Question

我是java的初学者，我不知道为什么我会收到此错误。
我使用的是Excel 2007

    Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/poi/UnsupportedFileFormatException
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
        at com.ExcelRead.SimpleExcelWriterExample.main(SimpleExcelWriterExample.java:15)
    Caused by: java.lang.ClassNotFoundException: org.apache.poi.UnsupportedFileFormatException
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
        ... 13 more

这是我的代码：

    package com.ExcelRead;

    import java.io.FileOutputStream;
    import java.io.IOException;

    import org.apache.poi.ss.usermodel.Cell;
    import org.apache.poi.ss.usermodel.Row;
    import org.apache.poi.xssf.usermodel.XSSFSheet;
    import org.apache.poi.xssf.usermodel.XSSFWorkbook;

    public class SimpleExcelWriterExample {


        public static void main(String[] args) throws IOException {
            XSSFWorkbook workbook = new XSSFWorkbook();
            XSSFSheet sheet = workbook.createSheet("Java Books");

            Object[][] bookData = {
                    {"Head First Java", "Kathy Serria", 79},
                    {"Effective Java", "Joshua Bloch", 36},
                    {"Clean Code", "Robert martin", 42},
                    {"Thinking in Java", "Bruce Eckel", 35},
            };

            System.out.println("array created");
            int rowCount = 0;

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

                int columnCount = 0;

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

            }
            System.out.println("inserted in bookData.");


            try (FileOutputStream outputStream = new FileOutputStream("JavaBooks.xlsx")) {

                System.out.println("JavaBooks................");
                workbook.write(outputStream);
            }
        }

    }



  ________________________________________________________________________________

我还添加了poi jar并且还构建了路径，这是pom.xml文件：

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>

        <groupId>com</groupId>
        <artifactId>ExcelRead</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>

        <name>ExcelRead</name>
        <url>http://maven.apache.org</url>

        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        </properties>

        <dependencies>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>3.8.1</version>
                <scope>test</scope>
            </dependency>

            <dependency>
                <groupId>org.apache.poi</groupId>
                <artifactId>poi</artifactId>
                <version>3.7</version>
            </dependency>


            <dependency>
                <groupId>org.apache.poi</groupId>
                <artifactId>poi-ooxml</artifactId>
                <version>3.13</version>
            </dependency>


            <dependency>
                <groupId>stax</groupId>
                <artifactId>stax-api</artifactId>
                <version>1.0</version>
            </dependency>


        </dependencies>
    </project>

有人可以帮我解决这个问题。我已经搜索了这个错误我发现缺少罐子的原因，但我已经检查过，罐子已成功下载。

Answer 1

您正在使用不同版本的POI部分。你应该让它们匹配。

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.7</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.13</version>
        </dependency>

线程＆＃34; main＆＃34;中的例外情况java.lang.NoClassDefFoundError：

1 个答案: