Basic Database Connection Java

 

 

Import Java. SQL. *; </P> <p> public class dbtest2 <br/> {<br/> string url = "JDBC: mysql: // localhost: 3306 /"; <br/> string user = "root"; <br/> string passwd = "root"; <br/> Public dbtest2 () throws classnotfoundexception <br/>{< br/> class. forname ("com. mySQL. JDBC. driver "); <br/>}< br/> Public static void main (string [] ARGs) <br/>{< br/>}< br/>} 

 

 

<Br/> Import Java. io. *; <br/> Import Java. SQL. *; <br/> public class connectiondemo <br/>{< br/> Public static void main (string [] ARGs) <br/>{< br/> string sql1 = "select * from A1"; <br/> string sql2 = "insert into A1 (AA, BB) values (null, 'aaa') "; <br/> try {<br/> dbsource = new simpledbsource (); <br/> connection conn = dbsource. getconnection (); <br/> statement stmt = Conn. createstatement (); <br/> resu Ltset rs = stmt.exe cutequery (sql1); <br/> resultsetmetadata rmeta = Rs. getmetadata (); <br/> int numcolumns = rmeta. getcolumncount (); <br/> system. out. println (numcolumns); <br/> // Rs. next (); <br/> // system. out. println (RS. getstring (1); <br/> // system. out. println (); <br/> while (RS. next () <br/>{< br/> // Rs. next (); <br/> // string str1 = Rs. getstring (0); <br/> // int a1 = Rs. getint (0); <br/> // system. out. println (Str1); <br/> // system. out. println (A1); <br/> for (INT I = 0; I <numcolumns; I ++) <br/>{< br/> string stemp = Rs. getstring (I + 1); <br/> system. out. println (stemp + ""); <br/>}< br/> system. out. println (); </P> <p >}< br/> for (INT I = 0; I <10000; I ++) <br/>{< br/> stmt.exe cuteupdate (sql2); <br/>}< br/> If (! Conn. isclosed () <br/>{< br/> system. out. println ("database connection enabled"); <br/>}< br/> dbsource. closeconnection (conn); <br/> If (Conn. isclosed () <br/>{< br/> system. out. println ("Database Connection closed"); <br/>}< br/>/*} catch (ioexception e) {<br/> E. printstacktrace (); */<br/>} catch (classnotfoundexception e) {<br/> E. printstacktrace (); <br/>} catch (sqlexception e) {<br/> E. printstacktrace (); <br/>}</P> <p> Import Java. SQL. *; </P> <p> Public interface dbsource {<br/> Public connection <br/> getconnection () throws sqlexception; <br/> Public void <br/> closeconnection (connection conn) throws sqlexception; <br/>}</P> <p> Import Java. util. *; <br/> Import Java. SQL. *; <br/> Import Java. io. *; </P> <p> public class simpledbsource implements dbsource <br/>{< br/> string URL; <br/> string user; <br/> string passwd; <br/> Public simpledbsource () throws classnotfoundexception <br/> {<br/> url = "JDBC: mysql: // localhost: 3306/demo "; <br/> User = "root"; <br/> passwd = "root"; <br/> class. forname ("com. mySQL. JDBC. driver "); <br/>}< br/> Public connection <br/> getconnection () throws sqlexception <br/>{< br/> return drivermanager. getconnection (URL, user, passwd); <br/>}< br/> Public void <br/> closeconnection (connection conn) throws sqlexception <br/>{< br/> Conn. close (); <br/>}< br/>}