读取XML遇非预期文本时，应抛出哪种Java预定义异常？

Alright, let's break this down clearly. First, let's recap your scenario: your XML is well-formed and valid (so parsing itself isn't the issue), but it violates a specific business/conventional rule—you expect an <offset>nnnn</offset> element at a certain position, but something else is there instead.

The best predefined Java exception for this case is IllegalStateException, and here's why:

• This exception is designed to signal that the current state of the content you're processing doesn't match the expectations required to perform the intended operation. Since your XML is syntactically correct but semantically wrong (breaks your agreed-upon structure), this fits perfectly.
• It's more appropriate than alternatives like IllegalArgumentException because that exception targets invalid input parameters, not situations where the input is syntactically valid but fails a business/conventional check.
• You shouldn't use XML parsing exceptions like SAXException or ParserConfigurationException here—those are for when the XML is malformed or the parser setup is broken, which you've already ruled out.

Here's a quick code example to illustrate how you'd use it:

// Assume you've already navigated to the target node in your parsed XML
Node targetNode = ...;

// Check if the node is <offset> with numeric content
if (!"offset".equals(targetNode.getNodeName()) || !targetNode.getTextContent().matches("\\d+")) {
    String foundContent = String.format("<%s>%s</%s>", 
        targetNode.getNodeName(), targetNode.getTextContent(), targetNode.getNodeName());
    throw new IllegalStateException(
        String.format("Expected <offset>nnnn</offset> at the specified position, but found: %s", foundContent)
    );
}

If you wanted to add more specificity (though not strictly necessary), you could create a custom exception that extends IllegalStateException, but since the question asks for a predefined class, IllegalStateException is the top pick.

内容的提问来源于stack exchange，提问作者DodgyCodeException