add examples

test/examples/diffutils/ComputeDifference.java

@@ -0,0 +1,44 @@
+package diffutils;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.LinkedList;
+import java.util.List;
+
+import difflib.Delta;
+import difflib.DiffUtils;
+import difflib.Patch;
+
+public class ComputeDifference {
+    static final String FS = File.separator;
+    static final String originalFilename = "test" + FS + "mocks" + FS + "original.txt";
+    static final String revisedFilename = "test" + FS + "mocks" + FS + "revised.txt";
+
+    private static List<String> fileToLines(String filename) {
+        List<String> lines = new LinkedList<String>();
+        String line = "";
+        try {
+            BufferedReader in = new BufferedReader(new FileReader(filename));
+            while ((line = in.readLine()) != null) {
+                lines.add(line);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static void main(String[] args) {
+        List<String> original = fileToLines(originalFilename);
+        List<String> revised  = fileToLines(revisedFilename);
+
+        // Compute diff. Get the Patch object. Patch is the container for computed deltas.
+        Patch patch = DiffUtils.diff(original, revised);
+
+        for (Delta delta: patch.getDeltas()) {
+            System.out.println(delta);
+        }
+    }
+}