Introduce query for capture JDK API usage

java/ql/src/Telemetry/APIUsage.qll

@@ -0,0 +1,20 @@
+import java
+
+private string jarName(CompilationUnit cu) {
+  result = cu.getParentContainer().toString().regexpCapture(".*/(.*\\.jar)/?.*", 1)
+}
+
+predicate isJavaRuntime(Callable call) {
+  jarName(call.getCompilationUnit()) = "rt.jar" or
+  call.getCompilationUnit().getParentContainer().toString().substring(0, 14) = "/modules/java."
+}
+
+// TODO Is this heuristic too broad?
+predicate isInterestingAPI(Callable call) {
+  call.getNumberOfParameters() > 0 and
+  not (
+    call.getReturnType() instanceof VoidType or
+    call.getReturnType() instanceof PrimitiveType or
+    call.getReturnType() instanceof BoxedType
+  )
+}

java/ql/src/Telemetry/JDKUsage.ql

@@ -0,0 +1,15 @@
+/**
+ * @name JDK API Usage
+ * @description A list of JDK APIs used in the source code.
+ * @id java/telemetry/jdk-apis
+ */
+
+import java
+import APIUsage
+
+from Callable call, CompilationUnit cu
+where
+  cu = call.getCompilationUnit() and
+  isJavaRuntime(call) and
+  isInterestingAPI(call)
+select cu, call as API, count(Call c | c.getCallee() = call) as calls order by calls desc