Init DB package

build.gradle

@@ -11,6 +11,7 @@ repositories {
 
 dependencies {
     implementation 'org.projectlombok:lombok:1.18.16'
+    implementation 'org.mariadb.jdbc:mariadb-java-client:2.7.1'
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.0'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
 }

src/main/java/DB/DB.java

@@ -0,0 +1,87 @@
+package DB;
+
+import lombok.Getter;
+
+import java.sql.*;
+
+public class DB {
+    static final private String host = "";
+    static final private String database = "";
+    static final private String user = "";
+    static final private String password = "";
+    @Getter static private Connection connection;
+
+    static public boolean connect() {
+        try {
+            if (connection == null || connection.isClosed()) {
+                connection = DriverManager.getConnection("jdbc:mariadb://"+host+"/"+database+"?user="+user+"&password="+password);
+                return true;
+            }
+        } catch (SQLException e) {
+            return false;
+        }
+        return false;
+    }
+
+    static public boolean disconnect() {
+        try {
+            if (connection != null && !connection.isClosed()) {
+                connection.close();
+                connection = null;
+            }
+        } catch (SQLException e) {
+            return false;
+        }
+        return false;
+    }
+
+    static public boolean isConnected() {
+        try {
+            if (connection != null && !connection.isClosed())
+                return true;
+        } catch (SQLException e) {
+            return false;
+        }
+        return false;
+    }
+
+    static public <T> T get(Class<T> cl, String table, String value, String check, String checkValue) {
+        try {
+            PreparedStatement ps = DB.getConnection().prepareStatement("SELECT "+value+" FROM "+table+" WHERE "+check+" = ?");
+            ps.setString(1, checkValue);
+            if (ps.execute()) {
+                ResultSet rs = ps.getResultSet();
+                rs.next();
+                Object returnValue;
+                if (cl == String.class)
+                    returnValue = rs.getString(value);
+                else if (cl == Integer.class)
+                    returnValue = rs.getInt(value);
+                else if (cl == Time.class)
+                    returnValue = rs.getTime(value);
+                else
+                    returnValue = rs.getObject(value);
+                ps.close();
+                return (T)returnValue;
+            }
+        } catch (SQLException e) {
+            return null;
+        }
+        return null;
+    }
+
+    static public boolean set(String table, String value, String newValue, String check, String checkValue) {
+        try {
+            PreparedStatement ps = DB.connection.prepareStatement("UPDATE "+table+" SET "+value+" = ? WHERE "+check+" = ?");
+            ps.setString(1, newValue);
+            ps.setString(2, checkValue);
+            int r = ps.executeUpdate();
+            ps.close();
+            if (r > 0)
+                return true;
+        } catch (SQLException e) {
+            return false;
+        }
+        return false;
+    }
+}