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This article mainly explains "what is the use of Servlet Context". The content of the explanation in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "what is the use of Servlet Context"?

The collection of all Servlet,JSP,JavaBean and other Web parts installed in a server under a specific URL namespace (for example, / myapplication) constitutes a Web application, each Web application (the same JVM), the container will have a background object, and the javax.servlet.Servlet Context interface provides a way to access this background object. You can get the background object in which the Servlet is running through the getServlet Context method of a Servlet instance. From this background object, you can access the following information or resources:

◆ initialization parameters

◆ objects stored in the background

◆ resources associated with this background

◆ log

You can call Servlet Context.getInitParameterNames () to return an enumerated object (Java.util.Enumeration) of initialization parameters, or directly specify a parameter name to get a specific parameter value: Servlet Context.getInitParameter (String name).

In addition, any type of object bound to a specific name can be stored in the background of Servlet, such as:

Context.setAttribute (String name, Object object)

The object object will be bound to the name name and stored in the Servlet background, which can be shared by other Servlet in the same background. Other Servlet can use context.getAttribute (String name) to get an object in the background, or context.removeAttribute (String name) to remove an object from the background.

The URL of a particular resource can be obtained by calling Servlet Context.getResource (String path), where the path parameter must start with "/" and will be resolved to a relative path relative to the root of the current Servlet background. This method is different from the java.lang.Class.getResource method based on the classloader. If you request a .JSP page through the Servlet Context.getResource method, you will get the source code of the JSP. To get the execution result, you can use the include method of the RequestDispatcher object. You can also get resources directly in the form of an input stream.

Public InputStream getResourceAsStream (String path)

Servlet Context provides log support, and you can simply write log information to the underlying Servlet log record by calling the Servlet Context.log (String msg) or Servlet Context.log (String msg,Throwable throwable) method, which can also write exception information and throwable trace stack.

Thank you for your reading, the above is the content of "what is the use of Servlet Context". After the study of this article, I believe you have a deeper understanding of what the use of Servlet Context is, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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