Replace <code> with {@code} throughout Javadoc

Issue: SPR-10128

spring-core/src/test/java/org/springframework/beans/factory/annotation/TestAutowired.java

@@ -27,7 +27,7 @@ public @interface TestAutowired {
 
 	/**
 	 * Declares whether the annotated dependency is required.
-	 * <p>Defaults to <code>true</code>.
+	 * <p>Defaults to {@code true}.
 	 */
 	boolean required() default true;
 

spring-core/src/test/java/org/springframework/core/io/support/PathMatchingResourcePatternResolverTests.java

@@ -31,7 +31,7 @@ import org.springframework.core.io.Resource;
 
 /**
  * If this test case fails, uncomment diagnostics in
- * <code>assertProtocolAndFilenames</code> method.
+ * {@code assertProtocolAndFilenames} method.
  *
  * @author Oliver Hutchison
  * @author Juergen Hoeller

spring-core/src/test/java/org/springframework/util/ResourceUtilsTests.java

@@ -58,7 +58,7 @@ public class ResourceUtilsTests extends TestCase {
 
 	/**
 	 * Dummy URLStreamHandler that's just specified to suppress the standard
-	 * <code>java.net.URL</code> URLStreamHandler lookup, to be able to
+	 * {@code java.net.URL} URLStreamHandler lookup, to be able to
 	 * use the standard URL class for parsing "rmi:..." URLs.
 	 */
 	private static class DummyURLStreamHandler extends URLStreamHandler {

spring-core/src/test/java/org/springframework/util/xml/AbstractStaxXMLReaderTestCase.java

@@ -144,7 +144,7 @@ public abstract class AbstractStaxXMLReaderTestCase {
 
 	protected abstract AbstractStaxXMLReader createStaxXmlReader(InputStream inputStream) throws XMLStreamException;
 
-	/** Easymock <code>ArgumentMatcher</code> implementation that matches SAX arguments. */
+	/** Easymock {@code AbstractMatcher} implementation that matches SAX arguments. */
 	protected static class SaxArgumentMatcher extends AbstractMatcher {
 
 		@Override