Close URL Connection netstat
hello all,
I hope you can help me.
Please have a look at my code below
I open an URL Connection but I can't close it.
If i type in a DOS Box netstat I see a lot of connection.
Now my question is how can I close the connection.
m_http.disconnect() seems not to work.
public class Unbenannt1 extends Applet
Button button1 = new Button();
private HttpURLConnection m_http = null;
private URL m_MyAlarmURL = null;
private URLConnection m_MyURLConnection = null;
private long m_TimeAlarmXML = 0;
private boolean m_TimeUpdate = true;
/**Das Applet initialisieren*/
public void init()
String a_str = "http://"+ getCodeBase().getHost() + "/x.xml";
try
m_MyAlarmURL = new URL( a_str );
catch ( MalformedURLException ie )
try
jbInit();
catch(Exception e)
e.printStackTrace();
/**Initialisierung der Komponenten*/
private void jbInit() throws Exception
button1.setLabel("button1");
button1.setBounds(new Rectangle(27, 28, 78, 27));
button1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(ActionEvent e) {
button1_actionPerformed(e);
setLayout(null);
setBackground(java.awt.Color.lightGray);
setSize(426,266);
this.add(button1, null);
void button1_actionPerformed(ActionEvent e)
int a_int = 0;
try
m_MyURLConnection = m_MyAlarmURL.openConnection();
m_http = (HttpURLConnection)m_MyURLConnection;
m_http.setRequestMethod( "HEAD" );
m_http.setUseCaches(false);
m_http.connect();
a_int = m_http.getResponseCode();
m_http.disconnect();
m_http = null;
m_MyURLConnection = null;
System.gc();
catch ( java.io.IOException ioe )
a_int = 404;
}Thanks a lot
Prediger
Usually those connections linger around for some time, and will then be closed by the OS once a certain timeout has been reached. I don't know how to change that timeout, though.
Btw: the docs don't claim that the connection will be closed. The description for disconnect() is "Indicates that other requests to the server are unlikely in the near future"
If you still see the connection after a while, then something is wrong, but I've seen connections like that hang around for several minutes even after the JVM was terminated.
Thomas
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Hi Experts,
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Alternate solutions, make this a two way asynchronous call, 1) You invoke the RFC asynchronously and close the connection, the RFC in turn will execute the query and transfer the data to JCO via another RFC call.
If this needs to be a synchronous call, then you will need to optimize the query to its best.
Regards,
Chen -
Open and close database connection jsp page
hi there, i wanna know about how to open database connection to Mysql at the beginning of the page and close the connection at the end of the page. The jsp page contain all processing code.
plz help me...thx thx<html>
<head>
<basefont face="Arial">
</head>
<body>
<%@ page language="java" import="java.sql.*" %>
<%!
// define variables
String id;
String firstName;
String lastName;
// define database parameters, change this according to your needs
String host="localhost";
String user="root";
String pass="";
String db="test";
String conn;
%>
<table border="1" cellspacing="1" cellpadding="5">
<tr>
<td><b>id</b></td>
<td><b>first name</b></td>
<td><b>last name</b></td>
</tr>
<%
Class.forName("org.gjt.mm.mysql.Driver");
// create connection string
conn = "jdbc:mysql://" + host + "/" + db + "?user=" + user
+ "&password=" + pass;
// pass database parameters to JDBC driver
Connection Conn = DriverManager.getConnection(conn);
// query statement
Statement SQLStatement = Conn.createStatement();
// generate query
// change this query according to your needs
String Query = "SELECT id, firstname, lastname FROM abook";
// get result
ResultSet SQLResult = SQLStatement.executeQuery(Query);
while(SQLResult.next())
id = SQLResult.getString("id");
firstName = SQLResult.getString("firstname");
lastName = SQLResult.getString("lastname");
out.println("<tr><td>" + id + "</td><td>" +
firstName + "</td><td>" + lastName + "</td></tr>");
// close connection
SQLResult.close();
SQLStatement.close();
Conn.close();
%>
</table>
</body>
</html>hi :-)
i've got that on the net as part of the tutorial on jsp (long long time ago)
you just have to be resourceful in finding solutions :-)
try google :-) there are lot's of tutorial available in there ;-)
goodluck ;-)
regards, -
How to correct close database connection after report generation
Hello
I have problem a with alive database connection after report creation and report closing. How to properly to close connection to database?
Best regards
Edited by: punkers84 on Jun 17, 2011 10:38 AMthat's what I am doing... after viewing the report, I call the close method on the window closing event of the container window. but the connection is still open. I had a lot of other issues with my jdbc driver but after downgrading to an older version those issues are resolved.Only this one is still there! Is there any other way to close the connection (like using dbcontroller or etc.)?
-
When to open and close database connection
im trying to connect to a oracle database using servlets
when should i open and close the connection
it works fine when i do both in the doPost() method
but when i tried to open connection in init() methd .. it doesnt seem to work
what should i do...
the connection is initialised in the init() method but is null in the doPost() method" im trying to connect to a oracle database using servlets
when should i open and close the connection
it works fine when i do both in the doPost() method
but when i tried to open connection in init() methd .. it doesnt seem to work
what should i do...
the connection is initialised in the init() method but is null in the doPost() method"
1:
without seeing the code i would say the the connection is null
because you are storing it as a servlet class variable which is
not thread safe.
2:
The best way to do it using connection pooling
detailed docs on the tomcat website
3:
if you are not using connection pooling, then
open and close the connection in the do* method
or
use init() to place the connection in the servletconfig
and close in destroy() and use synching to access -
How to close database connections in Crystal Reports
I am using the following code to connect to database. I can either pass JNDIName or I can provide values for others by leaving JNDI name empty.
If i use JNDI name, it will use a connection from the connection pool of App Server (in my case Weblogic), but it is not releasing the connection after use. Connection remains even if I logoff from the application. If i keep my max connections as 15 in weblogic, after clicking the page with crystal report 15 times all will remain active and users will not be able to login to the application.
If i use connectionString and others without using JNDI Name, it directly connects to database. So it creates a connection in database server directly without using connection pool of weblogic. If i check weblogic, it shows no connection in use as expected, but if i check database, i can see the no. of connections increasing everytime a user clicks a crystal report page.
When the connection touches the maximum allowed connection in server, every application using the same server goes down
How can I close the connection which was created for the viewing the report?
String reportName = "/reports/BankBalance.rpt";
ReportClientDocument clientDoc = (ReportClientDocument) session.getAttribute(reportName);
if (clientDoc == null)
clientDoc = new ReportClientDocument();
clientDoc.setReportAppServer(ReportClientDocument.inprocConnectionString);
// Open report
clientDoc.open(reportName, OpenReportOptions._openAsReadOnly);
String connectString = ""; // jdbc:sybase:Tds:DBSERVERNAME:9812/DBNAME?ServiceName=DBNAME
String driverName = ""; // com.sybase.jdbc3.jdbc.SybDriver
String JNDIName = "DS_APP";
String userName = "";
String password = "";
// Switch all tables on the main report and sub reports
CRJavaHelper.changeDataSource(clientDoc, userName, password, connectString, driverName, JNDIName);
// logon to database
CRJavaHelper.logonDataSource(clientDoc, userName, password);
// Store the report document in session
session.setAttribute(reportName, clientDoc);
// Create the CrystalReportViewer object
CrystalReportViewer crystalReportPageViewer = new CrystalReportViewer();
String reportSourceSessionKey = reportName+"ReportSource";
Object reportSource = session.getAttribute(reportSourceSessionKey);
if (reportSource == null)
reportSource = clientDoc.getReportSource();
session.setAttribute(reportSourceSessionKey, reportSource);
// set the reportsource property of the viewer
crystalReportPageViewer.setReportSource(reportSource);
crystalReportPageViewer.setHasRefreshButton(true);
crystalReportPageViewer.setToolPanelViewType(CrToolPanelViewTypeEnum.none);
// Process the report
crystalReportPageViewer.processHttpRequest(request, response, application, null);the sample shows how to clear RAS and Enterprise resources after viewing report.
1. If you use unmanaged RAS - as I can see you using setReportAppServer, then remove the enterprise related stuff : instantiating and cleaning code.
The sample code is meant to give you an idea on how you can release the resources after done with viewing report. In your case all you need to do for cleaning is call close() on ReportDocumentObject. The sample will need to be modified for your requirements. -
Hi all,
Currently we developed a application in NWDS, the same is operational from portal.
As per the requirment we have to run the RFC many times to extract the data from R/3. After running the RFC many times
we are getting the following Error "Error connecting using JCO.client: null"
But if we redeploy the application the problem is solved but after a while the same issue is persisting.
Please suggest how the problem can be solved ??
Thanks,
vijay.Hi venkat,
Thanks for the example suggested by you.
The following is the RFC iam executing many times.
Z_Hr_Aprsl_Init_Input input= new Z_Hr_Aprsl_Init_Input();
input.setI_Usrid("UserId");
wdContext.nodeZ_Hr_Aprsl_Init_Input_new().bind(input);
wdContext.nodeZ_Hr_Aprsl_Init_Input().currentZ_Hr_Aprsl_Init_InputElement().modelObject().execute();
the code iam using to close the connection is
JCO.Client client = JCO.getClient(" "); // Please specify the parameter to be used to refer the above RFC
client.disconnect();
Please suggest the required the parameter to close the RFC connection
Thanks
vijay
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