Fix equals and hashCode in IntRangeFilter and remove toString. #1088

pom.xml

@@ -883,7 +883,6 @@
 
 
           <regex><pattern>.*.filters.IntMatchFilter</pattern><branchRate>100</branchRate><lineRate>90</lineRate></regex>
-          <regex><pattern>.*.filters.IntRangeFilter</pattern><branchRate>100</branchRate><lineRate>90</lineRate></regex>
           <regex><pattern>.*.filters.SuppressElement</pattern><branchRate>69</branchRate><lineRate>78</lineRate></regex>
           <regex><pattern>.*.filters.SuppressionCommentFilter</pattern><branchRate>83</branchRate><lineRate>87</lineRate></regex>
           <regex><pattern>.*.filters.SuppressionCommentFilter\$.*</pattern><branchRate>41</branchRate><lineRate>69</lineRate></regex>

src/main/java/com/puppycrawl/tools/checkstyle/filters/IntRangeFilter.java

@@ -19,14 +19,13 @@
 
 package com.puppycrawl.tools.checkstyle.filters;
 
+import java.util.Objects;
+
 /**
  * This filter accepts an Integer in a range.
  * @author Rick Giles
  */
 class IntRangeFilter implements IntFilter {
-    /** hash function multiplicand */
-    private static final int HASH_MULT = 29;
-
     /** lower bound of the range */
     private final Integer lowerBound;
 
@@ -53,22 +52,19 @@ class IntRangeFilter implements IntFilter {
 
     @Override
     public int hashCode() {
-        return HASH_MULT * lowerBound.intValue() + upperBound.intValue();
+        return Objects.hash(lowerBound, upperBound);
     }
 
     @Override
-    public boolean equals(Object object) {
-        if (object instanceof IntRangeFilter) {
-            final IntRangeFilter other = (IntRangeFilter) object;
-            return this.lowerBound.equals(other.lowerBound)
-                && this.upperBound.equals(other.upperBound);
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
         }
-        return false;
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        final IntRangeFilter that = (IntRangeFilter) o;
+        return Objects.equals(lowerBound, that.lowerBound)
+                && Objects.equals(upperBound, that.upperBound);
     }
-
-    @Override
-    public String toString() {
-        return "IntRangeFilter[" + lowerBound + "," + upperBound + "]";
-    }
-
 }

src/test/java/com/puppycrawl/tools/checkstyle/filters/IntRangeFilterTest.java

@@ -22,6 +22,8 @@ package com.puppycrawl.tools.checkstyle.filters;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+
+import nl.jqno.equalsverifier.EqualsVerifier;
 import org.junit.Test;
 
 /** Tests IntRangeFilter */
@@ -66,4 +68,9 @@ public class IntRangeFilterTest {
         assertFalse("[0,2] != this", filter.equals(this));
         assertFalse("[0,2] != null", filter.equals(null));
     }
+
+    @Test
+    public void testEqualsAndHashCode() {
+        EqualsVerifier.forClass(IntRangeFilter.class).usingGetClass().verify();
+    }
 }