Include.java

/*
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 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * http://glassfish.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
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 * file and include the License file at packager/legal/LICENSE.txt.
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 * GPL Classpath Exception:
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package com.sun.jersey.server.impl.container.servlet;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.SimpleTagSupport;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * Includes a side JSP file for the "resolvingClass" class.
 *
 * <p>
 * This tag looks for a side JSP file of the given name
 * from the inheritance hierarchy of the "resolvingClass" class,
 * and includes the contents of it, just like <jsp:include>.
 *
 * <p>
 * For example, if the "resolvingClass" class is the <tt>Foo</tt> class,
 * which looks like the following:
 *
 * <pre>
 * class Foo extends Bar { ... }
 * class Bar extends Zot { ... }
 * </pre>
 *
 * <p>
 * And if you write:
 * <pre><xmp>
 * <st:include page="abc.jsp"/>
 * </xmp></pre>
 * then, it looks for the following files in this order,
 * and includes the first one found.
 * <ol>
 *  <li>a side-file of the Foo class named abc.jsp (/WEB-INF/Foo/abc.jsp)
 *  <li>a side-file of the Bar class named abc.jsp (/WEB-INF/Bar/abc.jsp)
 *  <li>a side-file of the Zot class named abc.jsp (/WEB-INF/Zot/abc.jsp)
 * </ol>
 *
 * @author Kohsuke Kawaguchi
 * @author Paul.Sandoz@Sun.Com
 */
public class Include extends SimpleTagSupport {

    private Class<?> resolvingClass;
    private String page;

    /**
     * Specifies the name of the JSP to be included.
     */
    public void setPage(String page) {
        this.page = page;
    }

    /**
     * Specifies the resolving class for which JSP will be included.
     */
    public void setResolvingClass(Class<?> resolvingClass) {
        this.resolvingClass = resolvingClass;
    }

    private Object getPageObject(String name) {
        return getJspContext().getAttribute(name, PageContext.PAGE_SCOPE);
    }

    public void doTag() throws JspException, IOException {
        Class<?> resolvingClass = (Class<?>)getJspContext().getAttribute("resolvingClass", PageContext.REQUEST_SCOPE);
        final Class<?> oldResolvingClass = resolvingClass;
        if (this.resolvingClass != null) {
            resolvingClass = this.resolvingClass;
        }

        ServletConfig cfg = (ServletConfig) getPageObject(PageContext.CONFIG);
        ServletContext sc = cfg.getServletContext();

        String basePath = (String)getJspContext().getAttribute("_basePath", PageContext.REQUEST_SCOPE);
        for (Class c = resolvingClass; c != Object.class; c = c.getSuperclass()) {
            String name = basePath + "/" + c.getName().replace('.', '/') + '/' + page;
            if (sc.getResource(name) != null) {
                // Tomcat returns a RequestDispatcher even if the JSP file doesn't exist.
                // so check if the resource exists first.
                RequestDispatcher disp = sc.getRequestDispatcher(name);
                if (disp != null) {
                    getJspContext().setAttribute("resolvingClass", resolvingClass, PageContext.REQUEST_SCOPE);
                    try {
                        HttpServletRequest request = (HttpServletRequest) getPageObject(PageContext.REQUEST);
                        disp.include(
                                request,
                                new Wrapper(
                                (HttpServletResponse) getPageObject(PageContext.RESPONSE),
                                new PrintWriter(getJspContext().getOut())));
                    } catch (ServletException e) {
                        throw new JspException(e);
                    } finally {
                        getJspContext().setAttribute("resolvingClass", oldResolvingClass, PageContext.REQUEST_SCOPE);
                    }
                    return;
                }
            }
        }

        throw new JspException("Unable to find '" + page + "' for " + resolvingClass);
    }
}

class Wrapper extends HttpServletResponseWrapper {

    private final PrintWriter pw;

    public Wrapper(HttpServletResponse httpServletResponse, PrintWriter w) {
        super(httpServletResponse);
        this.pw = w;
    }

    public PrintWriter getWriter() throws IOException {
        return pw;
    }
}