Java Connection MySQL database implementation code

1. Get the database connection and query code

 PackageConnectionmysql;Importjava.sql.Connection;ImportJava.sql.DriverManager;ImportJava.sql.ResultSet;Importjava.sql.SQLException;Importjava.sql.Statement; Public classConnectionmysql {//database connection user name    PrivateString userName = "root"; //Database connection Password    PrivateString pwd = "910214"; //setting up the database    PrivateString database = "JSP"; //setting up the JDBC driver    PrivateString dbdriver = "Com.mysql.jdbc.Driver"; //setting the database connection URL    PrivateString dbconnect = "jdbc:mysql://localhost:3306/" +database; //Connection Variables    PrivateConnection conn =NULL; PrivateStatement stmt =NULL; ResultSet RS=NULL; /*database-Driven registration*/     PublicConnectionmysql () {Try{class.forname (dbdriver); }        Catch(Exception ex) {System.out.println ("Connection failed:" +ex.getmessage ()); }    }        /*Establish database connection and its data query*/     PublicResultSet executeQuery (String sql)throwssqlexception{rs=NULL; Try{conn=drivermanager.getconnection (Dbconnect, UserName, PWD); stmt=conn.createstatement (); RS=stmt.executequery (SQL); }Catch(Exception ex) {System.out.println ("Connection failed:" +ex.getmessage ()); }//finally{//            //To close a database connection//stmt.close ();//conn.close ();//        }        returnrs; }        /*Establish database connections and database queries*/     Public voidExcuteupdate (String sql)throwsSQLException {stmt=NULL; Try{            //connecting to a databaseconn =drivermanager.getconnection (Dbconnect, UserName, PWD); stmt=conn.createstatement ();        Stmt.executeupdate (SQL); }Catch(Exception ex) {//Throwing Exceptions manually            Throw NewSQLException (Ex.getmessage ()); }//finally{//stmt.close ();//conn.close ();//        }    }        /** Consider database performance issues and need to release database resources, so the shutdown method*/    //Closing Statement Statements     Public voidclosestmt () {Try{stmt.close (); }Catch(SQLException ex) {System.out.println ("Failed to close database:" +ex.getmessage ()); }    }    //Close Connection     Public voidCloseconn () {Try{conn.close (); }Catch(SQLException ex) {System.out.println ("Shutdown Connection failed:" +ex.getmessage ()); }    }        }

2. Test code

 PackageConnectionmysql;ImportJava.sql.ResultSet;Importjava.sql.SQLException; Public classtestmysqlconnection {/*** Run Program Test*/     Public Static voidMain (string[] args) {//TODO auto-generated Method StubConnectionmysql Conmysql=NewConnectionmysql (); //querying database SQL statementsString sql = "Select Username,password from Userlogin"; Try{            //return query result setResultSet rs =conmysql.executequery (SQL); //Print query Data            if(Rs.next ()) {String username= rs.getstring (1); String Password= Rs.getstring (2); System.out.println ("User name:" +username); System.out.println ("Password:" +password);//System.out.println (rs.getstring (2));            }        }Catch(SQLException ex) {System.out.println ("Query failed:" +ex.getmessage ()); }finally{            //To close a database connectionconmysql.closestmt ();        Conmysql.closeconn (); }    }}

Java Connection MySQL database implementation code