Use the isEmpty method instead of comparing the value of size() to 0.

This closes #61 pull request at github/apache/ant repo

src/main/org/apache/tools/ant/ComponentHelper.java

@@ -850,7 +850,7 @@ public class ComponentHelper  {
         }
         checkedNamespaces.add(uri);
 
-        if (antTypeTable.size() == 0) {
+        if (antTypeTable.isEmpty()) {
             // Project instance doesn't know the tasks and types
             // defined in defaults.properties, likely created by the
             // user - without those definitions it cannot parse antlib

src/main/org/apache/tools/ant/Main.java

@@ -840,7 +840,7 @@ public class Main implements AntMain {
                 }
 
                 // make sure that we have a target to execute
-                if (targets.size() == 0) {
+                if (targets.isEmpty()) {
                     if (project.getDefaultTarget() != null) {
                         targets.addElement(project.getDefaultTarget());
                     }

src/main/org/apache/tools/ant/helper/AntXMLContext.java

@@ -377,7 +377,7 @@ public class AntXMLContext {
      */
     public void endPrefixMapping(String prefix) {
         List<String> list = prefixMapping.get(prefix);
-        if (list == null || list.size() == 0) {
+        if (list == null || list.isEmpty()) {
             return; // Should not happen
         }
         list.remove(list.size() - 1);
@@ -391,7 +391,7 @@ public class AntXMLContext {
      */
     public String getPrefixMapping(String prefix) {
         List<String> list = prefixMapping.get(prefix);
-        if (list == null || list.size() == 0) {
+        if (list == null || list.isEmpty()) {
             return null;
         }
         return (String) list.get(list.size() - 1);

src/main/org/apache/tools/ant/taskdefs/cvslib/CvsTagDiff.java

@@ -468,7 +468,7 @@ public class CvsTagDiff extends AbstractCvsTask {
      * @exception BuildException if a parameter is not correctly set
      */
     private void validate() throws BuildException {
-        if (null == mypackage && getModules().size() == 0) {
+        if (null == mypackage && getModules().isEmpty()) {
             throw new BuildException("Package/module must be set.");
         }
 

src/main/org/apache/tools/ant/taskdefs/optional/XMLValidateTask.java

@@ -288,7 +288,7 @@ public class XMLValidateTask extends Task {
     public void execute() throws BuildException {
         try {
             int fileProcessed = 0;
-            if (file == null && (filesets.size() == 0)) {
+            if (file == null && (filesets.isEmpty())) {
                 throw new BuildException(
                     "Specify at least one source - " + "a file or a fileset.");
             }

src/tests/junit/org/apache/tools/ant/IntrospectionHelperTest.java

@@ -739,7 +739,7 @@ public class IntrospectionHelperTest {
 
     public void addConfigured(Map m) {
         // Valid extension point
-        assertTrue(m.size() == 0);
+        assertTrue(m.isEmpty());
     }
 
     public void addConfigured(Hashtable h) {