Delete redundant variables

See spring-projectsgh-17864

Author: lijunyzzZ

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/validation/ValidationBindHandlerTests.java

@@ -198,8 +198,7 @@ private BindValidationException bindAndExpectValidationError(Runnable action) {
 			action.run();
 		}
 		catch (BindException ex) {
-			BindValidationException cause = (BindValidationException) ex.getCause();
-			return cause;
+			return (BindValidationException) ex.getCause();
 		}
 		throw new IllegalStateException("Did not throw");
 	}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/jackson/JsonObjectDeserializerTests.java

@@ -176,9 +176,8 @@ void getRequiredNodeWhenNodeIsNullNodeShouldThrowException() {
 	@Test
 	void getRequiredNodeWhenNodeIsFoundShouldReturnNode() {
 		JsonNode node = mock(JsonNode.class);
-		JsonNode tree = node;
-		given(tree.get("test")).willReturn(node);
-		assertThat(this.testDeserializer.testGetRequiredNode(tree, "test")).isEqualTo(node);
+		given(node.get("test")).willReturn(node);
+		assertThat(this.testDeserializer.testGetRequiredNode(node, "test")).isEqualTo(node);
 	}
 
 	static class TestJsonObjectDeserializer<T> extends JsonObjectDeserializer<T> {

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/context/ServletWebServerMvcIntegrationTests.java

@@ -187,9 +187,8 @@ ServletRegistrationBean<DispatcherServlet> dispatcherRegistration(DispatcherServ
 
 		@Bean
 		DispatcherServlet dispatcherServlet() {
-			DispatcherServlet dispatcherServlet = new DispatcherServlet();
 			// Can configure dispatcher servlet here as would usually do via init-params
-			return dispatcherServlet;
+			return new DispatcherServlet();
 		}
 
 		@Bean

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/AbstractServletWebServerFactoryTests.java

@@ -1084,8 +1084,7 @@ protected ClientHttpResponse getClientResponse(String url, HttpMethod method,
 			String[] parts = header.split(":");
 			request.getHeaders().add(parts[0], parts[1]);
 		}
-		ClientHttpResponse response = request.execute();
-		return response;
+		return request.execute();
 	}
 
 	protected void assertForwardHeaderIsUsed(ServletWebServerFactory factory) throws IOException, URISyntaxException {