Calling servlet from a java program

Hi
I need to call a servlet's doPost() method from a java program. I have a specific situation, where I need to call servlet from a java program. DUring this call I need to pass a file and two string to the servlet. Servelt after receiving the file and string uploads the file to the server at a specified location. I am stuck up as how to call servlet from a java program instead of a HTML or JSP.
Can anyone help me to start with this.
any suggestion is welcome.

You have to establish a URLConnection with servlet from your java program.
URL servletURL = new URL("http://localhost:8080/Myservlet?str1=abc&str2=def");
URLConnection servletConnection = servletURL.openConnection();you can get the objectOutputStream
ObjectOutputStream oos = new ObjectOutputStream (servletConnection.getOutputStream());
oos.writeObject(your file object);-------------------------------------------------
In the servlet u can get the strings using request.getParameter("str1");
In the servlet u can get the strings using request.getParameter("str2");
file = new ObjectInputStream (request.getInputStream()).readObject()a lot of resources are available on this ...
hope this helps :)

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Calling Servlet from a java prog?

Hi all,
I am calling servlet from a java prog (Java Agent in Lotus Notes) by using URL and URLConnection object. how can i trigger the Servlet By using doPost method .I have to send some parameter also.
Thanx
Muthu

you need to open a connection to the servlet. Then you must call getInputStream() and getOutputStream() and use them in any way you see fit. I was trying this before and could not get POST to work unless I openned the input stream from the servlet. Strange... but doGet worked without openning the input stream???
// open a connection....
// write to the servlet
servletConnection.getOutputStream().write("whatever");
servletConnection.getOutputStream().flush();
servletConnection.getOutputStream().close();
// grab what the servlet sends back, required to do a post.
byte [] in = new byte[100];
servletConnection.getInputStream().read(in);
servletConnection.getInputStream().close();

Calling a servlet from a java program

I could not find a forum for servlet hence am posting
here
I have a servlet that accepts prameters and
gives some out put .
I want to be able to call this servlet ( invoke )
from a Java Program .
How do i do that ..
Any sample code /pointer would be appreciated.
Deepa

hi
you can try this code.
URL url = new URL("http://localhost:8888/yourServlet?param1=value1");
URLConnection con = url.openConnection();
StringBuffer sBuf = new StringBuffer();
BufferedReader bReader = new BufferedReader(
new InputStreamReader(
con.getInputStream()));
String line = null;
while((line = bReader.readLine()) != null) {
sBuf.append(line);
System.out.println(sBuf);
hope this helps
Shrini

Calling Servlet from a java class

Hi,
I don�t know what I�m doing wrong...
I try to call a servlet located in a tomcat webserver, from a class, and capture its output. I use an URLConnection object... Everything is all right when I want to get an html page, but, it reports an IOException (FileNotFoundException) when the requested resource is a servlet.
This servlet is working correctly.
Can�t I use an URLConnection to access servlets?
Cheers

try setting up the user agent property of HTTP protocol to a browsers,its worth a shot.
Cheers
Khalid

Possibility of calling standard actions from a java program

Hi ,
I am working for a project where customer wants to have option of saving orders as draft only and later convert to order if need be. However since we do not want many drafts to reside on server there is a need to delete these at a specified time. For draft orders I am using order templates since they stay in the database without getting converted to orders. Now I do not know how to go about the deletion part.
i need to write a program that would run on the server and which would fetch the templates (drafts) that have been created till a particular time and call the delete action of the template. Now the question is how do i call these actions from a java program where this java program will have to run on the server end (ie will be a backend process).
Please suggest.
Thanks
Roopali

hello roopali,
you can create a separate thread that will run your
code that will check for stale drafts and delete them.
it is just like a session management program but here
we will be looking over the drafts and not the session
objects.
now if you want the invocation of the action from another
program, a socket program would suffice but opening ports
will cause you network connections thru firewall.
if you can make use of HTTP servlet as your service
provider e.g., you can then just pass some action params
to invoke it.
regards
jo

Is it possible to call a method in a servlet from a java script ?

I need to do a dynamic html page . In the page i select some things and then these things must communicate whit a servlet because the servlet will do some DB querys and update the same webpage.
So is it possible to actually call a method of a servlet from a java script? i want to do something that looks like this page:
http://www.hebdo.net/v5/search/search.asp?rubno=4000&cregion=1011&sid=69DHOTQ30307151
So when u select something in the first list the secodn list automaticly updates.
thank you very much

You can
1. load all the options when loading the page and
set second selection options when user selected
the first; or
2. reload the page when user select first selection
by 'onChange' event; or
3. using iframe so you only need to reload part of
the page.

Cannot call ANY stored functions from my Java program

My problem is that I cannot call ANY stored procedure from my Java
program. Here is the code for one of my stored procedures which runs
very well in PL/SQL:
PL/SQL code:
CREATE OR REPLACE PACKAGE types AS
TYPE cursorType IS REF CURSOR;
END;
CREATE OR REPLACE FUNCTION list_recs (id IN NUMBER)
RETURN types.cursorType IS tracks_cursor types.cursorType;
BEGIN
OPEN tracks_cursor FOR
SELECT * FROM accounts1
WHERE id = row_number;
RETURN tracks_cursor;
END;
variable c refcursor
exec :c := list_recs(11)
SQL> print c
COLUMN1 A1 ROW_NUMBER
rec_11 jacob 11
rec_12 jacob 11
rec_13 jacob 11
rec_14 jacob 11
rec_15 jacob 11
Here is my Java code:
import java.sql.*;
import java.io.*;
import oracle.jdbc.driver.*;
class list_recs
public static void main(String args[]) throws SQLException,
IOException
String query;
CallableStatement cstmt = null;
ResultSet cursor;
// input parameters for the stored function
String user_name = "jacob";
// user name and password
String user = "jnikom";
String pass = "jnikom";
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
try { Class.forName ("oracle.jdbc.driver.OracleDriver"); }
catch (ClassNotFoundException e)
{ System.out.println("Could not load driver"); }
Connection conn =
DriverManager.getConnection (
"jdbc:oracle:thin:@10.52.0.25:1521:bosdev",user,pass);
try
String sql = "{ ? = call list_recs(?) }";
cstmt = conn.prepareCall(sql);
// Use OracleTypes.CURSOR as the OUT parameter type
cstmt.registerOutParameter(1, OracleTypes.CURSOR);
String id = "11";
cstmt.setInt(2, Integer.parseInt(id));
// Execute the function and get the return object from the call
cstmt.executeQuery();
ResultSet rset = (ResultSet) cstmt.getObject(1);
while (rset.next())
System.out.print(rset.getString(1) + " ");
System.out.print(rset.getString(2) + " ");
System.out.println(rset.getString(3) + " ");
catch (SQLException e)
System.out.println("Could not call stored function");
e.printStackTrace();
return;
finally
cstmt.close();
conn.close();
System.out.println("Stored function was called");
Here is how I run it, using Win2K and Oracle9 on Solaris:
C:\Jacob\Work\Java\Test\Vaultus\Oracle9i\FunctionReturnsResultset>java
list_recs
Could not call stored function
java.sql.SQLException: ORA-00600: internal error code, arguments:
[ttcgcshnd-1], [0], [], [], [], [], [], []
at
oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:168)
at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:208)
at oracle.jdbc.ttc7.Oall7.receive(Oall7.java:543)
at oracle.jdbc.ttc7.TTC7Protocol.doOall7(TTC7Protocol.java:1405)
at oracle.jdbc.ttc7.TTC7Protocol.fetch(TTC7Protocol.java:889)
at
oracle.jdbc.driver.OracleStatement.<init>(OracleStatement.java:490)
at
oracle.jdbc.driver.OracleStatement.getCursorValue(OracleStatement.java:2661)
at
oracle.jdbc.driver.OracleStatement.getObjectValue(OracleStatement.java:4189)
at
oracle.jdbc.driver.OracleStatement.getObjectValue(OracleStatement.java:4123)
at
oracle.jdbc.driver.OracleCallableStatement.getObject(OracleCallableStatement.java:541)
at list_recs.main(list_recs.java:42)
C:\Jacob\Work\Java\Test\Vaultus\Oracle9i\FunctionReturnsResultset>
Any help is greatly appreciated,
Jacob Nikom

Thank you for your suggestion.
I tried it, but got the same result. I think the difference in the syntax is due to the Oracle versus SQL92 standard
conformance. Your statament is the Oracle version and mine is the SQL92. I think both statements are acceptable
by the Oracle.
Regards,
Jacob Nikom

Calling a servlet from a Java Stored Procedure

Hey,
I'm trying to call a servlet from a Java Stored Procedure and I get an error.
When I try to call the JSP-class from a main-method, everything works perfectly.
Java Stored Procedure:
public static void callServlet() {
try {
String servletURL = "http://127.0.0.1:7001/servletname";
URL url = new URL(servletURL);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setDoOutput(true);
conn.setRequestProperty("Pragma", "no-cache");
conn.connect();
ObjectInputStream ois = new ObjectInputStream(conn.getInputStream());
Integer client = (Integer)ois.readObject();
ois.close();
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conn.disconnect();
} catch (Exception e) {
e.printStackTrace();
Servlet:
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Integer id = new Integer(10);
OutputStream os = response.getOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(os);
oos.writeObject(id);
oos.flush();
oos.close();
response.setStatus(0);
Grant:
call dbms_java.grant_permission( 'JAVA_USER', 'SYS:java.net.SocketPermission','localhost', 'resolve');
call dbms_java.grant_permission( 'JAVA_USER','SYS:java.net.SocketPermission', '127.0.0.1:7001', 'connect,resolve');
Package:
CREATE OR REPLACE PACKAGE pck_jsp AS
PROCEDURE callServlet();
END pck_jsp;
CREATE OR REPLACE PACKAGE BODY pck_jsp AS
PROCEDURE callServlet()
AS LANGUAGE JAVA
NAME 'JSP.callServlet()';
END pck_jsp;
Architecture:
AS: BEA WebLogic 8.1.2
DB: Oracle 9i DB 2.0.4
Exception:
java.io.StreamCorruptedException: InputStream does not contain a serialized object
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java)
The Servlet and the class work together perfectly, only when I make the call from
within the database things go wrong.
Can anybody help me.
Thank in advance,
Bart Laeremans
... Desperately seeking knowledge ...

Look at HttpCallout.java in the following code sample
http://www.oracle.com/technology/sample_code/tech/java/jsp/samples/jwcache/Readme.html
Kuassi

Calling another application from a java program

Hi, Java ppl.
I wanted to know how can I call another program say a help application or an exe from a java program. anyone with any advice or a piece of code would help.
Thanks
Pradeep

I had the same situation and I tried the code that you sugested and it works. I was wondering, what am I expecting in the while loop that appears after the int inp; statement? Is some data going to be displayed on the screen? How essential is to have that while loop after the calling the exec() method?
Sorry for the amount of questions, I never tried this before.
Best regards,
Luis E.

Calling OCX Methods from a Java Program

Hi All,
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All inputs are highly appreciated.
Thanks
Tarek

JNI
http://java.sun.com/docs/books/tutorial/native1.1/index.html

Calling jsp page from a java program

Hello,
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The JSP page is already running fine in Tomcat.
Thanks and Regards,
Prasanna.

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An

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http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html
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Any help is appreciated.
Thanks,
Krishna

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Calling servlet from a java program

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