Enhanced ImportOrder check to support wildcard ('*') groups. Thanks to Steve McKay for patch #2891032.

src/checkstyle/com/puppycrawl/tools/checkstyle/checks/imports/ImportOrderCheck.java

@@ -25,7 +25,6 @@ import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 import com.puppycrawl.tools.checkstyle.checks.AbstractOptionCheck;
 
 /**
- * Class to check the ordering/grouping of imports. Features are:
  * <ul>
  * <li>groups imports: ensures that groups of imports come in a specific order
  * (e.g., java. comes first, javax. comes second, then everything else)</li>
@@ -54,9 +53,10 @@ import com.puppycrawl.tools.checkstyle.checks.AbstractOptionCheck;
  * </pre>
  *
  * <p>
- * There is always an additional, implied &quot;everything else&quot; package
- * group. If no &quot;groups&quot; property is supplied, all imports belong in
- * this &quot;everything else&quot; group.
+ * There is always a wildcard group to which everything not in a named group
+ * belongs. If an import does not match a named group, the group belongs to
+ * this wildcard group. The wildcard group position can be specified using the
+ * {@code *} character.
  * </p>
  *
  * <p>
@@ -77,12 +77,19 @@ import com.puppycrawl.tools.checkstyle.checks.AbstractOptionCheck;
  * @author Bill Schneider
  * @author o_sukhodolsky
  * @author David DIDIER
+ * @author Steve McKay
  */
 public class ImportOrderCheck
     extends AbstractOptionCheck<ImportOrderOption>
 {
+
+    /** the special wildcard that catches all remaining groups. */
+    private static final String WILDCARD_GROUP_NAME = "*";
+
     /** List of import groups specified by the user. */
     private String[] mGroups = new String[0];
+    /** The position of the "everything else" group. */
+    private int mWildcardGroupIndex;
     /** Require imports in group be separated. */
     private boolean mSeparated;
     /** Require imports in group. */
@@ -123,7 +130,12 @@ public class ImportOrderCheck
         for (int i = 0; i < aGroups.length; i++) {
             String pkg = aGroups[i];
 
-            if (!pkg.endsWith(".")) {
+            // if the pkg name is the wildcard, record the
+            // position for later reference
+            if (WILDCARD_GROUP_NAME.equals(pkg)) {
+                mWildcardGroupIndex = i;
+            }
+            else if (!pkg.endsWith(".")) {
                 pkg = pkg + ".";
             }
 
@@ -333,17 +345,16 @@ public class ImportOrderCheck
      */
     private int getGroupNumber(String aName)
     {
-        int i = 0;
-
         // find out what group this belongs in
         // loop over mGroups and get index
-        for (; i < mGroups.length; i++) {
+        for (int i = 0; i < mGroups.length; i++) {
             if (aName.startsWith(mGroups[i])) {
-                break;
+                return i;
             }
         }
 
-        return i;
+        // no match, so we return the wildcard group
+        return mWildcardGroupIndex;
     }
 
     /**

src/testinputs/com/puppycrawl/tools/checkstyle/imports/InputImportOrder_Wildcard.java

@@ -0,0 +1,12 @@
+
+// groups are configured as follows
+// com.puppycrawl,*,java
+// the trailing javax.crypto.Cipher; should be flagged as an error.
+
+import com.puppycrawl.tools.checkstyle.imports.InputImportOrder_Above;
+import javax.crypto.BadPaddingException;
+import java.util.List;
+import javax.crypto.Cipher;
+
+public class InputImportOrder_Wildcard {
+}

src/tests/com/puppycrawl/tools/checkstyle/checks/imports/ImportOrderCheckTest.java

@@ -141,4 +141,16 @@ public class ImportOrderCheckTest extends BaseCheckTestSupport
 
         verify(checkConfig, getPath("imports" + File.separator + "InputImportOrder_Bottom.java"), expected);
     }
+
+    @Test
+    public void testWildcard() throws Exception
+    {
+        final DefaultConfiguration checkConfig = createCheckConfig(ImportOrderCheck.class);
+        checkConfig.addAttribute("groups", "com,*,java");
+        final String[] expected = {
+                "9: Wrong order for 'javax.crypto.Cipher' import."
+        };
+
+        verify(checkConfig, getPath("imports" + File.separator + "InputImportOrder_Wildcard.java"), expected);
+    }
 }

src/xdocs/releasenotes.xml

@@ -12,6 +12,10 @@
     <section name="Release 5.1">
       <p>New features:</p>
       <ul>
+        <li>
+          Enhanced ImportOrder check to support wildcard ('*') groups.
+          Thanks to Steve McKay for patch #2891032.
+        </li>
         <li>
           Enhanced the naming checks ConstantName, MemberName, MethodName
           and StaticVariableName to utilise the access control tuning features