ExayExcel 阿里出品的ExayExcel

1.首先引入依赖

<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>easyexcel</artifactId>
			<version>1.1.2-beta5</version>
		</dependency>

2.创建ExcelModelListener

public class ExcelModelListener<T extends BaseRowModel> extends AnalysisEventListener<T> {
    private final List<T> rows = new ArrayList<>();

    @Override
    public void invoke(T object, AnalysisContext context) {
        rows.add(object);
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {
        System.out.println(rows.size());
    }

    public List<T> getRows() {
        return rows;
    }
}

3. 创建个util工具类，写一些公共方法

public class EsayExcelUtils {

    /**
     * 从Excel中读取文件，读取的文件是一个DTO类，该类必须继承BaseRowModel
     * 具体实例参考 ： OperationLog.java
     * 参考：https://github.com/alibaba/easyexcel
     */
    public static <T extends BaseRowModel> List<T> readExcel(final InputStream inputStream, final Class<? extends BaseRowModel> clazz) {
        if (null == inputStream) {
            throw new NullPointerException("the inputStream is null!");
        }
        ExcelModelListener<T> listener = new ExcelModelListener<>();
        // 这里因为EasyExcel-1.1.1版本的bug，所以需要选用下面这个标记已经过期的版本
        ExcelReader reader = new ExcelReader(inputStream,  valueOf(inputStream), null, listener);
        reader.read(new Sheet(1, 1, clazz));

        return listener.getRows();
    }


    public static void writeExcel(final File file, List<? extends BaseRowModel> list,ExcelTypeEnum fileType) {
        try (OutputStream out = new FileOutputStream(file)) {
            ExcelWriter writer = new ExcelWriter(out, fileType);
            //写第一个sheet,  有模型映射关系
            Class<? extends BaseRowModel> t = list.get(0).getClass();
            Sheet sheet = new Sheet(1, 0, t);
            writer.write(list, sheet);
            writer.finish();
        } catch (IOException e) {
            System.out.println(file.getName()+e);
        }
    }


    /**
     * 根据输入流，判断为xls还是xlsx，该方法原本存在于easyexcel 1.1.0 的ExcelTypeEnum中。
     */
    public static ExcelTypeEnum valueOf(InputStream inputStream) {
        try {
            FileMagic fileMagic = FileMagic.valueOf(inputStream);
            if (FileMagic.OLE2.equals(fileMagic)) {
                return ExcelTypeEnum.XLS;
            }
            if (FileMagic.OOXML.equals(fileMagic)) {
                return ExcelTypeEnum.XLSX;
            }
            throw new IllegalArgumentException("excelTypeEnum can not null");

        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

4.新增实体类，记得要getset方法

public class ExcelBean extends BaseRowModel {

    @ExcelProperty(value = "姓名",index = 0)
    private String name;

    @ExcelProperty(value = "年龄",index = 1)
    private String age;

    @ExcelProperty(value = "E-mail",index = 2)
    private String email;

    public ExcelBean(String name, String age, String email) {
        this.name = name;
        this.age = age;
        this.email = email;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

4.写个方法试一下

public static void main(String[] args) throws FileNotFoundException {
        //File file = new File("C:\\Users\\123\\Desktop\\新建XLSX工作表.xlsx");
        //InputStream fs = new FileInputStream(file);
        //读取
        //List<BaseRowModel> baseRowModels = EsayExcelUtils.readExcel(fs, ExcelBean.class);
        //写入
        List<ExcelBean> baseRowModels = new ArrayList<ExcelBean>();
        ExcelBean excelBean1 = new ExcelBean("老黑","82","lao_hei@163.com");
        ExcelBean excelBean2 = new ExcelBean("小黑","16","xiao_hei@163.com");
        baseRowModels.add(excelBean1);
        baseRowModels.add(excelBean2);
        EsayExcelUtils.writeExcel(new File("E:\\新建.xlsx"),baseRowModels, ExcelTypeEnum.XLSX);
    }