Java JAXB unmarshaller链接异常

Question

public void xmlParser() {
    try {
        Acquirer acquirer = (Acquirer) readXml(Constants.XML_PATH);
        System.out.println(acquirer.getDate());
    } catch (JAXBException | IOException e) {
        e.printStackTrace();
    }
}

/**
 * Initializes of JAXB Context and Unmarshaller.
 */
private static void createContext() {
    try {
        jaxbContext = JAXBContext.newInstance("com.test.xml.generated");
        unmarshaller = jaxbContext.createUnmarshaller();
    } catch (JAXBException e) {
        e.printStackTrace();
    }
}

/**
 * This reads the XML file from the resources in ClassPath.
 *
 * @param xmlFile XML file name as String with relative ClassPath
 * @return Unmarashalled XML file
 * @throws JAXBException
 * @throws IOException
 * @throws Exception
 */
public Object readXml(String xmlFile) throws JAXBException, IOException {
    if (jaxbContext == null) {
        createContext();
    }

    InputStream stream = getClass().getClassLoader().getResourceAsStream(xmlFile);
    BufferedInputStream buffredStream = new BufferedInputStream(stream);

***Error:***
    Object obj = unmarshaller.unmarshal(buffredStream);
    buffredStream.close();
    stream.close();
    return obj;

 }

javax.xml.bind.UnmarshalException - with linked exception:
[java.io.IOException: Stream closed]
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:246)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:214)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:157)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:125)

constants.xml_path=“/acquirer.xml”；

Answer 1

只需更改：

InputStream stream = getClass().getClassLoader().getResourceAsStream(xmlFile);

在：

InputStream stream = getClass().getResourceAsStream(xmlFile);

因为当您使用getClass().getClassLoader().getResourceAsStream(xmlFile)时，它返回null（找不到资源），并且BufferedInputStream然后在向构造函数提供null而不是输入流实例时抛出IOException。