feat: bulk insertion for DAOs [macata #99]

Author: DazedNConfused-

src/main/java/com/dazednconfused/catalauncher/database/base/BaseDAO.java

@@ -7,6 +7,7 @@
 import java.sql.Statement;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
@@ -27,6 +28,11 @@ public interface BaseDAO<T extends BaseEntity> {
      * */
     T insert(T t) throws DAOException;
 
+    /**
+     * Inserts the given {@link BaseEntity}(ies) into the table.
+     * */
+    int bulkInsert(Collection<T> t) throws DAOException;
+
     /**
      * Updates the given {@link BaseEntity}. It must have an ID set.
      * */

src/main/java/com/dazednconfused/catalauncher/database/mod/dao/ModH2DAOImpl.java

@@ -9,6 +9,8 @@
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Optional;
 
 import org.slf4j.Logger;
@@ -43,7 +45,7 @@ public String getDatabaseName() {
     public ModEntity insert(ModEntity entity) throws DAOException {
         LOGGER.debug("Inserting ModEntity [{}]...", entity);
 
-        String sql = "INSERT INTO " + MODS_TABLE_NAME + "" +
+        String sql = "INSERT INTO " + MODS_TABLE_NAME + " " +
             "(name, modinfo, created_date, updated_date) " +
             "VALUES " +
             "(?, ?, CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP())";
@@ -61,6 +63,39 @@ public ModEntity insert(ModEntity entity) throws DAOException {
         }
     }
 
+    @Override
+    public int bulkInsert(Collection<ModEntity> entities) throws DAOException {
+
+        if (entities == null || entities.isEmpty()) {
+            LOGGER.warn("No entities provided for bulk insert. No operation shall be performed.");
+            return 0;
+        }
+
+        LOGGER.debug("Bulk inserting [{}] ModEntity(ies)...", entities.size());
+
+        String sql = "INSERT INTO " + MODS_TABLE_NAME + " " +
+            "(name, modinfo, created_date, updated_date) " +
+            "VALUES " +
+            "(?, ?, CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP())";
+
+        try (Connection conn = this.getConnection(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            for (ModEntity entity : entities) {
+                pstmt.setString(1, entity.getName());
+                pstmt.setString(2, entity.getModinfo());
+                pstmt.addBatch();
+            }
+
+            int[] results = pstmt.executeBatch();
+
+            int insertedCount = Arrays.stream(results).filter(result -> result > 0).sum();
+            LOGGER.debug("Bulk inserted [{}] ModEntity(ies)", insertedCount);
+            return insertedCount;
+        } catch (SQLException e) {
+            LOGGER.error("An error occurred during bulk insert of ModEntity(ies)", e);
+            throw new DAOException(e);
+        }
+    }
+
     @Override
     public ModEntity update(ModEntity entity) throws DAOException {
         Optional<ModEntity> originalEntity = this.findById(entity.getId());

src/main/java/com/dazednconfused/catalauncher/database/mod/dao/ModfileH2DAOImpl.java

@@ -9,6 +9,8 @@
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Optional;
 
 import org.slf4j.Logger;
@@ -41,7 +43,7 @@ public String getDatabaseName() {
     public ModfileEntity insert(ModfileEntity entity) throws DAOException {
         LOGGER.debug("Inserting ModfileEntity [{}]...", entity);
 
-        String sql = "INSERT INTO " + TABLE_NAME + "" +
+        String sql = "INSERT INTO " + TABLE_NAME + " " +
             "(mod_id, path, hash, created_date, updated_date) " +
             "VALUES " +
             "(?, ?, ?, CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP())";
@@ -60,6 +62,40 @@ public ModfileEntity insert(ModfileEntity entity) throws DAOException {
         }
     }
 
+    @Override
+    public int bulkInsert(Collection<ModfileEntity> entities) throws DAOException {
+
+        if (entities == null || entities.isEmpty()) {
+            LOGGER.warn("No entities provided for bulk insert. No operation shall be performed.");
+            return 0;
+        }
+
+        LOGGER.debug("Bulk inserting [{}] ModfileEntity(ies)...", entities.size());
+
+        String sql = "INSERT INTO " + TABLE_NAME + " " +
+            "(mod_id, path, hash, created_date, updated_date) " +
+            "VALUES " +
+            "(?, ?, ?, CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP())";
+
+        try (Connection conn = this.getConnection(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            for (ModfileEntity entity : entities) {
+                pstmt.setLong(1, entity.getModId());
+                pstmt.setString(2, entity.getPath());
+                pstmt.setString(3, entity.getHash());
+                pstmt.addBatch();
+            }
+
+            int[] results = pstmt.executeBatch();
+
+            int insertedCount = Arrays.stream(results).filter(result -> result > 0).sum();
+            LOGGER.debug("Bulk inserted [{}] ModfileEntity(ies)", insertedCount);
+            return insertedCount;
+        } catch (SQLException e) {
+            LOGGER.error("An error occurred during bulk insert of ModfileEntity(ies)", e);
+            throw new DAOException(e);
+        }
+    }
+
     @Override
     public ModfileEntity update(ModfileEntity entity) throws DAOException {
         Optional<ModfileEntity> originalEntity = this.findById(entity.getId());

src/main/java/com/dazednconfused/catalauncher/database/mod/repository/ModH2RepositoryImpl.java

@@ -8,6 +8,7 @@
 import com.dazednconfused.catalauncher.database.mod.entity.ModfileEntity;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
@@ -60,6 +61,25 @@ public ModEntity insert(ModEntity entity) throws DAOException {
         return result;
     }
 
+    @Override
+    public int bulkInsert(Collection<ModEntity> entities) throws DAOException {
+        LOGGER.debug("Bulk inserting [{}] ModEntity(ies)...", entities.size());
+
+        int insertedCount = 0;
+
+        for (ModEntity entity : entities) {
+            ModEntity insertedEntity = this.insert(entity);
+            if (insertedEntity != null) {
+                this.insertChildEntities(insertedEntity.getId(), entity.getModfiles());
+                insertedCount++;
+            }
+        }
+
+        LOGGER.debug("Bulk inserted [{}] ModEntity(ies)", insertedCount);
+
+        return insertedCount;
+    }
+
     @Override
     public ModEntity update(ModEntity entity) throws DAOException {
         LOGGER.debug("Updating ModEntity: [{}]", entity);
@@ -121,10 +141,11 @@ public List<ModEntity> findAll() throws DAOException {
     private List<ModfileEntity> insertChildEntities(long modId, List<ModfileEntity> entities) throws DAOException {
         LOGGER.debug("Inserting [{}] ModfileEntity(s) associated to modId [{}]", entities.size(), modId);
 
-        List<ModfileEntity> result = entities.stream()
+        modfileDAO.bulkInsert(entities.stream()
             .peek(e -> e.setModId(modId)) // set/overwrite with entity ID
-            .map(modfileDAO::insert)
-            .collect(Collectors.toList());
+            .collect(Collectors.toList())
+        );
+        List<ModfileEntity> result = modfileDAO.findAllByModId(modId);
 
         LOGGER.debug("Inserted [{}] ModfileEntity(s) associated to modId [{}]", result.size(), modId);