[optimize] Replace StringWriter with StringBuilderWriter

Author: adamretter

exist-core/pom.xml

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -21,6 +45,8 @@
  */
 package org.exist.backup;
 
+import org.apache.commons.io.output.StringBuilderWriter;
+
 import java.io.*;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
@@ -38,7 +64,7 @@ public class ZipWriter implements BackupWriter
 {
     private String currentPath;
     private final ZipOutputStream out;
-    private StringWriter contents;
+    private StringBuilderWriter contents;
     private boolean dataWritten = false;
 
     public ZipWriter(final String zipFile, final String collection) throws IOException
@@ -53,9 +79,9 @@ public ZipWriter(final Path zipFile, final String collection) throws IOException
         currentPath = collection;
     }
 
-    public Writer newContents() throws IOException
+    public Writer newContents()
     {
-        contents = new StringWriter();
+        contents = new StringBuilderWriter();
         return( contents );
     }
 

exist-core/src/main/java/org/exist/backup/ZipWriter.java

@@ -45,6 +45,7 @@
  */
 package org.exist.client;
 
+import org.apache.commons.io.output.StringBuilderWriter;
 import org.exist.SystemProperties;
 import org.exist.backup.Backup;
 import org.exist.backup.CreateBackupDialog;
@@ -1750,16 +1751,17 @@ public static void showErrorMessage(final String message, final Throwable t) {
         msgArea.setEditable(false);
         msgArea.setBackground(null);
         if (t != null) {
-            final StringWriter out = new StringWriter();
-            final PrintWriter writer = new PrintWriter(out);
-            t.printStackTrace(writer);
-            final JTextArea stacktrace = new JTextArea(out.toString(), 20, 50);
-            stacktrace.setBackground(null);
-            stacktrace.setEditable(false);
-            scroll = new JScrollPane(stacktrace);
-            scroll.setPreferredSize(new Dimension(250, 300));
-            scroll.setBorder(BorderFactory
+            try (final StringBuilderWriter out = new StringBuilderWriter();
+                 final PrintWriter writer = new PrintWriter(out)) {
+                t.printStackTrace(writer);
+                final JTextArea stacktrace = new JTextArea(out.toString(), 20, 50);
+                stacktrace.setBackground(null);
+                stacktrace.setEditable(false);
+                scroll = new JScrollPane(stacktrace);
+                scroll.setPreferredSize(new Dimension(250, 300));
+                scroll.setBorder(BorderFactory
                     .createTitledBorder(Messages.getString("ClientFrame.215"))); //$NON-NLS-1$
+            }
         }
         final JOptionPane optionPane = new JOptionPane();
         optionPane.setMessage(new Object[]{msgArea, scroll});
@@ -1783,7 +1785,7 @@ public static int showErrorMessageQuery(final String message, final Throwable t)
 
         JScrollPane scrollStacktrace = null;
         if (t != null) {
-            try (final StringWriter out = new StringWriter();
+            try (final StringBuilderWriter out = new StringBuilderWriter();
                  final PrintWriter writer = new PrintWriter(out)) {
                 t.printStackTrace(writer);
                 final JTextArea stacktrace = new JTextArea(out.toString(), 20, 50);
@@ -1795,8 +1797,6 @@ public static int showErrorMessageQuery(final String message, final Throwable t)
                 scrollStacktrace.setPreferredSize(new Dimension(600, 300));
                 scrollStacktrace.setBorder(BorderFactory
                         .createTitledBorder(Messages.getString("ClientFrame.218"))); //$NON-NLS-1$
-            } catch (final IOException ioe) {
-                ioe.printStackTrace();
             }
         }
 

exist-core/src/main/java/org/exist/client/ClientFrame.java

@@ -83,6 +83,7 @@
 import javax.swing.border.BevelBorder;
 import javax.xml.transform.OutputKeys;
 
+import org.apache.commons.io.output.StringBuilderWriter;
 import org.exist.security.Account;
 import org.exist.storage.ElementIndex;
 import org.exist.util.ProgressIndicator;
@@ -186,16 +187,17 @@ private static void showErrorMessage(String message, Throwable t) {
         msgArea.setEditable(false);
         msgArea.setBackground(null);
         if (t != null) {
-            final StringWriter out = new StringWriter();
-            final PrintWriter writer = new PrintWriter(out);
-            t.printStackTrace(writer);
-            final JTextArea stacktrace = new JTextArea(out.toString(), 20, 50);
-            stacktrace.setBackground(null);
-            stacktrace.setEditable(false);
-            scroll = new JScrollPane(stacktrace);
-            scroll.setPreferredSize(new Dimension(250, 300));
-            scroll.setBorder(BorderFactory
+            try (final StringBuilderWriter out = new StringBuilderWriter();
+                 final PrintWriter writer = new PrintWriter(out)) {
+                t.printStackTrace(writer);
+                final JTextArea stacktrace = new JTextArea(out.toString(), 20, 50);
+                stacktrace.setBackground(null);
+                stacktrace.setEditable(false);
+                scroll = new JScrollPane(stacktrace);
+                scroll.setPreferredSize(new Dimension(250, 300));
+                scroll.setBorder(BorderFactory
                     .createTitledBorder("Exception Stacktrace:")); //$NON-NLS-1$
+            }
         }
         final JOptionPane optionPane = new JOptionPane();
         optionPane.setMessage(new Object[]{msgArea, scroll});

exist-core/src/main/java/org/exist/client/DocumentView.java

@@ -86,6 +86,7 @@
 import javax.swing.event.PopupMenuListener;
 import javax.xml.transform.OutputKeys;
 
+import org.apache.commons.io.output.StringBuilderWriter;
 import org.exist.security.PermissionDeniedException;
 import org.exist.util.Holder;
 import org.exist.xmldb.EXistXQueryService;
@@ -538,9 +539,10 @@ private void compileQuery() {
             tCompiled = t1 - t0;
 
             // In this way we can see the parsed structure meanwhile the query is
-            final StringWriter writer = new StringWriter();
-            service.dump(compiled, writer);
-            exprDisplay.setText(writer.toString());
+            try (final StringBuilderWriter writer = new StringBuilderWriter()) {
+                service.dump(compiled, writer);
+                exprDisplay.setText(writer.toString());
+            }
             resultTabs.setSelectedComponent(exprDisplayScrollPane);
 
             statusMessage.setText(Messages.getString(QUERY_DIALOG_COMPILATION) + ": " + tCompiled + "ms");
@@ -610,9 +612,10 @@ public void run() {
                 tCompiled = t1 - t0;
 
                 // In this way we can see the parsed structure meanwhile the query is
-                StringWriter writer = new StringWriter();
-                service.dump(compiled, writer);
-                exprDisplay.setText(writer.toString());
+                try (final StringBuilderWriter writer = new StringBuilderWriter()) {
+                    service.dump(compiled, writer);
+                    exprDisplay.setText(writer.toString());
+                }
 
                 result = service.execute(compiled);
                 tResult = System.currentTimeMillis() - t1;
@@ -623,9 +626,10 @@ public void run() {
                 }
 
                 // jmfg: Is this still needed? I don't think so
-                writer = new StringWriter();
-                service.dump(compiled, writer);
-                exprDisplay.setText(writer.toString());
+                try (final StringBuilderWriter writer = new StringBuilderWriter()) {
+                    service.dump(compiled, writer);
+                    exprDisplay.setText(writer.toString());
+                }
 
                 statusMessage.setText(Messages.getString("QueryDialog.retrievingmessage"));
                 final int howmany = count.getNumber().intValue();

exist-core/src/main/java/org/exist/client/QueryDialog.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -47,6 +71,7 @@
 import javax.xml.parsers.SAXParser;
 import javax.xml.parsers.SAXParserFactory;
 
+import org.apache.commons.io.output.StringBuilderWriter;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.exist.Database;
@@ -1267,24 +1292,22 @@ public static DocumentImpl save(final DBBroker broker, final Configurable instan
     protected static final Set<FullXmldbURI> saving = new ConcurrentSkipListSet<>();
 
     public static DocumentImpl save(final Configurable instance, final DBBroker broker, final Collection collection, final XmldbURI uri) throws IOException, ConfigurationException {
-        
-        final StringWriter writer = new StringWriter();
-        final SAXSerializer serializer = new SAXSerializer(writer, null);
-        
-        try {
+        final String data;
+        try (final StringBuilderWriter writer = new StringBuilderWriter()) {
+            final SAXSerializer serializer = new SAXSerializer(writer, null);
+
             serializer.startDocument();
             serialize(instance, serializer);
             serializer.endDocument();
-            
+
+            data = writer.toString();
+            if (data == null || data.isEmpty()) {
+                return null;
+            }
         } catch (final SAXException saxe) {
             throw new ConfigurationException(saxe.getMessage(), saxe);
         }
 
-        final String data = writer.toString();
-        if (data == null || data.length() == 0) {
-            return null;
-        }
-        
         FullXmldbURI fullURI = null;
         final BrokerPool pool = broker.getBrokerPool();
         final TransactionManager transact = pool.getTransactionManager();

exist-core/src/main/java/org/exist/config/Configurator.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -21,6 +45,7 @@
  */
 package org.exist.dom.persistent;
 
+import org.apache.commons.io.output.StringBuilderWriter;
 import org.apache.commons.io.output.UnsynchronizedByteArrayOutputStream;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -32,7 +57,6 @@
 import javax.xml.transform.TransformerException;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.StringWriter;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -52,14 +76,14 @@ private XMLUtil() {
     }
 
     public static final String dump(final DocumentFragment fragment) {
-        final StringWriter writer = new StringWriter();
-        final DOMSerializer serializer = new DOMSerializer(writer, null);
-        try {
+        try (final StringBuilderWriter writer = new StringBuilderWriter()) {
+            final DOMSerializer serializer = new DOMSerializer(writer, null);
             serializer.serialize(fragment);
+            return writer.toString();
         } catch(final TransformerException e) {
             //Nothing to do ?
         }
-        return writer.toString();
+        return null;
     }
 
     public static final String encodeAttrMarkup(final String str) {

exist-core/src/main/java/org/exist/dom/persistent/XMLUtil.java

@@ -45,6 +45,7 @@
  */
 package org.exist.http;
 
+import org.apache.commons.io.output.StringBuilderWriter;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.exist.EXistException;
@@ -1301,15 +1302,16 @@ private String getRequestContent(final HttpServletRequest request) throws IOExce
 
         final InputStream is = request.getInputStream();
         final Reader reader = new InputStreamReader(is, encoding);
-        final StringWriter content = new StringWriter();
-        final char ch[] = new char[4096];
-        int len = 0;
-        while ((len = reader.read(ch)) > -1) {
-            content.write(ch, 0, len);
-        }
+        try (final StringBuilderWriter content = new StringBuilderWriter()) {
+            final char ch[] = new char[4096];
+            int len = 0;
+            while ((len = reader.read(ch)) > -1) {
+                content.write(ch, 0, len);
+            }
 
-        final String xml = content.toString();
-        return xml;
+            final String xml = content.toString();
+            return xml;
+        }
     }
 
     /**

exist-core/src/main/java/org/exist/http/RESTServer.java

@@ -46,7 +46,6 @@
 package org.exist.management.client;
 
 import java.io.IOException;
-import java.io.StringWriter;
 
 import static com.evolvedbinary.j8fu.tuple.Tuple.Tuple;
 import static java.lang.management.ManagementFactory.CLASS_LOADING_MXBEAN_NAME;
@@ -71,6 +70,7 @@
 import javax.xml.transform.TransformerException;
 
 import com.evolvedbinary.j8fu.tuple.Tuple2;
+import org.apache.commons.io.output.StringBuilderWriter;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.exist.dom.QName;
@@ -208,10 +208,11 @@ public void connect(final String address, final int port) throws MalformedURLExc
      */
     public String generateReport(final String categories[]) throws TransformerException {
         final Element root = generateXMLReport(null, categories);
-        final StringWriter writer = new StringWriter();
-        final DOMSerializer streamer = new DOMSerializer(writer, defaultProperties);
-        streamer.serialize(root);
-        return writer.toString();
+        try (final StringBuilderWriter writer = new StringBuilderWriter()) {
+            final DOMSerializer streamer = new DOMSerializer(writer, defaultProperties);
+            streamer.serialize(root);
+            return writer.toString();
+        }
     }
 
     /**