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  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6.  
  7. class Ideone {
  8.  
  9. 	static class X implements Comparable<X> {
  10. 		String campo1;
  11.  
  12. 		X(String campo1) {
  13. 			this.campo1 = campo1;
  14. 		}
  15.  
  16. 		@Override
  17. 		public int hashCode() {
  18. 			final int prime = 31;
  19. 			int result = 1;
  20. 			result = prime * result + ((campo1 == null) ? 0 : campo1.hashCode());
  21. 			return result;
  22. 		}
  23.  
  24. 		@Override
  25. 		public boolean equals(Object obj) {
  26. 			if (this == obj)
  27. 				return true;
  28. 			if (obj == null)
  29. 				return false;
  30. 			if (getClass() != obj.getClass())
  31. 				return false;
  32. 			X other = (X) obj;
  33. 			if (campo1 == null) {
  34. 				if (other.campo1 != null)
  35. 					return false;
  36. 			} else if (!campo1.equals(other.campo1))
  37. 				return false;
  38. 			return true;
  39. 		}
  40.  
  41. 		@Override
  42. 		public int compareTo(X o) {
  43. 			return campo1.compareTo(o.campo1);
  44. 		}
  45.  
  46. 	}
  47.  
  48. 	public static void main(String[] args) {
  49.  
  50. 		X x1 = new X("A");
  51. 		X x2 = new X("B");
  52. 		X x3 = new X("C");
  53. 		Set<X> ts = new TreeSet<X>();
  54. 		ts.add(x2);
  55. 		ts.add(x3);
  56. 		System.out.println(ts.contains(x1));
  57.  
  58. 	}
  59.  
  60. }
  61.  
Success #stdin #stdout 0.07s 380160KB
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https://ideone.com/t3hdPx
language:
Java (HotSpot 12)
created:
10 years ago
visibility:
public

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