Readme in result zip file

core/src/main/java/de/jplag/reporting/jsonfactory/ComparisonReportWriter.java

@@ -16,19 +16,20 @@
 import de.jplag.reporting.FilePathUtil;
 import de.jplag.reporting.reportobject.model.ComparisonReport;
 import de.jplag.reporting.reportobject.model.Match;
+import de.jplag.reporting.reportobject.writer.JsonWriter;
 
 /**
  * Writes {@link ComparisonReport}s of given {@link JPlagResult} to the disk under the specified path. Instantiated with
  * a function that associates a submission to its id.
  */
 public class ComparisonReportWriter {
 
-    private final FileWriter fileWriter;
+    private final JsonWriter fileWriter;
     private final Function<Submission, String> submissionToIdFunction;
     private final Map<String, Map<String, String>> submissionIdToComparisonFileName = new ConcurrentHashMap<>();
     private final Map<String, AtomicInteger> fileNameCollisions = new ConcurrentHashMap<>();
 
-    public ComparisonReportWriter(Function<Submission, String> submissionToIdFunction, FileWriter fileWriter) {
+    public ComparisonReportWriter(Function<Submission, String> submissionToIdFunction, JsonWriter fileWriter) {
         this.submissionToIdFunction = submissionToIdFunction;
         this.fileWriter = fileWriter;
     }
@@ -59,7 +60,7 @@ private void writeComparisons(String path, List<JPlagComparison> comparisons) {
             var comparisonReport = new ComparisonReport(firstSubmissionId, secondSubmissionId,
                     Map.of(SimilarityMetric.AVG.name(), comparison.similarity(), SimilarityMetric.MAX.name(), comparison.maximalSimilarity()),
                     convertMatchesToReportMatches(comparison));
-            fileWriter.saveAsJSON(comparisonReport, path, fileName);
+            fileWriter.writeFile(comparisonReport, path, fileName);
         });
     }
 

core/src/main/java/de/jplag/reporting/reportobject/ReportObjectFactory.java

@@ -30,12 +30,13 @@
 import de.jplag.Submission;
 import de.jplag.reporting.FilePathUtil;
 import de.jplag.reporting.jsonfactory.ComparisonReportWriter;
-import de.jplag.reporting.jsonfactory.ToDiskWriter;
 import de.jplag.reporting.reportobject.mapper.ClusteringResultMapper;
 import de.jplag.reporting.reportobject.mapper.MetricMapper;
 import de.jplag.reporting.reportobject.model.OverviewReport;
 import de.jplag.reporting.reportobject.model.SubmissionFileIndex;
 import de.jplag.reporting.reportobject.model.Version;
+import de.jplag.reporting.reportobject.writer.JsonWriter;
+import de.jplag.reporting.reportobject.writer.TextWriter;
 
 /**
  * Factory class, responsible for converting a JPlagResult object to Overview and Comparison DTO classes and writing it
@@ -46,8 +47,13 @@ public class ReportObjectFactory {
 
     private static final Logger logger = LoggerFactory.getLogger(ReportObjectFactory.class);
 
-    private static final ToDiskWriter fileWriter = new ToDiskWriter();
+    private static final JsonWriter jsonFileWriter = new JsonWriter();
     public static final String OVERVIEW_FILE_NAME = "overview.json";
+
+    public static final String README_FILE_NAME = "README.txt";
+    private static final String[] README_CONTENT = new String[] {"This is a software plagiarism report generated by JPlag.",
+            "To view the report go to https://jplag.github.io/JPlag/ and drag the generated zip file onto the page."};
+
     public static final String SUBMISSIONS_FOLDER = "files";
     public static final String SUBMISSION_FILE_INDEX_FILE_NAME = "submissionFileIndex.json";
     public static final Version REPORT_VIEWER_VERSION = JPlag.JPLAG_VERSION;
@@ -73,6 +79,7 @@ public void createAndSaveReport(JPlagResult result, String path) {
             writeComparisons(result, path);
             writeOverview(result, path);
             writeSubmissionIndexFile(result, path);
+            writeReadMeFile(path);
 
             logger.info("Zipping report files...");
             zipAndDelete(path);
@@ -159,7 +166,7 @@ private File getFileToCopy(Language language, File file) {
     }
 
     private void writeComparisons(JPlagResult result, String path) {
-        ComparisonReportWriter comparisonReportWriter = new ComparisonReportWriter(submissionToIdFunction, fileWriter);
+        ComparisonReportWriter comparisonReportWriter = new ComparisonReportWriter(submissionToIdFunction, jsonFileWriter);
         submissionNameToNameToComparisonFileName = comparisonReportWriter.writeComparisonReports(result, path);
     }
 
@@ -194,8 +201,12 @@ private void writeOverview(JPlagResult result, String path) {
                 clusteringResultMapper.map(result), // clusters
                 totalComparisons); // totalComparisons
 
-        fileWriter.saveAsJSON(overviewReport, path, OVERVIEW_FILE_NAME);
+        jsonFileWriter.writeFile(overviewReport, path, OVERVIEW_FILE_NAME);
+
+    }
 
+    private void writeReadMeFile(String path) {
+        new TextWriter().writeFile(String.join(System.lineSeparator(), README_CONTENT), path, README_FILE_NAME);
     }
 
     private void writeSubmissionIndexFile(JPlagResult result, String path) {
@@ -210,7 +221,7 @@ private void writeSubmissionIndexFile(JPlagResult result, String path) {
             }
             fileIndex.fileIndexes().put(submissionNameToIdMap.get(submission.getName()), filePaths);
         }
-        fileWriter.saveAsJSON(fileIndex, path, SUBMISSION_FILE_INDEX_FILE_NAME);
+        jsonFileWriter.writeFile(fileIndex, path, SUBMISSION_FILE_INDEX_FILE_NAME);
     }
 
     private Set<Submission> getSubmissions(List<JPlagComparison> comparisons) {

core/src/main/java/de/jplag/reporting/reportobject/writer/DummyWriter.java

@@ -0,0 +1,17 @@
+package de.jplag.reporting.reportobject.writer;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This writer is used as a mock for testing purposes only.
+ */
+public class DummyWriter extends JsonWriter {
+    private static final Logger logger = LoggerFactory.getLogger(DummyWriter.class);
+    private static final String MESSAGE = "DummyWriter writes object {} to path {} with name {} as JSON.";
+
+    @Override
+    public void writeFile(Object fileToSave, String folderPath, String fileName) {
+        logger.info(MESSAGE, fileToSave, folderPath, fileName);
+    }
+}

core/src/main/java/de/jplag/reporting/reportobject/writer/FileWriter.java

@@ -0,0 +1,16 @@
+package de.jplag.reporting.reportobject.writer;
+
+/**
+ * Responsible for writing a specific file type to the disk.
+ * @param <T> Object that the FileWriter writes.
+ */
+public interface FileWriter<T> {
+
+    /**
+     * Saves the provided object to the provided path under the provided name
+     * @param fileContent The object to save
+     * @param folderPath The path to save the object to
+     * @param fileName The name to save the object under
+     */
+    void writeFile(T fileContent, String folderPath, String fileName);
+}

core/src/main/java/de/jplag/reporting/reportobject/writer/JsonWriter.java

@@ -0,0 +1,29 @@
+package de.jplag.reporting.reportobject.writer;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * Writes an object with {@link com.fasterxml.jackson.annotation.JsonProperty}s to the disk.
+ */
+public class JsonWriter implements FileWriter<Object> {
+    private static final Logger logger = LoggerFactory.getLogger(JsonWriter.class);
+    private static final ObjectMapper objectMapper = new ObjectMapper();
+    private static final String WRITE_ERROR = "Failed to write JSON file {}";
+
+    @Override
+    public void writeFile(Object fileToSave, String folderPath, String fileName) {
+        Path path = Path.of(folderPath, fileName);
+        try {
+            objectMapper.writeValue(path.toFile(), fileToSave);
+        } catch (IOException e) {
+            logger.error(WRITE_ERROR, e, path);
+        }
+    }
+
+}

core/src/main/java/de/jplag/reporting/reportobject/writer/TextWriter.java

@@ -0,0 +1,27 @@
+package de.jplag.reporting.reportobject.writer;
+
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.nio.file.Path;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Writes plain text to a file.
+ */
+public class TextWriter implements FileWriter<String> {
+
+    private static final Logger logger = LoggerFactory.getLogger(TextWriter.class);
+    private static final String WRITE_ERROR = "Failed to write text file {}";
+
+    @Override
+    public void writeFile(String fileContent, String folderPath, String fileName) {
+        String path = Path.of(folderPath, fileName).toString();
+        try (BufferedWriter writer = new BufferedWriter(new java.io.FileWriter(path))) {
+            writer.write(fileContent);
+        } catch (IOException e) {
+            logger.error(WRITE_ERROR, e, path);
+        }
+    }
+}

core/src/test/java/de/jplag/reporting/reportobject/mapper/ComparisonReportWriterTest.java

@@ -10,11 +10,11 @@
 import de.jplag.TestBase;
 import de.jplag.exceptions.ExitException;
 import de.jplag.reporting.jsonfactory.ComparisonReportWriter;
-import de.jplag.reporting.jsonfactory.DummyWriter;
-import de.jplag.reporting.jsonfactory.FileWriter;
+import de.jplag.reporting.reportobject.writer.DummyWriter;
+import de.jplag.reporting.reportobject.writer.JsonWriter;
 
 public class ComparisonReportWriterTest extends TestBase {
-    private final FileWriter fileWriter = new DummyWriter();
+    private final JsonWriter fileWriter = new DummyWriter();
 
     @Test
     public void firsLevelOfLookupMapComplete() throws ExitException {