What is reason for yellow exclamation mark ("!") in eclipse java project(package and classes)?

Question

Previously my project was in another machine. Then I added project into my new machine. After that I got error "error could not find or load main class". Then I remove JRE system library and again add. After that remove unused jar files and save the java build path. After that previous error removed and all code work finely. But every packages and classes from the beginning it shows yellow color exclamation mark. Doesn't give any error message. What is reason for that? How I remove it? Not red color. That's yellow color. (This happened to previously exist classes and packages. Not for newly creates classes)

![enter image description here][2]

Answer 1

Goto windows>showview>and select problems

This will show the details:

Answer 2

In Eclipse, these are often caused by Java compiler warnings, and can also be caused by various validation warnings (for XML files, JSP files, etc.)

To see the warning messages, go to Window => Show View => Problems.

This is a fairly comprehensive list from the Eclipse documentation. If anyone knows of another list — maybe with more details, or just the most common icons — feel free to add it.

Juno: JDT Icons

Indigo: JDT Icons

There are also some CDT icons at the bottom of this [help page][1].

If you're a Subversion user, the icons you're looking for may actually belong to Subclipse; see [this excellent answer]:What do the arrow icons in Subclipse mean? for more on those.

http://help.eclipse.org/galileo/index.jsp?topic=/org.eclipse.cdt.doc.user/reference/cdt_u_cproj_view.htm

Answer 3

These exclamation marks are denoting warnings. This sign will appear on the packages which contains classes with warnings (like unused imports, unused variables, using raw types, etc.). You can reach the class containing warnings and have a look what's causing these warnings. Once found, depending on the warning, you can take necessary actions.