overruled on other grounds by Nobelpharma AB v. Implant Innovations, Inc., 141 F.3d 1059, 1067-68 (Fed.Cir.1998). “In general, the presence of an ‘actual controversy’ within the meaning of the statute depends on ‘whether the facts alleged, under all the circumstances, show that there is a substantial controversy, between parties having adverse legal interests, of sufficient immediacy and reality to warrant the issuance of a declaratory judgment.’ ” EMC Corp. v. Norand Corp., 89 F.3d 807, 810 (Fed.Cir.1996) (quoting Maryland Cas. Co. v. Pacific Coal & Oil Co., 312 U.S. 270, 273, 61 S.Ct. 510, 85 L.Ed. 826 (1941)). The jurisdiction of federal courts to issue declaratory judgments is limited to “cases and controversies.” Marine Equip. Mgmt. Co. v. U.S., 4 F.3d 643, 646 (8th Cir.1993) (<HOLDING>); Minnesota Fed’n of Teachers v. Randall, 891
recognizing that the case or controversy requirement for standing is no less strict in a declaratory judgment proceeding than in any suit where other relief is sought holding that exhaustion requirement applies to excessive force claims holding that if a declaratory judgment will not end the controversy it is not proper holding that the requirement of an actual case or controversy is a jurisdictional prerequisite under the constitution holding that the case or controversy requirement applies with equal force to actions for declaratory judgment