问题描述
如何调试 - 失败的方法，返回null？
How do you debug getResource-style methods that are failing, returning null?
我确定它正在查找的文件是存在的，但它返回NULL。我怎么知道它试图找出任何不匹配的东西？
I am sure the file it's looking for is there, but it's returning NULL. How do I know what it is looking for to try to spot any mismatch?
推荐答案
因为 getResource（ ）搜索类路径（正如其他人提到的那样），在问题 getResource（）调用之前转储正在搜索的实际类路径可能会有所帮助：
Since getResource() searches the classpath (as others have mentioned), it might be helpful to dump the actual classpath being searched before your problemsome getResource() call:
log.debug("classpath is: " + System.getProperty("java.class.path"));
//the line that is returning null
... = Thread.currentThread().getContextClassLoader().getResource("foobar");
可能发生的事情是你认为在类路径上的文件/目录实际上不是（也许一路上某处设置了无效路径。）
What is probably happening is that the files/directories you think are on the classpath are actually not (perhaps an invalid path is being set somewhere along the way).
这篇关于调试getResource *的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！