Java操作Excel

package action; import java.io.FileOutputStream; import java.text.SimpleDateFormat; import java.util.List; 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; import com.opensymphony.xwork2.ActionSupport; import entity.Student; public class ExcleAction extends ActionSupport { /** * */ private static final long serialVersionUID = 2305566757087929807L; private List<Student> students; private String na; public String getNa() { return na; } public void setNa(String na) { this.na = na; } public List<Student> getStudents() { return students; } public void setStudents(List<Student> students) { this.students = students; } @Override public String execute() throws Exception { System.out.println("----------------------------------" + students.size()); // 第一步，创建一个webbook，对应一个Excel文件 HSSFWorkbook wb = new HSSFWorkbook(); // 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet HSSFSheet sheet = wb.createSheet("学生表一"); // 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short HSSFRow row = sheet.createRow(0); // 第四步，创建单元格，并设置值表头 设置表头居中 HSSFCellStyle style = wb.createCellStyle(); style.setAlignment(HSSFCellStyle.ALIGN_CENTER); HSSFCell cell = row.createCell(0); cell.setCellValue("学号"); cell.setCellStyle(style); cell = row.createCell(1); cell.setCellValue("姓名"); cell.setCellStyle(style); cell = row.createCell(2); cell.setCellValue("年龄"); cell.setCellStyle(style); cell = row.createCell(3); cell.setCellValue("生日"); cell.setCellStyle(style); // 第五步，写入实体数据 实际应用中这些数据从数据库得到， for (int i = 0; i < students.size(); i++) { row = sheet.createRow((int) i + 1); Student stu = (Student) students.get(i); // 第四步，创建单元格，并设置值 row.createCell(0).setCellValue((double) stu.getId()); row.createCell(1).setCellValue(stu.getName()); row.createCell(2).setCellValue((double) stu.getAge()); cell = row.createCell(3); cell.setCellValue(new SimpleDateFormat("yyyy-mm-dd").format(stu.getBirth())); } // 第六步，将文件存到指定位置 try { FileOutputStream fout = new FileOutputStream("D:/students.xls"); wb.write(fout); fout.close(); } catch (Exception e) { e.printStackTrace(); } System.out.println("success....................."); return SUCCESS; } }