Adding NumberUtils.max(byte[]) and NumberUtils.min(byte[]) as noted in LANG-289

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@467477 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/math/NumberUtils.java

@@ -751,6 +751,33 @@ public class NumberUtils {
         return min;
     }
 
+    /**
+     * <p>Returns the minimum value in an array.</p>
+     * 
+     * @param array  an array, must not be null or empty
+     * @return the minimum value in the array
+     * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
+     * @throws IllegalArgumentException if <code>array</code> is empty
+     */
+    public static byte min(byte[] array) {
+        // Validates input
+        if (array == null) {
+            throw new IllegalArgumentException("The Array must not be null");
+        } else if (array.length == 0) {
+            throw new IllegalArgumentException("Array cannot be empty.");
+        }
+    
+        // Finds and returns min
+        byte min = array[0];
+        for (int i = 1; i < array.length; i++) {
+            if (array[i] < min) {
+                min = array[i];
+            }
+        }
+    
+        return min;
+    }
+
      /**
      * <p>Returns the minimum value in an array.</p>
      * 
@@ -888,6 +915,33 @@ public class NumberUtils {
         return max;
     }
 
+    /**
+     * <p>Returns the maximum value in an array.</p>
+     * 
+     * @param array  an array, must not be null or empty
+     * @return the minimum value in the array
+     * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
+     * @throws IllegalArgumentException if <code>array</code> is empty
+     */
+    public static byte max(byte[] array) {
+        // Validates input
+        if (array == null) {
+            throw new IllegalArgumentException("The Array must not be null");
+        } else if (array.length == 0) {
+            throw new IllegalArgumentException("Array cannot be empty.");
+        }
+    
+        // Finds and returns max
+        byte max = array[0];
+        for (int i = 1; i < array.length; i++) {
+            if (array[i] > max) {
+                max = array[i];
+            }
+        }
+    
+        return max;
+    }
+
     /**
      * <p>Returns the maximum value in an array.</p>
      * 

src/test/org/apache/commons/lang/math/NumberUtilsTest.java

@@ -398,6 +398,32 @@ public class NumberUtilsTest extends TestCase {
         assertEquals(-10, NumberUtils.min(new short[] { -5, 0, -10, 5, 10 }));
     }
 
+    public void testMinByte() {
+        final byte[] b = null;
+        try {
+            NumberUtils.min(b);
+            fail("No exception was thrown for null input.");
+        } catch (IllegalArgumentException ex) {}
+
+        try {
+            NumberUtils.min(new byte[0]);
+            fail("No exception was thrown for empty input.");
+        } catch (IllegalArgumentException ex) {}
+
+        assertEquals(
+            "min(byte[]) failed for array length 1",
+            5,
+            NumberUtils.min(new byte[] { 5 }));
+
+        assertEquals(
+            "min(byte[]) failed for array length 2",
+            6,
+            NumberUtils.min(new byte[] { 6, 9 }));
+
+        assertEquals(-10, NumberUtils.min(new byte[] { -10, -5, 0, 5, 10 }));
+        assertEquals(-10, NumberUtils.min(new byte[] { -5, 0, -10, 5, 10 }));
+    }
+
     public void testMinDouble() {
         final double[] d = null;
         try {
@@ -554,6 +580,36 @@ public class NumberUtilsTest extends TestCase {
         assertEquals(10, NumberUtils.max(new short[] { -5, 0, 10, 5, -10 }));
     }
 
+    public void testMaxByte() {
+        final byte[] b = null;
+        try {
+            NumberUtils.max(b);
+            fail("No exception was thrown for null input.");
+        } catch (IllegalArgumentException ex) {}
+
+        try {
+            NumberUtils.max(new byte[0]);
+            fail("No exception was thrown for empty input.");
+        } catch (IllegalArgumentException ex) {}
+
+        assertEquals(
+            "max(byte[]) failed for array length 1",
+            5,
+            NumberUtils.max(new byte[] { 5 }));
+
+        assertEquals(
+            "max(byte[]) failed for array length 2",
+            9,
+            NumberUtils.max(new byte[] { 6, 9 }));
+
+        assertEquals(
+            "max(byte[]) failed for array length 5",
+            10,
+            NumberUtils.max(new byte[] { -10, -5, 0, 5, 10 }));
+        assertEquals(10, NumberUtils.max(new byte[] { -10, -5, 0, 5, 10 }));
+        assertEquals(10, NumberUtils.max(new byte[] { -5, 0, 10, 5, -10 }));
+    }
+
     public void testMaxDouble() {
         final double[] d = null;
         try {