No leading underscores in private names.

src/main/java/org/apache/commons/lang3/BitField.java

@@ -72,8 +72,8 @@ package org.apache.commons.lang3;
  */
 public class BitField {
 
-    private final int _mask;
+    private final int mask;
-    private final int _shift_count;
+    private final int shiftCount;
 
     /**
      * <p>Creates a BitField instance.</p>
@@ -83,8 +83,8 @@ public class BitField {
      *  that this BitField operates on
      */
     public BitField(final int mask) {
-        _mask = mask;
+        this.mask = mask;
-        _shift_count = mask == 0 ? 0 : Integer.numberOfTrailingZeros(mask);
+        this.shiftCount = mask == 0 ? 0 : Integer.numberOfTrailingZeros(mask);
     }
 
     /**
@@ -102,7 +102,7 @@ public class BitField {
      * @return the selected bits, shifted right appropriately
      */
     public int getValue(final int holder) {
-        return getRawValue(holder) >> _shift_count;
+        return getRawValue(holder) >> shiftCount;
     }
 
     /**
@@ -131,7 +131,7 @@ public class BitField {
      * @return the selected bits
      */
     public int getRawValue(final int holder) {
-        return holder & _mask;
+        return holder & mask;
     }
 
     /**
@@ -159,7 +159,7 @@ public class BitField {
      *  else {@code false}
      */
     public boolean isSet(final int holder) {
-        return (holder & _mask) != 0;
+        return (holder & mask) != 0;
     }
 
     /**
@@ -175,7 +175,7 @@ public class BitField {
      *  else {@code false}
      */
     public boolean isAllSet(final int holder) {
-        return (holder & _mask) == _mask;
+        return (holder & mask) == mask;
     }
 
     /**
@@ -189,7 +189,7 @@ public class BitField {
      *  parameter replacing the old bits
      */
     public int setValue(final int holder, final int value) {
-        return (holder & ~_mask) | ((value << _shift_count) & _mask);
+        return (holder & ~mask) | ((value << shiftCount) & mask);
     }
 
     /**
@@ -215,7 +215,7 @@ public class BitField {
      *  (set to {@code 0})
      */
     public int clear(final int holder) {
-        return holder & ~_mask;
+        return holder & ~mask;
     }
 
     /**
@@ -252,7 +252,7 @@ public class BitField {
      *  to {@code 1}
      */
     public int set(final int holder) {
-        return holder | _mask;
+        return holder | mask;
     }
 
     /**

src/main/java/org/apache/commons/lang3/StringUtils.java

@@ -2502,7 +2502,7 @@ public class StringUtils {
 
         int[] p = new int[n + 1]; // 'previous' cost array, horizontally
         int[] d = new int[n + 1]; // cost array, horizontally
-        int[] _d; // placeholder to assist in swapping p and d
+        int[] tmp; // placeholder to assist in swapping p and d
 
         // fill in starting table values
         final int boundary = Math.min(n, threshold) + 1;
@@ -2545,9 +2545,9 @@ public class StringUtils {
             }
 
             // copy current distance counts to 'previous row' distance counts
-            _d = p;
+            tmp = p;
             p = d;
-            d = _d;
+            d = tmp;
         }
 
         // if p[n] is greater than the threshold, there's no guarantee on it being the correct

src/main/java/org/apache/commons/lang3/builder/IDKey.java

@@ -32,15 +32,15 @@ final class IDKey {
 
         /**
          * Constructor for IDKey
-         * @param _value The value
+         * @param value The value
          */
-        IDKey(final Object _value) {
+        IDKey(final Object value) {
             // This is the Object hash code
-            id = System.identityHashCode(_value);
+            this.id = System.identityHashCode(value);
             // There have been some cases (LANG-459) that return the
             // same identity hash code for different objects.  So
             // the value is also added to disambiguate these cases.
-            value = _value;
+            this.value = value;
         }
 
         /**

src/main/java/org/apache/commons/lang3/text/FormattableUtils.java

@@ -138,8 +138,8 @@ public class FormattableUtils {
                 "Specified ellipsis '%1$s' exceeds precision of %2$s", ellipsis, Integer.valueOf(precision));
         final StringBuilder buf = new StringBuilder(seq);
         if (precision >= 0 && precision < seq.length()) {
-            final CharSequence _ellipsis = ObjectUtils.defaultIfNull(ellipsis, StringUtils.EMPTY);
+            final CharSequence actualEllipsis = ObjectUtils.defaultIfNull(ellipsis, StringUtils.EMPTY);
-            buf.replace(precision - _ellipsis.length(), seq.length(), _ellipsis.toString());
+            buf.replace(precision - actualEllipsis.length(), seq.length(), actualEllipsis.toString());
         }
         final boolean leftJustify = (flags & LEFT_JUSTIFY) == LEFT_JUSTIFY;
         for (int i = buf.length(); i < width; i++) {

src/main/java/org/apache/commons/lang3/text/translate/LookupTranslator.java

@@ -49,23 +49,23 @@ public class LookupTranslator extends CharSequenceTranslator {
     public LookupTranslator(final CharSequence[]... lookup) {
         lookupMap = new HashMap<>();
         prefixSet = new HashSet<>();
-        int _shortest = Integer.MAX_VALUE;
+        int tmpShortest = Integer.MAX_VALUE;
-        int _longest = 0;
+        int tmpLongest = 0;
         if (lookup != null) {
             for (final CharSequence[] seq : lookup) {
                 this.lookupMap.put(seq[0].toString(), seq[1].toString());
                 this.prefixSet.add(seq[0].charAt(0));
                 final int sz = seq[0].length();
-                if (sz < _shortest) {
+                if (sz < tmpShortest) {
-                    _shortest = sz;
+                    tmpShortest = sz;
                 }
-                if (sz > _longest) {
+                if (sz > tmpLongest) {
-                    _longest = sz;
+                    tmpLongest = sz;
                 }
             }
         }
-        shortest = _shortest;
+        this.shortest = tmpShortest;
-        longest = _longest;
+        this.longest = tmpLongest;
     }
 
     /**

src/test/java/org/apache/commons/lang3/reflect/MethodUtilsTest.java

@@ -296,9 +296,10 @@ public class MethodUtilsTest {
             assertArrayEquals(a.getRight(), b.getRight());
         }
 
-        static void verify(final ImmutablePair<String, Object[]> a, final Object _b) {
+        static void verify(final ImmutablePair<String, Object[]> a, final Object obj) {
-            @SuppressWarnings("unchecked") final ImmutablePair<String, Object[]> b = (ImmutablePair<String, Object[]>) _b;
+            @SuppressWarnings("unchecked")
-            verify(a, b);
+            final ImmutablePair<String, Object[]> pair = (ImmutablePair<String, Object[]>) obj;
+            verify(a, pair);
         }
 
     }