PostgreSQL class for Java

PostgreSQL.java

import java.sql.*;
import javax.swing.*;
import java.util.*;


public class PostgreSQL{
	private int _code;
	private String _type;
	private String[] database = {"postgres", "sqladmin", "org.postgresql.Driver", "jdbc:postgresql://localhost:5432/banco73b2017"};
	private Connection _pgsql;
	private ResultSet _result;
	private PreparedStatement _pStatement;
	private Statement _statement;

	public PostgreSQL(){

	}

	public void setCode(int value){
		this._code = value;
	}

	public void setType(String value){
		this._type = value;
	}

	public int getCode(){
		return this._code;
	}

	public String getType(){
		return this._type;
	}

	public void insert(String table, ArrayList<String> list){
		String sql_in = "INSERT INTO "+table+" VALUES(";
		this._pStatement = _pgsql.prepareStatement(null);
		try{
			int cont = 0;
			for(String any : list){
				if(cont == 0){
					sql_in+="?";
				}
				else{
					sql_in+=", ?";
				}
				_pStatement.setString(cont++, any);
			}
			sql_in+= ")";
			_pStatement.execute(sql_in);
			_pStatement.close();
		}
		catch(Exception e){

		}
	}

	public void select(String table, ArrayList<String> list){
		String sql_in = "SELECT ";
		this._pStatement = _pgsql.prepareStatement(null);
		try{
			int cont = 0;
			for(String any : list){
				if(cont == 0){
					sql_in+="?";
				}
				else{
					sql_in+=", ?";
				}
				_pStatement.setString(cont++, any);
			}
			sql_in+=" FROM "+table;
			_pStatement.execute(sql_in);
			_pStatement.close();
		}
		catch(Exception e){

		}
	}

	public void select(String table, ArrayList<String> list, ArrayList<String> where){
		String sql_in = "SELECT ";
		this._pStatement = _pgsql.prepareStatement(null);
		try{ 
			int cont = 0;
			for(String any : list){
				if(cont == 0){
					sql_in+="?";
				}
				else{
					sql_in+=", ?";
				}
				_pStatement.setString(cont++, any);
			}
			sql_in+=" FROM "+table;
			sql_in+= " WHERE TRUE ";
			for(String any : where){
				sql_in+= (" AND "+any);
			}
			_pStatement.execute(sql_in);
			_pStatement.close();
		}
		catch(Exception e){

		}
	}


	public void drop(String table, ArrayList<String> where){
		String sql_in = "DELETE FROM "+table+" WHERE TRUE";
		this._pStatement = _pgsql.prepareStatement(null);
		try{ 
			int cont = 0;
			for(String any : where){
				sql_in+=(" AND"+any);
			}
			_pStatement.execute(sql_in);
			_pStatement.close();
		}
		catch(Exception e){

		}
	}

	public void update(String table, ArrayList<String> list, ArrayList<String> where){
		String sql_in = "UPDATE "+table+" SET";
		this._pStatement = _pgsql.prepareStatement(null);
		try{ 
			int cont = 0;
			for(String any : list){
				if(cont == 0){
					sql_in+=any;
				}
				else{
					sql_in+=(", "+any);
				}
				cont++;
			}
			sql_in+= " WHERE TRUE ";
			for(String any : where){
				sql_in+=(" AND"+any);
			}
			_pStatement.execute(sql_in);
			_pStatement.close();
		}
		catch(Exception e){

		}
	}

	public void connect(){
		try{
			Class.forName(database[3]);
			_pgsql=DriverManager.getConnection(database[2],database[0],database[1]);
		}
		catch(Exception e){

		}
	}

	public void disconnect(){
		try{
			_pgsql.close();
		}
		catch(Exception e){

		}
	}
}

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