(r);
                for (int c = 0 ; c < cols.size() ; c++) {
                    HSSFCell cell = row.createCell(c);
                    cell.setCellValue(new HSSFRichTextString(cols.get(c)));
                }
            }

            
        } catch (Exception e) {
            
            e.printStackTrace();
        }finally{
            if(wb!=null){
                wb.write(os);
            }
            os.flush();
            os.close();
        }
}
    /**
     * 数据导入
     * @param is
     * @return
     * @throws IOException
     */
    public static List<List<String>> importFromExcel(InputStream is) throws IOException {
        HSSFWorkbook wb = new HSSFWorkbook(is);
        HSSFSheet sheet = wb.getSheetAt(0);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        List<List<String>> data = new ArrayList<List<String>>();
        try {
            for (int r = sheet.getFirstRowNum() ; r <= sheet.getLastRowNum() ; r++) {
                HSSFRow row = sheet.getRow(r);
                if (row == null) {
                    continue;
                }

                List<String> cols = new ArrayList<String>(); 
                for (int c = row.getFirstCellNum() ; c < row.getLastCellNum() ; c++) {
                    HSSFCell cell = row.getCell(c);
                    if (cell == null) {
                        cols.add("");
                    } else {
                        switch(cell.getCellType()) {
                        case HSSFCell.CELL_TYPE_STRING:
                            cols.add(cell.getStringCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_BOOLEAN:
                            cols.add(""+cell.getBooleanCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_NUMERIC:
                            if (org.apache.poi.ss.usermodel.DateUtil.isCellDateFormatted(cell)) {
                                cols.add(sdf.format(cell.getDateCellValue()));
                            } else {
                                cols.add(""+cell.getNumericCellValue());
                            }

                            break;
                        case HSSFCell.CELL_TYPE_FORMULA:
                            cols.add(cell.getCellFormula());
                            break;
                        case HSSFCell.CELL_TYPE_BLANK:
                            cols.add("");
                            break;
                        }                        
                    }
                }

                data.add(cols);
            }
        } finally {
            is.close();
        }
        return data;
    }
    /**
     * 
     * @param is
     * @param firstCellNum
     * @param lastCellNum
     * @return
     * @throws IOException
     */
    public static List<List<String>> importFromExcelWithCell(InputStream is,int firstCellNum,int lastCellNum) throws IOException {
        HSSFWorkbook wb = new HSSFWorkbook(is);
        HSSFSheet sheet = wb.getSheetAt(0);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        List<List<String>> data = new ArrayList<List<String>>();
        try {
            for (int r = sheet.getFirstRowNum() ; r <= sheet.getLastRowNum() ; r++) {
                HSSFRow row = sheet.getRow(r);
                if (row == null) {
                    continue;
                }

                List<String> cols = new ArrayList<String>(); 
                for (int c = firstCellNum ; c < lastCellNum ; c++) {
                    HSSFCell cell = row.getCell(c);
                    if (cell == null) {
                        cols.add("");
                    } else {
                        switch(cell.getCellType()) {
                        case HSSFCell.CELL_TYPE_STRING:
                            cols.add(cell.getStringCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_BOOLEAN:
                            cols.add(""+cell.getBooleanCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_NUMERIC:
                            if (org.apache.poi.ss.usermodel.DateUtil.isCellDateFormatted(cell)) {
                                cols.add(sdf.format(cell.getDateCellValue()));
                            } else {
                                cols.add(""+cell.getNumericCellValue());
                            }

                            break;
                        case HSSFCell.CELL_TYPE_FORMULA:
                            cols.add(cell.getCellFormula());
                            break;
                        case HSSFCell.CELL_TYPE_BLANK:
                            cols.add("");
                            break;
                        }                        
                    }
                }

                data.add(cols);
            }
        } finally {
            is.close();
        }
        return data;
    }
    /**
     * 该方法把num类型强转成了string
     * @param is
     * @param firstCellNum
     * @param lastCellNum
     * @return
     * @throws IOException
     */
    public static List<List<String>> importFromExcelWithCellWithNUm(InputStream is,int firstCellNum,int lastCellNum) throws IOException {
        HSSFWorkbook wb = new HSSFWorkbook(is);
        HSSFSheet sheet = wb.getSheetAt(0);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        DecimalFormat df = new DecimalFormat("#");
        List<List<String>> data = new ArrayList<List<String>>();
        try {
            for (int r = sheet.getFirstRowNum() ; r <= sheet.getLastRowNum() ; r++) {
                HSSFRow row = sheet.getRow(r);
                if (row == null) {
                    continue;
                }

                List<String> cols = new ArrayList<String>(); 
                for (int c = firstCellNum ; c < lastCellNum ; c++) {
                    HSSFCell cell = row.getCell(c);
                    if (cell == null) {
                        cols.add("");
                    } else {
                        switch(cell.getCellType()) {
                        case HSSFCell.CELL_TYPE_STRING:
                            cols.add(cell.getStringCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_BOOLEAN:
                            cols.add(""+cell.getBooleanCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_NUMERIC:
                            if (org.apache.poi.ss.usermodel.DateUtil.isCellDateFormatted(cell)) {
                                cols.add(sdf.format(cell.getDateCellValue()));
                            } else {

                                cols.add( ""+df.format(cell.getNumericCellValue()));
//                                cols.add(""+cell.getNumericCellValue());
                            }

                            break;
                        case HSSFCell.CELL_TYPE_FORMULA:
                            cols.add(cell.getCellFormula());
                            break;
                        case HSSFCell.CELL_TYPE_BLANK:
                            cols.add("");
                            break;
                        }                        
                    }
                }

                data.add(cols);
            }
        } finally {
            is.close();
        }
        return data;
    }

    /***
     * 该方法把导入excel时对于数字类型的数据进行处理
     * 一般情况下excel中数字太长会转化成科学计数法
     * @param is
     * @return
     * @throws IOException
     */
    public static List<List<String>> importExcelWithCellWithNum(InputStream is) throws IOException {
        HSSFWorkbook wb = new HSSFWorkbook(is);
        HSSFSheet sheet = wb.getSheetAt(0);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        DecimalFormat df = new DecimalFormat("#");
        List<List<String>> data = new ArrayList<List<String>>();
        try {
            for (int r = sheet.getFirstRowNum() ; r <= sheet.getLastRowNum() ; r++) {
                HSSFRow row = sheet.getRow(r);
                if (row == null) {
                    continue;
                }

                List<String> cols = new ArrayList<String>(); 
                for (int c = row.getFirstCellNum() ; c < row.getLastCellNum() ; c++) {
                    HSSFCell cell = row.getCell(c);
                    if (cell == null) {
                        cols.add("");
                    } else {
                        switch(cell.getCellType()) {
                        case HSSFCell.CELL_TYPE_STRING:
                            cols.add(cell.getStringCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_BOOLEAN:
                            cols.add(""+cell.getBooleanCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_NUMERIC:
                            if (org.apache.poi.ss.usermodel.DateUtil.isCellDateFormatted(cell)) {
                                cols.add(sdf.format(cell.getDateCellValue()));
                            } else {
                                cols.add( ""+df.format(cell.getNumericCellValue()));
                            }
                            break;
                        case HSSFCell.CELL_TYPE_FORMULA:
                            cols.add(cell.getCellFormula());
                            break;
                        case HSSFCell.CELL_TYPE_BLANK:
                            cols.add("");
                            break;
                        }                        
                    }
                }

                data.add(cols);
            }
        } finally {
            is.close();
        }
        return data;
    }
    
     
    public static List<List<String>> importExcelWithNullCell(InputStream is) throws IOException {
        HSSFWorkbook wb = new HSSFWorkbook(is);
        HSSFSheet sheet = wb.getSheetAt(0);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        DecimalFormat df = new DecimalFormat("#");
        List<List<String>> data = new ArrayList<List<String>>();
        
        try {
            int lastCellNum = sheet.getRow(sheet.getFirstRowNum()).getLastCellNum();
            
            for (int r = sheet.getFirstRowNum() ; r <= sheet.getLastRowNum() ; r++) {
                HSSFRow row = sheet.getRow(r);
                if (row == null) {
                    continue;
                }

                List<String> cols = new ArrayList<String>(); 
                for (int c = 0 ; c < lastCellNum ; c++) {
                    HSSFCell cell = row.getCell(c);
                    if (cell == null) {
                        cols.add("");
                    } else {
                        switch(cell.getCellType()) {
                        case HSSFCell.CELL_TYPE_STRING:
                            cols.add(cell.getStringCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_BOOLEAN:
                            cols.add(""+cell.getBooleanCellValue());
                            break;
                        case HSSFCell.CELL_TYPE_NUMERIC:
                            if (org.apache.poi.ss.usermodel.DateUtil.isCellDateFormatted(cell)) {
                                cols.add(sdf.format(cell.getDateCellValue()));
                            } else {
                                cols.add( ""+df.format(cell.getNumericCellValue()));
                            }
                            break;
                        case HSSFCell.CELL_TYPE_FORMULA:
                            cols.add(cell.getCellFormula());
                            break;
                        case HSSFCell.CELL_TYPE_BLANK:
                            cols.add("");
                            break;
                        }                        
                    }
                }

                data.add(cols);
            }
        } finally {
            is.close();
        }
        return data;
    }
    
        
    public static void main(String[] args) throws IOException {
        
        FileOutputStream os = new FileOutputStream(new File("d:/test.xls"));
        List<List<String>> data = new ArrayList<List<String>>();
        List<String> s = new ArrayList<String>();
        s.add("11");
        s.add("22");
        s.add("33");
        data.add(s);
        List<String> s1 = new ArrayList<String>();
        s1.add("11");
        s1.add("22");
        s1.add("33");
        data.add(s1);
        exportToExcel(os, data);
        System.out.println("data:"+data);
        
//        FileInputStream is = new FileInputStream(new File("d:/bank.xlsx"));
//        List<List<String>> data = importFromExcel(is);
//        System.out.println("data:"+data);
    }
      

}