Apache/commons-lang
1
0
Fork 0
mirror of https://github.com/apache/commons-lang.git synced 2025-02-08 11:05:09 +00:00
Code Issues Packages Projects Releases Wiki Activity

Update Null handling in StringUtils to handle nulls quietly

Browse Source 
git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137444 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Stephen Colebourne 2003-07-16 23:56:45 +00:00
parent 7b88508ce9
commit b026fbd30f
2 changed files with 26 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
src/java/org/apache/commons/lang/StringUtils.java
View File

@ -71,8 +71,15 @@
* <li>whitespace - the characters defined by {@link Character#isWhitespace(char)}
* </ul>
*
* <p>The <code>StringUtils</code> class varies in its handling of
* <code>null</code>. Each method should be consulted individually.</p>
* <p>The <code>StringUtils</code> tries to handle <code>null</code> input
* quietly. That is to say that a <code>null</code> will generally return a
* sensible value rather than throw an exception.
* Typically, <code>null</code> in gives <code>null</code> out.
* Each method should be consulted individually for full details.</p>
*
* <p>A side effect of the <code>null</code> handling is that a
* NullPointerException should be considered a bug in <code>StringUtils</code>.
* (Except for deprecated methods).</p>
*
* @author <a href="http://jakarta.apache.org/turbine/">Apache Jakarta Turbine</a>
* @author GenerationJavaCore
@ -90,7 +97,7 @@
* @author Arun Mammen Thomas
* @author <a href="mailto:ggregory@seagullsw.com">Gary Gregory</a>
* @since 1.0
* @version $Id: StringUtils.java,v 1.60 2003/07/16 23:45:39 scolebourne Exp $
* @version $Id: StringUtils.java,v 1.61 2003/07/16 23:56:45 scolebourne Exp $
*/
public class StringUtils {
@ -1626,25 +1633,27 @@ public static String escape(String str) {
* new string.</p>
*
* <pre>
* StringUtils.repeat(null, 2) = null
* StringUtils.repeat("", 0) = ""
* StringUtils.repeat("", 2) = ""
* StringUtils.repeat("a", 3) = "aaa"
* StringUtils.repeat("ab", 2) = "abab"
* StringUtils.repeat(null, 2) = NullPointerException
* StringUtils.repeat("a", -2) = NegativeArraySizeException
* StringUtils.repeat("a", -2) = ""
* </pre>
*
* @param str the String to repeat, must not be null
* @param repeat number of times to repeat str
* @return a new String consisting of the original String repeated
* @throws NegativeArraySizeException if <code>repeat &lt; 0</code>
* @throws NullPointerException if str is <code>null</code>
* @param str the String to repeat, may be null
* @param repeat number of times to repeat str, negative treated as zero
* @return a new String consisting of the original String repeated,
* <code>null</code> if null string input
*/
public static String repeat(String str, int repeat) {
int inputLength = str.length();
if (repeat == 0) {
if (str == null) {
return null;
}
if (repeat <= 0) {
return "";
}
int inputLength = str.length();
if (inputLength == 1 && repeat <= PAD_LIMIT) {
return padding(repeat, str.charAt(0));
}
@ -1904,8 +1913,8 @@ public static String leftPad(String str, int size, char padChar) {
* StringUtils.leftPad("bat", 8, "yz") = "yzyzybat"
* StringUtils.leftPad("bat", 1, "yz") = "bat"
* StringUtils.leftPad("bat", -1, "yz") = "bat"
* StringUtils.leftPad("bat", 1, null) = NullPointerException
* StringUtils.leftPad("bat", 1, "") = ArithmeticException
* StringUtils.leftPad("bat", 1, null) = IllegalArgumentException
* StringUtils.leftPad("bat", 1, "") = IllegalArgumentException
* </pre>
*
* @param str the String to pad out, may be null
@ -2841,7 +2850,7 @@ public static int differenceAt(String str1, String str2) {
/**
* <p>Find the Levenshtein distance between two Strings.</p>
*
* <P>This is the number of changes needed to change one String into
* <p>This is the number of changes needed to change one String into
* another. Where each change is a single character modification.</p>
*
* <p>This implemmentation of the levenshtein distance algorithm

8
src/test/org/apache/commons/lang/StringUtilsTest.java
View File

@ -70,7 +70,7 @@
* @author <a href="mailto:fredrik@westermarck.com>Fredrik Westermarck</a>
* @author Holger Krauth
* @author <a href="hps@intermeta.de">Henning P. Schmiedehausen</a>
* @version $Id: StringUtilsTest.java,v 1.24 2003/07/16 23:45:39 scolebourne Exp $
* @version $Id: StringUtilsTest.java,v 1.25 2003/07/16 23:56:44 scolebourne Exp $
*/
public class StringUtilsTest extends TestCase {
@ -279,16 +279,12 @@ public void testOverlayString() {
}
public void testRepeat() {
assertEquals(null, StringUtils.repeat(null, 2));
assertEquals("", StringUtils.repeat("ab", 0));
assertEquals("", StringUtils.repeat("", 3));
assertEquals("aaa", StringUtils.repeat("a", 3));
assertEquals("ababab", StringUtils.repeat("ab", 3));
assertEquals("abcabcabc", StringUtils.repeat("abc", 3));
try {
StringUtils.repeat(null, 0);
fail();
} catch (NullPointerException ex) {
}
}
public void testCenter() {