Java 使用POI实现Excel表格的导入导出

1.介绍

最近的项目需要导出数据到Excel表格里，写个Demo测试一下，还是比较简单的，写在博客里记录下来，分享给童鞋们。

需要导入POI.jar包，下载地址：http://download.csdn.net/detail/kong_gu_you_lan/9652468

2.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



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]]

4.写在最后

Demo和POI.jar下载地址：http://download.csdn.net/detail/kong_gu_you_lan/9652468

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