timetest.java

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// Introduced in Chapter 7
/** Time tests to compare performance of various algorithms. */
public class TimeTest {

  /** Number of Objects to store in each data structure. */
  public static final int LIST_LENGTH = 100;

  /** Number of times to perform the operation being timed. */
  public static final int TEST_RUNS = 1000000;

  /**
   * Store LIST_LENGTH Objects in list.  Time list's get() method,
   * printing the number of milliseconds taken.
   */
  public static void test(List<Object> list) {
    for (int i = 0; i < LIST_LENGTH; i++) {
      list.add(new Object());
    }
    long before = System.currentTimeMillis();
    for (int i = 0; i < TEST_RUNS; i++) {
      list.get(5);
    }
    long after = System.currentTimeMillis();
    System.out.println((after - before) + " milliseconds");
  }
  
  /** Compare ArrayList with LinkedList. */
  public static void main(String[] args) {
    System.out.print("ArrayList: ");
    test(new ArrayList<Object>());
    System.out.print("LinkedList: ");
    test(new LinkedList<Object>());
  }

}