Refactor dublin core utility

src/main/java/org/jabref/cli/ArgumentProcessor.java

@@ -223,6 +223,11 @@ private List<ParserResult> processArguments() {
             doAuxImport(loaded);
         }
 
+        if (cli.isXmpFacilities()) {
+            XmpUtilMain.executeXmpConsoleApplicaton();
+            System.exit(0);
+        }
+
         return loaded;
     }
 

src/main/java/org/jabref/cli/JabRefCLI.java

@@ -140,6 +140,10 @@ public String getExportMatches() {
         return cl.getOptionValue("exportMatches");
     }
 
+    public boolean isXmpFacilities() {
+        return cl.hasOption("readAndWriteXmpMetadata");
+    }
+
     public boolean isGenerateBibtexKeys() { return cl.hasOption("generateBibtexKeys"); }
 
     public boolean isAutomaticallySetFileLinks() { return cl.hasOption("automaticallySetFileLinks"); }
@@ -232,6 +236,11 @@ private Options getOptions() {
                 desc(Localization.lang("Automatically set file links")).
                 build());
 
+        options.addOption(Option.builder("xmp").
+                longOpt("readAndWriteXmpMetadata").
+                desc("Read and write xmp metadata from/to pdf files").
+                build());
+
         return options;
     }
 

src/main/java/org/jabref/cli/XmpUtilMain.java

@@ -0,0 +1,129 @@
+package org.jabref.cli;
+
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.StringWriter;
+import java.nio.file.Paths;
+import java.util.List;
+
+import javax.xml.transform.TransformerException;
+
+import org.jabref.Globals;
+import org.jabref.logic.bibtex.BibEntryWriter;
+import org.jabref.logic.bibtex.LatexFieldFormatter;
+import org.jabref.logic.importer.ImportFormatPreferences;
+import org.jabref.logic.importer.ParserResult;
+import org.jabref.logic.importer.fileformat.BibtexParser;
+import org.jabref.logic.xmp.XmpPreferences;
+import org.jabref.logic.xmp.XmpUtilReader;
+import org.jabref.logic.xmp.XmpUtilWriter;
+import org.jabref.model.database.BibDatabaseMode;
+import org.jabref.model.entry.BibEntry;
+import org.jabref.preferences.JabRefPreferences;
+
+public class XmpUtilMain {
+
+    private static XmpPreferences xmpPreferences;
+    private static ImportFormatPreferences importFormatPreferences;
+
+    private XmpUtilMain() {
+    }
+
+    /**
+     * Reads metadata from pdf and print all included bib entries to the console.
+     *
+     * @param filename Filename of the pdf file (.pdf)
+     */
+    private static void readPdfAndPrintBib(String filename) throws IOException {
+        if (filename.endsWith(".pdf")) {
+            List<BibEntry> entryList = XmpUtilReader.readXmp(filename, xmpPreferences);
+
+            BibEntryWriter bibtexEntryWriter = new BibEntryWriter(
+                    new LatexFieldFormatter(Globals.prefs.getLatexFieldFormatterPreferences()), false);
+
+            for (BibEntry entry : entryList) {
+                StringWriter writer = new StringWriter();
+                bibtexEntryWriter.write(entry, writer, BibDatabaseMode.BIBTEX);
+                System.out.println(writer.getBuffer());
+            }
+        } else {
+            System.err.println("Insert a file path (.pdf)");
+        }
+    }
+
+    /**
+     * Writes all entries included in the bib file to the metadata section of the pdf file.
+     *
+     * @param bibFile Filename of the bib file (.bib)
+     * @param pdfFile Filename of the pdf file (.pdf)
+     */
+    private static void writeBibFileToPdfMetadata(String bibFile, String pdfFile) throws FileNotFoundException, IOException, TransformerException {
+        if (bibFile.endsWith(".bib") && pdfFile.endsWith(".pdf")) {
+            try (FileReader reader = new FileReader(bibFile)) {
+                ParserResult result = new BibtexParser(importFormatPreferences, Globals.getFileUpdateMonitor()).parse(reader);
+                XmpUtilWriter.writeXmp(Paths.get(pdfFile), result.getDatabase().getEntries(), result.getDatabase(), xmpPreferences);
+                System.out.println("Metadata sucessfully written to Pdf.");
+            }
+        } else {
+            System.err.println("Insert correct file paths (.bib and .pdf)");
+        }
+    }
+
+    /**
+     * Print usage information for the console tool xmpUtil.
+     */
+    private static void printMenu() {
+        System.out.println("---------------------Menu-----------------------");
+        System.out.println("(0) Exit");
+        System.out.println("(1) Read metadata from PDF and print as bibtex");
+        System.out.println("(2) Write entries in bib file to Pdf metadata");
+        System.out.println("    To report bugs visit https://issues.jabref.org");
+        System.out.println("-------------------------------------------------");
+        System.out.print("Choose an option: ");
+    }
+
+    /**
+     * The tool is implemented as a console application with a read-evaluate-print cycle.
+     */
+    public static void executeXmpConsoleApplicaton() {
+        if (Globals.prefs == null) {
+            Globals.prefs = JabRefPreferences.getInstance();
+        }
+
+        xmpPreferences = Globals.prefs.getXMPPreferences();
+        importFormatPreferences = Globals.prefs.getImportFormatPreferences();
+
+        BufferedReader consoleReader = new BufferedReader(new InputStreamReader(System.in));
+
+        int option = -1;
+        while (option != 0) {
+            try {
+                XmpUtilMain.printMenu();
+                option = Integer.parseInt(consoleReader.readLine());
+
+                if (option == 0) {
+                    break;
+                } else if (option == 1) {
+                    System.out.print("Insert your filename (.pdf): ");
+                    String filename = consoleReader.readLine().trim();
+                    XmpUtilMain.readPdfAndPrintBib(filename);
+                } else if (option == 2) {
+                    System.out.print("Insert your filename (.bib): ");
+                    String bibFile = consoleReader.readLine().trim();
+                    System.out.print("Insert your filename (.pdf): ");
+                    String pdfFile = consoleReader.readLine().trim();
+                    XmpUtilMain.writeBibFileToPdfMetadata(bibFile, pdfFile);
+                }
+            } catch (IOException | TransformerException e) {
+                System.err.println(e.getMessage());
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        XmpUtilMain.executeXmpConsoleApplicaton();
+    }
+}