Add remove() methods to StringUtils

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137895 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/StringUtils.java

@@ -111,7 +111,7 @@ import java.util.List;
  * @author Al Chou
  * @author Michael Davey
  * @since 1.0
- * @version $Id: StringUtils.java,v 1.132 2004/07/30 01:55:42 ggregory Exp $
+ * @version $Id: StringUtils.java,v 1.133 2004/08/15 23:47:05 scolebourne Exp $
  */
 public class StringUtils {
     // Performance testing notes (JDK 1.4, Jul03, scolebourne)
@@ -2691,6 +2691,69 @@ public class StringUtils {
         return str;
     }
 
+    /**
+     * <p>Removes all occurances of a substring from within the source string.</p>
+     *
+     * <p>A <code>null</code> source string will return <code>null</code>.
+     * An empty ("") source string will return the empty string.
+     * A <code>null</code> remove string will return the source string.
+     * An empty ("") remove string will return the source string.</p>
+     *
+     * <pre>
+     * StringUtils.remove(null, *)        = null
+     * StringUtils.remove("", *)          = ""
+     * StringUtils.remove(*, null)        = *
+     * StringUtils.remove(*, "")          = *
+     * StringUtils.remove("queued", "ue") = "qd"
+     * StringUtils.remove("queued", "zz") = "queued"
+     * </pre>
+     *
+     * @param str  the source String to search, may be null
+     * @param remove  the String to search for and remove, may be null
+     * @return the substring with the string removed if found,
+     *  <code>null</code> if null String input
+     * @since 2.1
+     */
+    public static String remove(String str, String remove) {
+        if (isEmpty(str) || isEmpty(remove)) {
+            return str;
+        }
+        return replace(str, remove, "", -1);
+    }
+
+    /**
+     * <p>Removes all occurances of a character from within the source string.</p>
+     *
+     * <p>A <code>null</code> source string will return <code>null</code>.
+     * An empty ("") source string will return the empty string.</p>
+     *
+     * <pre>
+     * StringUtils.remove(null, *)       = null
+     * StringUtils.remove("", *)         = ""
+     * StringUtils.remove("queued", 'u') = "qeed"
+     * StringUtils.remove("queued", 'z') = "queued"
+     * </pre>
+     *
+     * @param str  the source String to search, may be null
+     * @param remove  the char to search for and remove, may be null
+     * @return the substring with the char removed if found,
+     *  <code>null</code> if null String input
+     * @since 2.1
+     */
+    public static String remove(String str, char remove) {
+        if (isEmpty(str) || str.indexOf(remove) == -1) {
+            return str;
+        }
+        char[] chars = str.toCharArray();
+        int pos = 0;
+        for (int i = 0; i < chars.length; i++) {
+            if (chars[i] != remove) {
+                chars[pos++] = chars[i];
+            }
+        }
+        return new String(chars, 0, pos);
+    }
+
     // Replacing
     //-----------------------------------------------------------------------
     /**

src/test/org/apache/commons/lang/StringUtilsTest.java

@@ -38,7 +38,7 @@ import junit.textui.TestRunner;
  * @author Phil Steitz
  * @author Gary D. Gregory
  * @author Al Chou
- * @version $Id: StringUtilsTest.java,v 1.60 2004/07/11 16:49:07 stevencaswell Exp $
+ * @version $Id: StringUtilsTest.java,v 1.61 2004/08/15 23:47:05 scolebourne Exp $
  */
 public class StringUtilsTest extends TestCase {
     
@@ -1322,5 +1322,51 @@ public class StringUtilsTest extends TestCase {
         assertEquals(StringUtils.removeEnd("domain.com", ""), "domain.com");   
         assertEquals(StringUtils.removeEnd("domain.com", null), "domain.com");   
     }
-}
 
+    public void testRemove_String() {
+        // StringUtils.remove(null, *)        = null
+        assertEquals(null, StringUtils.remove(null, null));
+        assertEquals(null, StringUtils.remove(null, ""));
+        assertEquals(null, StringUtils.remove(null, "a"));
+        
+        // StringUtils.remove("", *)          = ""
+        assertEquals("", StringUtils.remove("", null));
+        assertEquals("", StringUtils.remove("", ""));
+        assertEquals("", StringUtils.remove("", "a"));
+        
+        // StringUtils.remove(*, null)        = *
+        assertEquals(null, StringUtils.remove(null, null));
+        assertEquals("", StringUtils.remove("", null));
+        assertEquals("a", StringUtils.remove("a", null));
+        
+        // StringUtils.remove(*, "")          = *
+        assertEquals(null, StringUtils.remove(null, ""));
+        assertEquals("", StringUtils.remove("", ""));
+        assertEquals("a", StringUtils.remove("a", ""));
+        
+        // StringUtils.remove("queued", "ue") = "qd"
+        assertEquals("qd", StringUtils.remove("queued", "ue"));
+        
+        // StringUtils.remove("queued", "zz") = "queued"
+        assertEquals("queued", StringUtils.remove("queued", "zz"));
+    }
+
+    public void testRemove_char() {
+        // StringUtils.remove(null, *)       = null
+        assertEquals(null, StringUtils.remove(null, 'a'));
+        assertEquals(null, StringUtils.remove(null, 'a'));
+        assertEquals(null, StringUtils.remove(null, 'a'));
+        
+        // StringUtils.remove("", *)          = ""
+        assertEquals("", StringUtils.remove("", 'a'));
+        assertEquals("", StringUtils.remove("", 'a'));
+        assertEquals("", StringUtils.remove("", 'a'));
+        
+        // StringUtils.remove("queued", 'u') = "qeed"
+        assertEquals("qeed", StringUtils.remove("queued", 'u'));
+        
+        // StringUtils.remove("queued", 'z') = "queued"
+        assertEquals("queued", StringUtils.remove("queued", 'z'));
+    }
+
+}