test/testlibrary/jdk/test/lib/Utils.java

*** 32,42 ****
--- 32,44 ----
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.ArrayList;
  import java.util.Arrays;
+ import java.util.Collection;
  import java.util.Collections;
+ import java.util.Iterator;
  import java.util.List;
  import java.util.Random;
  import java.util.function.BooleanSupplier;
  import java.util.concurrent.TimeUnit;
  import java.util.regex.Matcher;
*** 377,386 ****
--- 379,410 ----
          }
          return RANDOM_GENERATOR;
      }
  
      /**
+      * Returns random element of non empty collection
+      *
+      * @param <T> a type of collection element
+      * @param collection collection of elements
+      * @return random element of collection
+      * @throws IllegalArgumentException if collection is empty
+      */
+     public static <T> T getRandomElement(Collection<T> collection)
+             throws IllegalArgumentException {
+         if (collection.isEmpty()) {
+             throw new IllegalArgumentException("Empty collection");
+         }
+         Random random = getRandomInstance();
+         int elementIndex = 1 + random.nextInt(collection.size() - 1);
+         Iterator<T> iterator = collection.iterator();
+         while (--elementIndex != 0) {
+             iterator.next();
+         }
+         return iterator.next();
+     }
+ 
+     /**
       * Wait for condition to be true
       *
       * @param condition, a condition to wait for
       */
      public static final void waitForCondition(BooleanSupplier condition) {
*** 455,460 ****
--- 479,520 ----
                          t.getClass().getSimpleName(), expectedException.getSimpleName()), t);
              }
          }
      }
  
+     /**
+      * Converts to VM type signature
+      *
+      * @param type Java type to convert
+      * @return string representation of VM type
+      */
+     public static String toJVMTypeSignature(Class<?> type) {
+         if (type.isPrimitive()) {
+             if (type == boolean.class) {
+                 return "Z";
+             } else if (type == byte.class) {
+                 return "B";
+             } else if (type == char.class) {
+                 return "C";
+             } else if (type == double.class) {
+                 return "D";
+             } else if (type == float.class) {
+                 return "F";
+             } else if (type == int.class) {
+                 return "I";
+             } else if (type == long.class) {
+                 return "J";
+             } else if (type == short.class) {
+                 return "S";
+             } else if (type == void.class) {
+                 return "V";
+             } else {
+                 throw new Error("Unsupported type: " + type);
+             }
+         }
+         String result = type.getName().replaceAll("\\.", "/");
+         if (!type.isArray()) {
+             return "L" + result + ";";
+         }
+         return result;
+     }
  }