Deprecate Utility for removal (gwtproject#10083)

This class is an odd mix of useful methods, and was used all over the
code base. Many of the methods have a better way to implement them in
modern Java (try-with-resources, `InputStream.transferTo()`,
`InputStream.readAllBytes()`, `java.nio` utilities), and some had odd
quirks or bugs (closing while writing a buffer file _must_ be allowed to
throw an error! don't double-buffer reads or writes!, especially when
you're just pulling the results into memory anyway!).

Some methods have been moved to their own types, to be closer to their
use and not effectively require every class have access to this same
package - SourceLevel, LinkerUtils, and CommandLineCreatorUtils

Also modified CompilerTest and RecompilerTest to also avoid deprecated
Guava `Files.createTempDir()`, `Files.write()`, etc in favor of
`java.nio.file.Files`.

The class itself has been deprecated for removal, allowing downstream
Generators/Linkers/etc time to update.

Fixes gwtproject#10031

Author: niloc132

build_tools/doctool/src/com/google/doctool/ResourceIncluder.java

@@ -15,7 +15,6 @@
  */
 package com.google.doctool;
 
-import java.io.ByteArrayOutputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
@@ -26,18 +25,6 @@
  */
 public class ResourceIncluder {
 
-  /**
-   * Copied from {@link com.google.gwt.util.tools.Utility#close(AutoCloseable)}.
-   */
-  public static void close(AutoCloseable is) {
-    try {
-      if (is != null) {
-        is.close();
-      }
-    } catch (Exception e) {
-    }
-  }
-
   public static String getResourceFromClasspathScrubbedForHTML(String partialPath)
           throws IOException {
     String contents;
@@ -46,35 +33,14 @@ public static String getResourceFromClasspathScrubbedForHTML(String partialPath)
     return contents;
   }
 
-  /**
-   * Copied from
-   * {@link com.google.gwt.util.tools.Utility#getFileFromClassPath(String)}.
-   */
   private static String getFileFromClassPath(String partialPath)
       throws IOException {
-    InputStream in = ResourceIncluder.class.getClassLoader().getResourceAsStream(
-        partialPath);
-    try {
+    try (InputStream in = ResourceIncluder.class.getClassLoader().getResourceAsStream(
+        partialPath)) {
       if (in == null) {
         throw new FileNotFoundException(partialPath);
       }
-      ByteArrayOutputStream os = new ByteArrayOutputStream();
-      byte[] buffer = new byte[1024];
-      int bytesRead;
-      while (true) {
-        bytesRead = in.read(buffer);
-        if (bytesRead >= 0) {
-          // Copy the bytes out.
-          os.write(buffer, 0, bytesRead);
-        } else {
-          // End of input stream.
-          break;
-        }
-      }
-
-      return os.toString(StandardCharsets.UTF_8);
-    } finally {
-      close(in);
+      return new String(in.readAllBytes(), StandardCharsets.UTF_8);
     }
   }
 

dev/codeserver/java/com/google/gwt/dev/codeserver/CodeServer.java

@@ -25,10 +25,10 @@
 import com.google.gwt.dev.util.DiskCachingUtil;
 import com.google.gwt.dev.util.log.PrintWriterTreeLogger;
 import com.google.gwt.thirdparty.guava.common.collect.ImmutableMap;
-import com.google.gwt.util.tools.Utility;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
 
 /**
  * <p>This class contains the {@link #main main method} that starts the code server for
@@ -201,7 +201,7 @@ private static OutboxTable makeOutboxTable(Options options, TreeLogger logger,
   private static File ensureWorkDir(Options options) throws IOException {
     File workDir = options.getWorkDir();
     if (workDir == null) {
-      workDir = Utility.makeTemporaryDirectory(null, "gwt-codeserver-");
+      workDir = Files.createTempDirectory("gwt-codeserver-").toFile();
     } else {
       if (!workDir.isDirectory()) {
         throw new IOException("workspace directory doesn't exist: " + workDir);

dev/codeserver/javatests/com/google/gwt/dev/codeserver/RecompilerTest.java

@@ -28,13 +28,13 @@
 import com.google.gwt.thirdparty.guava.common.base.Charsets;
 import com.google.gwt.thirdparty.guava.common.collect.ImmutableMap;
 import com.google.gwt.thirdparty.guava.common.collect.Lists;
-import com.google.gwt.thirdparty.guava.common.io.Files;
 
 import junit.framework.TestCase;
 
 import java.io.File;
 import java.io.FilenameFilter;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.HashMap;
@@ -68,7 +68,7 @@ private static void writeResourcesTo(List<MockResource> resources, File dir) thr
       File resourceFile =
           new File(dir.getAbsolutePath() + File.separator + applicationResource.getPath());
       resourceFile.getParentFile().mkdirs();
-      Files.write(applicationResource.getContent(), resourceFile, Charsets.UTF_8);
+      Files.write(resourceFile.toPath(), List.of(applicationResource.getContent()), Charsets.UTF_8);
     }
   }
 
@@ -163,7 +163,7 @@ public void testIncrementalRecompile_compileErrorDoesntCorruptMinimalRebuildCach
     PrintWriterTreeLogger logger = new PrintWriterTreeLogger();
     logger.setMaxDetail(TreeLogger.ERROR);
 
-    File sourcePath = Files.createTempDir();
+    File sourcePath = createTempDir();
     // Setup options to perform a per-file compile and compile the given module.
     Options options = new Options();
     options.parseArgs(new String[] {
@@ -175,12 +175,12 @@ public void testIncrementalRecompile_compileErrorDoesntCorruptMinimalRebuildCach
         fooResource);
     writeResourcesTo(originalResources, sourcePath);
 
-    File baseCacheDir = Files.createTempDir();
+    File baseCacheDir = createTempDir();
     UnitCache unitCache = UnitCacheSingleton.get(
         logger, null, baseCacheDir, new CompilerOptionsImpl(options));
     MinimalRebuildCacheManager minimalRebuildCacheManager =
         new MinimalRebuildCacheManager(logger, baseCacheDir, ImmutableMap.<String, String>of());
-    Recompiler recompiler = new Recompiler(OutboxDir.create(Files.createTempDir(), logger), null,
+    Recompiler recompiler = new Recompiler(OutboxDir.create(createTempDir(), logger), null,
         moduleName, options, unitCache, minimalRebuildCacheManager);
     Outbox outbox = new Outbox("Transactional Cache", recompiler, options, logger);
     OutboxTable outboxTable = new OutboxTable();
@@ -211,7 +211,7 @@ public void testIncrementalRecompile_modulePropertyEditsWork() throws UnableToCo
     PrintWriterTreeLogger logger = new PrintWriterTreeLogger();
     logger.setMaxDetail(TreeLogger.ERROR);
 
-    File sourcePath = Files.createTempDir();
+    File sourcePath = createTempDir();
     // Setup options to perform a per-file compile and compile the given module.
     Options options = new Options();
     options.parseArgs(new String[] {
@@ -223,12 +223,12 @@ public void testIncrementalRecompile_modulePropertyEditsWork() throws UnableToCo
         fooResource);
     writeResourcesTo(originalResources, sourcePath);
 
-    File baseCacheDir = Files.createTempDir();
+    File baseCacheDir = createTempDir();
     UnitCache unitCache = UnitCacheSingleton.get(
         logger, null, baseCacheDir, new CompilerOptionsImpl(options));
     MinimalRebuildCacheManager minimalRebuildCacheManager =
         new MinimalRebuildCacheManager(logger, baseCacheDir, ImmutableMap.<String, String>of());
-    Recompiler recompiler = new Recompiler(OutboxDir.create(Files.createTempDir(), logger), null,
+    Recompiler recompiler = new Recompiler(OutboxDir.create(createTempDir(), logger), null,
         moduleName, options, unitCache, minimalRebuildCacheManager);
     Outbox outbox = new Outbox("Transactional Cache", recompiler, options, logger);
     OutboxTable outboxTable = new OutboxTable();
@@ -276,4 +276,8 @@ private Result compileWithChanges(TreeLogger logger, JobRunner runner, Outbox ou
     runner.submit(job);
     return job.waitForResult();
   }
+
+  private static File createTempDir() throws IOException {
+    return Files.createTempDirectory("RecompilerTest").toFile();
+  }
 }

dev/core/src/com/google/gwt/core/ext/linker/EmittedArtifact.java

@@ -19,7 +19,7 @@
 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.dev.util.Util;
-import com.google.gwt.util.tools.Utility;
+import com.google.gwt.thirdparty.guava.common.io.Closeables;
 
 import java.io.BufferedInputStream;
 import java.io.IOException;
@@ -204,7 +204,7 @@ public void writeTo(TreeLogger logger, OutputStream out)
       logger.log(TreeLogger.ERROR, "Unable to copy artifact: " + getPartialPath(), e);
       throw new UnableToCompleteException();
     } finally {
-      Utility.close(in);
+      Closeables.closeQuietly(in);
     }
   }
 

dev/core/src/com/google/gwt/core/ext/linker/LinkerUtils.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2025 GWT Project Authors
+ *
+ * Licensed 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 com.google.gwt.core.ext.linker;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+
+/**
+ * Utility methods for Linkers.
+ */
+public class LinkerUtils {
+  /**
+   * Gets the contents of a file from the class path as a String. Note: this
+   * method is only guaranteed to work for resources in the same class loader
+   * that contains this {@link LinkerUtils} class.
+   *
+   * @param path the partial path to the resource on the class path
+   * @return the contents of the file
+   * @throws IOException if the file could not be found or an error occurred
+   *           while reading it
+   */
+  public static String readClasspathFileAsString(String path) throws IOException {
+    try (InputStream in = LinkerUtils.class.getClassLoader().getResourceAsStream(path)) {
+      if (in == null) {
+        throw new FileNotFoundException(path);
+      }
+      return new String(in.readAllBytes(), StandardCharsets.UTF_8);
+    }
+  }
+
+  private LinkerUtils() {
+  }
+}

dev/core/src/com/google/gwt/core/ext/linker/impl/HostedModeLinker.java

@@ -19,8 +19,8 @@
 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.core.ext.linker.ArtifactSet;
+import com.google.gwt.core.ext.linker.LinkerUtils;
 import com.google.gwt.core.ext.linker.Shardable;
-import com.google.gwt.util.tools.Utility;
 
 import java.io.IOException;
 
@@ -32,7 +32,7 @@
 public final class HostedModeLinker extends SelectionScriptLinker {
 
   public static String getHostedHtml() throws IOException {
-    return Utility.getFileFromClassPath("com/google/gwt/core/ext/linker/impl/hosted.html");
+    return LinkerUtils.readClasspathFileAsString("com/google/gwt/core/ext/linker/impl/hosted.html");
   }
 
   /**

dev/core/src/com/google/gwt/core/ext/linker/impl/SelectionScriptLinker.java

@@ -25,12 +25,12 @@
 import com.google.gwt.core.ext.linker.CompilationResult;
 import com.google.gwt.core.ext.linker.ConfigurationProperty;
 import com.google.gwt.core.ext.linker.EmittedArtifact;
+import com.google.gwt.core.ext.linker.LinkerUtils;
 import com.google.gwt.core.ext.linker.SelectionProperty;
 import com.google.gwt.core.ext.linker.SoftPermutation;
 import com.google.gwt.core.ext.linker.StatementRanges;
 import com.google.gwt.core.linker.SymbolMapsLinker;
 import com.google.gwt.dev.util.Util;
-import com.google.gwt.util.tools.Utility;
 
 import java.io.File;
 import java.io.IOException;
@@ -323,8 +323,8 @@ protected String fillSelectionScriptTemplate(StringBuffer selectionScript,
     String computeScriptBase;
     String processMetas;
     try {
-      computeScriptBase = Utility.getFileFromClassPath(COMPUTE_SCRIPT_BASE_JS);
-      processMetas = Utility.getFileFromClassPath(PROCESS_METAS_JS);
+      computeScriptBase = LinkerUtils.readClasspathFileAsString(COMPUTE_SCRIPT_BASE_JS);
+      processMetas = LinkerUtils.readClasspathFileAsString(PROCESS_METAS_JS);
     } catch (IOException e) {
       logger.log(TreeLogger.ERROR, "Unable to read selection script template",
           e);
@@ -566,7 +566,7 @@ protected StringBuffer readFileToStringBuffer(String filename,
       TreeLogger logger) throws UnableToCompleteException {
     StringBuffer buffer;
     try {
-      buffer = new StringBuffer(Utility.getFileFromClassPath(filename));
+      buffer = new StringBuffer(LinkerUtils.readClasspathFileAsString(filename));
     } catch (IOException e) {
       logger.log(TreeLogger.ERROR, "Unable to read file: " + filename, e);
       throw new UnableToCompleteException();

dev/core/src/com/google/gwt/core/ext/linker/impl/StandardLinkerContext.java

@@ -52,7 +52,6 @@
 import com.google.gwt.dev.resource.ResourceOracle;
 import com.google.gwt.dev.util.DefaultTextOutput;
 import com.google.gwt.dev.util.OutputFileSet;
-import com.google.gwt.util.tools.Utility;
 
 import java.io.BufferedOutputStream;
 import java.io.File;
@@ -521,10 +520,8 @@ public void produceOutput(TreeLogger logger, ArtifactSet artifacts,
           partialPath = partialPath.substring(1);
         }
       }
-      OutputStream artifactStream = null;
-      try {
-        artifactStream = new BufferedOutputStream(out.openForWrite(partialPath,
-            artifact.getLastModified()));
+      try (OutputStream artifactStream = new BufferedOutputStream(
+          out.openForWrite(partialPath, artifact.getLastModified()))) {
         artifact.writeTo(artifactLogger, artifactStream);
       } catch (IOException e) {
         artifactLogger.log(TreeLogger.ERROR,
@@ -533,8 +530,6 @@ public void produceOutput(TreeLogger logger, ArtifactSet artifacts,
         if (visibility != Visibility.Private) {
           throw new UnableToCompleteException();
         }
-      } finally {
-        Utility.close(artifactStream);
       }
     }
   }

dev/core/src/com/google/gwt/core/ext/soyc/coderef/EntityRecorder.java

@@ -38,11 +38,9 @@
 import com.google.gwt.thirdparty.json.JSONArray;
 import com.google.gwt.thirdparty.json.JSONException;
 import com.google.gwt.thirdparty.json.JSONObject;
-import com.google.gwt.util.tools.Utility;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.PrintWriter;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -170,14 +168,9 @@ private void recordCodeReferences(DependencyGraphRecorder codeGraph,
   }
 
   private String addArtifactFromJson(Object value, String named) throws IOException {
-    ByteArrayOutputStream baos = new ByteArrayOutputStream();
-    PrintWriter writer = new PrintWriter(baos);
-    writer.write(value.toString());
-    Utility.close(writer);
-
     // TODO(ocallau) Must be updated with the correct/final linker
     SyntheticArtifact artifact = new SyntheticArtifact(
-        SoycReportLinker.class, named, baos.toByteArray());
+        SoycReportLinker.class, named, value.toString().getBytes(StandardCharsets.UTF_8));
     artifact.setVisibility(Visibility.LegacyDeploy);
 
     toReturn.add(artifact);

dev/core/src/com/google/gwt/core/ext/soyc/impl/DependencyRecorder.java

@@ -22,7 +22,6 @@
 import com.google.gwt.dev.jjs.ast.JRunAsync;
 import com.google.gwt.dev.jjs.impl.ControlFlowAnalyzer;
 import com.google.gwt.dev.jjs.impl.codesplitter.MultipleDependencyGraphRecorder;
-import com.google.gwt.util.tools.Utility;
 
 import java.io.IOException;
 import java.io.OutputStream;
@@ -108,7 +107,10 @@ public void startDependencyGraph(String identifier, String extnds) {
 
   /**
    * Used to record dependencies of a program.
+   *
+   * @deprecated this method is unused internally, and may be removed in a future release.
    */
+  @Deprecated
   protected void recordDependenciesImpl(TreeLogger logger, JProgram jprogram) {
 
     logger = logger.branch(TreeLogger.DEBUG, "Creating dependencies file for the compile report");
@@ -129,7 +131,7 @@ protected void recordDependenciesImpl(TreeLogger logger, JProgram jprogram) {
       printPost();
 
       flushOutput();
-      Utility.close(writer);
+      writer.close();
 
     } catch (Throwable e) {
       logger.log(TreeLogger.WARN, "Could not write dependency file; proceeding anyway.", e);