org.apache.juneau.rest.vars.ServletInitParamVar Maven / Gradle / Ivy

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package org.apache.juneau.rest.vars;

import org.apache.juneau.http.response.*;
import org.apache.juneau.rest.*;
import org.apache.juneau.rest.servlet.*;
import org.apache.juneau.svl.*;

/**
 * Servlet init parameter variable resolver.
 *
 * 
 * The format for this var is "$I{key[,defaultValue]}".
 *
 * 

 * This variable resolver requires that a {@link RestRequest} bean be available in the session bean store.
 *
 * 

 * Values are pulled from the {@link RestServlet#getInitParameter(String)} method.
 *
 * 

 * Since this is a {@link SimpleVar}, any variables contained in the result will be recursively resolved.
 * Likewise, if the arguments contain any variables, those will be resolved before they are passed to this var.
 *
 * 
See Also:

 * 	SVL Variables
 * 
 */
public class ServletInitParamVar extends DefaultingVar {

	/** The name of this variable. */
	public static final String NAME = "I";

	/**
	 * Constructor.
	 */
	public ServletInitParamVar() {
		super(NAME);
	}

	@Override /* Var */
	public String resolve(VarResolverSession session, String key) {
		return session.getBean(RestRequest.class).orElseThrow(InternalServerError::new).getContext().getServletInitParameter(key);
	}

	@Override /* Var */
	public boolean canResolve(VarResolverSession session) {
		return session.getBean(RestRequest.class).isPresent();
	}
}