Move common TestPrincipal to spring-core test fixtures

See gh-23550

spring-core/src/testFixtures/java/org/springframework/core/testfixture/security/TestPrincipal.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2002-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.core.testfixture.security;
+
+import java.security.Principal;
+
+/**
+ * An implementation of {@link Principal} for testing.
+ *
+ * @author Rossen Stoyanchev
+ */
+public class TestPrincipal implements Principal {
+
+	private final String name;
+
+	public TestPrincipal(String name) {
+		this.name = name;
+	}
+
+	@Override
+	public String getName() {
+		return this.name;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (obj == this) {
+			return true;
+		}
+		if (!(obj instanceof TestPrincipal)) {
+			return false;
+		}
+		TestPrincipal p = (TestPrincipal) obj;
+		return this.name.equals(p.name);
+	}
+
+	@Override
+	public int hashCode() {
+		return this.name.hashCode();
+	}
+
+}