在 Java 中读取属性文件时出现 NullPointerException [英] NullPointerException when reading a properties file in Java

问题描述

我正在使用以下代码读取属性文件:

I am using the following code to read a properties file:

Properties pro = new Properties();
InputStream is = Thread.currentThread().getContextClassLoader().
    getResourceAsStream("resources.properties");

pro.load(is);

当我执行代码时，我收到以下错误:

And when I execute the code I'm getting the following error:

Exception in thread "main" java.lang.NullPointerException
  at java.util.Properties$LineReader.readLine(Properties.java:418)
  at java.util.Properties.load0(Properties.java:337)
  at java.util.Properties.load(Properties.java:325)
  at com.ibm.rqm.integration.RQMUrlUtility.RQMRestClient.getResource(RQMRestClient.java:66)
  at com.ibm.rqm.integration.RQMUrlUtility.RQMRestClient.main(RQMRestClient.java:50)

为什么我会收到 NullPointerException?我应该在哪里保存 resources.properties 文件?

Why am I getting a NullPointerException? And where should I save the resources.properties file?

推荐答案

看起来像 ClassLoader.getResourceAsStream(String name) 返回 null，然后导致 Properties.load 抛出 NullPointerException.

It looks like ClassLoader.getResourceAsStream(String name) returns null, which then causes Properties.load to throw NullPointerException.

以下是文档摘录:

URL getResource(String name):查找具有给定名称的资源.资源是一些数据(图像、音频、文本等)，可以通过类代码以独立于代码位置的方式访问.

URL getResource(String name): Finds the resource with the given name. A resource is some data (images, audio, text, etc) that can be accessed by class code in a way that is independent of the location of the code.

资源的名称是一个以 '/' 分隔的路径名，用于标识资源.

The name of a resource is a '/'-separated path name that identifies the resource.

返回:一个用于读取资源的URL对象，或者null如果:

Returns: A URL object for reading the resource, or null if:

• 找不到资源，或
• 调用者没有足够的权限来获取资源.

另见

• Java 教程/使用 getResource 加载图像
  • 有示例说明在目录/JAR 文件中的何处/如何放置和访问资源

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