JDBC

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class JdbcUtil {
    
    private String driver="oracle.jdbc.driver.OracleDriver";
    private String url="jdbc:oracle:thin:@localhost:8080: dbName";
    private String username="username";
    private String password="password";
    
    private Connection conn = null;
    private PreparedStatement pstmt = null;
    private ResultSet rst = null;
    
    public  UserEntity query(String value){
        String sql = "select user_id,user_name,phone from p_m_user where user_id =" + value;
        UserEntity user = new UserEntity();
        
        try {
            Class.forName(driver);
            conn = DriverManager.getConnection(url, username, password);
            pstmt = conn.prepareStatement(sql);
            rst = pstmt.executeQuery();
            if(rst.next()){
                user.setUser_id(rst.getString("user_id"));
                user.setUser_name(rst.getString("user_name"));
                user.setPhone(rst.getNString("phone"));
            }
            rst.close();
            pstmt.close();
            conn.close();
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch(SQLException e2){
            e2.printStackTrace();
        }
        return user;
    }