We Keep Coding

Android connection error java.lang.UnsupportedOperationException [duplicate]

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 :)

Connecting to database with JDBC URL

My requirement is to check can we connect to a database with no schema defined through a java program and create a database.
this works fine
Connection connection =
DriverManager.getConnection("jdbc:db2://wcspocca-db.cloudapp.net:50001/db2inst1","vmadmin","password#123;");
database: db2
schema: db2inst1
but
Connection connection =
DriverManager.getConnection("jdbc:db2://wcspocca-db.cloudapp.net:50001/","vmadmin","password#123;");
fails
WHY?
com.ibm.db2.jcc.am.mo: [jcc][10165][10045][4.7.85] Invalid database URL syntax: jdbc:db2://wcspocca-db.cloudapp.net:50001/. ERRORCODE=-4461, SQLSTATE=42815

DriverManager.getConnection("jdbc:db2://wcspocca-db.cloudapp.net:50001/!!DBNAME!!","vmadmin","password#123;");

How I usually connect to a database using jave is like the following: Spacing it out to allow you to read the text below
//Wide Scope Variables
static Connection conn = null; //right now this connection is off
static String dbURL = "database url"; //I use SQL developer and your able to grab the connection url there
static String user = "This can be empty and ask user for input of hard code the user name";
static String pass = "same as above";
In the method where you want to check the driver and connection I usually do it like this
//Register the Driver
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
}
catch(ClassNotFoundException e)
{
System.err.println(e.getMessage());
}
//Set up connection
try
{
conn = DriverManager.getConnection(dbURL,user,password);
conn.clearWarnings();
stmt = conn.createStatement();
}
catch(SQLException e)
{
System.err.println(e.getMessage());
}
The first try catch code registers the driver to the SQL developer then the second try catch sets up the connection to the database. This helped save me a lot of head aches and I find it the most Direct route when using java.

Because in the second example the database is not specified. You can find the requirements in the DB2 JDBC documentation:
>>-+-jdbc:db2:------+--//--server--+---------+--/--database----->
+-jdbc:db2j:net:-+ '-:--port-'
'-jdbc:ids:------'
>--+---------------------------+-------------------------------\><
'-:--| connection-options |-'
The database parameter is not optional.

check the url carefully, after the port number if you do not put database name which you want to connect then how it will connect. Its like you are giving a home address whitout the plot number.

Connect SYS DBA with no password using JAVA

I want to connect oracle DB with JAVA, I have code like this :
Class.forName("oracle.jdbc.driver.OracleDriver");
dbURL = "jdbc:oracle:thin:#localhost:1521:DB";
con = DriverManager.getConnection(dbURL, "sys as sysdba" , "");
return con;
it's not working, but I tried with command promt like this conn /as sysdba, it can be Connected. I have beed googling about this article but all of code not work.
Anyone can help.
Thanks

To log on as SYSDBA with the JDBC Thin driver you must configure the server to use the password file. So you need to provide password for sys.

Try catching the exception, it must provide more information about the problem.
public static Connection getConnection(String name, String pass) {
connection = null;
try {
Class.forName(JDBC_DRIVER);
connection = DriverManager.getConnection(DB_URL, name, pass);
} catch (Exception e) {
System.out.println(e.getMessage());
}
return connection;
}
Do you get the same error when trying to connect with a different username and password instead of "sys as sysdba" , "" ?
Also, in the dbURL, check if the url and database name are set correctly.
The problem most likely lies in the empty password. Try substituting "" with "()". If the sys really uses empty password, it must work. If it doesn't help, consider changing the password manually by alter user

Connection to Oracle Database with Java

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 ^_^

Access mysql data base from another system using java

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();
}
}