Authentication

Authentication is the process of verifying the identity of a user. This is usually done using a user name and a password. This process compares the provided user name and password with those stored in the database of an authentication server. There are four types of authentication as follows:......
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JSP Implicit Objects

Implicit objects in JSP are the Java objects that the JSP Container makes available to developers in each page. These objects need not be declared or instantiated by the JSP author. They are automatically instantiated by the container and are accessed using standard variables; hence, they are......
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JSTL Core Library

JSP Standard Tag Library (JSTL) is an extension of the JSP language. It includes various operations needed in almost all JSP pages, such as internationalization, conditional processing, XML parsing, making a database connection, etc. The important tags in the JSTL core library are as......
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How to install and configure Tomcat for Windows(tm)

To install and configure Tomcat, you will have to take the following steps: Download JDK 1.5 from Sun(tm) site at http://java.sun.com/javase/downloads/index_jdk5.jsp Install JDK to C:\Program Files\Java\jdk1.5.0_08 Download Tomcat 5 from......
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How can an existing session be invalidated?

An existing session can be invalidated in the following two ways: Setting timeout in the deployment descriptor : This can be done by specifying timeout between the <session-timeout> tags as follows: <session-config>......
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How can context attributes be made thread safe?

Context attributes are not thread safe, since multiple servlets and hence multiple threads in a Web-app can access these attributes. To make a context attribute thread safe, it is necessary to apply a lock on the context. This is done by synchronizing the ServletContext, so that when a thread......
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How can session variables be made thread-safe?

Session variables are not thread-safe. This is because there can be multiple requests from a client using more than one browser. These variables can be made thread-safe by synchronizing them, i.e., by acquiring a lock on the part of code that accesses these variables....
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How is a filter configured in the deployment descriptor?

A filter is configured in the deployment descriptor as follows: <filter>        <filter-name>Filter1</filter-name>        <display-name>filter1</display-name>    ......
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How is an El initialization parameter configured in the deployment descriptor?

An El initialization parameter initParam is configured in the deployment descriptor as follows: <context-param>    <param-name>parameterName</param-name>    <param-value>parameterValue</param-value> </context-param>......
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How is scripting disabled?

Scripting is disabled by setting the scripting-invalid element of the deployment descriptor to true. It is a subelement of jsp-property-group. Its valid values are true and false. The syntax for disabling scripting is as follows: <jsp-property-group>......
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