Implemented csv export. (#1385)

* Implemented csv export.

* Fixed sonarcloud issues.

* Added some tests for CsvPrinter.java

* Implemented suggestions from pr.

* Improved code style, spotless.

cli/src/main/java/de/jplag/cli/CLI.java

@@ -78,6 +78,8 @@ public static void main(String[] args) {
                 JPlagResult result = JPlag.run(options);
                 ReportObjectFactory reportObjectFactory = new ReportObjectFactory();
                 reportObjectFactory.createAndSaveReport(result, cli.getResultFolder());
+
+                OutputFileGenerator.generateCsvOutput(result, new File(cli.getResultFolder()), cli.options);
             }
         } catch (ExitException exception) {
             logger.error(exception.getMessage()); // do not pass exception here to keep log clean

cli/src/main/java/de/jplag/cli/CliOptions.java

@@ -88,6 +88,9 @@ public static class Advanced {
                 "--similarity-threshold"}, description = "Comparison similarity threshold [0.0-1.0]:  All  comparisons  above this threshold will "
                         + "be saved (default: ${DEFAULT-VALUE})%n")
         public double similarityThreshold = JPlagOptions.DEFAULT_SIMILARITY_THRESHOLD;
+
+        @Option(names = "--csv-export", description = "If present, a csv export will be generated in addition to the zip file.")
+        public boolean csvExport = false;
     }
 
     public static class Clustering {

cli/src/main/java/de/jplag/cli/OutputFileGenerator.java

@@ -0,0 +1,36 @@
+package de.jplag.cli;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import de.jplag.JPlagResult;
+import de.jplag.csv.comparisons.CsvComparisonOutput;
+
+public final class OutputFileGenerator {
+    private static final Logger LOGGER = LoggerFactory.getLogger(OutputFileGenerator.class);
+
+    private OutputFileGenerator() {
+        // Prevents default constructor
+    }
+
+    /**
+     * Exports the given result as csvs, if the csvExport is activated in the options. Both a full and an anonymized version
+     * will be written.
+     * @param result The result to export
+     * @param outputRoot The root folder for the output
+     * @param options The cli options
+     */
+    public static void generateCsvOutput(JPlagResult result, File outputRoot, CliOptions options) {
+        if (options.advanced.csvExport) {
+            try {
+                CsvComparisonOutput.writeCsvResults(result.getAllComparisons(), false, outputRoot, "results");
+                CsvComparisonOutput.writeCsvResults(result.getAllComparisons(), true, outputRoot, "results-anonymous");
+            } catch (IOException e) {
+                LOGGER.warn("Could not write csv results", e);
+            }
+        }
+    }
+}

core/src/main/java/de/jplag/csv/CsvDataMapper.java

@@ -0,0 +1,22 @@
+package de.jplag.csv;
+
+import java.util.Optional;
+
+/**
+ * Provides mappings for csv rows and optionally names for the columns. Needs to always return the same number of
+ * columns.
+ * @param <T> The type of data that is mapped
+ */
+public interface CsvDataMapper<T> {
+    /**
+     * Provides the cell values for one row
+     * @param value The original object
+     * @return The cell values
+     */
+    String[] provideData(T value);
+
+    /**
+     * @return The names of the columns if present
+     */
+    Optional<String[]> getTitleRow();
+}

core/src/main/java/de/jplag/csv/CsvPrinter.java

@@ -0,0 +1,144 @@
+package de.jplag.csv;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Optional;
+
+import de.jplag.util.FileUtils;
+
+/**
+ * Prints a csv according to the specification in
+ * <a href="https://datatracker.ietf.org/doc/html/rfc4180#section-2">...</a>. If you need to deviate from this
+ * definition slightly you can modify the line end and separator characters.
+ * @param <T>
+ */
+public class CsvPrinter<T> {
+    private static final char DEFAULT_SEPARATOR = ',';
+    private static final String DEFAULT_LINE_END = "\r\n"; // not System.lineSeparator(), because of csv specification
+    private static final char LITERAL = '"';
+
+    private final CsvDataMapper<T> dataSource;
+    private final List<String[]> data;
+
+    private char separator;
+    private String lineEnd;
+
+    /**
+     * @param dataSource The data source used to map the given object to rows.
+     */
+    public CsvPrinter(CsvDataMapper<T> dataSource) {
+        this.dataSource = dataSource;
+        this.data = new ArrayList<>();
+
+        this.separator = DEFAULT_SEPARATOR;
+        this.lineEnd = DEFAULT_LINE_END;
+    }
+
+    /**
+     * Adds a new row to this csv
+     * @param value the value to add
+     */
+    public void addRow(T value) {
+        this.data.add(this.dataSource.provideData(value));
+    }
+
+    /**
+     * Adds multiple rows to this csv
+     * @param values The values to add
+     */
+    public void addRows(Collection<T> values) {
+        values.forEach(this::addRow);
+    }
+
+    /**
+     * Changes the separator between cells
+     * @param separator The new separator
+     */
+    public void setSeparator(char separator) {
+        this.separator = separator;
+    }
+
+    /**
+     * Sets the string to separate lines with
+     * @param lineEnd the new line end
+     */
+    public void setLineEnd(String lineEnd) {
+        this.lineEnd = lineEnd;
+    }
+
+    /**
+     * Prints this csv with all current data to a file
+     * @param file The file to write
+     * @throws IOException on io errors
+     */
+    public void printToFile(File file) throws IOException {
+        try (Writer writer = FileUtils.openFileWriter(file)) {
+            this.printCsv(writer);
+        }
+    }
+
+    public String printToString() throws IOException {
+        String csv;
+
+        try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
+            try (Writer writer = new OutputStreamWriter(outputStream)) {
+                this.printCsv(writer);
+            }
+
+            csv = outputStream.toString();
+        }
+
+        return csv;
+    }
+
+    private void printCsv(Writer writer) throws IOException {
+        this.writeTitleRow(writer);
+
+        for (String[] datum : this.data) {
+            this.printRow(writer, datum);
+        }
+    }
+
+    private void writeTitleRow(Writer writer) throws IOException {
+        Optional<String[]> titleRow = this.dataSource.getTitleRow();
+        if (titleRow.isPresent()) {
+            this.printRow(writer, titleRow.get());
+        }
+    }
+
+    private void printRow(Writer writer, String[] data) throws IOException {
+        Iterator<String> dataIterator = Arrays.stream(data).iterator();
+
+        if (dataIterator.hasNext()) {
+            printCell(writer, dataIterator.next());
+        }
+
+        while (dataIterator.hasNext()) {
+            writer.write(this.separator);
+            printCell(writer, dataIterator.next());
+        }
+
+        writer.write(this.lineEnd);
+    }
+
+    private void printCell(Writer writer, String cellValue) throws IOException {
+        boolean literalsNeeded = cellValue.contains(String.valueOf(LITERAL));
+        String actualValue = cellValue;
+        if (literalsNeeded) {
+            writer.write(LITERAL);
+            actualValue = actualValue.replace("\"", "\"\"");
+        }
+        writer.write(actualValue);
+        if (literalsNeeded) {
+            writer.write(LITERAL);
+        }
+    }
+}

core/src/main/java/de/jplag/csv/CsvValue.java

@@ -0,0 +1,18 @@
+package de.jplag.csv;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Used with {@link ReflectiveCsvDataMapper} to identify fields and methods, that should be used for the csv.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.FIELD, ElementType.METHOD})
+public @interface CsvValue {
+    /**
+     * The index of the csv field. Has to be used as the compiler sometimes changes the order of fields/methods
+     */
+    int value();
+}

core/src/main/java/de/jplag/csv/HardcodedCsvDataMapper.java

@@ -0,0 +1,58 @@
+package de.jplag.csv;
+
+import java.util.Optional;
+import java.util.function.Function;
+
+/**
+ * Can be used to hardcode mappings to csv. Uses the given function to map values.
+ * @param <T> The mapped type.
+ */
+public class HardcodedCsvDataMapper<T> implements CsvDataMapper<T> {
+    private final Function<T, Object[]> mappingFunction;
+    private final int columnCount;
+
+    private String[] titles;
+
+    /**
+     * @param columnCount The number of columns
+     * @param mappingFunction The function returning the column values. Must return as many values as specified in
+     * columnCount
+     */
+    public HardcodedCsvDataMapper(int columnCount, Function<T, Object[]> mappingFunction) {
+        this.mappingFunction = mappingFunction;
+        this.columnCount = columnCount;
+        this.titles = null;
+    }
+
+    /**
+     * @param columnCount The number of columns
+     * @param mappingFunction The function returning the column values. Must return as many values as specified in
+     * columnCount
+     * @param titles The titles for the csv
+     */
+    public HardcodedCsvDataMapper(int columnCount, Function<T, Object[]> mappingFunction, String[] titles) {
+        this(columnCount, mappingFunction);
+        this.titles = titles;
+    }
+
+    @Override
+    public String[] provideData(T value) {
+        Object[] values = this.mappingFunction.apply(value);
+
+        if (values.length != this.columnCount) {
+            throw new IllegalStateException("You need to return the appropriate number of columns");
+        }
+
+        String[] data = new String[this.columnCount];
+        for (int i = 0; i < this.columnCount; i++) {
+            data[i] = String.valueOf(values[i]);
+        }
+
+        return data;
+    }
+
+    @Override
+    public Optional<String[]> getTitleRow() {
+        return Optional.ofNullable(this.titles);
+    }
+}

core/src/main/java/de/jplag/csv/ReflectiveCsvDataMapper.java

@@ -0,0 +1,89 @@
+package de.jplag.csv;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Optional;
+
+import org.apache.commons.math3.util.Pair;
+
+/**
+ * Mapped data automatically based on the exposed fields and methods.
+ * @param <T> The mapped type. Mark included methods and fields with @{@link CsvValue}
+ */
+public class ReflectiveCsvDataMapper<T> implements CsvDataMapper<T> {
+    private final List<Pair<Integer, GetterFunction<T>>> values;
+    private String[] titles;
+
+    /**
+     * @param type The mapped type.
+     */
+    public ReflectiveCsvDataMapper(Class<T> type) {
+        this.values = new ArrayList<>();
+
+        for (Field field : type.getFields()) {
+            if (field.getAnnotation(CsvValue.class) != null) {
+                this.values.add(new Pair<>(field.getAnnotation(CsvValue.class).value(), field::get));
+            }
+        }
+
+        for (Method method : type.getMethods()) {
+            if (method.getAnnotation(CsvValue.class) != null) {
+                if (method.getParameters().length != 0) {
+                    throw new IllegalStateException(
+                            String.format("Method %s in %s must not have parameters to be a csv value", method.getName(), type.getName()));
+                }
+                if (method.getReturnType().equals(Void.class)) {
+                    throw new IllegalStateException(
+                            String.format("Method %s in %s must not return void to be a csv value", method.getName(), type.getName()));
+                }
+
+                this.values.add(new Pair<>(method.getAnnotation(CsvValue.class).value(), method::invoke));
+            }
+        }
+
+        this.values.sort(Comparator.comparing(Pair::getKey));
+        this.titles = null;
+    }
+
+    /**
+     * @param type The mapped type
+     * @param titles The titles for the csv. Must be as many as @{@link CsvValue} annotation in the given type.
+     */
+    public ReflectiveCsvDataMapper(Class<T> type, String[] titles) {
+        this(type);
+
+        if (this.values.size() != titles.length) {
+            throw new IllegalArgumentException("Csv data must have the same number of tiles and values per row.");
+        }
+
+        this.titles = titles;
+    }
+
+    @Override
+    public String[] provideData(T value) {
+        String[] data = new String[this.values.size()];
+
+        for (int i = 0; i < data.length; i++) {
+            try {
+                data[i] = String.valueOf(this.values.get(i).getValue().get(value));
+            } catch (IllegalAccessException | InvocationTargetException e) {
+                throw new IllegalStateException(e);
+            }
+        }
+
+        return data;
+    }
+
+    @Override
+    public Optional<String[]> getTitleRow() {
+        return Optional.ofNullable(this.titles);
+    }
+
+    private interface GetterFunction<T> {
+        Object get(T instance) throws IllegalAccessException, InvocationTargetException;
+    }
+}