将XML相等的文件（空白除外）与xmlunit进行比较会产生差异

Question

使用xmlunit（版本2.6.0)比较两个XML文件，当它们应该被视为相等时，会产生差异。

XML 1：

<top><a>one</a><b>two</b></top>

<top>
  <a>one</a>
  <b>two</b>
</top>

DefaultNodeMatcher nodeMatcher = new DefaultNodeMatcher(ElementSelectors.byNameAndText);

Diff d = DiffBuilder.compare(xmlSource1)
            .withNodeMatcher(nodeMatcher)
            .withTest(xmlSource2).build();
    Iterable<Difference> diffList = d.getDifferences();
    Iterator<Difference> iterator = diffList.iterator();
    while(iterator.hasNext()) {
        Difference next = iterator.next();
        log.info("Difference: " + next);
    }

Difference: Expected child 'top' but was 'null' - comparing <top...> at /top[1] to <NULL> (DIFFERENT)
Difference: Expected child 'null' but was 'top' - comparing <NULL> to <top...> at /top[1] (DIFFERENT)

问：为什么他们被认为是不同的？如何通过忽略空格差异来进行这种比较？理想情况下，我希望.hasdifferences（）为false。

Answer 1

只需忽略空白空间（和注释）并检查差异中不包括相似性的地方（请参见checkforsalimal())：

Diff d = DiffBuilder.compare(xmlSource1).withTest(xmlSource2)
 .checkForSimilar()
 .withNodeMatcher(nodeMatcher)
 .ignoreWhitespace()
 .ignoreComments()
 .build();