新建項目沒有src/main/java 和 src/main/resources 兩個source文件的解決方法：
Step 1 : Create a Maven Webapp project. Right click on the Package Explorer pane go to New –> Maven Project
Step 2 : Select the archetype as “maven-archetype-webapp” and click on next and give the artifact id as “HelloWorld”.
Step 3 : After you create a maven web app project, you will be having the Web project created like below. Now we can that the HelloWorld Project doesn’t have src/main/java and src/test/java folders in it. It has only the src/main/resource folder.
Step 4 : Even when you try to create a new Source folder you will be getting the error like ” The Folder is already a source folder “.
Step 5 : Fixing this issue is very simple, Right Click on the project go to Properties. In that go to Build Path, you will be having an error like ” 2 build path entries are missing “
Step 6 : This error usually occurs where the JRE System Library is wrongly pointed. Now go to Libraries tab and change the JRE System Library to the correct version.
Step 7 : Once the JRE System Library is changed the issue should be resolved, all you need to do is to do an Update Project (Right on the Project –> Maven –> Update Project). Now you should have the src/main/java and src/test/java folders.
Happy Learning !! 🙂
來源：http://www.javainterviewpoint.com/missing-srcmainjava-folder-eclipse-maven/