heridev · August 11, 2018 15:24 · Aug 11, 2018 · Aug 11, 2018 · Aug 11, 2018
diff --git a/exceptions.md b/exceptions.md
@@ -71,7 +71,7 @@ public interface BookActivityView {
 ```
 
 And as our BooksActivity implements this interface we need to declare there our view method and the logic for that:
-```
+
 BooksActivity.java
 ```
 public class BooksActivity extend BaseActivity implements BooksActivityView {

diff --git a/exceptions.md b/exceptions.md
@@ -1,4 +1,5 @@
 Let's start changing the repository to trigger an exception(typo in the orderby clause):
+
 DatabaseBooksRepository.java
 ```
 public class DatabaseBooksRepository implements BooksRepository {

diff --git a/exceptions.md b/exceptions.md
@@ -0,0 +1,123 @@
+Let's start changing the repository to trigger an exception(typo in the orderby clause):
+DatabaseBooksRepository.java
+```
+public class DatabaseBooksRepository implements BooksRepository {
+  private final DatabaseHelper databaseHelper;
+  public DatabaseBooksRepository(Content context) {
+   databaseHelper = OpenHelperManager.getHelper(context, DatabaseHelper.class);
+  }
+
+  @Override
+  public List<Book> getBooks(){
+    try{
+      return databaseHelper.getbookDaO().queryBuilder()
+               .orderBy("orderXXX", tru)
+               .query();
+    } catch {
+      throw new RuntimeException("boom");
+    }
+  }
+}
+```
+
+the new scenario for testing it would look like this:
+BooksActivityPresenterTest.java
+```
+import org.junit.Test;
+import org.junit.Asserts;
+import org.junit.runner.RunWith;
+import org.mockito.junit.MockitoJUnitRunner;
+
+public class BooksActivityPresenterTest {
+ 
+ @Rule
+ public MockitoRule mockitoRule = MockitoJUnit.rule();
+
+ @Mock
+ BooksRepository booksRepository;
+
+ @Mock
+ BooksActivityView view;
+ 
+ BooksActivityPresenter presenter;
+
+ @Before
+ public void setUp() { presenter = new BooksActivityPresenter(view, booksRepository); }
+
+ @Test
+ public void shouldHandleAnException() {
+
+  Mockito.when(booksRepository.getBooks())
+                              .thenThrown(new RuntimeException("boom")));
+  
+  presenter.loadBooks();
+
+  Mockito.verify(view).displayError();
+ }
+}
+```
+
+Now we need to implement this new displayError method:
+BooksActivityView.js
+```
+public interface BookActivityView {
+  void displayBooks(List<Book> bookList);
+
+  void displayNoBooks();
+
+  void displayError();
+}
+```
+
+And as our BooksActivity implements this interface we need to declare there our view method and the logic for that:
+```
+BooksActivity.java
+```
+public class BooksActivity extend BaseActivity implements BooksActivityView {
+  private BooksActivityPresenter presenter;
+  @override
+  protected void onCreate(...){
+    ....
+  }
+
+  @Override public void displayBooks(List<book> bookList) {
+    ...
+  }
+
+  @Override public void displayNoBooks() {
+    ...
+  };
+
+  @Override public void displayError() {
+    Toast.makeText(this, "Errror accessing data", Toast.LENGTH_SHORT).show();
+  };
+}
+```
+
+And we need to reflect this change on the main:
+BooksActivityPresenter.java
+```
+public class BooksActivityPresenter {
+  public BooksActivityPresenter(BooksActivityView view, BooksRepository booksRepository) {
+    this.view = view;
+    this.booksRepository = booksRepository
+  }
+
+  public void loadBooks(){
+   List<Book> listBooks;
+   try {
+     listBooks = booksRepository.getBooks();
+     // Here the presenter does not know anything about the repository
+     // the presenter just wait for getting an array of values and that's it
+     if(listBooks.isEmpty()){
+       view.displayNoBooks();
+     } else {
+       view.displayBooks(bookList);
+     }
+   } catch(Exception e) {
+     view.displayError();
+   }
+
+  }
+}
+```