Usage of getResourceAsStream in Java

first, there are several getresourceasstream in Java:
1. Class.getresourceasstream (String Path): path does not start with '/' by default, the resource is fetched from the package where the class is located, and the '/' begins with the classpath root. It only constructs an absolute path through path, and eventually it gets the resources from the ClassLoader.

2. Class.getClassLoader.getResourceAsStream (String path): The default is obtained from the classpath root, path cannot start with '/', and eventually the resource is obtained by ClassLoader.

3. ServletContext. getResourceAsStream (String path): The default is to fetch resources from the WebApp root directory, and whether or not Tomcat starts with '/' does not matter, of course, this is related to the specific container implementation.

4. The application built-in object under JSP is an implementation of the above ServletContext.

Second, getResourceAsStream usage is roughly the following:

First: The file to be loaded and the. class file are in the same directory, for example: Com.x.y has a class me.class, and a resource file Myfile.xml

Then, you should have the following code:

Me.class.getResourceAsStream ("Myfile.xml");

Second: In the subdirectory of the Me.class directory, for example: Com.x.y under the class Me.class, while the Com.x.y.file directory has a resource file Myfile.xml

Then, you should have the following code:

Me.class.getResourceAsStream ("File/myfile.xml");

Third: Not under the Me.class directory, also not under the subdirectory, for example: Com.x.y under the class Me.class, while in the Com.x.file directory has a resource file Myfile.xml

Then, you should have the following code:

Me.class.getResourceAsStream ("/com/x/file/myfile.xml");

To summarize, maybe it's just two ways of writing

First: There is "/" in front

"/" represents the root of the project, such as the project name MyProject, "/" represents the MyProject

Me.class.getResourceAsStream ("/com/x/file/myfile.xml");

Second: There is no "/" in front

Directory representing the current class

Me.class.getResourceAsStream ("Myfile.xml");

Me.class.getResourceAsStream ("File/myfile.xml");

Finally, your own understanding:
The file path read by getResourceAsStream is limited to the source folder of the project, included in the project SRC root directory, and anywhere within the class package, but this method is not available if the profile path is in a folder other than the source folder.

Usage of getResourceAsStream in Java