DATACMNS-1235 - Polishing.

Original pull request: #265.

src/main/java/org/springframework/data/querydsl/SimpleEntityPathResolver.java

@@ -19,6 +19,7 @@ import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.util.Optional;
 
+import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
 
@@ -40,7 +41,15 @@ public class SimpleEntityPathResolver implements EntityPathResolver {
 
 	private final String querySuffix;
 
+	/**
+	 * Creates a new {@link SimpleEntityPathResolver} with the given query package suffix.
+	 * 
+	 * @param querySuffix must not be {@literal null}.
+	 */
 	public SimpleEntityPathResolver(String querySuffix) {
+
+		Assert.notNull(querySuffix, "Query suffix must not be null!");
+
 		this.querySuffix = querySuffix;
 	}
 
@@ -102,7 +111,9 @@ public class SimpleEntityPathResolver implements EntityPathResolver {
 	private String getQueryClassName(Class<?> domainClass) {
 
 		String simpleClassName = ClassUtils.getShortName(domainClass);
-		return String.format("%s%s.Q%s%s", domainClass.getPackage().getName(), querySuffix, getClassBase(simpleClassName),
+		String packageName = domainClass.getPackage().getName();
+
+		return String.format("%s%s.Q%s%s", packageName, querySuffix, getClassBase(simpleClassName),
 				domainClass.getSimpleName());
 	}
 
@@ -116,10 +127,6 @@ public class SimpleEntityPathResolver implements EntityPathResolver {
 
 		String[] parts = shortName.split("\\.");
 
-		if (parts.length < 2) {
-			return "";
-		}
-
-		return parts[0] + "_";
+		return parts.length < 2 ? "" : parts[0] + "_";
 	}
 }

src/test/java/org/springframework/data/querydsl/suffix/QUser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 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.
@@ -22,10 +22,14 @@ import com.querydsl.core.types.dsl.EntityPathBase;
 /**
  * Mimicks a class generated by Querydsl with a package suffix.
  *
- * @see org.springframework.data.querydsl.SimpleEntityPathResolverUnitTests
  * @author Jens Schauder
+ * @author Oliver Gierke
+ * @see org.springframework.data.querydsl.SimpleEntityPathResolverUnitTests
  */
 public class QUser extends EntityPathBase<User> {
+
+	private static final long serialVersionUID = -2346766110501428367L;
+
 	public static final QUser user = new QUser("user");
 
 	public QUser(String user) {