edu.unc.lib.dl.admin.controller.RESTProxyController.java Source code

Introduction

Here is the source code for edu.unc.lib.dl.admin.controller.RESTProxyController.java

Source

/**
 * Copyright 2008 The University of North Carolina at Chapel Hill
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package edu.unc.lib.dl.admin.controller;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.util.Enumeration;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.lang.NotImplementedException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import edu.unc.lib.dl.acl.util.GroupsThreadStore;
import edu.unc.lib.dl.httpclient.HttpClientUtil;

/**
 * @author Pedro Assuncao (assuncas@gmail.com)
 * @May 26, 2009
 * 
 */
@Controller
public class RESTProxyController {
    private static final Log log = LogFactory.getLog(RESTProxyController.class);
    @Autowired
    String servicesUrl = null;

    public String getServicesUrl() {
        return servicesUrl;
    }

    public void setServicesUrl(String servicesUrl) {
        this.servicesUrl = servicesUrl;
    }

    @RequestMapping(value = { "/services/rest", "/services/rest/*", "/services/rest/**/*" })
    public final void proxyAjaxCall(HttpServletRequest request, HttpServletResponse response) throws IOException {
        log.debug("Prepending service url " + this.servicesUrl + " to " + request.getRequestURI());
        String url = request.getRequestURI().replaceFirst(".*/services/rest/?", this.servicesUrl);
        if (request.getQueryString() != null)
            url = url + "?" + request.getQueryString();

        OutputStreamWriter writer = new OutputStreamWriter(response.getOutputStream());
        HttpClient client = new HttpClient();
        HttpMethod method = null;
        try {
            log.debug("Proxying ajax request to services REST api via " + request.getMethod());
            // Split this according to the type of request
            if (request.getMethod().equals("GET")) {
                method = new GetMethod(url);
            } else if (request.getMethod().equals("POST")) {
                method = new PostMethod(url);
                // Set any eventual parameters that came with our original
                // request (POST params, for instance)
                Enumeration<String> paramNames = request.getParameterNames();
                while (paramNames.hasMoreElements()) {
                    String paramName = paramNames.nextElement();
                    ((PostMethod) method).setParameter(paramName, request.getParameter(paramName));
                }
            } else {
                throw new NotImplementedException("This proxy only supports GET and POST methods.");
            }

            // Forward the user's groups along with the request
            method.addRequestHeader(HttpClientUtil.SHIBBOLETH_GROUPS_HEADER, GroupsThreadStore.getGroupString());
            method.addRequestHeader("On-Behalf-Of", GroupsThreadStore.getUsername());

            // Execute the method
            client.executeMethod(method);

            // Set the content type, as it comes from the server
            Header[] headers = method.getResponseHeaders();
            for (Header header : headers) {
                if ("Content-Type".equalsIgnoreCase(header.getName())) {
                    response.setContentType(header.getValue());
                }
            }
            try (InputStream responseStream = method.getResponseBodyAsStream()) {
                int b;
                while ((b = responseStream.read()) != -1) {
                    response.getOutputStream().write(b);
                }
            }
            response.getOutputStream().flush();
        } catch (HttpException e) {
            writer.write(e.toString());
            throw e;
        } catch (IOException e) {
            e.printStackTrace();
            writer.write(e.toString());
            throw e;
        } finally {
            if (method != null)
                method.releaseConnection();
        }
    }
}