diff --git a/pom.xml b/pom.xml
index 188835c..b4bb633 100644
--- a/pom.xml
+++ b/pom.xml
@@ -261,11 +261,18 @@
             <version>13.0</version>
             <scope>compile</scope>
         </dependency>
+
+
         <dependency>
             <groupId>com.google.code.gson</groupId>
             <artifactId>gson</artifactId>
             <version>2.8.0</version>
         </dependency>
+        <dependency>
+            <groupId>org.json</groupId>
+            <artifactId>json</artifactId>
+            <version>20180813</version>
+        </dependency>
 
         <dependency>
             <groupId>org.mariadb.jdbc</groupId>
diff --git a/src/main/java/de/hsel/itech/db/Database.java b/src/main/java/de/hsel/itech/db/Database.java
index b473d2d..8617ce0 100644
--- a/src/main/java/de/hsel/itech/db/Database.java
+++ b/src/main/java/de/hsel/itech/db/Database.java
@@ -7,12 +7,12 @@ import de.hsel.itech.db.pojo.Category;
 import de.hsel.itech.db.pojo.Publisher;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.json.JSONObject;
 import org.mariadb.jdbc.MariaDbPoolDataSource;
 
-import java.io.BufferedReader;
-import java.io.FileReader;
-import java.io.IOException;
+import java.io.*;
 import java.net.URL;
+import java.nio.charset.Charset;
 import java.sql.*;
 import java.time.Year;
 import java.util.AbstractMap;
@@ -105,7 +105,7 @@ public class Database {
      */
     @Nullable
     public Author getAuthor(long id) {
-        Map.Entry<ResultSet, Connection> entry = getResultSet(id, author);
+        Map.Entry<ResultSet, Connection> entry = getResultSetById(author, id);
         assert entry != null;
 
         ResultSet rs = entry.getKey();
@@ -127,7 +127,7 @@ public class Database {
      */
     @Nullable
     public Author getAuthor(String name) {
-        Map.Entry<ResultSet, Connection> entry = getResultSets(author, "name", name);
+        Map.Entry<ResultSet, Connection> entry = getResultSetsByValue(author, "name", name);
         assert entry != null;
         assert entry.getKey() != null;
 
@@ -152,7 +152,7 @@ public class Database {
      */
     @Nullable
     public Category getCategory(long id) {
-        Map.Entry<ResultSet, Connection> entry = getResultSet(id, category);
+        Map.Entry<ResultSet, Connection> entry = getResultSetById(category, id);
         assert entry != null;
         ResultSet rs = entry.getKey();
 
@@ -172,12 +172,17 @@ public class Database {
      */
     @Nullable
     public Category getCategory(String name) {
-        Map.Entry<ResultSet, Connection> entry = getResultSets(category, "name", name);
+        Map.Entry<ResultSet, Connection> entry = getResultSetsByValue(category, "name", name);
         assert entry != null;
 
         return getCategory(entry);
     }
 
+    /**
+     * get Category from database entry.
+     * @param entry entry
+     * @return Category
+     */
     @Nullable
     private Category getCategory(@NotNull Map.Entry<ResultSet, Connection> entry) {
         ResultSet rs = entry.getKey();
@@ -193,6 +198,11 @@ public class Database {
         return category;
     }
 
+    /**
+     * get all categories.
+     *
+     * @return list of categories
+     */
     @Nullable
     public List<Category> getCategories() {
         List<Long> ids = getIds(category);
@@ -203,23 +213,6 @@ public class Database {
         return categories;
     }
 
-    private List<Long> getIds(String table) {
-        Map.Entry<ResultSet, Connection> entry = getResultSets(table, "id");
-        assert entry != null;
-
-
-        List<Long> ids = new ArrayList<>();
-        try {
-            ResultSet rs = entry.getKey();
-            while (rs.next()) {
-                ids.add(rs.getLong("id"));
-            }
-            entry.getValue().close();
-        } catch (SQLException ex) {
-            ex.printStackTrace();
-        }
-        return ids;
-    }
 
     /**
      * gets publisher by id.
@@ -229,7 +222,7 @@ public class Database {
      */
     @Nullable
     public Publisher getPublisher(long id) {
-        Map.Entry<ResultSet, Connection> entry = getResultSet(id, publisher);
+        Map.Entry<ResultSet, Connection> entry = getResultSetById(publisher, id);
         assert entry != null;
 
         ResultSet rs = entry.getKey();
@@ -251,7 +244,7 @@ public class Database {
      */
     @Nullable
     public Publisher getPublisher(String name) {
-        Map.Entry<ResultSet, Connection> entry = getResultSets(publisher, "name", name);
+        Map.Entry<ResultSet, Connection> entry = getResultSetsByValue(publisher, "name", name);
         assert entry != null;
         assert entry.getKey() != null;
 
@@ -277,7 +270,7 @@ public class Database {
      */
     @Nullable
     private List<Integer> getAuthors(long id) {
-        Map.Entry<ResultSet, Connection> entry = getResultSets(id, authorBook, book);
+        Map.Entry<ResultSet, Connection> entry = getResultSetsById(authorBook, book, id);
         assert entry != null;
         try {
             List<Integer> list = new ArrayList<>();
@@ -301,28 +294,22 @@ public class Database {
      */
     @Nullable
     public Book getBook(long id) {
-        Map.Entry<ResultSet, Connection> entry = getResultSet(id, book);
+        Map.Entry<ResultSet, Connection> entry = getResultSetById(book, id);
         assert entry != null;
-        return getBook(entry);
-    }
-
-
-    private Book getBook(@NotNull Map.Entry<ResultSet, Connection> entry) {
-        ResultSet rs = entry.getKey();
-
-        Book book = null;
-        try {
-            book = buildBook(rs);
-            entry.getValue().close();
-        } catch (SQLException e) {
-            e.printStackTrace();
-        }
-        return book;
+        return buildBook(entry);
     }
 
+    /**
+     * builds book from entry.
+     *
+     * @param entry Map.Entry
+     * @return Book
+     */
     @Nullable
-    private Book buildBook(ResultSet rs) {
+    private Book buildBook(@NotNull Map.Entry<ResultSet, Connection> entry) {
+
         Book book = null;
+        ResultSet rs = entry.getKey();
         try {
             Category category = getCategory(rs.getLong(this.category));
             Publisher publisher = getPublisher(rs.getLong(this.publisher));
@@ -341,6 +328,7 @@ public class Database {
                     Year.of(rs.getInt("year")), rs.getInt("price"), rs.getString("description"),
                     rs.getString("image"));
 
+            entry.getValue().close();
         } catch (SQLException e) {
             e.printStackTrace();
         }
@@ -391,19 +379,6 @@ public class Database {
         return books;
     }
 
-    public boolean existsBook(long isbn) {
-        Map.Entry<ResultSet, Connection> entry = getResultSet(book, "isbn", isbn);
-        try {
-            if (entry != null && entry.getKey() != null) {
-                entry.getValue().close();
-                return true;
-            }
-        } catch (SQLException ex) {
-            ex.printStackTrace();
-        }
-        return false;
-    }
-
     /**
      * get books by category.
      *
@@ -415,6 +390,25 @@ public class Database {
         return getBooks(category.getId());
     }
 
+    /**
+     * exists book with isbn ?
+     *
+     * @param isbn isbn
+     * @return true if book with isbn exists
+     */
+    public boolean existsBook(long isbn) {
+        Map.Entry<ResultSet, Connection> entry = getResultSetByValue(book, "isbn", isbn);
+        try {
+            if (entry != null && entry.getKey() != null) {
+                entry.getValue().close();
+                return true;
+            }
+        } catch (SQLException ex) {
+            ex.printStackTrace();
+        }
+        return false;
+    }
+
 
     /**
      * Inserts book into database.
@@ -461,7 +455,7 @@ public class Database {
             if (dbCategory != null)
                 category = dbCategory;
             else {
-                insertCount += insert(new Category(book.getCategory().getName(), book.getCategory().getImage()));
+                insertCount += insert(new Category(book.getCategory().getName(), getRandomImage()));
                 category = getCategory(book.getCategory().getName());
             }
         } else category = book.getCategory();
@@ -656,21 +650,45 @@ public class Database {
         return deleteCount;
     }
 
+    /**
+     * get all ids from specified table.
+     *
+     * @param table table
+     * @return list of ids
+     */
+    private List<Long> getIds(String table) {
+        Map.Entry<ResultSet, Connection> entry = getColumnsFromResultSet(table, "id");
+        assert entry != null;
+
+
+        List<Long> ids = new ArrayList<>();
+        try {
+            ResultSet rs = entry.getKey();
+            while (rs.next()) {
+                ids.add(rs.getLong("id"));
+            }
+            entry.getValue().close();
+        } catch (SQLException ex) {
+            ex.printStackTrace();
+        }
+        return ids;
+    }
+
 
     /**
      * gets specific entry from database.
      *
-     * @param id    id from database
      * @param table table name
+     * @param id    id from database
      * @return {@link java.util.Map.Entry}
      */
     @Nullable
-    private Map.Entry<ResultSet, Connection> getResultSet(long id, String table) {
-        return getResultSet(table, "id", id);
+    private Map.Entry<ResultSet, Connection> getResultSetById(String table, long id) {
+        return getResultSetByValue(table, "id", id);
     }
 
     @Nullable
-    private Map.Entry<ResultSet, Connection> getResultSet(String table, String column, long value) {
+    private Map.Entry<ResultSet, Connection> getResultSetByValue(String table, String column, long value) {
         Connection connection = getConnection();
         try {
             assert connection != null;
@@ -691,20 +709,20 @@ public class Database {
     /**
      * gets specific entries from table.
      *
-     * @param id     id all entries should reference
      * @param table  table name
      * @param column column to match
+     * @param id     id all entries should reference
      * @return {@link java.util.Map.Entry}
      */
     @Nullable
-    private Map.Entry<ResultSet, Connection> getResultSets(long id, @NotNull String table, @NotNull String column) {
+    private Map.Entry<ResultSet, Connection> getResultSetsById(@NotNull String table, @NotNull String column, long id) {
         Connection connection = getConnection();
         try {
             assert connection != null;
             PreparedStatement statement = connection.prepareStatement("SELECT * FROM " + table + " WHERE " + column + " = ?");
             statement.setLong(1, id);
 
-            return getAllEntries(connection, statement);
+            return getAllEntriesFromResultSet(connection, statement);
         } catch (SQLException ex) {
             ex.printStackTrace();
         }
@@ -719,14 +737,14 @@ public class Database {
      * @return {@link java.util.Map.Entry}
      */
     @Nullable
-    private Map.Entry<ResultSet, Connection> getResultSets(@NotNull String table, @NotNull String column, @NotNull String value) {
+    private Map.Entry<ResultSet, Connection> getResultSetsByValue(@NotNull String table, @NotNull String column, @NotNull String value) {
         Connection connection = getConnection();
         try {
             assert connection != null;
             PreparedStatement statement = connection.prepareStatement("SELECT * FROM " + table + " WHERE " + column + " = ?");
             statement.setString(1, value);
 
-            return getAllEntries(connection, statement);
+            return getAllEntriesFromResultSet(connection, statement);
         } catch (SQLException ex) {
             ex.printStackTrace();
         }
@@ -741,13 +759,13 @@ public class Database {
      * @return {@link java.util.Map.Entry}
      */
     @Nullable
-    private Map.Entry<ResultSet, Connection> getResultSets(@NotNull String table, @NotNull String... columns) {
+    private Map.Entry<ResultSet, Connection> getColumnsFromResultSet(@NotNull String table, @NotNull String... columns) {
         Connection connection = getConnection();
         try {
             assert connection != null;
             PreparedStatement statement = connection.prepareStatement("SELECT (" + String.join(",", columns) + ") FROM " + table);
 
-            return getAllEntries(connection, statement);
+            return getAllEntriesFromResultSet(connection, statement);
         } catch (SQLException ex) {
             ex.printStackTrace();
         }
@@ -762,7 +780,7 @@ public class Database {
      * @return {@link java.util.Map.Entry}
      */
     @Nullable
-    private Map.Entry<ResultSet, Connection> getAllEntries(@NotNull Connection connection, @NotNull PreparedStatement statement) {
+    private Map.Entry<ResultSet, Connection> getAllEntriesFromResultSet(@NotNull Connection connection, @NotNull PreparedStatement statement) {
         try {
             ResultSet resultSet = statement.executeQuery();
             return new AbstractMap.SimpleEntry<>(resultSet, connection);
@@ -771,4 +789,28 @@ public class Database {
         }
         return null;
     }
+
+    @Nullable
+    private String getRandomImage() {
+        try {
+            InputStream is = new URL("https://api.unsplash.com/photos/random?client_id=bb18673959b1cfd053a4ecb58e85bb8d99a0050ae5b71dac3e7632916eead9aa").openStream();
+            try {
+                BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
+                StringBuilder sb = new StringBuilder();
+                int cp;
+                while ((cp = rd.read()) != -1) {
+                    sb.append((char) cp);
+                }
+                JSONObject json = new JSONObject(sb.toString());
+                return json.getString("id");
+            } finally {
+                is.close();
+            }
+
+
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/de/hsel/itech/servlet/AddBook.java b/src/main/java/de/hsel/itech/servlet/AddBook.java
index 32f8e36..321e023 100644
--- a/src/main/java/de/hsel/itech/servlet/AddBook.java
+++ b/src/main/java/de/hsel/itech/servlet/AddBook.java
@@ -37,7 +37,7 @@ public class AddBook extends HttpServlet {
         Utillity.addInput(out,"Beschreibung", "description");
         Utillity.addInput(out,"Verlag", "publisher");
         Utillity.addInput(out,"Kategorie", "category");
-        Utillity.addInput(out,"Bild", "image", "DxAzOKSiPoE");
+        Utillity.addInput(out,"Bild", "image");
         Utillity.addSubmitButton(out, "Hinzufügen");
         out.println("</form>");
 
diff --git a/src/test/java/de/hsel/itech/HelloTest.java b/src/test/java/de/hsel/itech/HelloTest.java
index f9cc0f2..feca89c 100644
--- a/src/test/java/de/hsel/itech/HelloTest.java
+++ b/src/test/java/de/hsel/itech/HelloTest.java
@@ -13,6 +13,6 @@ public class HelloTest {
 
     @Test
     void hello() {
-        assertEquals(2, 1+1);
+        assertEquals(2, 1 + 1);
     }
 }
\ No newline at end of file