allow interceptors to be registered via properties

src/test/java/some/custom/pkg1/CustomBean.java

@@ -0,0 +1,18 @@
+package some.custom.pkg1;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class CustomBean {
+
+	private String initFlag;
+
+	public CustomBean() {
+		initFlag = "I am alive";
+	}
+
+	public String getInitFlag() {
+		return initFlag;
+	}
+
+}

src/test/java/some/custom/pkg1/CustomInterceptorBean.java

@@ -0,0 +1,31 @@
+package some.custom.pkg1;
+
+import org.hl7.fhir.instance.model.api.IBaseResource;
+import org.hl7.fhir.r4.model.Extension;
+import org.hl7.fhir.r4.model.Patient;
+import org.hl7.fhir.r4.model.StringType;
+import org.springframework.stereotype.Component;
+
+import ca.uhn.fhir.interceptor.api.Hook;
+import ca.uhn.fhir.interceptor.api.Interceptor;
+import ca.uhn.fhir.interceptor.api.Pointcut;
+import ca.uhn.fhir.rest.api.RestOperationTypeEnum;
+import ca.uhn.fhir.rest.server.servlet.ServletRequestDetails;
+
+@Interceptor
+@Component
+public class CustomInterceptorBean {
+
+	@Hook(Pointcut.SERVER_INCOMING_REQUEST_PRE_HANDLED)
+	void preHandleResource(ServletRequestDetails servletRequestDetails, RestOperationTypeEnum opType) {
+		IBaseResource resource = servletRequestDetails.getResource();
+
+		// add an extension before saving the resource to mark it
+		if (opType == RestOperationTypeEnum.CREATE && resource instanceof Patient) {
+			Patient pat = (Patient) resource;
+			Extension ext = pat.addExtension();
+			ext.setUrl("http://some.custom.pkg1/CustomInterceptorBean");
+			ext.setValue(new StringType("CustomInterceptorBean wuz here"));
+		}
+	}
+}

src/test/java/some/custom/pkg1/CustomInterceptorPojo.java

@@ -0,0 +1,26 @@
+package some.custom.pkg1;
+
+import org.hl7.fhir.instance.model.api.IBaseResource;
+import org.hl7.fhir.r4.model.Extension;
+import org.hl7.fhir.r4.model.Patient;
+import org.hl7.fhir.r4.model.StringType;
+import ca.uhn.fhir.interceptor.api.Hook;
+import ca.uhn.fhir.interceptor.api.Pointcut;
+import ca.uhn.fhir.rest.api.RestOperationTypeEnum;
+import ca.uhn.fhir.rest.server.servlet.ServletRequestDetails;
+
+public class CustomInterceptorPojo {
+
+	@Hook(Pointcut.SERVER_INCOMING_REQUEST_PRE_HANDLED)
+	void preHandleResource(ServletRequestDetails servletRequestDetails, RestOperationTypeEnum opType) {
+		IBaseResource resource = servletRequestDetails.getResource();
+
+		// add an extension before saving the resource to mark it
+		if (opType == RestOperationTypeEnum.CREATE && resource instanceof Patient) {
+			Patient pat = (Patient) resource;
+			Extension ext = pat.addExtension();
+			ext.setUrl("http://some.custom.pkg1/CustomInterceptorPojo");
+			ext.setValue(new StringType("CustomInterceptorPojo wuz here"));
+		}
+	}
+}