This compilation unit is not on the build path of a Java project

Question

When I try to use ctrl+space this error is shown:

This compilation unit is not on the build path of a Java project.

I see tha

Answer 1

Add this to .project file

 
        
            framework
            
            
            
            
                
                    org.eclipse.wst.common.project.facet.core.builder
                    
                    
                
                
                    org.eclipse.jdt.core.javabuilder
                    
                    
                
                
                    org.eclipse.m2e.core.maven2Builder
                    
                    
                
                
                    org.eclipse.wst.validation.validationbuilder
                    
                    
                
            
            
                org.eclipse.jem.workbench.JavaEMFNature
                org.eclipse.wst.common.modulecore.ModuleCoreNature
                org.eclipse.jdt.core.javanature
                org.eclipse.m2e.core.maven2Nature
                org.eclipse.wst.common.project.facet.core.nature