Replaced String concatenation in loop

K0zka · K0zka · commit 8d801bffab68 · 2014-02-09T21:27:28.000+01:00
Replaced String concatenation in loop with StringBuilder
Unit test added

Signed-off-by: Laszlo Hornyak &lt;laszlo.hornyak@gmail.com&gt;
diff --git a/utils/src/com/cloud/utils/StringUtils.java b/utils/src/com/cloud/utils/StringUtils.java
@@ -95,17 +95,17 @@ public static List<String> csvTagsToList(String tags) {
      */
 
     public static String listToCsvTags(List<String> tagsList) {
-        String tags = "";
+        StringBuilder tags = new StringBuilder();
         if (tagsList.size() > 0) {
             for (int i = 0; i < tagsList.size(); i++) {
-                tags += tagsList.get(i);
+                tags.append(tagsList.get(i));
                 if (i != tagsList.size() - 1) {
-                    tags += ",";
+                    tags.append(',');
                 }
             }
         }
 
-        return tags;
+        return tags.toString();
     }
 
     public static String getExceptionStackInfo(Throwable e) {
diff --git a/utils/test/com/cloud/utils/StringUtilsTest.java b/utils/test/com/cloud/utils/StringUtilsTest.java
@@ -18,6 +18,11 @@
 
 import static org.junit.Assert.assertEquals;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import junit.framework.Assert;
+
 import org.junit.Test;
 
 public class StringUtilsTest {
@@ -216,4 +221,10 @@ public void testCleanSecretkeyFromRequestString() {
         String result = StringUtils.cleanString(input);
         assertEquals(result, expected);
     }
+
+    @Test
+    public void listToCsvTags() {
+        Assert.assertEquals("a,b,c", StringUtils.listToCsvTags(Arrays.asList("a","b", "c")));
+        Assert.assertEquals("", StringUtils.listToCsvTags(new ArrayList<String>()));
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -95,17 +95,17 @@ public static List<String> csvTagsToList(String tags) {`
`95`	`95`	`*/`
`96`	`96`
`97`	`97`	`public static String listToCsvTags(List<String> tagsList) {`
`98`		`- String tags = "";`
	`98`	`+ StringBuilder tags = new StringBuilder();`
`99`	`99`	`if (tagsList.size() > 0) {`
`100`	`100`	`for (int i = 0; i < tagsList.size(); i++) {`
`101`		`- tags += tagsList.get(i);`
	`101`	`+ tags.append(tagsList.get(i));`
`102`	`102`	`if (i != tagsList.size() - 1) {`
`103`		`- tags += ",";`
	`103`	`+ tags.append(',');`
`104`	`104`	`}`
`105`	`105`	`}`
`106`	`106`	`}`
`107`	`107`
`108`		`- return tags;`
	`108`	`+ return tags.toString();`
`109`	`109`	`}`
`110`	`110`
`111`	`111`	`public static String getExceptionStackInfo(Throwable e) {`