added header recipe

README.md

@@ -43,9 +43,9 @@ _No checks analyzed yet_
 
 ### Headers
 
-| Status | Check                                                                           | Recipe           | Coverage Notes |
-|--------|---------------------------------------------------------------------------------|------------------|----------------|
-| 🟢     | [`Header`](https://checkstyle.sourceforge.io/checks/header/header.html#Header ) | `TBD`            |                |
+| Status | Check                                                                           | Recipe           | Coverage Notes             |
+|--------|---------------------------------------------------------------------------------|------------------|----------------------------|
+| 🟡     | [`Header`](https://checkstyle.sourceforge.io/checks/header/header.html#Header ) | `TBD`            | only java files are fixed. |
 
 
 

config/import-control-test.xml

@@ -12,4 +12,5 @@
     <allow pkg="java.nio"/>
     <allow pkg="java.lang"/>
     <allow pkg="javax.xml.stream"/>
+    <allow pkg="com.puppycrawl.tools.checkstyle"/>
 </import-control>

config/import-control.xml

@@ -11,4 +11,5 @@
     <allow pkg="javax.xml.stream"/>
     <allow pkg="org.checkstyle"/>
     <allow pkg="java.util"/>
+    <allow pkg="com.puppycrawl.tools.checkstyle"/>
 </import-control>

src/main/java/org/checkstyle/autofix/parser/CheckstyleViolation.java

@@ -41,11 +41,11 @@ public CheckstyleViolation(Integer line, Integer column,
         this.fileName = fileName;
     }
 
-    public int getLine() {
+    public Integer getLine() {
         return line;
     }
 
-    public int getColumn() {
+    public Integer getColumn() {
         return column;
     }
 

src/main/java/org/checkstyle/autofix/recipe/Header.java

@@ -0,0 +1,198 @@
+///////////////////////////////////////////////////////////////////////////////////////////////
+// checkstyle-openrewrite-recipes: Automatically fix Checkstyle violations with OpenRewrite.
+// Copyright (C) 2025 The Checkstyle OpenRewrite Recipes 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 org.checkstyle.autofix.recipe;
+
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import org.checkstyle.autofix.parser.CheckstyleViolation;
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Recipe;
+import org.openrewrite.Tree;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.JavaIsoVisitor;
+import org.openrewrite.java.tree.J;
+import org.openrewrite.java.tree.JavaSourceFile;
+import org.openrewrite.java.tree.Space;
+
+import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
+import com.puppycrawl.tools.checkstyle.api.Configuration;
+
+public class Header extends Recipe {
+    private static final String HEADER_PROPERTY = "header";
+    private static final String HEADER_FILE_PROPERTY = "headerFile";
+    private static final String IGNORE_LINES_PROPERTY = "ignoreLines";
+    private static final String CHARSET_PROPERTY = "charset";
+
+    private final List<CheckstyleViolation> violations;
+    private final Configuration config;
+    private final Charset charset;
+
+    public Header(List<CheckstyleViolation> violations, Configuration config, Charset charset) {
+        this.violations = violations;
+        this.config = config;
+        this.charset = charset;
+    }
+
+    @Override
+    public String getDisplayName() {
+        return "Header recipe";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Adds headers to Java source files when missing.";
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        final String licenseHeader = extractLicenseHeader(config, charset);
+        final List<Integer> ignoreLines = extractIgnoreLines(config);
+        return new HeaderVisitor(violations, licenseHeader, ignoreLines);
+    }
+
+    private static String extractLicenseHeader(Configuration config, Charset charset) {
+        final String header;
+        try {
+            if (hasProperty(config, HEADER_PROPERTY)) {
+                header = config.getProperty(HEADER_PROPERTY);
+            }
+            else {
+                final Charset charsetToUse;
+                if (hasProperty(config, CHARSET_PROPERTY)) {
+                    charsetToUse = Charset.forName(config.getProperty(CHARSET_PROPERTY));
+                }
+                else {
+                    charsetToUse = charset;
+                }
+                final String headerFilePath = config.getProperty(HEADER_FILE_PROPERTY);
+                header = Files.readString(Path.of(headerFilePath), charsetToUse);
+            }
+        }
+        catch (CheckstyleException | IOException exception) {
+            throw new IllegalArgumentException("Failed to extract header from config", exception);
+        }
+        return header;
+    }
+
+    private static List<Integer> extractIgnoreLines(Configuration config) {
+        final List<Integer> ignoreLinesList;
+        try {
+            if (!hasProperty(config, IGNORE_LINES_PROPERTY)) {
+                ignoreLinesList = new ArrayList<>();
+            }
+            else {
+                final String ignoreLines = config.getProperty(IGNORE_LINES_PROPERTY);
+                ignoreLinesList = Arrays.stream(ignoreLines.split(","))
+                        .map(String::trim)
+                        .map(Integer::parseInt)
+                        .collect(Collectors.toList());
+            }
+        }
+        catch (CheckstyleException exception) {
+            throw new IllegalArgumentException(
+                    "Failed to extract ignore lines from config", exception);
+        }
+        return ignoreLinesList;
+    }
+
+    private static boolean hasProperty(Configuration config, String propertyName) {
+        return Arrays.asList(config.getPropertyNames()).contains(propertyName);
+    }
+
+    private static class HeaderVisitor extends JavaIsoVisitor<ExecutionContext> {
+        private final List<CheckstyleViolation> violations;
+        private final String licenseHeader;
+        private final List<Integer> ignoreLines;
+
+        HeaderVisitor(List<CheckstyleViolation> violations, String licenseHeader,
+                      List<Integer> ignoreLines) {
+            this.violations = violations;
+            this.licenseHeader = licenseHeader;
+            this.ignoreLines = ignoreLines;
+        }
+
+        @Override
+        public J visit(Tree tree, ExecutionContext ctx) {
+            J result = super.visit(tree, ctx);
+
+            if (tree instanceof JavaSourceFile) {
+                JavaSourceFile sourceFile = (JavaSourceFile) tree;
+                final Path filePath = sourceFile.getSourcePath().toAbsolutePath();
+
+                if (hasViolation(filePath)) {
+                    final String currentHeader = extractCurrentHeader(sourceFile);
+                    final String fixedHeader = fixHeaderLines(licenseHeader,
+                                                                currentHeader, ignoreLines);
+
+                    sourceFile = sourceFile.withPrefix(
+                            Space.format(fixedHeader + System.lineSeparator()));
+                }
+                result = super.visit(sourceFile, ctx);
+            }
+            return result;
+        }
+
+        private String extractCurrentHeader(JavaSourceFile sourceFile) {
+            return sourceFile.getComments().stream()
+                    .map(comment -> comment.printComment(getCursor()))
+                    .collect(Collectors.joining(System.lineSeparator()));
+        }
+
+        private static String fixHeaderLines(String licenseHeader,
+                                             String currentHeader, List<Integer> ignoreLines) {
+            final List<String> currentLines = Arrays
+                    .stream(currentHeader.split(System.lineSeparator()))
+                    .collect(Collectors.toList());
+            final List<String> licenseLines = Arrays.stream(licenseHeader.split(
+                    System.lineSeparator(), -1)).toList();
+
+            final Set<Integer> ignoredLineNumbers = new HashSet<>(ignoreLines);
+
+            for (int lineNumber = 1; lineNumber <= licenseLines.size(); lineNumber++) {
+                final String expectedLine = licenseLines.get(lineNumber - 1);
+
+                if (lineNumber <= currentLines.size()) {
+                    if (!ignoredLineNumbers.contains(lineNumber)
+                            && !expectedLine.equals(currentLines.get(lineNumber - 1))) {
+                        currentLines.set(lineNumber - 1, expectedLine);
+                    }
+                }
+                else {
+                    currentLines.add(expectedLine);
+                }
+            }
+
+            return String.join(System.lineSeparator(), currentLines);
+        }
+
+        private boolean hasViolation(Path filePath) {
+            return violations.removeIf(violation -> {
+                return filePath.equals(Path.of(violation.getFileName()).toAbsolutePath());
+            });
+        }
+    }
+}

src/main/java/org/checkstyle/autofix/recipe/UpperEll.java

@@ -70,7 +70,7 @@ private final class UpperEllVisitor extends JavaIsoVisitor<ExecutionContext> {
 
         @Override
         public J.CompilationUnit visitCompilationUnit(J.CompilationUnit cu, ExecutionContext ctx) {
-            this.sourcePath = cu.getSourcePath();
+            this.sourcePath = cu.getSourcePath().toAbsolutePath();
             return super.visitCompilationUnit(cu, ctx);
         }
 
@@ -97,9 +97,10 @@ private boolean isAtViolationLocation(J.Literal literal) {
             final int column = computeColumnPosition(cursor, literal, getCursor());
 
             return violations.stream().anyMatch(violation -> {
+                final Path absolutePath = Path.of(violation.getFileName()).toAbsolutePath();
                 return violation.getLine() == line
                         && violation.getColumn() == column
-                        && Path.of(violation.getFileName()).equals(sourcePath);
+                        && absolutePath.equals(sourcePath);
             });
         }
 

src/test/java/org/checkstyle/autofix/recipe/AbstractRecipeTest.java

@@ -21,13 +21,18 @@
 import static org.openrewrite.java.Assertions.java;
 
 import java.io.IOException;
+import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.Paths;
+import java.util.Arrays;
 
 import org.checkstyle.autofix.InputClassRenamer;
 import org.openrewrite.Recipe;
 import org.openrewrite.test.RewriteTest;
 
+import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
+import com.puppycrawl.tools.checkstyle.api.Configuration;
+
 public abstract class AbstractRecipeTest implements RewriteTest {
 
     private static final String BASE_TEST_RESOURCES_PATH = "src/test/resources/org"
@@ -37,9 +42,10 @@ private Recipe createPreprocessingRecipe() {
         return new InputClassRenamer();
     }
 
-    protected abstract Recipe getRecipe();
+    protected abstract Recipe getRecipe() throws CheckstyleException;
 
-    protected void testRecipe(String recipePath, String testCaseName) throws IOException {
+    protected void testRecipe(String recipePath, String testCaseName) throws IOException,
+            CheckstyleException {
         final String testCaseDir = testCaseName.toLowerCase();
         final String inputFileName = "Input" + testCaseName + ".java";
         final String outputFileName = "Output" + testCaseName + ".java";
@@ -60,4 +66,34 @@ protected void testRecipe(String recipePath, String testCaseName) throws IOExcep
             );
         });
     }
+
+    protected Configuration extractCheckConfiguration(Configuration config, String checkName) {
+
+        return Arrays.stream(config.getChildren())
+                .filter(child -> checkName.equals(child.getName()))
+                .findFirst()
+                .orElseThrow(() -> {
+                    return new IllegalArgumentException(checkName + "configuration not "
+                            + "found");
+                });
+    }
+
+    protected Charset getCharset(Configuration config) {
+        try {
+            final String charsetName;
+
+            if (Arrays.asList(config.getPropertyNames()).contains("charset")) {
+                charsetName = config.getProperty("charset");
+            }
+            else {
+                charsetName = Charset.defaultCharset().name();
+            }
+
+            return Charset.forName(charsetName);
+        }
+        catch (CheckstyleException exception) {
+            throw new IllegalArgumentException("Failed to extract charset from config.", exception);
+        }
+    }
+
 }

src/test/java/org/checkstyle/autofix/recipe/HeaderTest.java

@@ -0,0 +1,71 @@
+///////////////////////////////////////////////////////////////////////////////////////////////
+// checkstyle-openrewrite-recipes: Automatically fix Checkstyle violations with OpenRewrite.
+// Copyright (C) 2025 The Checkstyle OpenRewrite Recipes 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 org.checkstyle.autofix.recipe;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Properties;
+
+import org.checkstyle.autofix.parser.CheckstyleReportParser;
+import org.checkstyle.autofix.parser.CheckstyleViolation;
+import org.junit.jupiter.api.Test;
+import org.openrewrite.Recipe;
+
+import com.puppycrawl.tools.checkstyle.ConfigurationLoader;
+import com.puppycrawl.tools.checkstyle.PropertiesExpander;
+import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
+import com.puppycrawl.tools.checkstyle.api.Configuration;
+
+public class HeaderTest extends AbstractRecipeTest {
+
+    @Override
+    protected Recipe getRecipe() throws CheckstyleException {
+        final String reportPath = "src/test/resources/org/checkstyle/autofix/recipe/header"
+                + "/report.xml";
+
+        final String configPath = "src/test/resources/org/checkstyle/autofix/recipe/header"
+                + "/config.xml";
+
+        final Configuration config = ConfigurationLoader.loadConfiguration(
+                configPath, new PropertiesExpander(new Properties())
+        );
+
+        final List<CheckstyleViolation> violations =
+                CheckstyleReportParser.parse(Path.of(reportPath));
+
+        return new Header(violations,
+                extractCheckConfiguration(config, "Header"), getCharset(config));
+    }
+
+    @Test
+    void headerTest() throws IOException, CheckstyleException {
+        testRecipe("header", "HeaderBlankLines");
+    }
+
+    @Test
+    void headerCommentTest() throws IOException, CheckstyleException {
+        testRecipe("header", "HeaderComments");
+    }
+
+    @Test
+    void headerIncorrect() throws IOException, CheckstyleException {
+        testRecipe("header", "HeaderIncorrect");
+    }
+
+}