at groovy.util.GroovyScriptEngine.getResourceConnection(GroovyScriptEngine.java:126) there is a resource leak: groovyScriptConn.getInputStream(); The inputStream returned is never closed. Since this code block goal is to check whether the resource exists or not, one possible solution would be: groovyScriptConn.getInputStream().close(); or, as another alternative, adding a finally {} block, after catching the exceptions, in where that input stream would be closed (and any potential exception would be handled).