fix resource leak due to Files.walk and Files.lines

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/precommit/SplitPackagesAuditTask.java

@@ -49,6 +49,7 @@
 import java.util.TreeSet;
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import javax.inject.Inject;
 
@@ -301,12 +302,13 @@ private static void walkJavaFiles(Path root, String suffix, Consumer<Path> class
             if (Files.exists(root) == false) {
                 return;
             }
-            Files.walk(root)
-                .filter(p -> p.toString().endsWith(suffix))
-                .map(root::relativize)
-                .filter(p -> p.getNameCount() > 1) // module-info or other things without a package can be skipped
-                .filter(p -> p.toString().startsWith("META-INF") == false)
-                .forEach(classConsumer);
+	    try (Stream<Path> stream = Files.walk(root)) {
+                stream.filter(p -> p.toString().endsWith(suffix))
+                    .map(root::relativize)
+                    .filter(p -> p.getNameCount() > 1) // module-info or other things without a package can be skipped
+                    .filter(p -> p.toString().startsWith("META-INF") == false)
+                    .forEach(classConsumer);
+            }
         }
 
         private static String getPackageName(Path path) {

build-tools/src/main/java/org/elasticsearch/gradle/LoggedExec.java

@@ -32,6 +32,7 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.regex.Pattern;
+import java.util.stream.Stream;
 
 import javax.inject.Inject;
 
@@ -84,13 +85,13 @@ public void setSpoolOutput(boolean spoolOutput) {
             File spoolFile = new File(getProject().getBuildDir() + "/buffered-output/" + this.getName());
             out = new LazyFileOutputStream(spoolFile);
             outputLogger = logger -> {
-                try {
-                    // the file may not exist if the command never output anything
-                    if (Files.exists(spoolFile.toPath())) {
-                        Files.lines(spoolFile.toPath()).forEach(logger::error);
+                // the file may not exist if the command never output anything
+                if (Files.exists(spoolFile.toPath())) {
+                    try (Stream<String> stream = Files.lines(spoolFile.toPath())) {
+                        stream.forEach(logger::error);
+                    } catch (IOException e) {
+                        throw new RuntimeException("could not log", e);
                     }
-                } catch (IOException e) {
-                    throw new RuntimeException("could not log", e);
                 }
             };
         } else {

distribution/tools/launchers/src/main/java/org/elasticsearch/tools/launchers/BootstrapJvmOptions.java

@@ -18,6 +18,7 @@
 import java.util.Locale;
 import java.util.Properties;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 /**
  * This class looks for plugins whose "type" is "bootstrap". Such plugins
@@ -39,29 +40,31 @@ public static List<String> bootstrapJvmOptions(Path plugins) throws IOException
     private static List<PluginInfo> getPluginInfo(Path plugins) throws IOException {
         final List<PluginInfo> pluginInfo = new ArrayList<>();
 
-        final List<Path> pluginDirs = Files.list(plugins).collect(Collectors.toList());
-
-        for (Path pluginDir : pluginDirs) {
-            final List<String> jarFiles = new ArrayList<>();
-            final Properties props = new Properties();
-
-            final List<Path> pluginFiles = Files.list(pluginDir).collect(Collectors.toList());
-            for (Path pluginFile : pluginFiles) {
-                final String lowerCaseName = pluginFile.getFileName().toString().toLowerCase(Locale.ROOT);
-
-                if (lowerCaseName.endsWith(".jar")) {
-                    jarFiles.add(pluginFile.toString());
-                } else if (lowerCaseName.equals("plugin-descriptor.properties")) {
-                    try (InputStream stream = Files.newInputStream(pluginFile)) {
-                        props.load(stream);
-                    } catch (IOException e) {
-                        throw new UncheckedIOException(e);
+        try (Stream<Path> pluginsList = Files.list(plugins)) {
+            final List<Path> pluginDirs = pluginsList.collect(Collectors.toList());
+            for (Path pluginDir : pluginDirs) {
+                final List<String> jarFiles = new ArrayList<>();
+                final Properties props = new Properties();
+                try (Stream<Path> pluginDirList = Files.list(pluginDir)) {
+                    final List<Path> pluginFiles = pluginDirList.collect(Collectors.toList());
+                    for (Path pluginFile : pluginFiles) {
+                        final String lowerCaseName = pluginFile.getFileName().toString().toLowerCase(Locale.ROOT);
+
+                        if (lowerCaseName.endsWith(".jar")) {
+                            jarFiles.add(pluginFile.toString());
+                        } else if (lowerCaseName.equals("plugin-descriptor.properties")) {
+                            try (InputStream stream = Files.newInputStream(pluginFile)) {
+                                props.load(stream);
+                            } catch (IOException e) {
+                                throw new UncheckedIOException(e);
+                            }
+                        }
                     }
-                }
-            }
+		}
 
-            if (props.isEmpty() == false) {
-                pluginInfo.add(new PluginInfo(jarFiles, props));
+                if (props.isEmpty() == false) {
+                    pluginInfo.add(new PluginInfo(jarFiles, props));
+                }
             }
         }
 

x-pack/plugin/security/cli/src/main/java/org/elasticsearch/xpack/security/cli/EnrollNodeToCluster.java

@@ -71,6 +71,7 @@
 import java.util.Set;
 import java.util.function.BiFunction;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import static org.elasticsearch.common.ssl.PemUtils.parsePKCS8PemString;
 import static org.elasticsearch.discovery.SettingsBasedSeedHostsProvider.DISCOVERY_SEED_HOSTS_SETTING;
@@ -115,11 +116,15 @@ protected void execute(Terminal terminal, OptionSet options, Environment env) th
             // TODO: Files.list leaks a file handle because the stream is not closed
             // this effectively doesn't matter since enroll is run in a separate, short lived, process
             // but it should be fixed...
-            if (Files.isDirectory(dataPath) && Files.list(dataPath).findAny().isPresent()) {
-                throw new UserException(
-                    ExitCodes.CONFIG,
-                    "Aborting enrolling to cluster. It appears that this is not the first time this node starts."
-                );
+            if (Files.isDirectory(dataPath)) {
+                try (Stream<Path> stream = Files.list(dataPath)) {
+                    if (stream.findAny().isPresent()) {
+                        throw new UserException(
+                          ExitCodes.CONFIG,
+                          "Aborting enrolling to cluster. It appears that this is not the first time this node starts."
+                        );
+                    }
+                }
             }
         }