POI导出EXCEL

package common;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

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

public class Test {
//工作簿名称,可以取中文(就是另存为名称).
public static String outputFile="D:/test.xls";
/**
* @param args
*/
public static void main(String[] args) {
try {
File objFile = new File(outputFile);
HSSFWorkbook workbook = null;
HSSFSheet sheet = null;
HSSFRow row = null;
HSSFCell cell = null;
String table_name = "sheet";
//创建文件
if(!objFile.exists()){   //文件不存在
//创建新的Excel 工作簿
workbook = new HSSFWorkbook();
//在Excel工作簿中建一工作表，其名为缺省值
sheet = workbook.createSheet(table_name);
row = sheet.createRow((short)0);
cell = row.createCell((short)0);
cell.setCellValue("扫描件id");
row = sheet.createRow((short)0);
cell = row.createCell((short)1);
cell.setCellValue("是否入库");
for(int i=1;i<5;i++){
for(int j=0;j<2;j++){
row = sheet.createRow((short)i);
cell = row.createCell((short)j);
cell.setCellType(HSSFCell.CELL_TYPE_STRING);
//指定编码格式
cell.setEncoding(HSSFCell.ENCODING_UTF_16);
if(j==0){
cell.setCellValue(i);
}else{
cell.setCellValue("bb");
}
}
}
}else{
workbook = new HSSFWorkbook(new FileInputStream(outputFile));
sheet = workbook.getSheet(table_name);
//这儿,你可以测试读出一个已存在文件
//HSSFRow row = sheet.getRow(i);
//HSSFCell cell = row.getCell((short)j);
//输出单元内容，cell.getStringCellValue()就是取所在单元的值
//System.out.println("左上端单元是： " + cell.getStringCellValue());
for(int i=5;i<9;i++){
for(int j=0;j<2;j++){
row = sheet.createRow((short)i);
cell = row.createCell((short)j);
if(j==0){
cell.setCellValue(i);
}else{
cell.setCellValue("bb");
}
}
}
}
FileOutputStream fOut = new FileOutputStream(outputFile);
//把相应的Excel 工作簿存盘
workbook.write(fOut);
fOut.flush();
// 操作结束，关闭文件
fOut.close();
}catch (Exception e) {
System.out.println(e.getMessage());
}
}

}