Removing duplication

Author: byronka

src/integration_test/java/com/coveros/training/persistence/PersistenceLayerTests.java

@@ -345,15 +345,15 @@ public void testGetBorrowerName_WhenExceptionThrown() throws SQLException {
 
     /**
      * An exception of the right type should be thrown
-     * when an error occurs in the {@link PersistenceLayer#executeUpdateTemplate(SqlData)} method.
+     * when an error occurs in the {@link PersistenceLayer#executeUpdateTemplate} method.
      */
     @Test(expected = SqlRuntimeException.class)
     public void testExecuteUpdateTemplate_ExceptionThrown() throws SQLException {
         final DataSource dataSource = Mockito.mock(DataSource.class);
         when(dataSource.getConnection()).thenThrow(new SQLException());
         final PersistenceLayer persistenceLayer = new PersistenceLayer(dataSource);
 
-        persistenceLayer.executeUpdateTemplate(SqlData.createEmpty());
+        persistenceLayer.executeUpdateTemplate("","");
     }
 
     /**

src/main/java/com/coveros/training/persistence/PersistenceLayer.java

@@ -39,12 +39,9 @@ private static JdbcConnectionPool obtainConnectionPool() {
 
     /**
      * This command provides a template to execute updates (including inserts) on the database
-     *
-     * @param sqlData An object that contains the necessary components to run a SQL statement.
-     *                Usually contains some SQL text and some values that will be injected
-     *                into the statement at run-time.
      */
-    <T> void executeUpdateTemplate(SqlData<T> sqlData) {
+    void executeUpdateTemplate(String description, String preparedStatement, Object ... params) {
+        final SqlData<Object> sqlData = new SqlData<>(description, preparedStatement, params);
         try (Connection connection = dataSource.getConnection()) {
             try (PreparedStatement st = prepareStatementWithKeys(sqlData, connection)) {
                 executeUpdateOnPreparedStatement(sqlData, st);
@@ -68,16 +65,6 @@ public <T> long executeInsertTemplate(
         }
     }
 
-    private <T> long executeInsertTemplate(SqlData<T> sqlData) {
-        try (Connection connection = dataSource.getConnection()) {
-            try (PreparedStatement st = prepareStatementWithKeys(sqlData, connection)) {
-                return executeInsertOnPreparedStatement(sqlData, st);
-            }
-        } catch (SQLException ex) {
-            throw new SqlRuntimeException(ex);
-        }
-    }
-
     <T> long executeInsertOnPreparedStatement(SqlData<T> sqlData, PreparedStatement st) throws SQLException {
         sqlData.applyParametersToPreparedStatement(st);
         st.executeUpdate();
@@ -115,24 +102,24 @@ private <T> PreparedStatement prepareStatementWithKeys(SqlData<T> sqlData, Conne
     @Override
     public long saveNewBorrower(String borrowerName) {
         CheckUtils.checkStringNotNullOrEmpty(borrowerName);
-        return executeInsertTemplate(new SqlData<>(
+        return executeInsertTemplate(
                 "adds a new library borrower",
-                "INSERT INTO library.borrower (name) VALUES (?);", borrowerName));
+                "INSERT INTO library.borrower (name) VALUES (?);", borrowerName);
     }
 
     @Override
     public long createLoan(Book book, Borrower borrower, Date borrowDate) {
-        return executeInsertTemplate(new SqlData<>(
+        return executeInsertTemplate(
                 "Creates a new loan of a book to a borrower",
-                "INSERT INTO library.loan (book, borrower, borrow_date) VALUES (?, ?, ?);", book.id, borrower.id, borrowDate));
+                "INSERT INTO library.loan (book, borrower, borrow_date) VALUES (?, ?, ?);", book.id, borrower.id, borrowDate);
     }
 
     @Override
     public long saveNewBook(String bookTitle) {
         CheckUtils.checkStringNotNullOrEmpty(bookTitle);
-        return executeInsertTemplate(new SqlData<>(
+        return executeInsertTemplate(
                 "Creates a new book in the database",
-                "INSERT INTO library.book (title) VALUES (?);", bookTitle));
+                "INSERT INTO library.book (title) VALUES (?);", bookTitle);
     }
 
     @Override
@@ -147,25 +134,25 @@ public long saveNewUser(String username) {
     public void updateBorrower(long id, String borrowerName) {
         CheckUtils.checkIntParamPositive(id);
         CheckUtils.checkStringNotNullOrEmpty(borrowerName);
-        executeUpdateTemplate(new SqlData<>(
+        executeUpdateTemplate(
                 "Updates the borrower's data",
-                "UPDATE library.borrower SET name = ? WHERE id = ?;", borrowerName, id));
+                "UPDATE library.borrower SET name = ? WHERE id = ?;", borrowerName, id);
     }
 
     @Override
     public void deleteBook(long id) {
         CheckUtils.checkIntParamPositive(id);
-        executeUpdateTemplate(new SqlData<>(
+        executeUpdateTemplate(
                 "Deletes a book from the database",
-                "DELETE FROM library.book WHERE id = ?;", id));
+                "DELETE FROM library.book WHERE id = ?;", id);
     }
 
     @Override
     public void deleteBorrower(long id) {
         CheckUtils.checkIntParamPositive(id);
-        executeUpdateTemplate(new SqlData<>(
+        executeUpdateTemplate(
                 "Deletes a borrower from the database",
-                "DELETE FROM library.borrower WHERE id = ?;", id));
+                "DELETE FROM library.borrower WHERE id = ?;", id);
     }
 
     @Override
@@ -391,9 +378,9 @@ public Optional<Boolean> areCredentialsValid(String username, String password) {
     public void updateUserWithPassword(long id, String password) {
         CheckUtils.checkIntParamPositive(id);
         String hashedPassword = createHashedValueFromPassword(password);
-        executeUpdateTemplate(new SqlData<>(
+        executeUpdateTemplate(
                 "Updates the user's password field with a new hash",
-                "UPDATE auth.user SET password_hash = ? WHERE id = ?;", hashedPassword, id));
+                "UPDATE auth.user SET password_hash = ? WHERE id = ?;", hashedPassword, id);
     }
 
     private String createHashedValueFromPassword(String password) {