8252999: Cleanup: replace .equals("") with .isEmpty() within all codebase

make/jdk/src/classes/build/tools/compileproperties/CompileProperties.java

@@ -260,7 +260,7 @@ private static boolean createFile(String propertiesPath, String outputPath,
             }
 
             String packageString = "";
-            if (packageName != null && !packageName.equals("")) {
+            if (packageName != null && !packageName.isEmpty()) {
                 packageString = "package " + packageName + ";\n\n";
             }
 

make/jdk/src/classes/build/tools/generatebreakiteratordata/CharacterCategory.java

@@ -119,7 +119,7 @@ public static void main(String[] args) {
          * Generates data in older format (1.4.X and earlier) and creates
          * the old CategoryMap if "oldFilename" is not null.
          */
-        if (!oldDatafile.equals("")) {
+        if (!oldDatafile.isEmpty()) {
             generateOldData();
             generateOldDatafile();
         }

make/jdk/src/classes/build/tools/generatebreakiteratordata/GenerateBreakIteratorData.java

@@ -161,8 +161,8 @@ private static void processArgs(String[] args) {
      * Make locale name ("_language_country_valiant")
      */
     private static String getLocaleName() {
-        if (language.equals("")) {
-            if (!country.equals("") || !valiant.equals("")) {
+        if (language.isEmpty()) {
+            if (!country.isEmpty() || !valiant.isEmpty()) {
                 language = "en";
             } else {
                 return "";
@@ -172,10 +172,10 @@ private static String getLocaleName() {
         StringBuffer sb = new StringBuffer();
         sb.append('_');
         sb.append(language);
-        if (!country.equals("") || !valiant.equals("")) {
+        if (!country.isEmpty() || !valiant.isEmpty()) {
             sb.append('_');
             sb.append(country);
-            if (!valiant.equals("")) {
+            if (!valiant.isEmpty()) {
                 sb.append('_');
                 sb.append(valiant);
             }

make/jdk/src/classes/build/tools/generatebreakiteratordata/RuleBasedBreakIteratorBuilder.java

@@ -2022,7 +2022,7 @@ protected void writeTables(String datafile) {
         final String outputDir;
         String tmpbuf = GenerateBreakIteratorData.getOutputDirectory();
 
-        if (tmpbuf.equals("")) {
+        if (tmpbuf.isEmpty()) {
             filename = datafile;
             outputDir = "";
         } else {
@@ -2039,7 +2039,7 @@ protected void writeTables(String datafile) {
         }
 
         try {
-            if (!outputDir.equals("")) {
+            if (!outputDir.isEmpty()) {
                 new File(outputDir).mkdirs();
             }
             BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(filename));

make/jdk/src/classes/build/tools/pandocfilter/json/JSONParser.java

@@ -375,7 +375,7 @@ public JSONValue parseValue() {
     }
 
     public JSONValue parse(String s) {
-        if (s == null || s.equals("")) {
+        if (s == null || s.isEmpty()) {
             return null;
         }
 

make/langtools/tools/anttasks/SelectToolTask.java

@@ -151,7 +151,7 @@ public void execute() {
         }
 
         // finally, return required values, if any
-        if (toolProperty != null && !(toolName == null || toolName.equals(""))) {
+        if (toolProperty != null && !(toolName == null || toolName.isEmpty())) {
             p.setProperty(toolProperty, toolName);
 
             if (argsProperty != null && toolArgs != null)
@@ -169,7 +169,7 @@ void showGUI(Properties fileProps) {
         toolName = tool.toolName;
         toolArgs = argsField.getText();
         if (defaultCheck.isSelected()) {
-            if (toolName.equals("")) {
+            if (toolName.isEmpty()) {
                 fileProps.remove("tool.name");
                 fileProps.remove("tool.bootstrap");
             } else {
@@ -243,7 +243,7 @@ public void focusLost(FocusEvent e) {
 
         final JOptionPane p = new JOptionPane(body);
         okButton = new JButton("OK");
-        okButton.setEnabled(toolProperty == null || (toolName != null && !toolName.equals("")));
+        okButton.setEnabled(toolProperty == null || (toolName != null && !toolName.isEmpty()));
         okButton.addActionListener(e -> {
             JDialog d = (JDialog) SwingUtilities.getAncestorOfClass(JDialog.class, p);
             d.setVisible(false);
@@ -304,7 +304,7 @@ String getDefaultArgsForTool(Properties props, ToolChoices tool) {
         if (tool == null)
             return "";
         String toolName = tool.toolName;
-        return toolName.equals("") ? "" : props.getProperty(toolName + ".args", "");
+        return toolName.isEmpty() ? "" : props.getProperty(toolName + ".args", "");
     }
 
     // Ant task parameters

make/langtools/tools/compileproperties/CompileProperties.java

@@ -247,7 +247,7 @@ private boolean createFile(String propertiesPath, String outputPath,
             }
 
             String packageString = "";
-            if (packageName != null && !packageName.equals("")) {
+            if (packageName != null && !packageName.isEmpty()) {
                 packageString = "package " + packageName + ";\n\n";
             }
 

src/demo/share/jfc/TableExample/JDBCAdapter.java

@@ -246,7 +246,7 @@ public void setValueAt(Object value, int row, int column) {
             // that editing is possible, we'll just lock on everything.
             for (int col = 0; col < getColumnCount(); col++) {
                 String colName = getColumnName(col);
-                if (colName.equals("")) {
+                if (colName.isEmpty()) {
                     continue;
                 }
                 if (col != 0) {

src/hotspot/share/prims/jvmtiEnvFill.java

@@ -211,7 +211,7 @@ boolean readGaps() throws IOException {
                 top.add(line);
             } else {
                 trimmed = line.trim();
-                if (!trimmed.equals("") && !trimmed.startsWith("//") && !trimmed.startsWith("#")) {
+                if (!trimmed.isEmpty() && !trimmed.startsWith("//") && !trimmed.startsWith("#")) {
                     error("only comments and blank lines allowed between functions");
                 }
                 before.add(line);

src/java.management/share/classes/javax/management/openmbean/CompositeDataSupport.java

@@ -136,7 +136,7 @@ private static SortedMap<String, Object> makeMap(
         SortedMap<String, Object> map = new TreeMap<String, Object>();
         for (int i = 0; i < itemNames.length; i++) {
             String name = itemNames[i];
-            if (name == null || name.equals(""))
+            if (name == null || name.isEmpty())
                 throw new IllegalArgumentException("Null or empty item name");
             if (map.containsKey(name))
                 throw new OpenDataException("Duplicate item name " + name);
@@ -264,7 +264,7 @@ public CompositeType getCompositeType() {
      */
     public Object get(String key) {
 
-        if ( (key == null) || (key.trim().equals("")) ) {
+        if ( (key == null) || (key.trim().isEmpty()) ) {
             throw new IllegalArgumentException("Argument key cannot be a null or empty String.");
         }
         if ( ! contents.containsKey(key.trim())) {
@@ -302,7 +302,7 @@ public Object[] getAll(String[] keys) {
      */
     public boolean containsKey(String key) {
 
-        if ( (key == null) || (key.trim().equals("")) ) {
+        if ( (key == null) || (key.trim().isEmpty()) ) {
             return false;
         }
         return contents.containsKey(key);

src/java.naming/share/classes/javax/naming/ldap/Rdn.java

@@ -195,7 +195,7 @@ public Rdn(String type, Object value) throws InvalidNameException {
         if (value == null) {
             throw new NullPointerException("Cannot set value to null");
         }
-        if (type.equals("") || isEmptyValue(value)) {
+        if (type.isEmpty() || isEmptyValue(value)) {
             throw new InvalidNameException(
                 "type or value cannot be empty, type:" + type +
                 " value:" + value);

src/java.security.jgss/share/classes/javax/security/auth/kerberos/ServicePermission.java

@@ -339,7 +339,7 @@ private static int getMask(String action) {
             throw new NullPointerException("action can't be null");
         }
 
-        if (action.equals("")) {
+        if (action.isEmpty()) {
             throw new IllegalArgumentException("action can't be empty");
         }
 

src/java.security.jgss/share/classes/sun/security/jgss/wrapper/SunNativeProvider.java

@@ -80,7 +80,7 @@ public HashMap<String, String> run() {
                         String[] gssLibs;
                         String defaultLib
                                 = System.getProperty("sun.security.jgss.lib");
-                        if (defaultLib == null || defaultLib.trim().equals("")) {
+                        if (defaultLib == null || defaultLib.trim().isEmpty()) {
                             String osname = System.getProperty("os.name");
                             if (osname.startsWith("Linux")) {
                                 gssLibs = new String[]{

src/java.security.jgss/share/classes/sun/security/krb5/Config.java

@@ -1361,7 +1361,7 @@ private String getKDCFromDNS(String realm) throws KrbException {
             kdcs += srvs[i].trim() + " ";
         }
         kdcs = kdcs.trim();
-        if (kdcs.equals("")) {
+        if (kdcs.isEmpty()) {
             return null;
         }
         return kdcs;

src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/c14n/implementations/Canonicalizer20010315.java

@@ -339,7 +339,7 @@ protected void handleParent(Element e, NameSpaceSymbTable ns) {
             String NName = e.getPrefix();
             String NValue = e.getNamespaceURI();
             String Name;
-            if (NName == null || NName.equals("")) {
+            if (NName == null || NName.isEmpty()) {
                 NName = "xmlns";
                 Name = "xmlns";
             } else {

src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/c14n/implementations/CanonicalizerBase.java

@@ -592,7 +592,7 @@ protected void handleParent(Element e, NameSpaceSymbTable ns) {
             String NName = e.getPrefix();
             String NValue = e.getNamespaceURI();
             String Name;
-            if (NName == null || NName.equals("")) {
+            if (NName == null || NName.isEmpty()) {
                 NName = XMLNS;
                 Name = XMLNS;
             } else {

src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/utils/RFC2253Parser.java

@@ -72,7 +72,7 @@ public static String normalize(String dn) {
      */
     public static String normalize(String dn, boolean toXml) {
         //if empty string
-        if (dn == null || dn.equals("")) {
+        if (dn == null || dn.isEmpty()) {
             return "";
         }
 

src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/utils/resolver/implementations/ResolverDirectHTTP.java

@@ -210,7 +210,7 @@ public boolean engineCanResolveURI(ResourceResolverContext context) {
             return false;
         }
 
-        if (context.uriToResolve.equals("") || context.uriToResolve.charAt(0) == '#') {
+        if (context.uriToResolve.isEmpty() || context.uriToResolve.charAt(0) == '#') {
             LOG.debug("quick fail for empty URIs and local ones");
             return false;
         }

src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/utils/resolver/implementations/ResolverFragment.java

@@ -58,7 +58,7 @@ public XMLSignatureInput engineResolveURI(ResourceResolverContext context)
         Document doc = context.attr.getOwnerElement().getOwnerDocument();
 
         Node selectedElem = null;
-        if (context.uriToResolve.equals("")) {
+        if (context.uriToResolve.isEmpty()) {
             /*
              * Identifies the node-set (minus any comment nodes) of the XML
              * resource containing the signature
@@ -121,7 +121,7 @@ public boolean engineCanResolveURI(ResourceResolverContext context) {
             return false;
         }
 
-        if (context.uriToResolve.equals("") ||
+        if (context.uriToResolve.isEmpty() ||
             context.uriToResolve.charAt(0) == '#' && !context.uriToResolve.startsWith("#xpointer(")
         ) {
             LOG.debug("State I can resolve reference: \"{}\"", context.uriToResolve);

src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/utils/resolver/implementations/ResolverLocalFilesystem.java

@@ -115,7 +115,7 @@ public boolean engineCanResolveURI(ResourceResolverContext context) {
             return false;
         }
 
-        if (context.uriToResolve.equals("") || context.uriToResolve.charAt(0) == '#' ||
+        if (context.uriToResolve.isEmpty() || context.uriToResolve.charAt(0) == '#' ||
             context.uriToResolve.startsWith("http:")) {
             return false;
         }

src/java.xml.crypto/share/classes/org/jcp/xml/dsig/internal/dom/DOMReference.java

@@ -165,7 +165,7 @@ public DOMReference(String uri, String type, DigestMethod dm,
         }
         this.digestMethod = dm;
         this.uri = uri;
-        if (uri != null && !uri.equals("")) {
+        if (uri != null && !uri.isEmpty()) {
             try {
                 new URI(uri);
             } catch (URISyntaxException e) {

src/java.xml.crypto/share/classes/org/jcp/xml/dsig/internal/dom/DOMRetrievalMethod.java

@@ -112,7 +112,7 @@ public DOMRetrievalMethod(String uri, String type,
             }
         }
         this.uri = uri;
-        if (!uri.equals("")) {
+        if (!uri.isEmpty()) {
             try {
                 new URI(uri);
             } catch (URISyntaxException e) {

src/java.xml/share/classes/com/sun/org/apache/xalan/internal/utils/XMLSecurityManager.java

@@ -446,14 +446,14 @@ public static void printWarning(String parserClassName, String propertyName, SAX
     private boolean getSystemProperty(Limit limit, String sysPropertyName) {
         try {
             String value = SecuritySupport.getSystemProperty(sysPropertyName);
-            if (value != null && !value.equals("")) {
+            if (value != null && !value.isEmpty()) {
                 values[limit.ordinal()] = Integer.parseInt(value);
                 states[limit.ordinal()] = State.SYSTEMPROPERTY;
                 return true;
             }
 
             value = SecuritySupport.readJAXPProperty(sysPropertyName);
-            if (value != null && !value.equals("")) {
+            if (value != null && !value.isEmpty()) {
                 values[limit.ordinal()] = Integer.parseInt(value);
                 states[limit.ordinal()] = State.JAXPDOTPROPERTIES;
                 return true;

src/java.xml/share/classes/com/sun/org/apache/xalan/internal/xsltc/compiler/XSLTC.java

@@ -460,7 +460,7 @@ public boolean compile(InputSource input, String name) {
                 if (name != null) {
                     setClassName(name);
                 }
-                else if (systemId != null && !systemId.equals("")) {
+                else if (systemId != null && !systemId.isEmpty()) {
                     setClassName(Util.baseName(systemId));
                 }
 
@@ -770,7 +770,7 @@ public int registerAttribute(QName name) {
             _attributes.put(name.toString(), code);
             final String uri = name.getNamespace();
             final String local = "@"+name.getLocalPart();
-            if ((uri != null) && (!uri.equals("")))
+            if ((uri != null) && (!uri.isEmpty()))
                 _namesIndex.add(uri+":"+local);
             else
                 _namesIndex.add(local);
@@ -810,7 +810,7 @@ public int registerNamespacePrefix(QName name) {
         code = _nextGType++;
         _namespacePrefixes.put(name.toString(), code);
         final String uri = name.getNamespace();
-        if ((uri != null) && (!uri.equals(""))){
+        if ((uri != null) && (!uri.isEmpty())){
             // namespace::ext2:ped2 will be made empty in TypedNamespaceIterator
             _namesIndex.add("?");
         } else{

src/java.xml/share/classes/com/sun/org/apache/xalan/internal/xsltc/dom/DocumentCache.java

@@ -256,7 +256,7 @@ public DOM retrieveDocument(String baseURI, String href, Translet trs) {
         CachedDocument doc;
 
     String uri = href;
-    if (baseURI != null && !baseURI.equals("")) {
+    if (baseURI != null && !baseURI.isEmpty()) {
         try {
             uri = SystemIDResolver.getAbsoluteURI(uri, baseURI);
         } catch (TransformerException te) {

src/java.xml/share/classes/com/sun/org/apache/xalan/internal/xsltc/dom/LoadDocument.java

@@ -159,13 +159,13 @@ private static DTMAxisIterator document(String uri, String base,
         MultiDOM multiplexer = (MultiDOM)dom;
 
         // Prepend URI base to URI (from context)
-        if (base != null && !base.equals("")) {
+        if (base != null && !base.isEmpty()) {
             uri = SystemIDResolver.getAbsoluteURI(uri, base);
         }
 
         // Return an empty iterator if the URI is clearly invalid
         // (to prevent some unncessary MalformedURL exceptions).
-        if (uri == null || uri.equals("")) {
+        if (uri == null || uri.isEmpty()) {
             return(EmptyIterator.getInstance());
         }
 

src/java.xml/share/classes/com/sun/org/apache/xalan/internal/xsltc/trax/SAX2DOM.java

@@ -197,7 +197,7 @@ public void startElement(String namespace, String localName, String qName,
             String attURI = attrs.getURI(i);
             String type = (attrs.getType(i) == null) ?
                     XMLSymbols.fCDATASymbol : attrs.getType(i);
-            if (attrs.getLocalName(i).equals("")) {
+            if (attrs.getLocalName(i).isEmpty()) {
                 tmp.setAttribute(attQName, attrs.getValue(i));
                 if (type.equals("ID")) {
                     tmp.setIdAttribute(attQName, true);

src/java.xml/share/classes/com/sun/org/apache/xerces/internal/dom/DocumentImpl.java

@@ -542,7 +542,7 @@ protected void addEventListener(NodeImpl node, String type,
     {
         // We can't dispatch to blank type-name, and of course we need
         // a listener to dispatch to
-        if (type == null || type.equals("") || listener == null)
+        if (type == null || type.isEmpty() || listener == null)
             return;
 
         // Each listener may be registered only once per type per phase.
@@ -586,7 +586,7 @@ protected void removeEventListener(NodeImpl node, String type,
                                        boolean useCapture)
     {
         // If this couldn't be a valid listener registration, ignore request
-        if (type == null || type.equals("") || listener == null)
+        if (type == null || type.isEmpty() || listener == null)
             return;
         List<LEntry> nodeListeners = getEventListeners(node);
         if (nodeListeners == null)
@@ -690,7 +690,7 @@ protected boolean dispatchEvent(NodeImpl node, Event event) {
 
         // VALIDATE -- must have been initialized at least once, must have
         // a non-null non-blank name.
-        if(!evt.initialized || evt.type == null || evt.type.equals("")) {
+        if(!evt.initialized || evt.type == null || evt.type.isEmpty()) {
             String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "UNSPECIFIED_EVENT_TYPE_ERR", null);
             throw new EventException(EventException.UNSPECIFIED_EVENT_TYPE_ERR, msg);
         }

src/java.xml/share/classes/com/sun/org/apache/xerces/internal/impl/XMLStreamReaderImpl.java

@@ -1051,7 +1051,7 @@ public String getNamespacePrefix(int index) {
                 || fEventType == XMLEvent.NAMESPACE) {
             //namespaceContext is dynamic object.
             String prefix = fScanner.getNamespaceContext().getDeclaredPrefixAt(index);
-            return prefix.equals("") ? null : prefix;
+            return prefix.isEmpty() ? null : prefix;
         } else {
             throw new IllegalStateException("Current state " + getEventTypeString(fEventType)
                     + " is not among the states " + getEventTypeString(XMLEvent.START_ELEMENT)