I can't connect to my Oracle database server. This is the code :
import java.util.*;
import java.sql.*;
import java.io.IOException;
public class Knigi {
public static void main(String[] args) {
String baza_DRIVER="oracle.jdbc.driver.OracleDriver";
String baza_STRING="jdbc:oracle:thin:#localhost:1521:";
String baza_USERNAME="knigi";
String baza_PASSWORD="knigi";
Locale.setDefault(Locale.ENGLISH); // Vazhno e bidejkji Oracle treba da znae kakvi poraki da pojavuva
try {
Driver Driver = (Driver)Class.forName(baza_DRIVER).newInstance();
Connection Conn = DriverManager.getConnection(baza_STRING,baza_USERNAME,baza_PASSWORD);
PreparedStatement Statement = Conn.prepareStatement("SELECT * FROM zhanrovi");
ResultSet zhanrovi = Statement.executeQuery();
boolean isEmpty = !zhanrovi.next();
boolean hasData = !isEmpty;
while (hasData) {
System.out.println("Zhanr: "+zhanrovi.getString("ZH_IME"));
PreparedStatement Statement2 =
Conn.prepareStatement("select * from knigi where ZH_BR = ?");
Statement2.setInt(1,zhanrovi.getInt("ZH_BR"));
ResultSet knigi = Statement2.executeQuery();
boolean isEmpty2 = !knigi.next();
boolean hasData2 = !isEmpty2;
if (isEmpty2) {
System.out.println(" - nema knigi");
} else {
System.out.println(" - Knigi:");
};
while (hasData2) {
System.out.println(
" " +
knigi.getString("ISBN") +
" - " +
knigi.getString("NASLOV")+" ");
hasData2=knigi.next();
}
knigi.close();
hasData=zhanrovi.next();
}
zhanrovi.close();
Conn.close();
} catch (Exception e) {
System.out.println(e);
}
}
}
And I am getting this message:
java.sql.SQLException: Io exception: Connection refused(DESCRIPTION=(TMP=)(VSNNUM=186646784)(ERR=12504)(ERROR_STACK=(ERROR=(CODE=12504)(EMFI=4))(ERROR=(CODE=12504)(EMFI=4))))
In school, this example works. Where is the problem??
Try this, might help
jdbc:oracle:thin://<host>:<port>/<SERVICE_NAME>
service_name=SID of the database, most often ORCL.
cheers,
Do you have your DB server running at your local machine at: localhost:1521?
Your school machine might have DB server running on it but your home machine simply doesn't.
The db connection URL "jdbc:oracle:thin:#localhost:1521:" is normally not hard coded. Point it to localhost almost always fail it when you run your code on a different machine.
There are three major instances when you get such Connection refused error
There is no database server running at the host:port you have specified i.e at localhost:1521
Password you have entered is wrong.
The port you have specified is blocked by a firewall or you are behind some proxy that does not allow you to connect to that port.
You can manually try to connect to your database from command line and see if the connection is live.
Question has been closed ... I had to do a tunneling because my Faculty server has closed connection from out side the faculty network, also they told me that the password had been changed ....
btw tnx for the answers they helped me to connect to my local server and access my local data base ..
Thanks again mates ^_^
Related
This question already has answers here:
UnsupportedOperationException with DriverManager.getConnection() on Android
(3 answers)
Closed 3 years ago.
I have a problem on android studio when I try to make a connection to a mysql database
This is the code:
public Connection getMySqlConnection()
{
/* Declare and initialize a sql Connection variable. */
Connection ret = null;
try
{
/* Register for jdbc driver class. */
Class.forName("com.mysql.cj.jdbc.Driver");
/* Create connection url. */
String mysqlConnUrl = "jdbc:mysql://ip/ristorante?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC";
/* db user name. */
String mysqlUserName = "guest";
/* db password. */
String mysqlPassword = "guestpass";
/* Get the Connection object. */
ret = DriverManager.getConnection(mysqlConnUrl , mysqlUserName , mysqlPassword );
/* Get related meta data for this mysql server to verify db connect successfully.. */
DatabaseMetaData dbmd = ret.getMetaData();
String dbName = dbmd.getDatabaseProductName();
String dbVersion = dbmd.getDatabaseProductVersion();
String dbUrl = dbmd.getURL();
String userName = dbmd.getUserName();
String driverName = dbmd.getDriverName();
System.out.println("Database Name is " + dbName);
System.out.println("Database Version is " + dbVersion);
System.out.println("Database Connection Url is " + dbUrl);
System.out.println("Database User Name is " + userName);
System.out.println("Database Driver Name is " + driverName);
}catch(Exception ex)
{
ex.printStackTrace();
}finally
{
return ret;
}
}
This is the main error:
W/System.err: java.lang.UnsupportedOperationException
at java.util.regex.Matcher.group(Matcher.java:383)
at com.mysql.cj.conf.ConnectionUrlParser.isConnectionStringSupported(ConnectionUrlParser.java:152)
at com.mysql.cj.conf.ConnectionUrl.acceptsUrl(ConnectionUrl.java:258)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:195)
at java.sql.DriverManager.getConnection(DriverManager.java:569)
at java.sql.DriverManager.getConnection(DriverManager.java:219)
at com.example.spara.restaurant.activity_home.getMySqlConnection(activity_home.java:163)
at com.example.spara.restaurant.activity_home.onCreate(activity_home.java:80)
I tried the same code in eclipse java and it worked.
I had tried several times in different ways but without positive results.
so the database connection works.
I just cannot find a solution, I hope you can help me.
I have a same problem as yours. When I find a guy meeting a same proble with me in StackOverFlow, I am so exciting. But When I find there is 0 answer, I feel so hopeless and sad. (ಥ_ಥ)
After painful tryings , I replace mysql-connector-java 8.x with 5.1.47. Then the confusing errors java.lang.UnsupportedOperationException disappear. ( But I don't know whether other bugs will appear. At least other bugs appear at sql connect stage and they look resolvable. I think it may be related with SDK version? ) hope I can help you :)
This question already has answers here:
Connect Java to a MySQL database
(14 answers)
Closed 7 years ago.
I'm trying to create a connection to a database in my Java program. I'm not sure if i have the correct address for it though in my code.
Below is my connection code:
public static Connection ConnectDB() {
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "n1nlhdb5501-02.shr.prod.ams1.secureserver.net";
Connection conn = DriverManager.getConnection(url, "user1", "password");
return conn;
} catch (Exception e) {
System.err.println(e.getMessage());
return null;
}
}
Unfortunately, Im really unsure of whether I have put the correct information into the url and the "Class.forname()" lines. I know the one is to load the actual driver and the other is the address of the database but i'm not sure if the information I have input is correct, because the connection is unsuccessful.
Is there anyway I could find the exact address that i need to use in the url string through an SQL statement maybe?
Also, I'm not sure if I'm loading the correct drivers for the jar file which i'm using, its called 'mysql-connector-java-5.1.35-bin.jar'
All help appreciated!
Thanks in advance
Marko
This is how you can connect MySQL database using Java.
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://x.x.x.x:3306/databaseName", "username", "password");
Statement smt = con.createStatement(); //Create Statement to interact
ResultSet r = smt.executeQuery("select * from users where(AccountID='" + q + "');");
while (r.next()) {
name = r.getString("name");
}
con.close
} catch (Exception e) {
e.printStackTrace();
}
In your case URL will be like...
String URL = "jdbc:mysql://n1nlhdb5501-02.shr.prod.ams1.secureserver.net:3306/databaseName"
Edit:
It seems 3306 port is closed.
Nmap scan report for n1nlhdb5501-02.shr.prod.ams1.secureserver.net (37.148.204.135)
Host is up (0.075s latency).
Not shown: 97 filtered ports
PORT STATE SERVICE
80/tcp open http
443/tcp open https
3306/tcp closed mysql
I am working on a interface in java swing.we have four system connected with a lan.the interface is for accessing the database from the other system in the same local area network i used the following code to access the database by giving the ip address,database name,tablename but i could not connect the other systems database.how can i do this?
public void dbconnection() {
String name = "";
String port = "3306";
String user = "systech";
String pass = "systech";
String dbname = "cascade_demo";
String host="192.168.1.61";
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://"+host+":"+ port + "/" + dbname;
System.out.println("URL:" + url);
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con = DriverManager.getConnection(url, user, pass);
String qry2 = "select * from item_master";
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(qry2);
while (rs.next()) {
name = rs.getString(1);
System.out.println("Name:" + name);
}
rs.close();
st.close();
con.close();
} catch (Exception e) {
System.out.println("Exception:" + e);
}
}
Use below code
public void dbconnection() {
String name = "";
String port = "3306";
String user = "systech";
String pass = "systech";
String dbname = "cascade_demo";
String host="192.168.1.61";
try {
String url = "jdbc:mysql://"+host+":"+ port + "/" + dbname;
Class.forName("com.mysql.jdbc.Driver").newInstance ();
Connection con = DriverManager.getConnection(url, user, pass);
String qry2 = "select * from item_master";
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(qry2);
while (rs.next()) {
System.out.println("Name:" + rs.getString(1));
}
rs.close();
st.close();
con.close();
} catch (Exception e) {
System.out.println("Exception:" + e);
}
}
Also, make sure to include jar file for connecting. You will get jar file here.
Update 1:
So, you have a
CommunicationsException: Communications link failure
I'm quoting from this answer which also contains a step-by-step MySQL+JDBC tutorial:
If you get a SQLException: Connection refused or Connection timed out or a MySQL specific CommunicationsException:
Communications link failure, then it means that the DB isn't reachable at all. This can have one or more of the following causes:
IP address or hostname in JDBC URL is wrong.
Hostname in JDBC URL is not recognized by local DNS server.
Port number is missing or wrong in JDBC URL.
DB server is down.
DB server doesn't accept TCP/IP connections.
DB server has run out of connections.
Something in between Java and DB is blocking connections, e.g. a firewall or proxy.
To solve the one or the other, follow the following advices:
Verify and test them with ping.
Refresh DNS or use IP address in JDBC URL instead.
Verify it based on my.cnf of MySQL DB.
Start the DB.
Verify if mysqld is started without the --skip-networking option.
Restart the DB and fix your code accordingly that it closes connections in finally.
Disable firewall and/or configure firewall/proxy to allow/forward the port.
Update 2
If your system is Windows, go to Start>>Run.
Type command. This will open command prompt.
Type "ping 192.168.1.61"
You might get reply in below format.
Pinging 192.168.1.61 [192.168.1.61] with 32 bytes of data:
Reply from 192.168.1.61: bytes=32 time=101ms TTL=124
If you don't get something in above format, then your MYSQL Server with ip 192.168.1.61 is NOT REACHABLE. Ask your team to start the server first. :(
If you have Linux version, open terminal and follow step 3.
Also check below link. Those might help you...
http://www.cyberciti.biz/tips/how-do-i-enable-remote-access-to-mysql-database-server.html
You should down load the jdbc driver and replace
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
by
Class.forName("com.mysql.jdbc.Driver");
If you still have issues asfter replacing Obdc stuff, please post the exception.
ALso check firewall settings and DB permissions.
If you'll get exception your app will not free system resources. This will work better:
} finally {
try {
rs.close();
st.close();
con.close();
} catch( Exception e ) {
e.printStackTrace();
}
}
I am using the SphinxQL MySQL client which stores indexes as "tables" but has no real notion of a "database"...One specifies the port (9306 in my case) at which the sphinx mysql instance listens and in theory should be able to communicate as normal.
I have the following test code:
import java.sql.*;
public class Dbtest {
public static void main (String[] args) {
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:9306",
"user","password");
con.setReadOnly(true);
Statement stmt = con.createStatement();
ResultSet res = stmt.executeQuery("SELECT * from index_turned_table");
while (res.next()) {
String stuff1 = res.getString(1);
String stuff2 = res.getString(2);
System.out.println("Adding " + stuff1);
System.out.println("Adding " + stuff2);
}
res.close();
stmt.close();
con.close();
}
catch(Exception e)
{
System.out.println (e);
}
}
Upon execution, the code just hangs and does nothing and doesn't print out an exception. What are useful things I can do to figure this out or if any one has direct experience what might be going on?
This work with 1.10-beta http://www.olegsmith.com/2010/12/scalalift-sphinxql.html
and not work with 2.0.1-beta. Use mysql-connector-java 5.1.15.
Your SphinxQL instance is listening on port 9306. Your MySQL is listening on some other port, likely on the default 3306. You can use MySQL JDBC driver to connect to MySQL, but you cannot use it to connect to SphinxQL. It just doesn't understand JDBC driver communication protocol.
for a school database project we are making a database program (user GUI and the database). Using Microsoft Access 2010 I created the database and populated it with some sample data, and saved it in .mdb format and placed it in my project folder.
When running it in eclipse the following code works fine, connects and even retrieves the query. However I find that I am unable to export the code to a jar and run it (which is required for the project, give them a working copy of your program on a CD or flash drive), and I'm also unable to port the code over to Netbeans to have it work, as well as trying to compile on a Linux machine.
I assume this is a problem with including drivers or trying to use Microsoft access. The error I get when running the jar or running on Netbeans is given below the code. So I ask either how do I include drivers to make the program portable, or how else can I approach this problem?
Thanks in advance
import java.sql.*;
public class JDBCTest {
static Connection connection;
static Statement statement;
public static void main(String args[]){
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance();
String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=TLDATABASEDBM.mdb";
connection = DriverManager.getConnection( database ,"","");
buildStatement();
executeQuery();
}catch(Exception e){
e.printStackTrace();
System.out.println("Error!");
}
}
public static void buildStatement() throws SQLException {
statement = connection.createStatement();
}
public static void executeQuery() throws SQLException {
boolean foundResults = statement.execute("SELECT * FROM tblStaff AS x WHERE City='Calgary'");
if(foundResults){
ResultSet set = statement.getResultSet();
if(set!=null) displayResults(set);
}else {
connection.close();
}
}
public static void displayResults(ResultSet rs) throws SQLException {
ResultSetMetaData metaData = rs.getMetaData();
int columns=metaData.getColumnCount();
String text="";
while(rs.next()){
for(int i=1;i<=columns;++i) {
text+=""+metaData.getColumnName(i)+":\t";
text+=rs.getString(i);
//text+="</"+metaData.getColumnName(i)+">";
text+="\n";
}
text+="\n";
}
System.out.println(text);
}
}
The error mentioned above:
java.sql.SQLException: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
at sun.jdbc.odbc.JdbcOdbc.createSQLException(JdbcOdbc.java:6957)
at sun.jdbc.odbc.JdbcOdbc.standardError(JdbcOdbc.java:7114)
at sun.jdbc.odbc.JdbcOdbc.SQLDriverConnect(JdbcOdbc.java:3073)
at sun.jdbc.odbc.JdbcOdbcConnection.initialize(JdbcOdbcConnection.java:323)
at sun.jdbc.odbc.JdbcOdbcDriver.connect(JdbcOdbcDriver.java:174)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:207)
at tldatabase.DataConnect.makeConnection(DataConnect.java:35)
at tldatabase.Main.main(Main.java:24)
I know the post was years ago but I felt like answering the question for those who are just experiencing this right now. It took me a while to know the answer to the question so here's the solution:
http://wiki.netbeans.org/FaqSettingHeapSize
Follow the "Running the 32-bit JVM".
All you have to do is find the netbeans.conf in the installation folder of your netbeans and change the directory from something like this:
netbeans_jdkhome="C:\Program Files\Java\jdk1.6.0_24"
to this:
netbeans_jdkhome="C:\Program Files (x86)\Java\jdk1.6.0_21"
The problem is netbeans might be running in 64 bit but MS Access only support 32-bit. So doing this would hopefully solve the problem. Also make sure to install this:
http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=23734
The main problem lies in the line:
String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=TLDATABASEDBM.mdb";
Make sure that the .mdb file is in the correct directory.
Check the file extension as .mdb or .mdbacc.
Also, if you want to use the same DSN every time, it is better to add the DSN(Data Source Name) into the respective system on which the mdb is stored.
I think that your app do not see TLDATABASEDBM.mdb in current directory. You can give full path to this file in connection string or add system DSN in ODBC Manager and then connect to it with connection string like: jdbc:odbc:TLDATABASEDBM
Honestly, I dont like what I am going to say... but, it solved the same issue for me... mysteriously... :(((
on the line where you are defining the database variable, I changed ...(.mdb)... into ...(.mdb, *.accdb)...
All the best for figuring out what difference that made!
package javaapplication1;
import java.sql.*;
public class MSaccess_archive {
public static void main(String[] args) {
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
// set this to a MS Access DB you have on your machine
String filename = "mdbTEST.mdb";
String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=";
database+= filename.trim() + ";DriverID=22;}"; // add on to the end
// now we can get the connection from the DriverManager
Connection con = DriverManager.getConnection( database ,"","");
Statement stmt = con.createStatement();
stmt.execute("select * from student"); // execute query in table student
ResultSet rs = stmt.getResultSet(); // get any Result that came from our query
if (rs != null)
while ( rs.next() ){
System.out.println("Name: " + rs.getInt("Age") + " ID: "+rs.getString("Course"));
}
stmt.close();
con.close();
}
catch (Exception err) {
System.out.println("ERROR: " + err);
}
}
}