Thread: Applet Connectivity - PLEASE help
OK, I'll say right up front I'm a postgres novice at best.
I've spent quite some time researching this tonight and trying out a few
things to no avail.
The basic question is can an applet connect to a postgres database and
if so how (I need specific details)?
Postgres, the database, the web server and signed applet are all on the
same machine.
I'm using Postgres 8.2 and Java 1.5 w/ the postgresql-8.2-504.jdbc3 jdbc
driver.
The software works when run through my IDE (Eclipse) but not as an
applet in a browser.
I've set listen_addresses = '*' in postgresql.conf and my pg_hba
settings are:
local all all md5
host all all 127.0.0.1/32 trust.
Here's the code I'm using to try to make the connection where
strServer = :jdbc:postgresql://localhost/Arco
strDriver = org.postgresql.Driver
strUser = postgres
strPswd = fred
public DBConnection(Trace trace, JApplet p_applet)
throws Exception
{
URL dbIniURL;
URLConnection urlConn;
BufferedReader in;
int vals = 0;
String nextVal;
String strProp;
String strVal;
String strUser = "";
String strPswd = "";
int pos;
Properties props = new Properties();
try
{
System.out.println("Instantiate DBConnection.");
dbIniURL = new URL(p_applet.getDocumentBase(), "db.ini");
urlConn = dbIniURL.openConnection();
in = new BufferedReader(new
InputStreamReader(urlConn.getInputStream()));
while (vals < 4)
{
nextVal = in.readLine();
vals = vals + 1;
System.out.println("db.ini: " + nextVal.trim());
pos = nextVal.indexOf(":");
if (pos>0)
{
strProp = nextVal.substring(0,pos);
strVal = nextVal.substring(pos+1);
if (strProp.compareToIgnoreCase("Server") == 0)
{
strServer = strVal;
}
else if (strProp.compareToIgnoreCase("Driver") == 0)
{
strDriver = strVal;
}
else if (strProp.compareToIgnoreCase("User") == 0)
{
strUser = strVal;
}
else if (strProp.compareToIgnoreCase("Password") == 0)
{
strPswd = strVal;
}
}
}
drv = (Driver)Class.forName(strDriver).newInstance();
DriverManager.registerDriver(drv);
props.setProperty("user",strUser.trim());
props.setProperty("password",strPswd.trim());
System.out.println("Attempting to connecting to postgres
db...");
dbConn= DriverManager.getConnection(strServer, props);
System.out.println("Connected to postgres db.");
}
catch (IOException ioe)
{
System.out.println("Error trying to connect to postgres db:");
ioe.printStackTrace();
throw new Exception(ioe.getMessage());
}
}
The error I get in the console is:
Java Plug-in 1.6.0
Using JRE version 1.6.0 Java HotSpot(TM) Client VM
User home directory = C:\Documents and Settings\Marc
----------------------------------------------------
c: clear console window
f: finalize objects on finalization queue
g: garbage collect
h: display this help message
l: dump classloader list
m: print memory usage
o: trigger logging
p: reload proxy configuration
q: hide console
r: reload policy configuration
s: dump system and deployment properties
t: dump thread list
v: dump thread stack
x: clear classloader cache
0-5: set trace level to <n>
----------------------------------------------------
Init applet.
Call new DBConnection.
Instantiate DBConnection.
db.ini: Server:jdbc:postgresql://localhost/Arco
db.ini: Driver:org.postgresql.Driver
Attempting to connecting to postgres db...
org.postgresql.util.PSQLException: Something unusual has occured to
cause the driver to fail. Please report this exception.
at org.postgresql.Driver.connect(Driver.java:276)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at db.DBConnection.<init>(DBConnection.java:169)
at ui.BaseApplet.init(BaseApplet.java:138)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.security.AccessControlException: access denied
(java.net.SocketPermission 127.0.0.1:5432 connect,resolve)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkConnect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at org.postgresql.core.PGStream.<init>(PGStream.java:59)
at
org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:77)
at
org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:66)
at
org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:125)
at
org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:30)
at org.postgresql.jdbc3.Jdbc3Connection.<init>(Jdbc3Connection.java:24)
at org.postgresql.Driver.makeConnection(Driver.java:382)
at org.postgresql.Driver.connect(Driver.java:260)
... 6 more
I think that covers it. I'm pretty wiped out being as I've been working
on this for about 4 hrs now.
Your help is really appreciated!
Thanks,
Marc
It's not a PostgreSQL-specific error. Applets run in a sandbox which
limits the damage they can do. Specifically what's biting you in this
case is that applets are only allowed to establish network connections
back to the IP address they came from. You can see this because you're
getting a java.security.AccessControlException thrown in the stack trace
when the JDBC driver tries to connect to the server at "localhost".
-- Mark Lewis
On Tue, 2007-01-23 at 00:26 -0500, Marc wrote:
> OK, I'll say right up front I'm a postgres novice at best.
> I've spent quite some time researching this tonight and trying out a few
> things to no avail.
> The basic question is can an applet connect to a postgres database and
> if so how (I need specific details)?
> Postgres, the database, the web server and signed applet are all on the
> same machine.
> I'm using Postgres 8.2 and Java 1.5 w/ the postgresql-8.2-504.jdbc3 jdbc
> driver.
> The software works when run through my IDE (Eclipse) but not as an
> applet in a browser.
> I've set listen_addresses = '*' in postgresql.conf and my pg_hba
> settings are:
> local all all md5
> host all all 127.0.0.1/32 trust.
>
> Here's the code I'm using to try to make the connection where
> strServer = :jdbc:postgresql://localhost/Arco
> strDriver = org.postgresql.Driver
> strUser = postgres
> strPswd = fred
>
> public DBConnection(Trace trace, JApplet p_applet)
> throws Exception
> {
> URL dbIniURL;
> URLConnection urlConn;
> BufferedReader in;
> int vals = 0;
> String nextVal;
> String strProp;
> String strVal;
> String strUser = "";
> String strPswd = "";
> int pos;
> Properties props = new Properties();
>
> try
> {
> System.out.println("Instantiate DBConnection.");
>
> dbIniURL = new URL(p_applet.getDocumentBase(), "db.ini");
> urlConn = dbIniURL.openConnection();
> in = new BufferedReader(new
> InputStreamReader(urlConn.getInputStream()));
>
> while (vals < 4)
> {
> nextVal = in.readLine();
> vals = vals + 1;
>
> System.out.println("db.ini: " + nextVal.trim());
>
> pos = nextVal.indexOf(":");
>
> if (pos>0)
> {
> strProp = nextVal.substring(0,pos);
> strVal = nextVal.substring(pos+1);
>
> if (strProp.compareToIgnoreCase("Server") == 0)
> {
> strServer = strVal;
> }
> else if (strProp.compareToIgnoreCase("Driver") == 0)
> {
> strDriver = strVal;
> }
> else if (strProp.compareToIgnoreCase("User") == 0)
> {
> strUser = strVal;
> }
> else if (strProp.compareToIgnoreCase("Password") == 0)
> {
> strPswd = strVal;
> }
> }
> }
>
> drv = (Driver)Class.forName(strDriver).newInstance();
> DriverManager.registerDriver(drv);
>
>
> props.setProperty("user",strUser.trim());
> props.setProperty("password",strPswd.trim());
>
> System.out.println("Attempting to connecting to postgres
> db...");
> dbConn= DriverManager.getConnection(strServer, props);
> System.out.println("Connected to postgres db.");
> }
> catch (IOException ioe)
> {
> System.out.println("Error trying to connect to postgres db:");
> ioe.printStackTrace();
> throw new Exception(ioe.getMessage());
> }
> }
>
> The error I get in the console is:
> Java Plug-in 1.6.0
> Using JRE version 1.6.0 Java HotSpot(TM) Client VM
> User home directory = C:\Documents and Settings\Marc
>
>
> ----------------------------------------------------
> c: clear console window
> f: finalize objects on finalization queue
> g: garbage collect
> h: display this help message
> l: dump classloader list
> m: print memory usage
> o: trigger logging
> p: reload proxy configuration
> q: hide console
> r: reload policy configuration
> s: dump system and deployment properties
> t: dump thread list
> v: dump thread stack
> x: clear classloader cache
> 0-5: set trace level to <n>
> ----------------------------------------------------
>
> Init applet.
> Call new DBConnection.
> Instantiate DBConnection.
> db.ini: Server:jdbc:postgresql://localhost/Arco
> db.ini: Driver:org.postgresql.Driver
> Attempting to connecting to postgres db...
> org.postgresql.util.PSQLException: Something unusual has occured to
> cause the driver to fail. Please report this exception.
> at org.postgresql.Driver.connect(Driver.java:276)
> at java.sql.DriverManager.getConnection(Unknown Source)
> at java.sql.DriverManager.getConnection(Unknown Source)
> at db.DBConnection.<init>(DBConnection.java:169)
> at ui.BaseApplet.init(BaseApplet.java:138)
> at sun.applet.AppletPanel.run(Unknown Source)
> at java.lang.Thread.run(Unknown Source)
> Caused by: java.security.AccessControlException: access denied
> (java.net.SocketPermission 127.0.0.1:5432 connect,resolve)
> at java.security.AccessControlContext.checkPermission(Unknown Source)
> at java.security.AccessController.checkPermission(Unknown Source)
> at java.lang.SecurityManager.checkPermission(Unknown Source)
> at java.lang.SecurityManager.checkConnect(Unknown Source)
> at java.net.Socket.connect(Unknown Source)
> at java.net.Socket.connect(Unknown Source)
> at java.net.Socket.<init>(Unknown Source)
> at java.net.Socket.<init>(Unknown Source)
> at org.postgresql.core.PGStream.<init>(PGStream.java:59)
> at
> org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:77)
> at
> org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:66)
> at
> org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:125)
> at
> org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:30)
> at org.postgresql.jdbc3.Jdbc3Connection.<init>(Jdbc3Connection.java:24)
> at org.postgresql.Driver.makeConnection(Driver.java:382)
> at org.postgresql.Driver.connect(Driver.java:260)
> ... 6 more
>
> I think that covers it. I'm pretty wiped out being as I've been working
> on this for about 4 hrs now.
> Your help is really appreciated!
>
> Thanks,
> Marc
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: if posting/reading through Usenet, please send an appropriate
> subscribe-nomail command to majordomo@postgresql.org so that your
> message can get through to the mailing list cleanly
Try sending requests back with parameters to a servlet and get the servlet
to do the database work.
Hemi
----- Original Message -----
From: "Marc" <mhorv@comcast.net>
To: <pgsql-jdbc@postgresql.org>; <pgsql-novice@postgresql.org>
Sent: Tuesday, January 23, 2007 6:26 PM
Subject: [JDBC] Applet Connectivity - PLEASE help
> OK, I'll say right up front I'm a postgres novice at best.
> I've spent quite some time researching this tonight and trying out a few
> things to no avail.
> The basic question is can an applet connect to a postgres database and if
> so how (I need specific details)?
> Postgres, the database, the web server and signed applet are all on the
> same machine.
> I'm using Postgres 8.2 and Java 1.5 w/ the postgresql-8.2-504.jdbc3 jdbc
> driver.
> The software works when run through my IDE (Eclipse) but not as an applet
> in a browser.
> I've set listen_addresses = '*' in postgresql.conf and my pg_hba settings
> are:
> local all all md5
> host all all 127.0.0.1/32 trust.
>
> Here's the code I'm using to try to make the connection where
> strServer = :jdbc:postgresql://localhost/Arco
> strDriver = org.postgresql.Driver
> strUser = postgres
> strPswd = fred
>
> public DBConnection(Trace trace, JApplet p_applet)
> throws Exception
> {
> URL dbIniURL;
> URLConnection urlConn;
> BufferedReader in;
> int vals = 0;
> String nextVal;
> String strProp;
> String strVal;
> String strUser = "";
> String strPswd = "";
> int pos;
> Properties props = new Properties();
>
> try
> {
> System.out.println("Instantiate DBConnection.");
> dbIniURL = new URL(p_applet.getDocumentBase(), "db.ini");
> urlConn = dbIniURL.openConnection();
> in = new BufferedReader(new
> InputStreamReader(urlConn.getInputStream()));
> while (vals < 4)
> {
> nextVal = in.readLine();
> vals = vals + 1;
> System.out.println("db.ini: " + nextVal.trim());
>
> pos = nextVal.indexOf(":");
>
> if (pos>0)
> {
> strProp = nextVal.substring(0,pos);
> strVal = nextVal.substring(pos+1);
>
> if (strProp.compareToIgnoreCase("Server") == 0)
> {
> strServer = strVal;
> }
> else if (strProp.compareToIgnoreCase("Driver") == 0)
> {
> strDriver = strVal;
> }
> else if (strProp.compareToIgnoreCase("User") == 0)
> {
> strUser = strVal;
> }
> else if (strProp.compareToIgnoreCase("Password") == 0)
> {
> strPswd = strVal;
> }
> }
> }
> drv = (Driver)Class.forName(strDriver).newInstance();
> DriverManager.registerDriver(drv);
> props.setProperty("user",strUser.trim());
> props.setProperty("password",strPswd.trim());
>
> System.out.println("Attempting to connecting to postgres
> db...");
> dbConn= DriverManager.getConnection(strServer, props);
> System.out.println("Connected to postgres db.");
> }
> catch (IOException ioe)
> {
> System.out.println("Error trying to connect to postgres db:");
> ioe.printStackTrace();
> throw new Exception(ioe.getMessage());
> }
> }
>
> The error I get in the console is:
> Java Plug-in 1.6.0
> Using JRE version 1.6.0 Java HotSpot(TM) Client VM
> User home directory = C:\Documents and Settings\Marc
>
>
> ----------------------------------------------------
> c: clear console window
> f: finalize objects on finalization queue
> g: garbage collect
> h: display this help message
> l: dump classloader list
> m: print memory usage
> o: trigger logging
> p: reload proxy configuration
> q: hide console
> r: reload policy configuration
> s: dump system and deployment properties
> t: dump thread list
> v: dump thread stack
> x: clear classloader cache
> 0-5: set trace level to <n>
> ----------------------------------------------------
>
> Init applet.
> Call new DBConnection.
> Instantiate DBConnection.
> db.ini: Server:jdbc:postgresql://localhost/Arco
> db.ini: Driver:org.postgresql.Driver
> Attempting to connecting to postgres db...
> org.postgresql.util.PSQLException: Something unusual has occured to cause
> the driver to fail. Please report this exception.
> at org.postgresql.Driver.connect(Driver.java:276)
> at java.sql.DriverManager.getConnection(Unknown Source)
> at java.sql.DriverManager.getConnection(Unknown Source)
> at db.DBConnection.<init>(DBConnection.java:169)
> at ui.BaseApplet.init(BaseApplet.java:138)
> at sun.applet.AppletPanel.run(Unknown Source)
> at java.lang.Thread.run(Unknown Source)
> Caused by: java.security.AccessControlException: access denied
> (java.net.SocketPermission 127.0.0.1:5432 connect,resolve)
> at java.security.AccessControlContext.checkPermission(Unknown Source)
> at java.security.AccessController.checkPermission(Unknown Source)
> at java.lang.SecurityManager.checkPermission(Unknown Source)
> at java.lang.SecurityManager.checkConnect(Unknown Source)
> at java.net.Socket.connect(Unknown Source)
> at java.net.Socket.connect(Unknown Source)
> at java.net.Socket.<init>(Unknown Source)
> at java.net.Socket.<init>(Unknown Source)
> at org.postgresql.core.PGStream.<init>(PGStream.java:59)
> at
> org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:77)
> at
> org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:66)
> at
> org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:125)
> at
> org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:30)
> at org.postgresql.jdbc3.Jdbc3Connection.<init>(Jdbc3Connection.java:24)
> at org.postgresql.Driver.makeConnection(Driver.java:382)
> at org.postgresql.Driver.connect(Driver.java:260)
> ... 6 more
>
> I think that covers it. I'm pretty wiped out being as I've been working on
> this for about 4 hrs now.
> Your help is really appreciated!
>
> Thanks,
> Marc
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: if posting/reading through Usenet, please send an appropriate
> subscribe-nomail command to majordomo@postgresql.org so that your
> message can get through to the mailing list cleanly
Have a look at this tutorial: http://java.sun.com/developer/technicalArticles/Security/Signed/ Am Dienstag, den 23.01.2007, 00:26 -0500 schrieb Marc: > OK, I'll say right up front I'm a postgres novice at best. > I've spent quite some time researching this tonight and trying out a few > things to no avail. > The basic question is can an applet connect to a postgres database and > if so how (I need specific details)? > Postgres, the database, the web server and signed applet are all on the > same machine. > I'm using Postgres 8.2 and Java 1.5 w/ the postgresql-8.2-504.jdbc3 jdbc > driver. > The software works when run through my IDE (Eclipse) but not as an > applet in a browser. > I've set listen_addresses = '*' in postgresql.conf and my pg_hba > settings are: > local all all md5 > host all all 127.0.0.1/32 trust. > > Here's the code I'm using to try to make the connection where > strServer = :jdbc:postgresql://localhost/Arco > strDriver = org.postgresql.Driver > strUser = postgres > strPswd = fred > > public DBConnection(Trace trace, JApplet p_applet) > throws Exception > { > URL dbIniURL; > URLConnection urlConn; > BufferedReader in; > int vals = 0; > String nextVal; > String strProp; > String strVal; > String strUser = ""; > String strPswd = ""; > int pos; > Properties props = new Properties(); > > try > { > System.out.println("Instantiate DBConnection."); > > dbIniURL = new URL(p_applet.getDocumentBase(), "db.ini"); > urlConn = dbIniURL.openConnection(); > in = new BufferedReader(new > InputStreamReader(urlConn.getInputStream())); > > while (vals < 4) > { > nextVal = in.readLine(); > vals = vals + 1; > > System.out.println("db.ini: " + nextVal.trim()); > > pos = nextVal.indexOf(":"); > > if (pos>0) > { > strProp = nextVal.substring(0,pos); > strVal = nextVal.substring(pos+1); > > if (strProp.compareToIgnoreCase("Server") == 0) > { > strServer = strVal; > } > else if (strProp.compareToIgnoreCase("Driver") == 0) > { > strDriver = strVal; > } > else if (strProp.compareToIgnoreCase("User") == 0) > { > strUser = strVal; > } > else if (strProp.compareToIgnoreCase("Password") == 0) > { > strPswd = strVal; > } > } > } > > drv = (Driver)Class.forName(strDriver).newInstance(); > DriverManager.registerDriver(drv); > > > props.setProperty("user",strUser.trim()); > props.setProperty("password",strPswd.trim()); > > System.out.println("Attempting to connecting to postgres > db..."); > dbConn= DriverManager.getConnection(strServer, props); > System.out.println("Connected to postgres db."); > } > catch (IOException ioe) > { > System.out.println("Error trying to connect to postgres db:"); > ioe.printStackTrace(); > throw new Exception(ioe.getMessage()); > } > } > > The error I get in the console is: > Java Plug-in 1.6.0 > Using JRE version 1.6.0 Java HotSpot(TM) Client VM > User home directory = C:\Documents and Settings\Marc > > > ---------------------------------------------------- > c: clear console window > f: finalize objects on finalization queue > g: garbage collect > h: display this help message > l: dump classloader list > m: print memory usage > o: trigger logging > p: reload proxy configuration > q: hide console > r: reload policy configuration > s: dump system and deployment properties > t: dump thread list > v: dump thread stack > x: clear classloader cache > 0-5: set trace level to <n> > ---------------------------------------------------- > > Init applet. > Call new DBConnection. > Instantiate DBConnection. > db.ini: Server:jdbc:postgresql://localhost/Arco > db.ini: Driver:org.postgresql.Driver > Attempting to connecting to postgres db... > org.postgresql.util.PSQLException: Something unusual has occured to > cause the driver to fail. Please report this exception. > at org.postgresql.Driver.connect(Driver.java:276) > at java.sql.DriverManager.getConnection(Unknown Source) > at java.sql.DriverManager.getConnection(Unknown Source) > at db.DBConnection.<init>(DBConnection.java:169) > at ui.BaseApplet.init(BaseApplet.java:138) > at sun.applet.AppletPanel.run(Unknown Source) > at java.lang.Thread.run(Unknown Source) > Caused by: java.security.AccessControlException: access denied > (java.net.SocketPermission 127.0.0.1:5432 connect,resolve) > at java.security.AccessControlContext.checkPermission(Unknown Source) > at java.security.AccessController.checkPermission(Unknown Source) > at java.lang.SecurityManager.checkPermission(Unknown Source) > at java.lang.SecurityManager.checkConnect(Unknown Source) > at java.net.Socket.connect(Unknown Source) > at java.net.Socket.connect(Unknown Source) > at java.net.Socket.<init>(Unknown Source) > at java.net.Socket.<init>(Unknown Source) > at org.postgresql.core.PGStream.<init>(PGStream.java:59) > at > org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:77) > at > org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:66) > at > org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:125) > at > org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:30) > at org.postgresql.jdbc3.Jdbc3Connection.<init>(Jdbc3Connection.java:24) > at org.postgresql.Driver.makeConnection(Driver.java:382) > at org.postgresql.Driver.connect(Driver.java:260) > ... 6 more > > I think that covers it. I'm pretty wiped out being as I've been working > on this for about 4 hrs now. > Your help is really appreciated! > > Thanks, > Marc > > ---------------------------(end of broadcast)--------------------------- > TIP 1: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly