POI学习

 package poi;

import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Iterator;

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;

public class POIExcelReader {

/**
 * 读Excel文件的例子
 * @param args
 * @throws Exception
 * date:20080129
 */ 
 
 public static void main(String[] args) throws Exception {
  
  //以Excel文件创建文件输入流
  InputStream myxls = new FileInputStream("src/poi/name.xls");
  //以文件输入流创建文档对象
  HSSFWorkbook wb = new HSSFWorkbook(myxls);
  
  //获取第一张工作表
  HSSFSheet sheet = wb.getSheetAt(0);
  
  //遍历工作表的第一行
  Iterator it = sheet.rowIterator();
  
  while(it.hasNext()){
   
   HSSFRow row = (HSSFRow)it.next();
   
//   for(short i=0; i<3 ; i++){
//    HSSFCell cell = row.getCell(i);  //这里getCell的参数要求是short型的
//    if(cell.getCellType()== HSSFCell.CELL_TYPE_STRING){
//     System.out.println("单元格是字符串，值是:"+cell.getRichStringCellValue().getString());
//    }
//    else if(cell.getCellType()==HSSFCell.CELL_TYPE_NUMERIC){
//     System.out.println("单元格是数字，值是:"+cell.getNumericCellValue());
//    }else{
//     System.out.println("单元格的值不是字符串或数值!");
//    }
//    
//   }
   
      //遍历行的第一列(上面的用直接设置i也可以)
   Iterator cellIt = row.cellIterator();
   while(cellIt.hasNext()){
    HSSFCell cell = (HSSFCell)cellIt.next();
    
    //在读取单元值之前，先获取单元格的数据类型
    if(cell.getCellType()== HSSFCell.CELL_TYPE_STRING){
     System.out.println("单元格是字符串，值是:"+cell.getRichStringCellValue().getString());
    }
    else if(cell.getCellType()==HSSFCell.CELL_TYPE_NUMERIC){
     System.out.println("单元格是数字，值是:"+cell.getNumericCellValue());
    }else{
     System.out.println("单元格的值不是字符串或数值!");
    }
   }
  }
  

 }

}

创建Excel文档

package poi;

import java.io.FileOutputStream;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

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 MySqlExcel {

 /**
  * 创建Excel文档
  * @param args
  */
 
 public MySqlExcel() throws Exception{
  Connection conn = null;
  Statement stmt = null;
  ResultSet rs = null;
  Class.forName("com.mysql.jdbc.Driver");
  String url = "jdbc:mysql://localhost/test";
  conn = DriverManager.getConnection(url,"root","admin");
  
  HSSFWorkbook wb = new HSSFWorkbook();
  
  HSSFSheet sheet = wb.createSheet("sheet1");
  
  stmt = conn.createStatement();
  String sql = "select * from userinfo";
  
  rs = stmt.executeQuery(sql);
  short i = 0;
  
  while(rs.next()){
   //创建电子表格的一行
   HSSFRow row = sheet.createRow(i);
   
   for(short j=1; j<4 ; j++){
    HSSFCell cell = row.createCell((short)(j-1));
    
    HSSFRichTextString strCell = new HSSFRichTextString(rs.getString(j));;
    cell.setCellValue(strCell);
    
    
   }
   
   i++;
  }
  
  OutputStream out = new FileOutputStream("src/poi/导出的电子表格.xls");
  wb.write(out);
  out.close();
  System.out.println("从数据库中导出成功");
  rs.close();
  stmt.close();
  conn.close();
  
  
 }
   
 
 public static void main(String[] args) throws Exception {
  
         new MySqlExcel();
 }

}