Added initial version

Management-Server/src/main/java/ms/system/mysql/SQLEntryHandler.java

@@ -0,0 +1,202 @@
+package ms.system.mysql;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * Handles an SQL entry.
+ * @author Emperor
+ * @param <T> The entry type.
+ */
+public abstract class SQLEntryHandler<T> {
+
+	/**
+	 * The connection.
+	 */
+	protected Connection connection;
+	
+	/**
+	 * The entry.
+	 */
+	protected T entry;
+	
+	/**
+	 * The result set.
+	 */
+	protected ResultSet result;
+
+	/**
+	 * The table name.
+	 */
+	protected String table;
+
+	/**
+	 * The column name.
+	 */
+	private String column;
+
+	/**
+	 * The value to use.
+	 */
+	protected String value;
+	
+	/**
+	 * Constructs a new {@code SQLEntryHandler} {@code Object}.
+	 * @param entry The entry.
+	 * @param table The table name.
+	 * @param column column name.
+	 * @param value The column value.
+	 */
+	public SQLEntryHandler(T entry, String table, String column, String value) {
+		this.entry = entry;
+		this.table = table;
+		this.column = column;
+		this.value = value;
+	}
+	
+	/**
+	 * Reads the SQL entry.
+	 * @param entry The entry.
+	 */
+	public static void read(SQLEntryHandler<?> entry) {
+		entry.connection = entry.getConnection();
+		if (entry.connection == null) {
+			//System.err.println("Could not read SQL data: connection is null!");
+			return;
+		}
+		try {
+			entry.read();
+			if (entry.result == null || !entry.result.next()) {
+				entry.create();
+			} else {
+				entry.parse();
+			}
+		} catch (SQLException e) {
+			e.printStackTrace();
+		} 
+		SQLManager.close(entry.connection);
+		entry.connection = null;
+	}
+
+	/**
+	 * Writes the entry data on the SQL database.
+	 * @param entry The entry.
+	 */
+	public static void write(SQLEntryHandler<?> entry) {
+		write(entry, entry.getConnection(), true);
+	}
+
+	/**
+	 * Reads the SQL entry.
+	 * @param entry The entry.
+	 */
+	public static void write(SQLEntryHandler<?> entry, Connection connection, boolean commit) {
+		if (connection == null) {
+			//System.err.println("Could not write SQL data: connection is null!");
+			return;
+		}
+		entry.connection = connection;
+		try {
+			if (!commit) {
+				entry.connection.setAutoCommit(false);
+			}
+			entry.save();
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+		if (commit) {
+			SQLManager.close(entry.connection);
+		}
+		entry.connection = null;
+	}
+	
+	/**
+	 * Reads the table from the SQL database.
+	 * @throws SQLException When an SQL exception occurs.
+	 */
+	public void read() throws SQLException {
+		PreparedStatement statement = connection.prepareStatement("SELECT " + getReadSelection() + " FROM " + table + " WHERE " + column + " = ?");
+		statement.setString(1, value);
+		result = statement.executeQuery();
+	}
+	
+	/**
+	 * Gets the result.
+	 * @return the result.
+	 */
+	public ResultSet getResult() {
+		return result;
+	}
+	
+	/**
+	 * Gets the selection.
+	 * @return The selection.
+	 */
+	public String getReadSelection() {
+		return "*";
+	}
+	
+	/**
+	 * Gets the writing statement.
+	 * @param create If we are creating a new row.
+	 * @param columns The columns to update.
+	 */
+	public PreparedStatement getWritingStatement(boolean create, String...columns) {
+		PreparedStatement statement = null;
+		try {
+			StringBuilder sb = new StringBuilder();
+			if (create) {
+				sb.append("INSERT INTO ").append(table).append(" (").append(column);
+				for (String name : columns) {
+					sb.append(",").append(name);
+				}
+				sb.append(") VALUES (?");
+				for (int i = 0; i < columns.length; i++) {
+					sb.append(",?");
+				}
+				sb.append(")");
+			} else {
+				sb.append("UPDATE ").append(table).append(" SET ");
+				for (int i = 0; i < columns.length; i++) {
+					sb.append(columns[i]).append("=?");
+					if (i < columns.length - 1) {
+						sb.append(",");
+					}
+				}
+				sb.append(" WHERE ").append(column).append("=?");
+			}
+			statement = connection.prepareStatement(sb.toString());
+			statement.setString(create ? 1 : columns.length + 1, value);
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+		return statement;
+	}
+	
+	/**
+	 * Parses the entry.
+	 * @throws SQLException When an SQL exception occurs.
+	 */
+	public abstract void parse() throws SQLException;
+
+	/**
+	 * Creates a new row in the database.
+	 * @throws SQLException When an SQL exception occurs.
+	 */
+	public abstract void create() throws SQLException;
+	
+	/**
+	 * Saves the entry.
+	 * @throws SQLException When an SQL exception occurs.
+	 */
+	public abstract void save() throws SQLException;
+	
+	/**
+	 * Gets the connection.
+	 * @return The connection.
+	 */
+	public abstract Connection getConnection();
+	
+}