Java webfilter annotation examples

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Sure! Here are some examples of using the @WebFilter annotation in Java:

  1. Basic Usage:

The @WebFilter annotation is used to declare a filter that should be applied to one or more servlets. Here's an example:

@WebFilter(filterName = "MyFilter", urlPatterns = { "/my-servlet" })
public class MyFilter implements Filter {
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        // perform filtering
        chain.doFilter(req, res);
    }
}

In this example, the @WebFilter annotation is used to declare a filter named MyFilter that will be applied to the servlet mapped to the URL pattern /my-servlet.

  1. Using @WebInitParam:

You can also use the @WebInitParam annotation to define filter initialization parameters. Here's an example:

@WebFilter(filterName = "MyFilter", urlPatterns = { "/my-servlet" },
    initParams = { @WebInitParam(name = "param1", value = "value1"),
                   @WebInitParam(name = "param2", value = "value2") })
public class MyFilter implements Filter {
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        // perform filtering
        chain.doFilter(req, res);
    }
}

In this example, the @WebFilter annotation defines two initialization parameters, param1 and param2, with values value1 and value2, respectively.

  1. Specifying Filter Order:

You can also use the @WebFilter annotation to specify the order in which filters should be applied. Here's an example:

@WebFilter(filterName = "MyFilter", urlPatterns = { "/my-servlet" }, order = 1)
public class MyFilter implements Filter {
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        // perform filtering
        chain.doFilter(req, res);
    }
}

In this example, the @WebFilter annotation specifies that the filter should be applied first, using the order attribute.

These are just a few examples of the many ways that you can use the @WebFilter annotation in Java. The annotation is a powerful tool for configuring filters in your web application.