use Locale.ROOT for equalsIgnoreCase

src/main/java/org/apache/xmlbeans/SchemaProperty.java

@@ -27,7 +27,7 @@
  * can only be defined once, so each attribute obviously is a coherent
  * group on its own.
  * <p>
- * A SchemaProperty represents a summary of the the elements with a
+ * A SchemaProperty represents a summary of the elements with a
  * given name or the attribute with a given name.  It represents the
  * summary cardinality of the fields, the summary default and fixed
  * values, and so on.  When inferring information about an element

src/main/java/org/apache/xmlbeans/SchemaTypeSystem.java

@@ -31,7 +31,7 @@
  * <p>
  * Since every component is defined in a single SchemaTypeSystem, no
  * SchemaTypeSystem other than {@link XmlBeans#getBuiltinTypeSystem()}
- * includes any of the the built-in types.  That means
+ * includes any of the built-in types.  That means
  * you cannot ordinarily load instances using a single
  * SchemaTypeSystem by itself. Instead, you will want to combine a path of
  * SchemaTypeSystems together using {@link XmlBeans#typeLoaderUnion}

src/main/java/org/apache/xmlbeans/XmlDocumentProperties.java

@@ -15,6 +15,8 @@
 
 package org.apache.xmlbeans;
 
+import static org.apache.xmlbeans.impl.util.StringUtil.equalsIgnoreCase;
+
 /**
  * This class is used to attach arbitrary information to an XML
  * document.  It also defines several well-known types of
@@ -81,7 +83,7 @@ public abstract class XmlDocumentProperties
      */
     public boolean getStandalone ( ) {
         Object flag = get( STANDALONE );
-        return flag != null && flag.toString().equalsIgnoreCase("true");
+        return flag != null && equalsIgnoreCase(flag.toString(), "true");
     }
 
     /**

src/main/java/org/apache/xmlbeans/impl/common/NameUtil.java

@@ -18,6 +18,8 @@
 import javax.xml.namespace.QName;
 import java.util.*;
 
+import static org.apache.xmlbeans.impl.util.StringUtil.equalsIgnoreCase;
+
 public class NameUtil {
     // punctuation characters
     public final static char HYPHEN = '\u002D';
@@ -436,7 +438,7 @@ private static List<String> splitDNS(String dns) {
 
         // JAXB draft example implies removal of www
         if (result.size() >= 3 &&
-            result.get(result.size() - 1).toLowerCase(Locale.ROOT).equals("www")) {
+            equalsIgnoreCase(result.get(result.size() - 1), "www")) {
             result.remove(result.size() - 1);
         }
 
@@ -450,7 +452,7 @@ private static String processFilename(String filename) {
         if (i > 0 && (
             i + 1 + 2 == filename.length() ||
             i + 1 + 3 == filename.length() ||
-            "html".equals(filename.substring(i + 1).toLowerCase(Locale.ROOT)))) {
+            equalsIgnoreCase("html", filename.substring(i + 1)))) {
             return filename.substring(0, i);
         }
 

src/main/java/org/apache/xmlbeans/impl/schema/StscState.java

@@ -33,6 +33,8 @@
 import java.util.*;
 import java.util.function.Consumer;
 
+import static org.apache.xmlbeans.impl.util.StringUtil.equalsIgnoreCase;
+
 /**
  * This class represents the state of the SchemaTypeSystemCompiler as it's
  * going.
@@ -428,14 +430,14 @@ public boolean shouldDownloadURI(String uriString) {
 
         try {
             URI uri = new URI(uriString);
-            if (uri.getScheme().equalsIgnoreCase("jar") ||
-                uri.getScheme().equalsIgnoreCase("zip")) {
+            if (equalsIgnoreCase(uri.getScheme(), "jar") ||
+                    equalsIgnoreCase(uri.getScheme(), "zip")) {
                 // It may be local or not, depending on the embedded URI
                 String s = uri.getSchemeSpecificPart();
                 int i = s.lastIndexOf('!');
                 return shouldDownloadURI(i > 0 ? s.substring(0, i) : s);
             }
-            return uri.getScheme().equalsIgnoreCase("file");
+            return equalsIgnoreCase(uri.getScheme(), "file");
         } catch (Exception e) {
             return false;
         }

src/main/java/org/apache/xmlbeans/impl/soap/MimeHeaders.java

@@ -18,6 +18,8 @@
 import java.util.Iterator;
 import java.util.Vector;
 
+import static org.apache.xmlbeans.impl.util.StringUtil.equalsIgnoreCase;
+
 /**
  * A container for {@code MimeHeader} objects, which
  *   represent the MIME headers present in a MIME part of a
@@ -48,7 +50,7 @@ private MimeHeader nextMatch() {
                 }
 
                 for (String name : names) {
-                    if (!mimeheader.getName().equalsIgnoreCase(name)) {
+                    if (!equalsIgnoreCase(mimeheader.getName(), name)) {
                         continue;
                     }
 
@@ -133,13 +135,13 @@ public MimeHeaders() {
      */
     public String[] getHeader(String name) {
 
-        Vector vector = new Vector<>();
+        Vector<String> vector = new Vector<>();
 
         for (int i = 0; i < headers.size(); i++) {
             MimeHeader mimeheader = headers.elementAt(i);
 
-            if (mimeheader.getName().equalsIgnoreCase(name)
-                    && (mimeheader.getValue() != null)) {
+            if (equalsIgnoreCase(mimeheader.getName(), name)
+                    && mimeheader.getValue() != null) {
                 vector.addElement(mimeheader.getValue());
             }
         }
@@ -184,7 +186,7 @@ public void setHeader(String name, String value) {
         for (int i = 0; i < headers.size(); i++) {
             MimeHeader mimeheader = headers.elementAt(i);
 
-            if (mimeheader.getName().equalsIgnoreCase(name)) {
+            if (equalsIgnoreCase(mimeheader.getName(), name)) {
                 if (!flag) {
                     headers.setElementAt(new MimeHeader(mimeheader
                         .getName(), value), i);
@@ -228,7 +230,7 @@ public void addHeader(String name, String value) {
         for (int j = i - 1; j >= 0; j--) {
             MimeHeader mimeheader = headers.elementAt(j);
 
-            if (mimeheader.getName().equalsIgnoreCase(name)) {
+            if (equalsIgnoreCase(mimeheader.getName(), name)) {
                 headers.insertElementAt(new MimeHeader(name, value), j + 1);
 
                 return;
@@ -240,16 +242,16 @@ public void addHeader(String name, String value) {
 
     /**
      * Remove all {@code MimeHeader} objects whose name
-     * matches the the given name.
+     * matches the given name.
      * @param  name  a {@code String} with the
      *     name of the header for which to search
      */
     public void removeHeader(String name) {
 
         for (int i = 0; i < headers.size(); i++) {
-            MimeHeader mimeheader = (MimeHeader) headers.elementAt(i);
+            MimeHeader mimeheader = headers.elementAt(i);
 
-            if (mimeheader.getName().equalsIgnoreCase(name)) {
+            if (equalsIgnoreCase(mimeheader.getName(), name)) {
                 headers.removeElementAt(i--);
             }
         }

src/main/java/org/apache/xmlbeans/impl/soap/Node.java

@@ -24,7 +24,7 @@
 public interface Node extends org.w3c.dom.Node {
 
     /**
-     * Returns the the value of the immediate child of this {@code Node}
+     * Returns the value of the immediate child of this {@code Node}
      * object if a child exists and its value is text.
      * @return  a {@code String} with the text of the immediate child of
      *    this {@code Node} object if (1) there is a child and

src/main/java/org/apache/xmlbeans/impl/soap/SOAPHeader.java

@@ -95,7 +95,7 @@ SOAPHeaderElement addHeaderElement(Name name)
     /**
      * Returns a list of all the {@code SOAPHeaderElement}
      *   objects in this {@code SOAPHeader} object that have
-     *   the the specified actor and detaches them from this {@code
+     *   the specified actor and detaches them from this {@code
      *   SOAPHeader} object.
      *
      *   <P>This method allows an actor to process only the parts of

src/main/java/org/apache/xmlbeans/impl/store/CharUtil.java

@@ -455,7 +455,7 @@ public Object saveChars(
         int cchMore = cchSave - cchAlloc;
 
         if (cchMore > 0) {
-            // If we're here the the buffer got consumed.  So, this time it must allocate a new
+            // If we're here the buffer got consumed.  So, this time it must allocate a new
             // buffer capable of containing all of the remaining text (no matter how large) and
             // return the beginning part of it.
 

src/main/java/org/apache/xmlbeans/impl/store/DomImpl.java

@@ -34,6 +34,8 @@
 import java.util.function.Function;
 import java.util.function.Supplier;
 
+import static org.apache.xmlbeans.impl.util.StringUtil.equalsIgnoreCase;
+
 // DOM Level 3
 
 public final class DomImpl {
@@ -598,16 +600,16 @@ public static boolean _domImplementation_hasFeature(Locale l, String feature, St
             return false;
         }
 
-        if (version != null && version.length() > 0 &&
+        if (version != null && !version.isEmpty() &&
             !version.equals("1.0") && !version.equals("2.0")) {
             return false;
         }
 
-        if (feature.equalsIgnoreCase("core")) {
+        if (equalsIgnoreCase(feature, "core")) {
             return true;
         }
 
-        return feature.equalsIgnoreCase("xml");
+        return equalsIgnoreCase(feature, "xml");
     }
 
     //////////////////////////////////////////////////////////////////////////////////////

src/main/java/org/apache/xmlbeans/impl/store/Locale.java

@@ -48,6 +48,7 @@
 import java.util.Map;
 import java.util.Objects;
 
+import static org.apache.xmlbeans.impl.util.StringUtil.equalsIgnoreCase;
 import static org.apache.xmlbeans.impl.values.TypeStore.*;
 
 @SuppressWarnings("SynchronizationOnLocalVariableOrMethodParameter")
@@ -2183,7 +2184,7 @@ protected boolean isAttrOfTypeId(QName aqn, QName eqn) {
                 // as most documents are either without schema or based on xml schema
                 // which ID attributes aren't promoted by the SAXParser, the workaround
                 // is to simply accept all "id" attributes
-                return "id".equalsIgnoreCase(aqn.getLocalPart());
+                return equalsIgnoreCase("id", aqn.getLocalPart());
             }
             String pre = aqn.getPrefix();
             String lName = aqn.getLocalPart();

src/main/java/org/apache/xmlbeans/impl/store/Xobj.java

@@ -1382,7 +1382,7 @@ void disconnectChildrenUsers() {
      * with a return value of null, which indicates an illegal
      * state, where there is no mapping for the given prefix.
      * <p>
-     * If the the default namespace is not explicitly mapped in the xml,
+     * If the default namespace is not explicitly mapped in the xml,
      * the xml spec says that it should be mapped to the no-namespace.
      * When the 'defaultAlwaysMapped' parameter is true, the default namepsace
      * will return the no-namespace even if it is not explicity

src/main/java/org/apache/xmlbeans/impl/tool/XMLBean.java

@@ -545,7 +545,7 @@ public void setFork(boolean f) {
     }
 
     /**
-     * Sets the the name of the javac executable.
+     * Sets the name of the javac executable.
      *
      * <p>Ignored unless fork is true or extJavac has been specified
      * as the compiler.</p>

src/main/java/org/apache/xmlbeans/impl/util/MathUtil.java

@@ -1,20 +1,3 @@
-/* ====================================================================
-   Licensed to the Apache Software Foundation (ASF) under one or more
-   contributor license agreements.  See the NOTICE file distributed with
-   this work for additional information regarding copyright ownership.
-   The ASF licenses this file to You under the Apache License, Version 2.0
-   (the "License"); you may not use this file except in compliance with
-   the License.  You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-==================================================================== */
-
 /* ====================================================================
    Licensed to the Apache Software Foundation (ASF) under one or more
    contributor license agreements.  See the NOTICE file distributed with
@@ -34,7 +17,7 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 package org.apache.xmlbeans.impl.util;
 
 /**
- * Utility methods for dealing with conversions
+ * Internal Use Only. Utility methods for dealing with conversions
  */
 public class MathUtil {
     private MathUtil() {}

src/main/java/org/apache/xmlbeans/impl/util/StringUtil.java

@@ -0,0 +1,41 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+package org.apache.xmlbeans.impl.util;
+
+import java.util.Locale;
+
+/**
+ * Internal Use Only.
+ * @since 5.4.0
+ */
+public class StringUtil {
+    private StringUtil() {}
+
+    /**
+     * Uses Locale.ROOT. Does null safe checks.
+     */
+    public static boolean equalsIgnoreCase(String s1, String s2) {
+        if (s1 == null) {
+            return s2 == null;
+        } else if (s2 == null) {
+            return false;
+        } else if (s1.length() != s2.length()) {
+            return false;
+        }
+        return s1.toLowerCase(Locale.ROOT).equals(s2.toLowerCase(Locale.ROOT));
+    }
+}

src/test/java/org/apache/xmlbeans/impl/util/TestStringUtil.java

@@ -0,0 +1,38 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+package org.apache.xmlbeans.impl.util;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class TestStringUtil {
+    @Test
+    void equalsIgnoreCase() {
+        assertTrue(StringUtil.equalsIgnoreCase(null, null), "2 nulls are equal");
+        assertFalse(StringUtil.equalsIgnoreCase(null, ""), "null and empty strings are not equal");
+        assertFalse(StringUtil.equalsIgnoreCase("", null), "null and empty strings are not equal");
+        assertFalse(StringUtil.equalsIgnoreCase("abc", "abcd"), "different lengths do not match");
+        assertFalse(StringUtil.equalsIgnoreCase("abcd", "abc"), "different lengths do not match");
+        assertTrue(StringUtil.equalsIgnoreCase("abc", "abc"), "abc and abc match");
+        assertTrue(StringUtil.equalsIgnoreCase("abc", "Abc"), "abc and Abc match");
+        assertFalse(StringUtil.equalsIgnoreCase("İ", "i"), "Turkish dotted İ and i do not match (root locale)");
+        assertFalse(StringUtil.equalsIgnoreCase("İ", "I"), "Turkish dotted İ and I do not match (root locale)");
+        assertFalse(StringUtil.equalsIgnoreCase("ı", "I"), "Turkish dotless ı and I do not match (root locale)");
+    }
+}

src/test/java/org/w3c/domts/level2/core/attrgetownerelement01.java

@@ -33,7 +33,7 @@
 /**
  * The "getOwnerElement()" will return the Element node this attribute is attached to or
  * null if this attribute is not in use.
- * Retreive the default attribute defaultAttr and check its owner element.  Verify if the name
+ * Retrieve the default attribute defaultAttr and check its owner element.  Verify if the name
  * the nodeName of the returned ownerElement is emp:employee.
  *
  * @see <a href="http://www.w3.org/TR/DOM-Level-2-Core/core#Attr-ownerElement">http://www.w3.org/TR/DOM-Level-2-Core/core#Attr-ownerElement</a>

test/docs/BuildingAndRunningTests.txt

@@ -6,7 +6,7 @@ Requirements:
 * Ensure  JAVA_HOME and ANT_HOME (Requires Ant 1.6 or higher) are set up in your environment
 
 
-BUILING AND RUNNING CHECKIN TESTS:
+BUILDING AND RUNNING CHECKIN TESTS:
 (NOTE: does not perform a checkin, just runs tests)
 It is recommended that you call at least clean.tests before a checkintest run.