EasyExecl读取Execl数据

参考位置: https://www.jianshu.com/p/80505fb72493

0.execl数据结构

1.pom.xml文件

     com.alibaba
     easyexcel
     1.1.2-beta5

2.根据execl建立实体数据

@Data
public class DemoData extends BaseRowModel {

    @ExcelProperty(value = "序号", index = 0)
    private Integer id;

    @ExcelProperty(value = "名称", index = 1)
    private String  name;

    @ExcelProperty(value = "文本类型", index = 2)
    private String type;

    @ExcelProperty(value = "格式", index = 3)
    private String format;

    @ExcelProperty(value = "供应商", index = 4)
    private String cp;

    @ExcelProperty(value = "合同到期时间", index = 5)
    private String expireDate;

}

3.建立监听

@Slf4j
public class ExcelListener extends AnalysisEventListener {
    private final List rows = new ArrayList<>();

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

    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {
        log.info("read {} rows %n", rows.size());
    }

    public List getRows() {
        return rows;
    }
}

4.execl工具类

@Slf4j
public final class ExcelUtil {
    /**
     * 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 ： MemberMarketDto.java
     * 参考：https://github.com/alibaba/easyexcel
     * 字符流必须支持标记，FileInputStream 不支持标记，可以使用BufferedInputStream 代替
     * BufferedInputStream bis = new BufferedInputStream(new FileInputStream(...));
     */
    public static  List readExcel(final InputStream inputStream, final Class clazz) {
        if (null == inputStream) {
            throw new NullPointerException("the inputStream is null!");
        }
        ExcelListener listener = new ExcelListener<>();
        // 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);
        //读取Sheet1   从第2行开始读取
        reader.read(new com.alibaba.excel.metadata.Sheet(1, 2, clazz));

        return listener.getRows();
    }


    public static void writeExcel(final File file, List list) {
        try (OutputStream out = new FileOutputStream(file)) {
            ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX);
            //写第一个sheet,  有模型映射关系
            Class t = list.get(0).getClass();
            Sheet sheet = new Sheet(1, 0, t);
            writer.write(list, sheet);
            writer.finish();
        } catch (IOException e) {
            log.warn("fail to write to excel file: file[{}]", 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);
        }
    }
}

5.测试读取数据

public static void main(String[] args) {
        try (FileInputStream inputStream = new FileInputStream("C:\\Users\\Administrator\\Desktop\\demo.xls")) {
            List demoDataList = ExcelUtil.readExcel(new BufferedInputStream(inputStream), DemoData.class);
            System.out.println(demoDataList);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }