import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.InputStream;import java.io.OutputStream;import java.util.ArrayList;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;public class ExcelOperate {  public static void main(String[] args) {    // 创建Excel表格    createExcel(getStudent());    // 读取Excel表格    List<Student> list = readExcel();    System.out.println(list.toString());  }  /**   * 初始化数据   *    * @return 数据   */  private static List<Student> getStudent() {    List<Student> list = new ArrayList<Student>();    Student student1 = new Student("小明", 8, "二年级");    Student student2 = new Student("小光", 9, "三年级");    Student student3 = new Student("小花", 10, "四年级");    list.add(student1);    list.add(student2);    list.add(student3);    return list;  }  /**   * 创建Excel   *    * @param list   *      数据   */  private static void createExcel(List<Student> list) {    // 创建一个Excel文件    HSSFWorkbook workbook = new HSSFWorkbook();    // 创建一个工作表    HSSFSheet sheet = workbook.createSheet("学生表一");    // 添加表头行    HSSFRow hssfRow = sheet.createRow(0);    // 设置单元格格式居中    HSSFCellStyle cellStyle = workbook.createCellStyle();    cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);    // 添加表头内容    HSSFCell headCell = hssfRow.createCell(0);    headCell.setCellValue("姓名");    headCell.setCellStyle(cellStyle);    headCell = hssfRow.createCell(1);    headCell.setCellValue("年龄");    headCell.setCellStyle(cellStyle);    headCell = hssfRow.createCell(2);    headCell.setCellValue("年级");    headCell.setCellStyle(cellStyle);    // 添加数据内容    for (int i = 0; i < list.size(); i++) {      hssfRow = sheet.createRow((int) i + 1);      Student student = list.get(i);      // 创建单元格，并设置值      HSSFCell cell = hssfRow.createCell(0);      cell.setCellValue(student.getName());      cell.setCellStyle(cellStyle);      cell = hssfRow.createCell(1);      cell.setCellValue(student.getAge());      cell.setCellStyle(cellStyle);      cell = hssfRow.createCell(2);      cell.setCellValue(student.getGrade());      cell.setCellStyle(cellStyle);    }    // 保存Excel文件    try {      OutputStream outputStream = new FileOutputStream("D:/students.xls");      workbook.write(outputStream);      outputStream.close();    } catch (Exception e) {      e.printStackTrace();    }  }  /**   * 读取Excel   *    * @return 数据集合   */  private static List<Student> readExcel() {    List<Student> list = new ArrayList<Student>();    HSSFWorkbook workbook = null;    try {      // 读取Excel文件      InputStream inputStream = new FileInputStream("D:/students.xls");      workbook = new HSSFWorkbook(inputStream);      inputStream.close();    } catch (Exception e) {      e.printStackTrace();    }    // 循环工作表    for (int numSheet = 0; numSheet < workbook.getNumberOfSheets(); numSheet++) {      HSSFSheet hssfSheet = workbook.getSheetAt(numSheet);      if (hssfSheet == null) {        continue;      }      // 循环行      for (int rowNum = 1; rowNum <= hssfSheet.getLastRowNum(); rowNum++) {        HSSFRow hssfRow = hssfSheet.getRow(rowNum);        if (hssfRow == null) {          continue;        }        // 将单元格中的内容存入集合        Student student = new Student();        HSSFCell cell = hssfRow.getCell(0);        if (cell == null) {          continue;        }        student.setName(cell.getStringCellValue());        cell = hssfRow.getCell(1);        if (cell == null) {          continue;        }        student.setAge((int) cell.getNumericCellValue());        cell = hssfRow.getCell(2);        if (cell == null) {          continue;        }        student.setGrade(cell.getStringCellValue());        list.add(student);      }    }    return list;  }}

public class Student {  private String name;  private int age;  private String grade;  public Student() {  }  public Student(String name, int age, String grade) {    super();    this.name = name;    this.age = age;    this.grade = grade;  }  public String getName() {    return name;  }  public void setName(String name) {    this.name = name;  }  public int getAge() {    return age;  }  public void setAge(int age) {    this.age = age;  }  public String getGrade() {    return grade;  }  public void setGrade(String grade) {    this.grade = grade;  }  @Override  public String toString() {    return "Student [name=" + name + ", age=" + age + ", grade=" + grade        + "]";  }}

[Student [name=小明, age=8, grade=二年级], Student [name=小光, age=9, grade=三年级], Student [name=小花, age=10, grade=四年级]]