Added the deletion manager

src/main/java/de/gnmyt/SQLToolkit/manager/DeletionManager.java

@@ -0,0 +1,119 @@
+package de.gnmyt.SQLToolkit.manager;
+
+import de.gnmyt.SQLToolkit.drivers.MySQLConnection;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+
+public class DeletionManager {
+
+    private final Logger LOG = MySQLConnection.LOG;
+
+    private final MySQLConnection connection;
+    private final HashMap<String, Object> whereList;
+    private final ArrayList<Object> databaseParameters;
+    public ArrayList<String> optionalQuery;
+    private String tableName;
+
+    /**
+     * Advanced constructor for the {@link DeletionManager}
+     *
+     * @param connection The current connection
+     * @param tableName  The table name
+     */
+    public DeletionManager(MySQLConnection connection, String tableName) {
+        this.whereList = new HashMap<>();
+        this.databaseParameters = new ArrayList<>();
+        this.optionalQuery = new ArrayList<>();
+        this.connection = connection;
+        from(tableName);
+    }
+
+    /**
+     * Basic constructor for the {@link DeletionManager}
+     *
+     * @param connection The current connection
+     */
+    public DeletionManager(MySQLConnection connection) {
+        this.whereList = new HashMap<>();
+        this.databaseParameters = new ArrayList<>();
+        this.optionalQuery = new ArrayList<>();
+        this.connection = connection;
+    }
+
+    /**
+     * Get the temp-generated parameters
+     *
+     * @return ArrayList of parameters
+     */
+    private ArrayList<Object> getTempParams() {
+        ArrayList<Object> tempParameters = new ArrayList<>();
+        whereList.forEach((k, v) -> tempParameters.add(v));
+        tempParameters.addAll(databaseParameters);
+        return tempParameters;
+    }
+
+    /**
+     * Sets the table name
+     *
+     * @param tableName The table name
+     * @return this class
+     */
+    public DeletionManager from(String tableName) {
+        this.tableName = tableName;
+        return this;
+    }
+
+    /**
+     * Adding another 'where'-statement
+     *
+     * @param column Table column name
+     * @param value  Table value name
+     * @return this class
+     */
+    public DeletionManager where(String column, Object value) {
+        whereList.put(column, value);
+        return this;
+    }
+
+    /**
+     * Executes the 'delete'-statement
+     */
+    public void execute() {
+        connection.update(prepareStatement(), getTempParams());
+    }
+
+    /**
+     * Adding another factors
+     *
+     * @param query  MySQL Query
+     * @param params Optional parameters for the Query
+     * @return this class
+     */
+    public DeletionManager add(String query, Object... params) {
+        optionalQuery.add(query);
+        this.databaseParameters.addAll(Arrays.asList(params));
+        return this;
+    }
+
+    /**
+     * Get the current statement query
+     *
+     * @return the current statement query
+     */
+    private String prepareStatement() {
+        StringBuilder query = new StringBuilder().append("DELETE FROM ").append(tableName);
+
+        if (!whereList.isEmpty()) query.append(" WHERE ");
+
+        for (int i = 0; i < whereList.size(); i++) {
+            if (i > 0) query.append(" AND ");
+            query.append(whereList.keySet().toArray()[i]).append(" = ?");
+        }
+
+        return query.toString();
+    }
+
+}