SOLR dataimport data import source code analysis (9)

The above SOLR dataimport source code mainly implements the Data Reading Function

Next we will look at the source code of data connection implementation:

Private connection getconnection () throws exception {
Long currtime = system. currenttimemillis ();
If (currtime-connlastused> conn_time_out ){
Synchronized (this ){
Connection tmpconn = factory. Call ();
Closeconnection ();
Connlastused = system. currenttimemillis ();
Return conn = tmpconn;
}

} Else {
Connlastused = currtime;
Return conn;
}

}

The synchronized keyword is used to enable
Conn access
Thread security. Factory is a callable <connection> type object generated in the initialization method.

The callable interface of Java is defined as follows:

Public interface callable <v> {
V call () throws exception;

}

Factory Initialization

Public void Init (context, properties initprops ){
// Other Code omitted

Factory = createconnectionfactory (context, initprops );
}

The createconnectionfactory (context, initprops) code is as follows:

Protected callable <connection> createconnectionfactory (final context,

Final properties initprops ){
// Final variableresolver resolver = context. getvariableresolver ();
Resolvevariables (context, initprops );
Final string jndiname = initprops. getproperty (jndi_name );
Final string url = initprops. getproperty (URL );
Final string driver = initprops. getproperty (driver );

If (url = NULL & jndiname = NULL)
Throw new dataimporthandlerexception (severe,
"Jdbc url or JNDI name has to be specified ");

If (driver! = NULL ){
Try {
Docbuilder. loadclass (driver, context. getsolrcore ());
} Catch (classnotfoundexception e ){
Wrapandthrow (severe, e, "cocould not load driver:" + driver );
}
} Else {
If (jndiname = NULL ){
Throw new dataimporthandlerexception (severe, "one of driver or jndiname must be specified in the data source ");
}
}

String S = initprops. getproperty ("maxrows ");
If (s! = NULL ){
Maxrows = integer. parseint (s );
}

Return factory = new callable <connection> (){
Public connection call () throws exception {
Log.info ("Creating a connection for entity"
+ Context. getentityattribute (dataimporter. Name) + "with URL :"
+ URL );
Long start = system. currenttimemillis ();
Connection c = NULL;
Try {
If (URL! = NULL ){
C = drivermanager. getconnection (URL, initprops );
} Else if (jndiname! = NULL ){
Initialcontext CTX = new initialcontext ();
Object jndival = CTX. Lookup (jndiname );
If (jndival instanceof javax. SQL. datasource ){
Javax. SQL. datasource = (javax. SQL. datasource) jndival;
String user = (string) initprops. Get ("user ");
String pass = (string) initprops. Get ("password ");
If (user = NULL | user. Trim (). Equals ("")){
C = datasource. getconnection ();
} Else {
C = datasource. getconnection (user, pass );
}
} Else {
Throw new dataimporthandlerexception (severe,
"The JNDI name: '" + jndiname + "' is not a valid javax. SQL. datasource ");
}
}
} Catch (sqlexception e ){
// Drivermanager does not allow you to use a driver which is not loaded through
// The Class Loader of the class which is trying to make the connection.
// This is a workaround for cases where the user puts the driver jar in
// SOLR. Home/lib or SOLR. Home/CORE/lib directories.
Driver d = (driver) docbuilder. loadclass (driver, context. getsolrcore (). newinstance ();
C = D. Connect (URL, initprops );
}
If (C! = NULL ){
If (Boolean. parseboolean (initprops. getproperty ("readonly "))){
C. setreadonly (true );
// Add other sane defaults
C. setautocommit (true );
C. settransactionisolation (connection. transaction_read_uncommitted );
C. setholdability (resultset. close_cursors_at_commit );
}
If (! Boolean. parseboolean (initprops. getproperty ("autocommit "))){
C. setautocommit (false );
}
String transactionisolation = initprops. getproperty ("transactionisolation ");
If ("transaction_read_uncommitted". Equals (transactionisolation )){
C. settransactionisolation (connection. transaction_read_uncommitted );
} Else if ("transaction_read_committed". Equals (transactionisolation )){
C. settransactionisolation (connection. transaction_read_committed );
} Else if ("transaction_repeatable_read". Equals (transactionisolation )){
C. settransactionisolation (connection. transaction_repeatable_read );
} Else if ("transaction_serializable". Equals (transactionisolation )){
C. settransactionisolation (connection. transaction_serializable );
} Else if ("transaction_none". Equals (transactionisolation )){
C. settransactionisolation (connection. transaction_none );
}
String holdability = initprops. getproperty ("holdability ");
If ("close_cursors_at_commit". Equals (holdability )){
C. setholdability (resultset. close_cursors_at_commit );
} Else if ("hold_cursors_over_commit". Equals (holdability )){
C. setholdability (resultset. hold_cursors_over_commit );
}
}
Log.info ("time taken for getconnection ():"
+ (System. currenttimemillis ()-Start ));
Return C;
}
};
}

The connection object is generated here.