Question

How to find the number of errors(marked in red) in an eclipse project programmatically?

Answer 1

There are two major steps:

1. You need an access to Eclipse API – write your own plugin for Eclipse or use a scripting plugin like Groovy Monkey

2. Using Eclipse API get problem markers for resource you intrested in – check this link: How to work with resource markers

If you want to retrieve only JDT error markers you should write something like this:

public static IMarker[] calculateCompilationErrorMarkers(IProject project)
{
    ArrayList <IMarker> result = new ArrayList <IMarker>();
    IMarker[] markers = null;
    markers = project.findMarkers(IJavaModelMarker.JAVA_MODEL_PROBLEM_MARKER, true, IResource.DEPTH_INFINITE);
    for (IMarker marker: markers)
    {
        Integer severityType = (Integer) marker.getAttribute(IMarker.SEVERITY);
        if (severityType.intValue() == IMarker.SEVERITY_ERROR)
                result.add(marker);
    }
    return result.toArray(new IMarker[result.size()]);
}