Applying patch from LANG-461 from Vincent Ricard to add toByte and toShort methods to NumberUtils

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@788276 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -288,6 +288,101 @@ public class NumberUtils {
       }
     }
 
+     //-----------------------------------------------------------------------
+     /**
+     * <p>Convert a <code>String</code> to a <code>byte</code>, returning
+     * <code>zero</code> if the conversion fails.</p>
+     *
+     * <p>If the string is <code>null</code>, <code>zero</code> is returned.</p>
+     *
+     * <pre>
+     *   NumberUtils.toByte(null) = 0
+     *   NumberUtils.toByte("")   = 0
+     *   NumberUtils.toByte("1")  = 1
+     * </pre>
+     *
+     * @param str  the string to convert, may be null
+     * @return the byte represented by the string, or <code>zero</code> if
+     *  conversion fails
+     */
+    public static byte toByte(String str) {
+        return toByte(str, (byte) 0);
+    }
+
+    /**
+     * <p>Convert a <code>String</code> to a <code>byte</code>, returning a
+     * default value if the conversion fails.</p>
+     *
+     * <p>If the string is <code>null</code>, the default value is returned.</p>
+     *
+     * <pre>
+     *   NumberUtils.toByte(null, 1) = 1
+     *   NumberUtils.toByte("", 1)   = 1
+     *   NumberUtils.toByte("1", 0)  = 1
+     * </pre>
+     *
+     * @param str  the string to convert, may be null
+     * @param defaultValue  the default value
+     * @return the byte represented by the string, or the default if conversion fails
+     */
+    public static byte toByte(String str, byte defaultValue) {
+        if(str == null) {
+            return defaultValue;
+        }
+        try {
+            return Byte.parseByte(str);
+        } catch (NumberFormatException nfe) {
+            return defaultValue;
+        }
+    }
+
+    /**
+     * <p>Convert a <code>String</code> to a <code>short</code>, returning
+     * <code>zero</code> if the conversion fails.</p>
+     *
+     * <p>If the string is <code>null</code>, <code>zero</code> is returned.</p>
+     *
+     * <pre>
+     *   NumberUtils.toShort(null) = 0
+     *   NumberUtils.toShort("")   = 0
+     *   NumberUtils.toShort("1")  = 1
+     * </pre>
+     *
+     * @param str  the string to convert, may be null
+     * @return the short represented by the string, or <code>zero</code> if
+     *  conversion fails
+     */
+    public static short toShort(String str) {
+        return toShort(str, (short) 0);
+    }
+
+    /**
+     * <p>Convert a <code>String</code> to an <code>short</code>, returning a
+     * default value if the conversion fails.</p>
+     *
+     * <p>If the string is <code>null</code>, the default value is returned.</p>
+     *
+     * <pre>
+     *   NumberUtils.toShort(null, 1) = 1
+     *   NumberUtils.toShort("", 1)   = 1
+     *   NumberUtils.toShort("1", 0)  = 1
+     * </pre>
+     *
+     * @param str  the string to convert, may be null
+     * @param defaultValue  the default value
+     * @return the short represented by the string, or the default if conversion fails
+     */
+    public static short toShort(String str, short defaultValue) {
+        if(str == null) {
+            return defaultValue;
+        }
+        try {
+            return Short.parseShort(str);
+        } catch (NumberFormatException nfe) {
+            return defaultValue;
+        }
+    }
+
     //-----------------------------------------------------------------------
     // must handle Long, Float, Integer, Float, Short,
     //                  BigDecimal, BigInteger and Byte

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

@@ -150,6 +150,42 @@ public class NumberUtilsTest extends TestCase {
         assertTrue("toDouble(String,int) 2 failed", NumberUtils.toDouble("a", 5.0d) == 5.0d);
     }
 
+     /**
+     * Test for {@link NumberUtils#toByte(String)}.
+     */
+    public void testToByteString() {
+        assertTrue("toByte(String) 1 failed", NumberUtils.toByte("123") == 123);
+        assertTrue("toByte(String) 2 failed", NumberUtils.toByte("abc") == 0);
+        assertTrue("toByte(empty) failed", NumberUtils.toByte("") == 0);
+        assertTrue("toByte(null) failed", NumberUtils.toByte(null) == 0);
+    }
+
+    /**
+     * Test for {@link NumberUtils#toByte(String, byte)}.
+     */
+    public void testToByteStringI() {
+        assertTrue("toByte(String,byte) 1 failed", NumberUtils.toByte("123", (byte) 5) == 123);
+        assertTrue("toByte(String,byte) 2 failed", NumberUtils.toByte("12.3", (byte) 5) == 5);
+    }
+
+    /**
+     * Test for {@link NumberUtils#toShort(String)}.
+     */
+    public void testToShortString() {
+        assertTrue("toShort(String) 1 failed", NumberUtils.toShort("12345") == 12345);
+        assertTrue("toShort(String) 2 failed", NumberUtils.toShort("abc") == 0);
+        assertTrue("toShort(empty) failed", NumberUtils.toShort("") == 0);
+        assertTrue("toShort(null) failed", NumberUtils.toShort(null) == 0);
+    }
+
+    /**
+     * Test for {@link NumberUtils#toShort(String, short)}.
+     */
+    public void testToShortStringI() {
+        assertTrue("toShort(String,short) 1 failed", NumberUtils.toShort("12345", (short) 5) == 12345);
+        assertTrue("toShort(String,short) 2 failed", NumberUtils.toShort("1234.5", (short) 5) == 5);
+    }
+
     public void testCreateNumber() {
         // a lot of things can go wrong
         assertEquals("createNumber(String) 1 failed", new Float("1234.5"), NumberUtils.createNumber("1234.5"));