java的poi技术读取和导入Excel实例

//该类有main方法，主要负责运行程序，同时该类中也包含了用poi读取Excel(2003版)
 
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
 
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;
 
 
/**
 * 
 * @author Hongten</br>
 * 
 * 
 */
public class XlsMain {
 
  public static void main(String[] args) throws IOException {
    XlsMain xlsMain = new XlsMain();
    XlsDto xls = null;
    List<XlsDto> list = xlsMain.readXls();
     
    try {
      XlsDto2Excel.xlsDto2Excel(list);
    } catch (Exception e) {
      e.printStackTrace();
    }
    for (int i = 0; i < list.size(); i++) {
      xls = (XlsDto) list.get(i);
      System.out.println(xls.getXh() + "  " + xls.getXm() + "  "
          + xls.getYxsmc() + "  " + xls.getKcm() + "  "
          + xls.getCj());
    }
 
  }
 
  /**
   * 读取xls文件内容
   * 
   * @return List<XlsDto>对象
   * @throws IOException
   *       输入/输出(i/o)异常
   */
  private List<XlsDto> readXls() throws IOException {
    InputStream is = new FileInputStream("pldrxkxxmb.xls");
    HSSFWorkbook hssfWorkbook = new HSSFWorkbook(is);
    XlsDto xlsDto = null;
    List<XlsDto> list = new ArrayList<XlsDto>();
    // 循环工作表Sheet
    for (int numSheet = 0; numSheet < hssfWorkbook.getNumberOfSheets(); numSheet++) {
      HSSFSheet hssfSheet = hssfWorkbook.getSheetAt(numSheet);
      if (hssfSheet == null) {
        continue;
      }
      // 循环行Row
      for (int rowNum = 1; rowNum <= hssfSheet.getLastRowNum(); rowNum++) {
        HSSFRow hssfRow = hssfSheet.getRow(rowNum);
        if (hssfRow == null) {
          continue;
        }
        xlsDto = new XlsDto();
        // 循环列Cell
        // 0学号 1姓名 2学院 3课程名 4 成绩
        // for (int cellNum = 0; cellNum <=4; cellNum++) {
        HSSFCell xh = hssfRow.getCell(0);
        if (xh == null) {
          continue;
        }
        xlsDto.setXh(getValue(xh));
        HSSFCell xm = hssfRow.getCell(1);
        if (xm == null) {
          continue;
        }
        xlsDto.setXm(getValue(xm));
        HSSFCell yxsmc = hssfRow.getCell(2);
        if (yxsmc == null) {
          continue;
        }
        xlsDto.setYxsmc(getValue(yxsmc));
        HSSFCell kcm = hssfRow.getCell(3);
        if (kcm == null) {
          continue;
        }
        xlsDto.setKcm(getValue(kcm));
        HSSFCell cj = hssfRow.getCell(4);
        if (cj == null) {
          continue;
        }
        xlsDto.setCj(Float.parseFloat(getValue(cj)));
        list.add(xlsDto);
      }
    }
    return list;
  }
 
  /**
   * 得到Excel表中的值
   * 
   * @param hssfCell
   *      Excel中的每一个格子
   * @return Excel中每一个格子中的值
   */
  @SuppressWarnings("static-access")
  private String getValue(HSSFCell hssfCell) {
    if (hssfCell.getCellType() == hssfCell.CELL_TYPE_BOOLEAN) {
      // 返回布尔类型的值
      return String.valueOf(hssfCell.getBooleanCellValue());
    } else if (hssfCell.getCellType() == hssfCell.CELL_TYPE_NUMERIC) {
      // 返回数值类型的值
      return String.valueOf(hssfCell.getNumericCellValue());
    } else {
      // 返回字符串类型的值
      return String.valueOf(hssfCell.getStringCellValue());
    }
  }
 
}

//该类主要负责向Excel(2003版)中插入数据

import java.io.FileOutputStream;
import java.io.OutputStream;
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 XlsDto2Excel {
 
  /**
   * 
   * @param xls
   *      XlsDto实体类的一个对象
   * @throws Exception
   *       在导入Excel的过程中抛出异常
   */
  public static void xlsDto2Excel(List<XlsDto> xls) throws Exception {
    // 获取总列数
    int CountColumnNum = xls.size();
    // 创建Excel文档
    HSSFWorkbook hwb = new HSSFWorkbook();
    XlsDto xlsDto = null;
    // sheet 对应一个工作页
    HSSFSheet sheet = hwb.createSheet("pldrxkxxmb");
    HSSFRow firstrow = sheet.createRow(0); // 下标为0的行开始
    HSSFCell[] firstcell = new HSSFCell[CountColumnNum];
    String[] names = new String[CountColumnNum];
    names[0] = "学号";
    names[1] = "姓名";
    names[2] = "学院";
    names[3] = "课程名";
    names[4] = "成绩";
    for (int j = 0; j < CountColumnNum; j++) {
      firstcell[j] = firstrow.createCell(j);
      firstcell[j].setCellValue(new HSSFRichTextString(names[j]));
    }
    for (int i = 0; i < xls.size(); i++) {
      // 创建一行
      HSSFRow row = sheet.createRow(i + 1);
      // 得到要插入的每一条记录
      xlsDto = xls.get(i);
      for (int colu = 0; colu <= 4; colu++) {
        // 在一行内循环
        HSSFCell xh = row.createCell(0);
        xh.setCellValue(xlsDto.getXh());
        HSSFCell xm = row.createCell(1);
        xm.setCellValue(xlsDto.getXm());
        HSSFCell yxsmc = row.createCell(2);
        yxsmc.setCellValue(xlsDto.getYxsmc());
        HSSFCell kcm = row.createCell(3);
        kcm.setCellValue(xlsDto.getKcm());
        HSSFCell cj = row.createCell(4);
        cj.setCellValue(xlsDto.getCj());
(xlsDto.getMessage());
      }
    }
    // 创建文件输出流，准备输出电子表格
    OutputStream out = new FileOutputStream("POI2Excel/pldrxkxxmb.xls");
    hwb.write(out);
    out.close();
    System.out.println("数据库导出成功");
  }
 
}
 

//该类是一个实体类

public class XlsDto {
  /**
   * 选课号
   */
  private Integer xkh;
  /**
   * 学号
   */
  private String xh;
  /**
   * 姓名
   */
  private String xm;
  /**
   * 学院
   */
  private String yxsmc;
  /**
   * 课程号
   */
  private Integer kch;
  /**
   * 课程名
   */
  private String kcm;
  /**
   * 成绩
   */
  private float cj;
  public Integer getXkh() {
    return xkh;
  }
  public void setXkh(Integer xkh) {
    this.xkh = xkh;
  }
  public String getXh() {
    return xh;
  }
  public void setXh(String xh) {
    this.xh = xh;
  }
  public String getXm() {
    return xm;
  }
  public void setXm(String xm) {
    this.xm = xm;
  }
  public String getYxsmc() {
    return yxsmc;
  }
  public void setYxsmc(String yxsmc) {
    this.yxsmc = yxsmc;
  }
  public Integer getKch() {
    return kch;
  }
  public void setKch(Integer kch) {
    this.kch = kch;
  }
  public String getKcm() {
    return kcm;
  }
  public void setKcm(String kcm) {
    this.kcm = kcm;
  }
  public float getCj() {
    return cj;
  }
  public void setCj(float cj) {
    this.cj = cj;
  }
   
}