This is for NoticeTask for issue #34459

buildSrc/src/main/java/org/elasticsearch/gradle/NoticeTask.java

@@ -0,0 +1,200 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch 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.elasticsearch.gradle;
+
+import org.gradle.api.DefaultTask;
+import org.gradle.api.tasks.InputFile;
+import org.gradle.api.tasks.OutputFile;
+import org.gradle.api.tasks.TaskAction;
+
+import java.io.IOException;
+import java.io.File;
+import java.io.FileReader;
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.*;
+import java.util.stream.Stream;
+
+/**
+ * A task to create a notice file which includes dependencies' notices.
+ */
+public class NoticeTask extends DefaultTask {
+
+    @InputFile
+    private File inputFile = getProject().getRootProject().file("NOTICE.txt");
+    @OutputFile
+    private File outputFile = new File(getProject().getBuildDir(), "notices/" + getName() + "/NOTICE.txt");
+
+    /** Directories to include notices from */
+    private List<File> licensesDirs = new ArrayList<>();
+
+    public File getInputFile() {
+        return inputFile;
+    }
+
+    public void setInputFile(File inputFile) {
+        this.inputFile = inputFile;
+    }
+
+    public File getOutputFile() {
+        return outputFile;
+    }
+
+    public void setOutputFile(File outputFile) {
+        this.outputFile = outputFile;
+    }
+
+    public void licensesDir(File licensesDir) {
+        licensesDirs.add(licensesDir);
+    }
+
+    public void addLicenseDir(File licenseDir){
+        this.licensesDir(licenseDir);
+    }
+    public List<File> getLicensesDirs(){
+        return Collections.unmodifiableList(this.licensesDirs);
+    }
+
+//    public static String getText(File file){
+//        return getText(file, StandardCharsets.UTF_8);
+//    }
+
+    /**
+     * Add notices from the specified directory.
+     */
+
+    public NoticeTask() {
+        setDescription("Create a notice file from dependencies");
+        // Default licenses directory is ${projectDir}/licenses (if it exists)
+        File licensesDir = new File(getProject().getProjectDir(), "licenses");
+        if (licensesDir.exists()) {
+            licensesDirs.add(licensesDir);
+        }
+
+    }
+
+    @TaskAction
+    public void generateNotice() {
+        final StringBuilder output = new StringBuilder();
+
+        try{
+            Files.lines(this.inputFile.toPath(), StandardCharsets.UTF_8)
+                .forEach(s -> {
+                    output.append(s.trim());
+                    output.append("\n");
+                });
+            output.append("\n\n");
+
+        } catch (IOException e) {
+            e.printStackTrace();
+            throw new RuntimeException(e);
+        }
+
+        // This is a map rather than a set so that the sort order is the 3rd
+        // party component names, unaffected by the full path to the various files
+        final Map<String, File> seen = new TreeMap<>();
+        licensesDirs.stream()
+            .flatMap(file -> {
+                try {
+                    return Files.walk(file.toPath());
+                } catch (IOException e) {
+                    e.printStackTrace();
+//                    throw new RuntimeException("failed to walk for " + file.toString());
+                    return Stream.empty();
+                }
+            })
+            .filter(path -> path.toString().endsWith("-NOTICE.txt"))
+            .map(Path::toFile)
+            .forEach(licenseFile -> {
+                // Here we remove the "-NOTICE.txt" so the name can be used later for the -LICENSE.txt file
+                final String name =
+                    licenseFile.getName().substring(0,licenseFile.getName().length() - "-NOTICE.txt".length());
+
+                if (seen.containsKey(name)){
+                    File prevLicenseFile = seen.get(name);
+                    if (getText(prevLicenseFile).equals(getText(licenseFile)) == false){
+                        throw new RuntimeException("Two different notices exist for dependency '" +
+                            name + "': " + prevLicenseFile + " and " + licenseFile);
+                    }
+                }else {
+                    seen.put(name,licenseFile);
+                }
+            });
+
+
+        for (Map.Entry<String,File> entry : seen.entrySet()){
+            final String name = entry.getKey();
+            final File file = entry.getValue();
+            final File licenseFile = new File(file.getParentFile(),name + "-LICENSE.txt");
+
+            appendFileToOutput(file, name, "NOTICE", output);
+            appendFileToOutput(licenseFile,name, "LICENSE", output);
+        }
+
+        writeToFile(outputFile,output.toString(),StandardCharsets.UTF_8);
+    }
+
+    public static void appendFileToOutput(File file, final String name, final String type, StringBuilder output) {
+        String text = getText(file);
+
+        if (text.trim().isEmpty()) {
+            return;
+        }
+
+        output.append("================================================================================\n");
+        output.append(name + " " + type + "\n");
+        output.append("================================================================================\n");
+        output.append(text);
+        output.append("\n\n");
+    }
+
+    public static void writeToFile(File file, String output, Charset charset){
+
+        try(BufferedWriter out = Files.newBufferedWriter(file.toPath(),charset)){
+            out.write(output);
+            out.flush();
+        }catch (IOException exception){
+            exception.printStackTrace();
+            throw new RuntimeException("Unable to write to file " + file.getName());
+        }
+
+    }
+
+    public static String getText(File file){
+        final StringBuilder builder = new StringBuilder();
+        try(BufferedReader reader = new BufferedReader(new FileReader(file))){
+            char[] buffer = new char[8192];
+            int read;
+
+            while ((read = reader.read(buffer)) != -1){
+                builder.append(buffer,0,read);
+            }
+
+        }catch (IOException e){
+            e.printStackTrace();
+            throw new RuntimeException("Unable to read file " + file.toString());
+        }
+        return builder.toString();
+    }
+}