Conectar Java con Firebird
Hola
Me he bajado jaybird, y en uno de los ejemplos me da error en donde os marco en negrita, de momento me gustaría saber que hacer para solucionarlo y si se puede en este post configurar una conexión a firebird desde java, estoy usando eclipse.
el error que me da es este, parece muy evidente , pero lo que no sé que hacer es como solucionarlo.
Driver not found in class path
org.firebirdsql.jdbc.FBDriver
Código:
public class DriverExample
{
// Make a connection to an employee.gdb on your local machine,
// and demonstrate basic JDBC features.
// Notice that main() uses its own local variables rather than
// static class variables, so it need not be synchronized.
public static void main (String args[]) throws Exception
{
// Modify the following hardwired settings for your environment.
// Note: localhost is a TCP/IP keyword which resolves to your local machine's IP address.
// If localhost is not recognized, try using your local machine's name or
// the loopback IP address 127.0.0.1 in place of localhost.
String databaseURL = "jdbc:firebirdsql:localhost/3050:c:/database/employee.gdb";
//String databaseURL = "jdbc:firebirdsql:native:localhost/3050:c:/database/employee.gdb";
//String databaseURL = "jdbc:firebirdsql:local:c:/database/employee.gdb";
//String databaseURL = "jdbc:firebirdsql:embedded:c:/database/employee.gdb";
String user = "sysdba";
String password = "masterkey";
String driverName = "org.firebirdsql.jdbc.FBDriver";
// As an exercise to the reader, add some code which extracts databaseURL,
// user, and password from the program args[] to main().
// As a further exercise, allow the driver name to be passed as well,
// and modify the code below to use driverName rather than the hardwired
// string "org.firebirdsql.jdbc.FBDriver" so that this code becomes
// driver independent. However, the code will still rely on the
// predefined table structure of employee.gdb.
// Here are the JDBC objects we're going to work with.
// We're defining them outside the scope of the try block because
// they need to be visible in a finally clause which will be used
// to close everything when we are done.
// The finally clause will be executed even if an exception occurs.
java.sql.Driver d = null;
java.sql.Connection c = null;
java.sql.Statement s = null;
java.sql.ResultSet rs = null;
// Any return from this try block will first execute the finally clause
// towards the bottom of this file.
try {
// Let's try to register the Firebird JCA-JDBC driver with the driver manager
// using one of various registration alternatives...
int registrationAlternative = 1;
switch (registrationAlternative) {
case 1:
// This is the standard alternative and simply loads the driver class.
// Class.forName() instructs the java class loader to load
// and initialize a class. As part of the class initialization
// any static clauses associated with the class are executed.
// Every driver class is required by the jdbc specification to automatically
// create an instance of itself and register that instance with the driver
// manager when the driver class is loaded by the java class loader
// (this is done via a static clause associated with the driver class).
//
// Notice that the driver name could have been supplied dynamically,
// so that an application is not hardwired to any particular driver
// as would be the case if a driver constructor were used, eg.
// new org.firebirdsql.jdbc.FBDriver().
try {
Class.forName ("org.firebirdsql.jdbc.FBDriver");
}
catch (java.lang.ClassNotFoundException e) {
// A call to Class.forName() forces us to consider this exception :-)...
System.out.println ("Firebird JCA-JDBC driver not found in class path");
System.out.println (e.getMessage ());
return;
}
break;
case 2:
// There is a bug in some JDK 1.1 implementations, eg. with Microsoft
// Internet Explorer, such that the implicit driver instance created during
// class initialization does not get registered when the driver is loaded
// with Class.forName().
// See the FAQ at http://java.sun.com/jdbc for more info on this problem.
// Notice that in the following workaround for this bug, that if the bug
// is not present, then two instances of the driver will be registered
// with the driver manager, the implicit instance created by the driver
// class's static clause and the one created explicitly with newInstance().
// This alternative should not be used except to workaround a JDK 1.1
// implementation bug.
try {
java.sql.DriverManager.registerDriver (
(java.sql.Driver) Class.forName ("org.firebirdsql.jdbc.FBDriver").newInstance ()
);
}
catch (java.lang.ClassNotFoundException e) {
// A call to Class.forName() forces us to consider this exception :-)...
System.out.println ("Driver not found in class path");
System.out.println (e.getMessage ());
return;
}
catch (java.lang.IllegalAccessException e) {
// A call to newInstance() forces us to consider this exception :-)...
System.out.println ("Unable to access driver constructor, this shouldn't happen!");
System.out.println (e.getMessage ());
return;
}
catch (java.lang.InstantiationException e) {
// A call to newInstance() forces us to consider this exception :-)...
// Attempt to instantiate an interface or abstract class.
System.out.println ("Unable to create an instance of driver class, this shouldn't happen!");
System.out.println (e.getMessage ());
return;
}
catch (java.sql.SQLException e) {
// A call to registerDriver() forces us to consider this exception :-)...
System.out.println ("Driver manager failed to register driver");
showSQLException (e);
return;
}
break;
case 3:
// Add the Firebird JCA-JDBC driver name to your system's jdbc.drivers property list.
// The driver manager will load drivers from this system property list.
// System.getProperties() may not be allowed for applets in some browsers.
// For applets, use one of the Class.forName() alternatives above.
java.util.Properties sysProps = System.getProperties ();
StringBuffer drivers = new StringBuffer ("org.firebirdsql.jdbc.FBDriver");
String oldDrivers = sysProps.getProperty ("jdbc.drivers");
if (oldDrivers != null)
drivers.append (":" + oldDrivers);
sysProps.put ("jdbc.drivers", drivers.toString ());
System.setProperties (sysProps);
break;
case 4:
// Advanced: This is a non-standard alternative, and is tied to
// a particular driver implementation, but is very flexible.
//
// It may be possible to configure a driver explicitly, either thru
// the use of non-standard driver constructors, or non-standard
// driver "set" methods which somehow tailor the driver to behave
// differently from the default driver instance.
// Under this alternative, a driver instance is created explicitly
// using a driver specific constructor. The driver may then be
// tailored differently from the default driver instance which is
// created automatically when the driver class is loaded by the java class loader.
// For example, perhaps a driver instance could be created which
// is to behave like some older version of the driver.
//
// d = new org.firebirdsql.jdbc.FBDriver ();
// DriverManager.registerDriver (d);
// c = DriverManager.getConnection (...);
//
// Since two drivers, with differing behavior, are now registered with
// the driver manager, they presumably must recognize different jdbc
// subprotocols. For example, the tailored driver may only recognize
// "jdbc:interbase:old_version://...", whereas the default driver instance
// would recognize the standard "jdbc:interbase://...".
// There are currently no methods, such as the hypothetical setVersion(),
// for tailoring an Firebird JCA-JDBC driver so this 4th alternative is academic
// and not necessary for Firebird JCA-JDBC driver.
//
// It is also possible to create a tailored driver instance which
// is *not* registered with the driver manager as follows
//
// d = new org.firebirdsql.jdbc.FBDriver ();
// c = d.connect (...);
//
// this is the most usual case as this does not require differing
// jdbc subprotocols since the connection is obtained thru the driver
// directly rather than thru the driver manager.
d = new org.firebirdsql.jdbc.FBDriver (); // Aquí me da error
}
// At this point the driver should be registered with the driver manager.
// Try to find the registered driver that recognizes interbase URLs...
try {
// We pass the entire database URL, but we could just pass "jdbc:interbase:"
d = java.sql.DriverManager.getDriver (databaseURL);
System.out.println ("Firebird JCA-JDBC driver version " +
d.getMajorVersion () +
"." +
d.getMinorVersion () +
" registered with driver manager.");
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to find Firebird JCA-JDBC driver among the registered drivers.");
showSQLException (e);
return;
}
// Advanced info: Class.forName() loads the java class for the driver.
// All JDBC drivers are required to have a static clause that automatically
// creates an instance of themselves and registers that instance
// with the driver manager. So there is no need to call
// DriverManager.registerDriver() explicitly unless the driver allows
// for tailored driver instances to be created (each instance recognizing
// a different jdbc sub-protocol).
// Now that Firebird JCA-JDBC driver is registered with the driver manager,
// try to get a connection to an employee.gdb database on this local machine
// using one of two alternatives for obtaining connections...
int connectionAlternative = 1;
switch (connectionAlternative) {
case 1:
// This alternative is driver independent;
// the driver manager will find the right driver for you based on the jdbc subprotocol.
// In the past, this alternative did not work with applets in some browsers because of a
// bug in the driver manager. I believe this has been fixed in the jdk 1.1 implementations.
try {
c = java.sql.DriverManager.getConnection (databaseURL, user, password);
System.out.println ("Connection established.");
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to establish a connection through the driver manager.");
showSQLException (e);
return;
}
break;
case 2:
// If you're working with a particular driver d, which may or may not be registered,
// you can get a connection directly from it, bypassing the driver manager...
try {
java.util.Properties connectionProperties = new java.util.Properties ();
connectionProperties.put ("user", user);
connectionProperties.put ("password", password);
c = d.connect (databaseURL, connectionProperties);
System.out.println ("Connection established.");
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to establish a connection through the driver.");
showSQLException (e);
return;
}
break;
}
// Let's disable the default autocommit so we can undo our changes later...
try {
c.setAutoCommit (false);
System.out.println ("Auto-commit is disabled.");
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to disable autocommit.");
showSQLException (e);
return;
}
// Now that we have a connection, let's try to get some meta data...
try {
java.sql.DatabaseMetaData dbMetaData = c.getMetaData ();
// Ok, let's query a driver/database capability
if (dbMetaData.supportsTransactions ())
System.out.println ("Transactions are supported.");
else
System.out.println ("Transactions are not supported.");
// What are the views defined on this database?
java.sql.ResultSet tables = dbMetaData.getTables (null, null, "%", new String[] {"VIEW"});
while (tables.next ()) {
System.out.println (tables.getString ("TABLE_NAME") + " is a view.");
}
tables.close ();
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to extract database meta data.");
showSQLException (e);
// What the heck, who needs meta data anyway ;-(, let's continue on...
}
// Let's try to submit some static SQL on the connection.
// Note: This SQL should throw an exception on employee.gdb because
// of an integrity constraint violation.
try {
s = c.createStatement ();
s.executeUpdate ("update employee set salary = salary + 10000");
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to increase everyone's salary.");
showSQLException (e);
// We expected this to fail, so don't return, let's keep going...
}
// Let's submit some static SQL which produces a result set.
// Notice that the statement s is reused with a new SQL string.
try {
rs = s.executeQuery ("select full_name from employee where salary < 50000");
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to submit a static SQL query.");
showSQLException (e);
// We can't go much further without a result set, return...
return;
}
// The query above could just as easily have been dynamic SQL,
// eg. if the SQL had been entered as user input.
// As a dynamic query, we'd need to query the result set meta data
// for information about the result set's columns.
try {
java.sql.ResultSetMetaData rsMetaData = rs.getMetaData ();
System.out.println ("The query executed has " +
rsMetaData.getColumnCount () +
" result columns.");
System.out.println ("Here are the columns: ");
for (int i = 1; i <= rsMetaData.getColumnCount (); i++) {
System.out.println (rsMetaData.getColumnName (i) +
" of type " +
rsMetaData.getColumnTypeName (i));
}
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to extract result set meta data.");
showSQLException (e);
// What the heck, who needs meta data anyway ;-(, let's continue on...
}
// Ok, lets step thru the results of the query...
try {
System.out.println ("Here are the employee's whose salary < $50,000");
while (rs.next ()) {
System.out.println (rs.getString ("full_name"));
}
}
catch (java.sql.SQLException e) {
System.out.println ("Unable to step thru results of query");
showSQLException (e);
return;
}
// As an exercise to the reader, rewrite this code so that required
// table structures are created dynamically using executeUpdate() on DDL.
// In this way the code will be able to run against any database file rather
// than just a previously setup employee.gdb.
// Just to get you started, you'll want to define a method something like
// the following...
//
// private static void createTableStructures (java.sql.Connection c) throws java.sql.SQLException
// {
// // Some drivers don't force commit on DDL, Firebird JCA-JDBC driver does,
// // see DatabaseMetaData.dataDefinitionCausesTransactionCommit().
// // This is not necessary for Firebird JCA-JDBC driver, but may be for other drivers...
// c.setAutoCommit (true);
//
// java.sql.Statement s = c.createStatement();
//
// // Drop table EMPLOYEE if it already exists, if not that's ok too.
// try { s.executeUpdate ("drop table EMPLOYEE"); } catch (java.sql.SQLException e) {}
//
// // Ok, now that we're sure the table isn't already there, create it...
// s.executeUpdate ("create table EMPLOYEE (...)");
//
// // Ok, now populate the EMPLOYEE table...
// s.executeUpdate ("insert into EMPLOYEE values (...)");
//
// s.close();
// c.setAutoCommit (false);
// }
//
}
// This finally clause will be executed even if "return" was called in case of any exceptions above.
finally {
System.out.println ("Closing database resources and rolling back any changes we made to the database.");
// Now that we're all finished, let's release database resources.
try { if (rs!=null) rs.close (); } catch (java.sql.SQLException e) { showSQLException (e); }
try { if (s!=null) s.close (); } catch (java.sql.SQLException e) { showSQLException (e); }
// Before we close the connection, let's rollback any changes we may have made.
try { if (c!=null) c.rollback (); } catch (java.sql.SQLException e) { showSQLException (e); }
try { if (c!=null) c.close (); } catch (java.sql.SQLException e) { showSQLException (e); }
}
}
// Display an SQLException which has occured in this application.
private static void showSQLException (java.sql.SQLException e)
{
// Notice that a SQLException is actually a chain of SQLExceptions,
// let's not forget to print all of them...
java.sql.SQLException next = e;
while (next != null) {
System.out.println (next.getMessage ());
System.out.println ("Error Code: " + next.getErrorCode ());
System.out.println ("SQL State: " + next.getSQLState ());
next = next.getNextException ();
}
}
}
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21-12-2008
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