santhosh.R gowda

Hi,

I had a large string content which consists of more than 10 thousand words, hence each time i called the respective java the string gets initialized,so it hits performance,is there any way to improve performance?

hello

When i download pdf , bmp files from the server thats running in tomcat 5.5.20 it takes a lot of time. Please suggest on any parameters to improve the same.


thanks.

Hi All

I need to find duplicate values in ArrayList is there any method to find duplicate values..?

Example

List list = new ArrayList();
list.add("a");
list.add("a");
list.add("b");
list.add("c");
list.add("c");

Here a and c are duplicate values.

i need the output as [a,c]

I already done using set but i need Any API to solve

*i need not use any iteration logic to find just i need any API to find*

Dear James

Please can you explain your answer more clearly...

Dear All

As we know if we make class final the class cant be extend by another class

so my question is if we make class final what is the use of making methods final even though we cant override that method because we cant extending the class
so why in java API String methods are final

Dear All,

In collection i saw where they are recommanding to use List l= new ArrayList();
why not ArrayList l= new ArrayList();

Dear All,

As my server is throwing out of memory error and i'm using 4 GB RAM in my server
and when when my application is running its displaying out of memory Error and even though i had written one program to check free memory its displaying TotalMemory =64MB and free memory = 42 MB if i set heapsize in commond promt is it effect the tomact using the heap or i want to set it in tomcat level

Please Can anybody shed some light on this
issue?

Dear All

As we know in Downcasting we need to specify the class name (Hardcoded)

like
Class x { } Class y extends x { Public static void main(String args[]) { y ob= new y(); x=y; y ob1=(y)x;// here i hard coded y in braces } }
Is it possible to make dynamically like i ll aasign the' y ' to one string value

Thanks

Seetharaman Venkatasamy

Dear All,

I'm having one requirement such that 0001 should be incremented to 0002 but when we use regular + operator its giving 2 instead of 0002 how to add including zeros also

Dear All

Kindly help me in converting the Microsoft word 2007/10 to Microsoft word 2003 .Which Api can i use in this work and suggetion's

Dear All,

Please can any body tell the performance of enhanced for loop and for loop in execution

Dear All,

in my web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <display-name>Test</display-name> <servlet> <servlet-name>action</servlet-name> <servlet-class>MainController</servlet-class> <load-on-startup>2</load-on-startup> </servlet> <servlet> <description> </description> <display-name>MainController</display-name> <servlet-name>MainController</servlet-name> <servlet-class>MainController</servlet-class> </servlet> <servlet-mapping> <servlet-name>action</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>MainController</servlet-name> <url-pattern>/MainController</url-pattern> </servlet-mapping> <session-config> <session-timeout>30</session-timeout> </session-config> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>implicit.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <env-entry> <env-entry-name>maxExemptions</env-entry-name> <env-entry-type>java.lang.Integer</env-entry-type> <env-entry-value>10</env-entry-value> </env-entry> <resource-env-ref> <description> Object factory for MyBean instances. </description> <resource-env-ref-name> bean/MyBeanFactory </resource-env-ref-name> <resource-env-ref-type> com.mycompany.MyBean </resource-env-ref-type> </resource-env-ref> </web-app>

in server.xml

<?xml version='1.0' encoding='utf-8'?> <!-- Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --> <!-- Note: A "Server" is not itself a "Container", so you may not define subcomponents such as "Valves" at this level. Documentation at /docs/config/server.html --> <Server port="8005" shutdown="SHUTDOWN"> <!--APR library loader. Documentation at /docs/apr.html --> <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" /> <!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html --> <Listener className="org.apache.catalina.core.JasperListener" /> <!-- Prevent memory leaks due to use of particular java/javax APIs--> <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" /> <!-- JMX Support for the Tomcat server. Documentation at /docs/non-existent.html --> <Listener className="org.apache.catalina.mbeans.ServerLifecycleListener" /> <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" /> <!-- Global JNDI resources Documentation at /docs/jndi-resources-howto.html --> <GlobalNamingResources> <!-- Editable user database that can also be used by UserDatabaseRealm to authenticate users --> <Resource name="UserDatabase" auth="Container" type="org.apache.catalina.UserDatabase" description="User database that can be updated and saved" factory="org.apache.catalina.users.MemoryUserDatabaseFactory" pathname="conf/tomcat-users.xml" bar="23" /> <Resource name="bean/MyFactory" auth="Container" type="com.mycompany.MyBean" factory="com.mycompany.MyBeanFactory"/> </GlobalNamingResources> <!-- A "Service" is a collection of one or more "Connectors" that share a single "Container" Note: A "Service" is not itself a "Container", so you may not define subcomponents such as "Valves" at this level. Documentation at /docs/config/service.html --> <Service name="Catalina"> <!--The connectors can use a shared executor, you can define one or more named thread pools--> <!-- <Executor name="tomcatThreadPool" namePrefix="catalina-exec-" maxThreads="150" minSpareThreads="4"/> --> <!-- A "Connector" represents an endpoint by which requests are received and responses are returned. Documentation at : Java HTTP Connector: /docs/config/http.html (blocking & non-blocking) Java AJP Connector: /docs/config/ajp.html APR (HTTP/AJP) Connector: /docs/apr.html Define a non-SSL HTTP/1.1 Connector on port 8080 --> <Connector port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" /> <!-- A "Connector" using the shared thread pool--> <!-- <Connector executor="tomcatThreadPool" port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" /> --> <!-- Define a SSL HTTP/1.1 Connector on port 8443 This connector uses the JSSE configuration, when using APR, the connector should be using the OpenSSL style configuration described in the APR documentation --> <!-- <Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true" maxThreads="150" scheme="https" secure="true" clientAuth="false" sslProtocol="TLS" /> --> <!-- Define an AJP 1.3 Connector on port 8009 --> <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" /> <!-- An Engine represents the entry point (within Catalina) that processes every request. The Engine implementation for Tomcat stand alone analyzes the HTTP headers included with the request, and passes them on to the appropriate Host (virtual host). Documentation at /docs/config/engine.html --> <!-- You should set jvmRoute to support load-balancing via AJP ie : <Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1"> --> <Engine name="Catalina" defaultHost="localhost"> <!--For clustering, please take a look at documentation at: /docs/cluster-howto.html (simple how to) /docs/config/cluster.html (reference documentation) --> <!-- <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/> --> <!-- The request dumper valve dumps useful debugging information about the request and response data received and sent by Tomcat. Documentation at: /docs/config/valve.html --> <!-- <Valve className="org.apache.catalina.valves.RequestDumperValve"/> --> <!-- This Realm uses the UserDatabase configured in the global JNDI resources under the key "UserDatabase". Any edits that are performed against this UserDatabase are immediately available for use by the Realm. --> <Realm className="org.apache.catalina.realm.UserDatabaseRealm" resourceName="UserDatabase"/> <!-- Define the default virtual host Note: XML Schema validation will not work with Xerces 2.2. --> <Host name="localhost" appBase="webapps" unpackWARs="true" autoDeploy="true" xmlValidation="false" xmlNamespaceAware="false"> <!-- SingleSignOn valve, share authentication between web applications Documentation at: /docs/config/valve.html --> <!-- <Valve className="org.apache.catalina.authenticator.SingleSignOn" /> --> <!-- Access log processes all example. Documentation at: /docs/config/valve.html --> <!-- <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log." suffix=".txt" pattern="common" resolveHosts="false"/> --> <Context path="/Test" docBase="Test" crossContext="true" reloadable="true" debug="1"> <Resource name="bean/MyBeanFactory" auth="Container" type="com.mycompany.MyBean" factory="org.apache.naming.factory.BeanFactory" bar="23"/> </Context> </Host> </Engine> </Service> </Server>

Java code

try{ javax.naming.Context ctx = new javax.naming.InitialContext(); javax.naming.Context env = (Context) ctx.lookup("java:comp/env"); MyBean bean = (MyBean) env.lookup("bean/MyBeanFactory"); //System.out.println(bean); } catch(Exception e) { e.printStackTrace(); }

Its printing " javax.naming.NamingException: Cannot create resource instance"

Im using Tomcat 6.0

please give me hand in this issue i'm worried from last two days

Bean Class
package com.mycompany; public class MyBean { private String foo = "Default Foo"; public String getFoo() { return (this.foo); } public void setFoo(String foo) { this.foo = foo; } private int bar = 0; public int getBar() { return (this.bar); } public void setBar(int bar) { this.bar = bar; } }


Web.xml
resource-env-ref> <Description> Object factory for MyBean instances. </Description> <resource-env-ref-name> bean/MyBeanFactory </resource-env-ref-name> <resource-env-ref-type> com.mycompany.MyBean </resource-env-ref-type> <resource-env-ref>


Java code to acces
Context initCtx = new InitialContext(); Context envCtx = (Context) initCtx.lookup("java:comp/env"); MyBean bean = (MyBean) envCtx.lookup("bean/MyBeanFactory"); writer.println("foo = " + bean.getFoo() + ", bar = " + bean.getBar());

I'm getting the following exception

javax.naming.NamingException: Cannot create resource instance

Dear All,

I want to know the difference between Collection<?> and Collection<Object>

public void print(Collection<Object>0) { } public void print(Collection<?>0) { }

they are telling

Object is not a super type of all kinds of collections

Please can you elaborate this statement because Object is super of all the kinds as i know