Thread: Error while trying to connect to postgresql

Error while trying to connect to postgresql

From
Danish Siddiqui
Date:
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

Re: Error while trying to connect to postgresql

From
"Xavier Poinsard"
Date:
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
>


Re: Error while trying to connect to postgresql

From
"Xavier Poinsard"
Date:
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
>


Re: Error while trying to connect to postgresql

From
Danish Siddiqui
Date:
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