Avoid String concatenation for not-null assertion in BeanProperty/DirectFieldBindingResult

Issue: SPR-16455

(cherry picked from commit 9c069f6)

spring-context/src/main/java/org/springframework/validation/BeanPropertyBindingResult.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -21,7 +21,6 @@ import java.io.Serializable;
 import org.springframework.beans.BeanWrapper;
 import org.springframework.beans.ConfigurablePropertyAccessor;
 import org.springframework.beans.PropertyAccessorFactory;
-import org.springframework.util.Assert;
 
 /**
  * Default implementation of the {@link Errors} and {@link BindingResult}
@@ -102,7 +101,9 @@ public class BeanPropertyBindingResult extends AbstractPropertyBindingResult imp
 	 * @see #getTarget()
 	 */
 	protected BeanWrapper createBeanWrapper() {
-		Assert.state(this.target != null, "Cannot access properties on null bean instance '" + getObjectName() + "'!");
+		if (this.target == null) {
+			throw new IllegalStateException("Cannot access properties on null bean instance '" + getObjectName() + "'");
+		}
 		return PropertyAccessorFactory.forBeanPropertyAccess(this.target);
 	}
 

spring-context/src/main/java/org/springframework/validation/DirectFieldBindingResult.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -18,7 +18,6 @@ package org.springframework.validation;
 
 import org.springframework.beans.ConfigurablePropertyAccessor;
 import org.springframework.beans.PropertyAccessorFactory;
-import org.springframework.util.Assert;
 
 /**
  * Special implementation of the Errors and BindingResult interfaces,
@@ -90,7 +89,9 @@ public class DirectFieldBindingResult extends AbstractPropertyBindingResult {
 	 * @see #getTarget()
 	 */
 	protected ConfigurablePropertyAccessor createDirectFieldAccessor() {
-		Assert.state(this.target != null, "Cannot access fields on null target instance '" + getObjectName() + "'!");
+		if (this.target == null) {
+			throw new IllegalStateException("Cannot access fields on null target instance '" + getObjectName() + "'");
+		}
 		return PropertyAccessorFactory.forDirectFieldAccess(this.target);
 	}