feature: #1319 add table module pattern (#1742)

* modify table module pattern

* fix code smells

* resolve conversation

Co-authored-by: tao-sun2 <sustc18st@gmai.com>
Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

table-module/src/main/java/com/iluwatar/tablemodule/UserTableModule.java

@@ -0,0 +1,96 @@
+package com.iluwatar.tablemodule;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import javax.sql.DataSource;
+
+import lombok.extern.slf4j.Slf4j;
+
+
+/**
+ * This class organizes domain logic with the user table in the
+ * database. A single instance of this class contains the various
+ * procedures that will act on the data.
+ */
+@Slf4j
+public class UserTableModule {
+  /**
+   * Public element for creating schema.
+   */
+  public static final String CREATE_SCHEMA_SQL =
+          "CREATE TABLE IF NOT EXISTS USERS (ID NUMBER, USERNAME VARCHAR(30) "
+                  + "UNIQUE,PASSWORD VARCHAR(30))";
+  /**
+   * Public element for deleting schema.
+   */
+  public static final String DELETE_SCHEMA_SQL = "DROP TABLE USERS IF EXISTS";
+  private final DataSource dataSource;
+
+
+  /**
+   * Public constructor.
+   *
+   * @param userDataSource the data source in the database
+   */
+  public UserTableModule(final DataSource userDataSource) {
+    this.dataSource = userDataSource;
+  }
+
+
+  /**
+   * Login using username and password.
+   *
+   * @param username the username of a user
+   * @param password the password of a user
+   * @return the execution result of the method
+   * @throws SQLException if any error
+   */
+  public int login(final String username, final String password)
+          throws SQLException {
+    var sql = "select count(*) from USERS where username=? and password=?";
+    ResultSet resultSet = null;
+    try (var connection = dataSource.getConnection();
+         var preparedStatement =
+                 connection.prepareStatement(sql)
+    ) {
+      var result = 0;
+      preparedStatement.setString(1, username);
+      preparedStatement.setString(2, password);
+      resultSet = preparedStatement.executeQuery();
+      while (resultSet.next()) {
+        result = resultSet.getInt(1);
+      }
+      if (result == 1) {
+        LOGGER.info("Login successfully!");
+      } else {
+        LOGGER.info("Fail to login!");
+      }
+      return result;
+    } finally {
+      if (resultSet != null) {
+        resultSet.close();
+      }
+    }
+  }
+
+  /**
+   * Register a new user.
+   *
+   * @param user a user instance
+   * @return the execution result of the method
+   * @throws SQLException if any error
+   */
+  public int registerUser(final User user) throws SQLException {
+    var sql = "insert into USERS (username, password) values (?,?)";
+    try (var connection = dataSource.getConnection();
+         var preparedStatement =
+                 connection.prepareStatement(sql)
+    ) {
+      preparedStatement.setString(1, user.getUsername());
+      preparedStatement.setString(2, user.getPassword());
+      var result = preparedStatement.executeUpdate();
+      LOGGER.info("Register successfully!");
+      return result;
+    }
+  }
+}