X-Git-Url: http://jaekl.net/gitweb/?a=blobdiff_plain;f=prod%2Fnet%2Fjaekl%2Fcfb%2Futil%2FUtil.java;h=99ef6e846f78b9b082cfbbc7d4e8db7f94e9fae6;hb=a4a577abc3f9b2b1147caafd1cb39fa8c2622cd4;hp=c0e7b1ca4b592ee9c2decc8e168fe3994ba3ec00;hpb=08a530ef53cc4756f5e632b69c78830872ebd9f4;p=cfb.git

diff --git a/prod/net/jaekl/cfb/util/Util.java b/prod/net/jaekl/cfb/util/Util.java
index c0e7b1c..99ef6e8 100644
--- a/prod/net/jaekl/cfb/util/Util.java
+++ b/prod/net/jaekl/cfb/util/Util.java
@@ -1,13 +1,79 @@
 package net.jaekl.cfb.util;
 
+// Copyright (C) 2015 Christian Jaekl
+
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.util.Iterator;
+import java.util.List;
 
 public class Util {
-	public static String stringify(Throwable thr) {
+	// Returns true iff. a and b contain equal items in the same order
+	public static boolean listsAreEqual(List<?> a, List<?> b)
+	{
+		if ((null == a) || (null == b)) {
+			return (a == b);
+		}
+		
+		if (0 == a.size()) {
+			return (0 == b.size());
+		}
+		
+		if (a.size() != b.size()) {
+			return false;
+		}
+		
+		Iterator<?> iterA = a.iterator();
+		Iterator<?> iterB = b.iterator();
+		
+		while (iterA.hasNext()) {
+			Object elemA = iterA.next();
+			Object elemB = iterB.next();
+			
+			if (! objsAreEqual(elemA, elemB)) {
+				return false;
+			}
+		}
+		
+		return true;
+	}
+	
+	// Test for equality, while taking care to avoid 
+	// dereferencing a null pointer.
+	// Note that two null pointers are considered equal.
+	public static boolean objsAreEqual(Object a, Object b) 
+	{
+		if ((null == a) || (null == b)) {
+			return (a == b);
+		}
+		
+		if ((a instanceof Number) && (b instanceof Number)) {
+			Number aNum = (Number)a;
+			Number bNum = (Number)b;
+			
+			return (   (aNum.longValue()   == bNum.longValue())
+					|| (aNum.doubleValue() == bNum.doubleValue()) );
+		}
+		
+		return a.equals(b);
+	}
+	
+	// Return 1 if obj is null, or obj.hashCode() otherwise
+	public static int objHashCode(Object obj)
+	{
+		if (null == obj) {
+			return 1;
+		}
+		return obj.hashCode();
+	}
+	
+	// Convert a Throwable to the string representation 
+	// that is generated by printStackTrace().
+	public static String stringify(Throwable thr) 
+	{
 		StringWriter sw = new StringWriter();
 		PrintWriter pw = new PrintWriter(sw);
 		thr.printStackTrace(pw);
 		return sw.toString();
-	}
+	}	
 }