Apache POI-Giving NoclassDefError

Question

    public static void main(String [] args){
        String excelFilePath = "D:\\JavaBooks.xls";

        try {
            FileInputStream inputStream = new FileInputStream(new File(excelFilePath));
            Workbook workbook = WorkbookFactory.create(inputStream);

            Sheet sheet = workbook.getSheetAt(0);

            Object[][] bookData = {
                    {"The Passionate Programmer", "Chad Fowler", 16},
                    {"Software Craftmanship", "Pete McBreen", 26},
                    {"The Art of Agile Development", "James Shore", 32},
                    {"Continuous Delivery", "Jez Humble", 41},
            };

            int rowCount = sheet.getLastRowNum();

            for (Object[] aBook : bookData) {
                Row row = sheet.createRow(++rowCount);

                int columnCount = 0;

                Cell cell = row.createCell(columnCount);
                cell.setCellValue(rowCount);

                for (Object field : aBook) {
                    cell = row.createCell(++columnCount);
                    if (field instanceof String) {
                        cell.setCellValue((String) field);
                    } else if (field instanceof Integer) {
                        cell.setCellValue((Integer) field);
                    }
                }

            }

            inputStream.close();

            FileOutputStream outputStream = new FileOutputStream("D:\\JavaBooks.xls");
            workbook.write(outputStream);
            workbook.close();
            outputStream.close();

        } catch (IOException | EncryptedDocumentException
                ex) {
            ex.printStackTrace();
        }
    }

}

执行此代码时出现错误线程“主”中的异常java.lang.NoClassDefFoundError：org / apache / commons / math3 / util / ArithmeticUtils在org.apache.poi.poifs.property.RootProperty.setSize（RootProperty.java:59）在org.apache.poi.poifs.property.DirectoryProperty（DirectoryProperty.java:52）在org.apache.poi.poifs.property.RootProperty（RootProperty.java:31）在org.apache.poi.poifs.property.PropertyTable。（PropertyTable.java:58）在org.apache.poi.poifs.filesystem.POIFSFileSystem。（POIFSFileSystem.java:102）在org.apache.poi.poifs.filesystem.POIFSFileSystem。（POIFSFileSystem.java:274）在org.apache.poi.ss.usermodel.WorkbookFactory.create（WorkbookFactory.java:252）在org.apache.poi.ss.usermodel.WorkbookFactory.create（WorkbookFactory.java:221）在NewClass.main（NewClass.java:31）引起原因：java.lang.ClassNotFoundException：org.apache.commons.math3.util.ArithmeticUtils在java.net.URLClassLoader.findClass（URLClassLoader.java:381）在java.lang.ClassLoader.loadClass（ClassLoader.java:424）在sun.misc.Launcher $ AppClassLoader.loadClass（Launcher.java:335）在java.lang.ClassLoader.loadClass（ClassLoader.java:357）...另外9个

Answer 1

将Apache Commons数学添加到您的依赖项。

例如在Maven中：

<dependency>
  <groupId>org.apache.commons</groupId>
  <artifactId>commons-math3</artifactId>
  <version>3.6.1</version>
</dependency>

此处有更多选项：https://mvnrepository.com/artifact/org.apache.commons/commons-math3/3.6.1

有关ClassNotFoundErrors的更多信息，可以在这里找到Why am I getting a NoClassDefFoundError in Java?