HBX-3189: Improve the implementation of classes StringUtil and NameConverter

Signed-off-by: Koen Aers <koen.aers@gmail.com>

Author: koentsje

orm/src/main/java/org/hibernate/tool/internal/util/NameConverter.java

@@ -5,9 +5,9 @@
 
 final public class NameConverter {
 
-	private static Set<String> RESERVED_KEYWORDS;
+	private static final Set<String> RESERVED_KEYWORDS;
 	static {
-		RESERVED_KEYWORDS = new HashSet<String>();
+		RESERVED_KEYWORDS = new HashSet<>();
 
 		RESERVED_KEYWORDS.add( "abstract" );
 		RESERVED_KEYWORDS.add( "continue" );
@@ -61,29 +61,26 @@ final public class NameConverter {
 		RESERVED_KEYWORDS.add( "while" );
 	}
 
-	private NameConverter() {
-
-	}
+	private NameConverter() {}
 
 	/**
 	 * Converts a database name (table or column) to a java name (first letter capitalised). 
 	 * employee_name -> EmployeeName.
-	 *
+	 * <p>
 	 * Derived from middlegen's dbnameconverter.
 	 * @param s The database name to convert.
 	 * 
 	 * @return The converted database name.
 	 */
 	public static String toUpperCamelCase(String s) {
-		if ( "".equals(s) ) {
+		if (s.isEmpty()) {
 			return s;
 		}
-		StringBuffer result = new StringBuffer();
+		StringBuilder result = new StringBuilder();
 
 		boolean capitalize = true;
 		boolean lastCapital = false;
 		boolean lastDecapitalized = false;
-		String p = null;
 		for (int i = 0; i < s.length(); i++) {
 			String c = s.substring(i, i + 1);
 			if ( "_".equals(c) || " ".equals(c) || "-".equals(c) ) {
@@ -104,26 +101,16 @@ public static String toUpperCamelCase(String s) {
 			//if(forceFirstLetter && result.length()==0) capitalize = false;
 
 			if (capitalize) {
-				if (p == null || !p.equals("_") ) {
-					result.append(c.toUpperCase() );
-					capitalize = false;
-					p = c;
-				}
-				else {
-					result.append(c.toLowerCase() );
-					capitalize = false;
-					p = c;
-				}
-			}
+                result.append(c.toUpperCase());
+                capitalize = false;
+            }
 			else {
 				result.append(c.toLowerCase() );
 				lastDecapitalized = true;
-				p = c;
-			}
-			
-		}
-		String r = result.toString();
-		return r;
+            }
+
+        }
+        return result.toString();
 	}
 
 	static public String simplePluralize(String singular) {

orm/src/main/java/org/hibernate/tool/internal/util/StringUtil.java

@@ -1,5 +1,6 @@
 package org.hibernate.tool.internal.util;
 
+import java.util.Objects;
 import java.util.StringTokenizer;
 
 /**
@@ -27,7 +28,7 @@ public static String[] split(String str, String separator) {
         StringTokenizer tok = null;
         if (separator == null) {
             tok = new StringTokenizer(str);
-        } 
+        }
         else {
             tok = new StringTokenizer(str, separator);
         }
@@ -42,26 +43,24 @@ public static String[] split(String str, String separator) {
             lastTokenBegin = str.indexOf(list[i], lastTokenEnd);
             lastTokenEnd = lastTokenBegin + list[i].length();
             i++;
-        }  
+        }
         return list;
     }
 
     public static String leftPad(String str, int size) {
         size = (size - str.length() );
         if (size > 0) {
-            StringBuffer buffer = new StringBuffer(size);
-            for (int i = 0; i < size; i++) {
-                buffer.append(" ");
-            }
-            str = buffer.toString() + str;
+            str = " ".repeat(size) + str;
         }
         return str;
     }
 
-	public static boolean isEqual(String str1, String str2) {
-		if(str1==str2) return true;
-		if(str1!=null && str1.equals(str2) ) return true;
-		return false;
-	}
-	
+    public static boolean isEqual(String str1, String str2) {
+        return Objects.equals( str1, str2 );
+    }
+
+    public static boolean isEmptyOrNull(String string) {
+        return string == null || string.isEmpty();
+    }
+
 }