Java 分析时发生InputStream异常

我从客户机获得一个HttpservletRequest，我正在尝试解析该请求（使用JAXB、DOM）。为此，我使用以下代码

String str_request = IOUtils.toString(request.getInputStream());
System.out.println("String is " + str_request);
requestStream = new ByteArrayInputStream(str_request.getBytes());

我的问题是，当我将requestStream传递给我的解析器方法时，一个方法工作正常，但另一个失败。我猜inputStream有问题，但我无法解决这个问题。有谁能提出解决这个问题的办法吗

Dom解析器方法：

public String parseMethodName(InputStream request) throws SAXException,
                                                          IOException,
                                                          ParserConfigurationException {

    System.out.println("in parseMethodName");
    DocumentBuilderFactory dbFactory =
        DocumentBuilderFactory.newInstance();
    DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
    System.out.println("bfor parse");
    Document doc = dBuilder.parse(request);
    System.out.println("After parse");
    methodName =
            doc.getElementsByTagName("methodName").item(0).getTextContent();
}

System.out.println("in parse ******");
JAXBContext context = JAXBContext.newInstance(MethodCall.class);
System.out.println("bfor unmarshall ****");
Unmarshaller um = context.createUnmarshaller();
System.out.println("After unmarshall ****");
mc = (MethodCall) um.unmarshal(is);

JAXB解析器方法：

public String parseMethodName(InputStream request) throws SAXException,
                                                          IOException,
                                                          ParserConfigurationException {

    System.out.println("in parseMethodName");
    DocumentBuilderFactory dbFactory =
        DocumentBuilderFactory.newInstance();
    DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
    System.out.println("bfor parse");
    Document doc = dBuilder.parse(request);
    System.out.println("After parse");
    methodName =
            doc.getElementsByTagName("methodName").item(0).getTextContent();
}

System.out.println("in parse ******");
JAXBContext context = JAXBContext.newInstance(MethodCall.class);
System.out.println("bfor unmarshall ****");
Unmarshaller um = context.createUnmarshaller();
System.out.println("After unmarshall ****");
mc = (MethodCall) um.unmarshal(is);

我得到以下例外情况：

javax.xml.bind.UnmarshalException
 - with linked exception:
[org.xml.sax.SAXParseException: Premature end of file.]
        at javax.xml.bind.helpers.AbstractUnmarshallerImpl.createUnmarshalException(AbstractUnmarshallerImpl.java:315)
        at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.createUnmarshalException(UnmarshallerImpl.java:481)
        at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:199)
        at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:168)
        at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:137)
        at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:184)

---

您不应该将输入流转换为字符串，然后再转换回字节数组。这只是要求丢失数据，特别是当您在将字符串转换为字节数组时使用平台默认编码时

查看您使用的

IOUtils

类是否包含将

InputStream

完全读取到

字节[]

的方法，并将其用作

ByteArrayInputStream

的基础

请注意，如果要多次读取数据，则需要重置流，或者围绕同一字节数组创建一个新流