pom.xml

@@ -105,6 +105,12 @@
                 </exclusion>
             </exclusions>
         </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.11.1</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/com/github/difflib/unifieddiff/UnifiedDiff.java

@@ -15,30 +15,33 @@
  */
 package com.github.difflib.unifieddiff;
 
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 
 /**
  *
  * @author Tobias Warneke (t.warneke@gmx.net)
  */
-public final class UnifiedDiff {
+public class UnifiedDiff {
 
-    private UnifiedDiff(InputStream stream) throws IOException {
-        try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream));) {
-            while (reader.ready()) {
-                String line = reader.readLine();
-                LOG.info(line);
-            }
-        }
+    private String header;
+    private final List<UnifiedDiffFile> files = new ArrayList<>();
 
+    public String getHeader() {
+        return header;
     }
-    private static final Logger LOG = Logger.getLogger(UnifiedDiff.class.getName());
 
-    public static UnifiedDiff parse(InputStream stream) throws IOException {
-        return new UnifiedDiff(stream);
+    public void setHeader(String header) {
+        this.header = header;
     }
+
+    void addFile(UnifiedDiffFile file) {
+        files.add(file);
+    }
+
+    public List<UnifiedDiffFile> getFiles() {
+        return Collections.unmodifiableList(files);
+    }
+
 }

src/main/java/com/github/difflib/unifieddiff/UnifiedDiffFile.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2019 java-diff-utils.
+ *
+ * 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.github.difflib.unifieddiff;
+
+/**
+ *
+ * @author Tobias Warneke (t.warneke@gmx.net)
+ */
+public class UnifiedDiffFile {
+
+    private String diffCommand;
+    private String fromFile;
+    private String toFile;
+    private String index;
+
+    public String getDiffCommand() {
+        return diffCommand;
+    }
+
+    public void setDiffCommand(String diffCommand) {
+        this.diffCommand = diffCommand;
+    }
+
+    public String getFromFile() {
+        return fromFile;
+    }
+
+    public void setFromFile(String fromFile) {
+        this.fromFile = fromFile;
+    }
+
+    public String getToFile() {
+        return toFile;
+    }
+
+    public void setToFile(String toFile) {
+        this.toFile = toFile;
+    }
+
+    public void setIndex(String index) {
+        this.index = index;
+    }
+
+    public String getIndex() {
+        return index;
+    }
+}

src/main/java/com/github/difflib/unifieddiff/UnifiedDiffParser.java

@@ -0,0 +1,167 @@
+/*
+ * Copyright 2019 java-diff-utils.
+ *
+ * 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.github.difflib.unifieddiff;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.function.BiConsumer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.regex.MatchResult;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ *
+ * @author Tobias Warneke (t.warneke@gmx.net)
+ */
+public final class UnifiedDiffParser {
+
+    private final UnifiedDiffReader READER;
+    private final UnifiedDiff data = new UnifiedDiff();
+    private final UnifiedDiffLine[] PARSER_RULES = new UnifiedDiffLine[]{
+        new UnifiedDiffLine("^\\s+", (m, l) -> LOG.info("normal " + l)),
+        new UnifiedDiffLine(true, "^diff\\s", UnifiedDiffParser::processDiff),
+        new UnifiedDiffLine(true, "^index\\s[\\da-zA-Z]+\\.\\.[\\da-zA-Z]+(\\s(\\d+))?$", UnifiedDiffParser::processIndex)
+    };
+    private UnifiedDiffFile actualFile;
+
+    UnifiedDiffParser(Reader reader) {
+        this.READER = new UnifiedDiffReader(reader);
+    }
+
+    // schema = [[/^\s+/, normal], [/^diff\s/, start], [/^new file mode \d+$/, new_file], 
+    // [/^deleted file mode \d+$/, deleted_file], [/^index\s[\da-zA-Z]+\.\.[\da-zA-Z]+(\s(\d+))?$/, index], 
+    // [/^---\s/, from_file], [/^\+\+\+\s/, to_file], [/^@@\s+\-(\d+),?(\d+)?\s+\+(\d+),?(\d+)?\s@@/, chunk], 
+    // [/^-/, del], [/^\+/, add], [/^\\ No newline at end of file$/, eof]];
+    private UnifiedDiff parse() throws IOException {
+        boolean header = true;
+        String headerTxt = "";
+        while (READER.ready()) {
+            String line = READER.readLine();
+            if (processLine(header, line) == false) {
+                if (header) {
+                    headerTxt += line + "\n";
+                } else {
+                    break;
+                }
+            } else {
+                header = false;
+                data.setHeader(headerTxt);
+            }
+        }
+        return data;
+    }
+
+    static String[] parseFileNames(String line) {
+        String[] split = line.split(" ");
+        return new String[]{
+            split[2].replaceAll("^a/", ""),
+            split[3].replaceAll("^b/", "")
+        };
+    }
+
+    private static final Logger LOG = Logger.getLogger(UnifiedDiffParser.class.getName());
+
+    public static UnifiedDiff parseUnifiedDiff(InputStream stream) throws IOException {
+        UnifiedDiffParser parser = new UnifiedDiffParser(new BufferedReader(new InputStreamReader(stream)));
+        return parser.parse();
+    }
+
+    private boolean processLine(boolean header, String line) {
+        for (UnifiedDiffLine rule : PARSER_RULES) {
+            if (header && rule.isStopsHeaderParsing() || !header) {
+                if (rule.processLine(line)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    private void initFileIfNecessary() {
+        if (actualFile == null) {
+            actualFile = new UnifiedDiffFile();
+        }
+    }
+
+    private void processDiff(MatchResult match, String line) {
+        initFileIfNecessary();
+        LOG.log(Level.INFO, "start {0}", line);
+        String[] fromTo = parseFileNames(READER.lastLine());
+        actualFile.setFromFile(fromTo[0]);
+        actualFile.setToFile(fromTo[1]);
+    }
+
+    private void processIndex(MatchResult match, String line) {
+        initFileIfNecessary();
+        LOG.log(Level.INFO, "index {0}", line);
+        actualFile.setIndex(line.substring(6));
+    }
+
+    class UnifiedDiffLine {
+
+        private final Pattern pattern;
+        private final BiConsumer<MatchResult, String> command;
+        private final boolean stopsHeaderParsing;
+
+        public UnifiedDiffLine(String pattern, BiConsumer<MatchResult, String> command) {
+            this(false, pattern, command);
+        }
+
+        public UnifiedDiffLine(boolean stopsHeaderParsing, String pattern, BiConsumer<MatchResult, String> command) {
+            this.pattern = Pattern.compile(pattern);
+            this.command = command;
+            this.stopsHeaderParsing = stopsHeaderParsing;
+        }
+
+        public boolean processLine(String line) {
+            Matcher m = pattern.matcher(line);
+            if (m.find()) {
+                command.accept(m.toMatchResult(), line);
+                return true;
+            } else {
+                return false;
+            }
+        }
+
+        public boolean isStopsHeaderParsing() {
+            return stopsHeaderParsing;
+        }
+    }
+}
+
+class UnifiedDiffReader extends BufferedReader {
+
+    private String lastLine;
+
+    public UnifiedDiffReader(Reader reader) {
+        super(reader);
+    }
+
+    @Override
+    public String readLine() throws IOException {
+        lastLine = super.readLine();
+        return lastLine();
+    }
+
+    String lastLine() {
+        return lastLine;
+    }
+}

src/test/java/com/github/difflib/unifieddiff/UnifiedDiffParserTest.java

@@ -16,6 +16,7 @@
 package com.github.difflib.unifieddiff;
 
 import java.io.IOException;
+import static org.assertj.core.api.Java6Assertions.assertThat;
 import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.Before;
@@ -26,9 +27,9 @@ import org.junit.Test;
  *
  * @author Tobias Warneke (t.warneke@gmx.net)
  */
-public class UnifiedDiffTest {
+public class UnifiedDiffParserTest {
 
-    public UnifiedDiffTest() {
+    public UnifiedDiffParserTest() {
     }
 
     @BeforeClass
@@ -49,9 +50,15 @@ public class UnifiedDiffTest {
 
     @Test
     public void testSimpleParse() throws IOException {
-        UnifiedDiff diff = UnifiedDiff.parse(UnifiedDiffTest.class.getResourceAsStream("jsqlparser_patch_1.diff"));
+        UnifiedDiff diff = UnifiedDiffParser.parseUnifiedDiff(UnifiedDiffParserTest.class.getResourceAsStream("jsqlparser_patch_1.diff"));
 
         System.out.println(diff);
     }
 
+    @Test
+    public void testParseDiffBlock() {
+        String[] files = UnifiedDiffParser.parseFileNames("diff --git a/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java b/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java");
+        assertThat(files).containsExactly("src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java", "src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java");
+    }
+
 }