Obtaining connection to database in JBoss?

java, jboss, postgresql, servlets

Solution

you can use DataSource to get Connection like

javax.naming.Context ic = new javax.naming.InitialContext();
javax.naming.Context ctx = (javax.naming.Context) ic.lookup("java:");
javax.sql.DataSource ds = (javax.sql.DataSource) ctx.lookup("PostgresDS");
java.sql.Connection con = ds.getConnection();

Problem

This is my jboss/deploy/postgres-ds.xml file. The connection url, username and password is given here. How do I obtain a connection to this database in my servlet. ``` <local-tx-datasource> <jndi-name>PostgresDS</jndi-name> <connection-url>jdbc:postgresql://localhost:5432/postgres</connection-url> <driver-class>org.postgresql.Driver</driver-class> <user-name>postgres</user-name> <password>qwerty</password> <!-- sql to call when connection is created <new-connection-sql>some arbitrary sql</new-connection-sql> --> <!-- sql to call on an existing pooled connection when it is obtained from pool <check-valid-connection-sql>some arbitrary sql</check-valid-connection-sql> --> <!-- corresponding type-mapping in the standardjbosscmp-jdbc.xml (optional) --> </local-tx-datasource> ``` Should I obtain the connection like this in every servlet : ``` Connection conn =null; // Create connection object String database = "postgres"; // Name of database String user = "postgres"; // String password = "qwerty"; String url = "jdbc:postgresql://localhost:5432/" + database; ResultSet rs = null; ResultSetMetaData rsm = null; try{ Class.forName("org.postgresql.Driver").newInstance(); //.newInstance() } catch(Exception e) { System.err.println(e); } try{ conn = DriverManager.getConnection(url, user, password); }catch(SQLException se) { System.err.println(se); } ``` If this has to be done everytime, then why give the url, username and password in the postgres-ds.xml file?

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