prod/net/jaekl/cfb/util/Util.java

   1 package net.jaekl.cfb.util;
   2
   3 // Copyright (C) 2015 Christian Jaekl
   4
   5 import java.io.PrintWriter;
   6 import java.io.StringWriter;
   7 import java.util.Iterator;
   8 import java.util.List;
   9
  10 public class Util {
  11         // Returns true iff. a and b contain equal items in the same order
  12         public static boolean listsAreEqual(List<?> a, List<?> b)
  13         {
  14                 if ((null == a) || (null == b)) {
  15                         return (a == b);
  16                 }
  17
  18                 if (0 == a.size()) {
  19                         return (0 == b.size());
  20                 }
  21
  22                 if (a.size() != b.size()) {
  23                         return false;
  24                 }
  25
  26                 Iterator<?> iterA = a.iterator();
  27                 Iterator<?> iterB = b.iterator();
  28
  29                 while (iterA.hasNext()) {
  30                         Object elemA = iterA.next();
  31                         Object elemB = iterB.next();
  32
  33                         if (! objsAreEqual(elemA, elemB)) {
  34                                 return false;
  35                         }
  36                 }
  37
  38                 return true;
  39         }
  40
  41         // Test for equality, while taking care to avoid
  42         // dereferencing a null pointer.
  43         // Note that two null pointers are considered equal.
  44         public static boolean objsAreEqual(Object a, Object b)
  45         {
  46                 if ((null == a) || (null == b)) {
  47                         return (a == b);
  48                 }
  49
  50                 if ((a instanceof Number) && (b instanceof Number)) {
  51                         Number aNum = (Number)a;
  52                         Number bNum = (Number)b;
  53
  54                         return (   (aNum.longValue()   == bNum.longValue())
  55                                         || (aNum.doubleValue() == bNum.doubleValue()) );
  56                 }
  57
  58                 return a.equals(b);
  59         }
  60
  61         // Return 1 if obj is null, or obj.hashCode() otherwise
  62         public static int objHashCode(Object obj)
  63         {
  64                 if (null == obj) {
  65                         return 1;
  66                 }
  67                 return obj.hashCode();
  68         }
  69
  70         // Convert a Throwable to the string representation
  71         // that is generated by printStackTrace().
  72         public static String stringify(Throwable thr)
  73         {
  74                 StringWriter sw = new StringWriter();
  75                 PrintWriter pw = new PrintWriter(sw);
  76                 thr.printStackTrace(pw);
  77                 return sw.toString();
  78         }
  79 }