Implement DepSessionFactory Part-

Author: Chamal-Peiris

.gitignore

@@ -0,0 +1,4 @@
+.idea/
+target/
+
+*.iml

.idea/uiDesigner.xml

@@ -13,4 +13,14 @@
         <maven.compiler.target>8</maven.compiler.target>
     </properties>
 
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>8.0.29</version>
+        </dependency>
+
+    </dependencies>
+
 </project>

LICENSE.txt

@@ -1,25 +1,66 @@
 package lk.ijse.dep8.orm.annotations;
 
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Field;
 import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
 import java.util.ArrayList;
 import java.util.List;
 
 
 public class DepSessionFactory {
-  private List<Class<?>> entityClassList=new ArrayList<>();
-  private Connection connection;
-
-  public DepSessionFactory addAnnotatedClass(Class<?> entityClass){
-      if(entityClass.getDeclaredAnnotations(Entity.class)==null){
-          throw new RuntimeException("Invalid Entity class");
-      }
-      entityClassList.add(entityClassClass);
-    return this;
-  }
-  public DepSessionFactory setConnection(Connection connection){
-   this.connection=connection;
-   return this;
-  }
+    private final List<Class<?>> entityClassList = new ArrayList<>();
+    private Connection connection;
 
+    public DepSessionFactory addAnnotatedClass(Class<?> entityClass){
+        if (entityClass.getDeclaredAnnotation(Entity.class) == null){
+            throw new RuntimeException("Invalid entity class");
+        }
+        entityClassList.add(entityClass);
+        return this;
+    }
 
+    public DepSessionFactory setConnection(Connection connection){
+        this.connection = connection;
+        return this;
+    }
+
+    public DepSessionFactory build(){
+        if (this.connection == null){
+            throw new RuntimeException("Failed to build without a connection");
+        }
+        return this;
+    }
+
+    public void bootstrap() throws SQLException {
+        for (Class<?> entity : entityClassList) {
+            String tableName = entity.getDeclaredAnnotation(Entity.class).value();
+            if (tableName.trim().isEmpty()) tableName = entity.getSimpleName();
+            List<String> columns = new ArrayList<>();
+            String primaryKey = null;
+
+            Field[] fields = entity.getDeclaredFields();
+            for (Field field : fields) {
+                Id primaryKeyField = field.getDeclaredAnnotation(Id.class);
+                if (primaryKeyField != null) {
+                    primaryKey = field.getName();
+                    continue;
+                }
+
+                String columnName = field.getName();
+                columns.add(columnName);
+            }
+            if (primaryKey == null) throw new RuntimeException("Entity without a primary key");
+
+            StringBuilder sb = new StringBuilder();
+            sb.append("CREATE TABLE ").append(tableName).append("(");
+            for (String column : columns) {
+                sb.append(column).append(" VARCHAR(255),");
+            }
+            sb.append(primaryKey).append("VARCHAR(255) PRIMARY KEY)");
+            Statement stm = connection.createStatement();
+            stm.executeQuery(sb.toString());
+        }
+    }
 }