Java利用POI实现导入导出Excel表格示例代码

介绍

jakarta poi 是一套用于访问微软格式文档的java api。jakarta poi有很多组件组成，其中有用于操作excel格式文件的hssf和用于操作word的hwpf，在各种组件中目前只有用于操作excel的hssf相对成熟。官方主页http://poi.apache.org/index.html，api文档http://poi.apache.org/apidocs/index.html

实现

已经在代码中加入了完整的注释。

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;
  }
}

附上student类的代码

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
        + "]";
  }
}

测试结果

导出的excel表格

students

打印读取的excel数据

[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]]

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可以留言交流。