Notes when saving files in Java

When I first started learning Java, I found that many programmers often make a mistake. When they save a Java file, they often save the file name, for example, * .java.txt, and the file name looks like :*. java. This is caused by the default settings of Windows. By default, Windows will "Hide extensions of known file types ". To avoid this problem, we recommend that you disable the "Hide extensions of known file types" function in Windows.
To disable the "Hide extensions of known file types" function, open the "tool" menu in any file area of Windows (the resource manager can also, click Folder Options in the tool menu... "menu items. The" Folder Options "dialog box is displayed. Click the" View "Tab page in the dialog box. Dialog Box:

, Remove the hook before the "Hide file type extension" option, so that all files can be displayed with real file names, so as to avoid errors such as HelloWorld.java.txt.