implemented methods to extract fulltext link from an API call

dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/transformation/xslt/DataFetcher.java

@@ -6,6 +6,7 @@ import net.sf.saxon.s9api.*;
 import org.apache.commons.io.IOUtils;
 import org.json.JSONObject;
 import java.io.IOException;
+import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
@@ -18,16 +19,6 @@ import java.util.List;
 
 public class DataFetcher implements ExtensionFunction, Serializable {
 
-    /**
-     * this method fetches JSON from a provided URL and returns it as Dublin Core
-     */
-    public static List<String> fetchAndTransform(URL url) throws IOException {
-
-        JSONObject jsonObject = getJson(url);
-        List<String> authors = getAuthorsFromJson(jsonObject);
-        return transformListToDublinCore(authors);
-    }
-
     /**
      * This method fetches JSON object from a given URL
      * @param url a url in the metadata for fetching authors in JSON format
@@ -88,14 +79,39 @@ public class DataFetcher implements ExtensionFunction, Serializable {
         return dublinCoreAuthors;
     }
 
-    /**
+     /**
-     * todo: add documentation
+     * This is a public method which fetches authors and transform them into Dublin Core
      */
     public static String getAndTransformAuthors(URL url) throws IOException{
         return String.join(", ", transformListToDublinCore(getAuthorsFromJson(getJson(url))));
     }
 
 
+    /**
+     * This method extracts link to fulltext from a given JSON
+     *
+     * @return
+     */
+    static private String getLinkToFulltextFromJson(JSONObject jsonObject) throws MalformedURLException {
+
+        // note: Link to JSON containing fulltextlink is in "primary_file" attribute.
+        // And in the resultant JSON,  “links->download” contains the URL to fulltext
+
+        return jsonObject
+                .getJSONObject("data")
+                .getJSONObject("links")
+                .getString("download");
+    }
+
+    /**
+     * This is a public method which fetches link to full text and returns it as a suitable format
+     */
+    public static String getFullTextLinkAndTransform (URL url )throws IOException{
+
+        return getLinkToFulltextFromJson(getJson(url));
+    }
+
+
     @Override
     public QName getName() {
         return null;

dhp-workflows/dhp-aggregation/src/test/java/eu/dnetlib/dhp/transformation/xslt/DataFetcherTest.java

@@ -6,6 +6,7 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
+import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
@@ -57,4 +58,11 @@ class DataFetcherTest {
     }
 
 
+    @Test
+    void getLinkToFulltextFromJson() throws URISyntaxException, IOException {
+        URL linkToFullTextDocument = new URI("https://api.osf.io/v2/files/5de7c96f84c479000c7928af/?format=json").toURL();
+        System.out.println(DataFetcher.getFullTextLinkAndTransform(linkToFullTextDocument));
+
+
+    }
 }