Обсуждение: Error while trying to connect to postgresql
Hi,
Can some one help me out with this problem. Ive been searching around
for some help but couldnt find any...
Im trying to connect PostgreSQL with Java..
import java.sql.*;
class PostgreSQLTest{
public static void main(String[] args){
Class.forName("org.postgresql.Driver");
String url="jdbcostgresql://localhost/postgres";
Connection db = DriverManager.getConnection("url", "postgres", "");
System.out.println("Connection Created");
db.close();
}
}
# javac PostgreSQLTest.java
PostgreSQLTest.java:5: unreported exception
java.lang.ClassNotFoundException; must be caught or declared to be thrown
Class.forName("org.postgresql.Driver");
^
PostgreSQLTest.java:7: unreported exception java.sql.SQLException; must
be caught or declared to be thrown
Connection db = DriverManager.getConnection("url", "postgres", "");
^
PostgreSQLTest.java:10: unreported exception java.sql.SQLException; must
be caught or declared to be thrown
db.close();
^
3 errors
# echo $CLASSPATH
:/usr/local/jdk1.6.0/lib/tools.jar:/usr/local/pgsql/share/java/postgresql-8.1-408.jdbc3.jar:/usr/local/jdk1.6.0/lib/:/home/danish/:/home/danish/PostgreSQLTest.java
Thanks
Danish
Hi, Your url is wrong. It should look like "jdbc:postgresql://localhost/postgres". See http://jdbc.postgresql.org/documentation/82/connect.html for more info. Regards. Danish Siddiqui a écrit : > Hi, > Can some one help me out with this problem. Ive been searching around > for some help but couldnt find any... > > Im trying to connect PostgreSQL with Java.. > > import java.sql.*; > > class PostgreSQLTest{ > public static void main(String[] args){ > Class.forName("org.postgresql.Driver"); > String url="jdbcostgresql://localhost/postgres"; > Connection db = DriverManager.getConnection("url", "postgres", ""); > > System.out.println("Connection Created"); > db.close(); > } > } > > # javac PostgreSQLTest.java > > PostgreSQLTest.java:5: unreported exception > java.lang.ClassNotFoundException; must be caught or declared to be thrown > Class.forName("org.postgresql.Driver"); > ^ > PostgreSQLTest.java:7: unreported exception java.sql.SQLException; must > be caught or declared to be thrown > Connection db = DriverManager.getConnection("url", "postgres", ""); > ^ > PostgreSQLTest.java:10: unreported exception java.sql.SQLException; must > be caught or declared to be thrown > db.close(); > ^ > 3 errors > > > # echo $CLASSPATH > :/usr/local/jdk1.6.0/lib/tools.jar:/usr/local/pgsql/share/java/postgresql-8.1-408.jdbc3.jar:/usr/local/jdk1.6.0/lib/:/home/danish/:/home/danish/PostgreSQLTest.java > > > Thanks > Danish > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Have you searched our list archives? > > http://archives.postgresql.org >
Sorry, I answered too quickly to your email. Your compilation problem is that you must catch SQLException and ClassNotFoundException using the java try-catch syntax. See http://java.sun.com/docs/books/jls/third_edition/html/exceptions.html Regards. Danish Siddiqui a écrit : > Hi, > Can some one help me out with this problem. Ive been searching around > for some help but couldnt find any... > > Im trying to connect PostgreSQL with Java.. > > import java.sql.*; > > class PostgreSQLTest{ > public static void main(String[] args){ > Class.forName("org.postgresql.Driver"); > String url="jdbcostgresql://localhost/postgres"; > Connection db = DriverManager.getConnection("url", "postgres", ""); > > System.out.println("Connection Created"); > db.close(); > } > } > > # javac PostgreSQLTest.java > > PostgreSQLTest.java:5: unreported exception > java.lang.ClassNotFoundException; must be caught or declared to be thrown > Class.forName("org.postgresql.Driver"); > ^ > PostgreSQLTest.java:7: unreported exception java.sql.SQLException; must > be caught or declared to be thrown > Connection db = DriverManager.getConnection("url", "postgres", ""); > ^ > PostgreSQLTest.java:10: unreported exception java.sql.SQLException; must > be caught or declared to be thrown > db.close(); > ^ > 3 errors > > > # echo $CLASSPATH > :/usr/local/jdk1.6.0/lib/tools.jar:/usr/local/pgsql/share/java/postgresql-8.1-408.jdbc3.jar:/usr/local/jdk1.6.0/lib/:/home/danish/:/home/danish/PostgreSQLTest.java > > > Thanks > Danish > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Have you searched our list archives? > > http://archives.postgresql.org >
Xavier Poinsard wrote: > Hi, > > Your url is wrong. It should look like > "jdbc:postgresql://localhost/postgres". > See http://jdbc.postgresql.org/documentation/82/connect.html for more info. > > Regards. > > Danish Siddiqui a écrit : > >> Hi, >> Can some one help me out with this problem. Ive been searching around >> for some help but couldnt find any... >> >> Im trying to connect PostgreSQL with Java.. >> >> import java.sql.*; >> >> class PostgreSQLTest{ >> public static void main(String[] args){ >> Class.forName("org.postgresql.Driver"); >> String url="jdbcostgresql://localhost/postgres"; >> Connection db = DriverManager.getConnection("url", "postgres", ""); >> >> System.out.println("Connection Created"); >> db.close(); >> } >> } >> >> # javac PostgreSQLTest.java >> >> PostgreSQLTest.java:5: unreported exception >> java.lang.ClassNotFoundException; must be caught or declared to be thrown >> Class.forName("org.postgresql.Driver"); >> ^ >> PostgreSQLTest.java:7: unreported exception java.sql.SQLException; must >> be caught or declared to be thrown >> Connection db = DriverManager.getConnection("url", "postgres", ""); >> ^ >> PostgreSQLTest.java:10: unreported exception java.sql.SQLException; must >> be caught or declared to be thrown >> db.close(); >> ^ >> 3 errors >> >> >> # echo $CLASSPATH >> :/usr/local/jdk1.6.0/lib/tools.jar:/usr/local/pgsql/share/java/postgresql-8.1-408.jdbc3.jar:/usr/local/jdk1.6.0/lib/:/home/danish/:/home/danish/PostgreSQLTest.java >> >> >> Thanks >> Danish >> >> ---------------------------(end of broadcast)--------------------------- >> TIP 4: Have you searched our list archives? >> >> http://archives.postgresql.org >> >> > > > I got it working somehow after I added a try and catch block and the error you pointed out... import java.sql.*; class PostgreSQLTest{ public static void main(String[] args){ try{ Class.forName("org.postgresql.Driver"); String url="jdbc:postgresql://127.0.0.1/javatest"; Connection db = DriverManager.getConnection(url, "danish", "postgresqljavatest"); //System.out.println("Connection Created"); Statement st = db.createStatement(); ResultSet rs = st.executeQuery("SELECT * FROM employee"); while (rs.next()) { //System.out.print("Column 1 returned "); System.out.println(rs.getString(1)); } rs.close(); st.close(); db.close();}catch(Exception e){ System.out.println(e);} } } Thanks Danish