PDFBox - PDFBox 加载 PDF 异常清单（数据为 null、数据为空、数据异常、文件为 null、文件不存在、文件异常）

一、数据为 null

java 复制代码

private static byte[] getData() {
    return null;
}

java 复制代码

byte[] data = getData();

try (PDDocument document = PDDocument.load(data)) {

} catch (IOException e) {
    e.printStackTrace();
}

异常未被捕获，目标捕获的异常是 IOException，实际的异常是 NullPointerException，输出结果如下

Exception in thread "main" java.lang.NullPointerException: Cannot read the array length because "input" is null

二、数据为空

java 复制代码

private static byte[] getData() {
    return new byte[0];
}

java 复制代码

byte[] data = getData();

try (PDDocument document = PDDocument.load(data)) {

} catch (IOException e) {
    e.printStackTrace();
}

异常被捕获，输出结果如下

java.io.IOException: Error: End-of-File, expected line at offset 0

三、数据异常（PDF 文件损坏）

java 复制代码

private static byte[] getData() {
    try {
        File pdfFile = new File("pdf/example.pdf");

        InputStream pdfInputStream = new FileInputStream(pdfFile);

        ByteArrayOutputStream pdfBuffer = new ByteArrayOutputStream();
        int nRead;
        byte[] data = new byte[1024];
        while ((nRead = pdfInputStream.read(data, 0, data.length)) != -1) {
            pdfBuffer.write(data, 0, nRead);
        }

        byte[] bytes = pdfBuffer.toByteArray();

        for (int i = 0; i < 100; i++) {
            bytes[i] = (byte) (bytes[i] + 1);
        }

        return bytes;
    } catch (IOException e) {
        e.printStackTrace();
    }

    return null;
}

java 复制代码

byte[] data = getData();

try (PDDocument document = PDDocument.load(data)) {

} catch (IOException e) {
    e.printStackTrace();
}

异常被捕获，输出结果如下

java.io.IOException: Error: Header doesn't contain versioninfo

四、数据异常（非 PDF 文件）

java 复制代码

private static byte[] getData() {
    try {
        File pdfFile = new File("image/test.jpeg");

        InputStream pdfInputStream = new FileInputStream(pdfFile);

        ByteArrayOutputStream pdfBuffer = new ByteArrayOutputStream();
        int nRead;
        byte[] data = new byte[1024];
        while ((nRead = pdfInputStream.read(data, 0, data.length)) != -1) {
            pdfBuffer.write(data, 0, nRead);
        }

        byte[] bytes = pdfBuffer.toByteArray();

        for (int i = 0; i < 100; i++) {
            bytes[i] = (byte) (bytes[i] + 1);
        }

        return bytes;
    } catch (IOException e) {
        e.printStackTrace();
    }

    return null;
}

java 复制代码

byte[] data = getData();

try (PDDocument document = PDDocument.load(data)) {

} catch (IOException e) {
    e.printStackTrace();
}

复制代码

java.io.IOException: Error: Header doesn't contain versioninfo

五、文件为 null

java 复制代码

private static File getFile() {
    return null;
}

java 复制代码

File file = getFile();

try (PDDocument document = PDDocument.load(file)) {

} catch (IOException e) {
    e.printStackTrace();
}

System.out.println("next");

异常未被捕获，目标捕获的异常是 IOException，实际的异常是 NullPointerException，输出结果如下

Exception in thread "main" java.lang.NullPointerException

六、文件不存在

java 复制代码

private static File getFile() {
    return new File("pdf/test123.pdf");
}

java 复制代码

File file = getFile();

try (PDDocument document = PDDocument.load(file)) {

} catch (IOException e) {
    e.printStackTrace();
}

System.out.println("next");

异常被捕获，输出结果如下

java.io.FileNotFoundException: pdf\test123.pdf (系统找不到指定的文件。)

七、文件异常（非 PDF 文件）

java 复制代码

private static File getFile() {
    return new File("image/test.jpeg");
}

java 复制代码

File file = getFile();

try (PDDocument document = PDDocument.load(file)) {

} catch (IOException e) {
    e.printStackTrace();
}

System.out.println("next");

异常被捕获，输出结果如下

java.io.IOException: Error: Header doesn't contain versioninfo