eclipse - JDBC connectivity issue while connecting to college server -
i have tried connect college server workplace , receive response:
connection failed! check output console my code:
public jdbcbasicexample() { // todo auto-generated constructor stub } public static void main(string[] argv) { system.out.println("-------- mysql jdbc connection testing ------------"); try { class.forname("com.mysql.jdbc.driver"); } catch (classnotfoundexception e) { system.out.println("where mysql jdbc driver?"); e.printstacktrace(); return; } system.out.println("mysql jdbc driver registered!"); connection connection = null; try { connection = drivermanager .getconnection("jdbc:mysql://collegeservername:portnumber/databasenameinserver", "username","password"); } catch (sqlexception e) { system.out.println("connection failed! check output console"); e.printstacktrace(); return; } if (connection != null) { system.out.println("you made it, take control database now!"); } else { system.out.println("failed make connection!"); } } i getting following error:
com.mysql.jdbc.exceptions.jdbc4.communicationsexception: communications link failure last packet sent server 0 milliseconds ago. driver has not received packets server. @ sun.reflect.nativeconstructoraccessorimpl.newinstance0(native method) @ sun.reflect.nativeconstructoraccessorimpl.newinstance(unknown source) @ sun.reflect.delegatingconstructoraccessorimpl.newinstance(unknown source) @ java.lang.reflect.constructor.newinstance(unknown source) @ com.mysql.jdbc.util.handlenewinstance(util.java:411) @ com.mysql.jdbc.sqlerror.createcommunicationsexception(sqlerror.java:1121) @ com.mysql.jdbc.mysqlio.readpacket(mysqlio.java:675) @ com.mysql.jdbc.mysqlio.dohandshake(mysqlio.java:1086) @ com.mysql.jdbc.connectionimpl.coreconnect(connectionimpl.java:2486) @ com.mysql.jdbc.connectionimpl.connectonetryonly(connectionimpl.java:2519) @ com.mysql.jdbc.connectionimpl.createnewio(connectionimpl.java:2304) @ com.mysql.jdbc.connectionimpl.<init>(connectionimpl.java:834) @ com.mysql.jdbc.jdbc4connection.<init>(jdbc4connection.java:47) @ sun.reflect.nativeconstructoraccessorimpl.newinstance0(native method) @ sun.reflect.nativeconstructoraccessorimpl.newinstance(unknown source) @ sun.reflect.delegatingconstructoraccessorimpl.newinstance(unknown source) @ java.lang.reflect.constructor.newinstance(unknown source) @ com.mysql.jdbc.util.handlenewinstance(util.java:411) @ com.mysql.jdbc.connectionimpl.getinstance(connectionimpl.java:416) @ com.mysql.jdbc.nonregisteringdriver.connect(nonregisteringdriver.java:346) @ java.sql.drivermanager.getconnection(unknown source) @ java.sql.drivermanager.getconnection(unknown source) @ testingdatabase.jdbcbasicexample.main(jdbcbasicexample.java:29) caused by: java.io.eofexception: can not read response server. expected read 4 bytes, read 0 bytes before connection unexpectedly l`enter code here`ost. @ com.mysql.jdbc.mysqlio.readfully(mysqlio.java:3119) @ com.mysql.jdbc.mysqlio.readpacket(mysqlio.java:599) ... 16 more can please me resolve this? new , have tried many other ways replacing collegeservername:portnumber ip address though didnt work. have tried other remote address , port name no success. kindly give me suggestions.
connection fail simple check list:
- your networking working properly.
- is there firewall in college server blocks or allows connections set of ip address?
- the address , port of database server correct?? check make sure external ip available internally.
- does mysql service start?? (check system service list , tcp listening list, mysql listen connection??)
- can login database via mysql shell workspace?? (open terminal, enter
mysql -h your_database_host -u your_username -plogin) - does database allow remote access?? (check my.cnf file in databaes server , remove line
bind-address=127.0.0.1)
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