org.openmrs.module.webservices.rest.web.v1_0.controller.BaseRestController.java Source code

Introduction

Here is the source code for org.openmrs.module.webservices.rest.web.v1_0.controller.BaseRestController.java

Source

/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.module.webservices.rest.web.v1_0.controller;

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

import org.apache.commons.lang.StringUtils;
import org.openmrs.api.APIAuthenticationException;
import org.openmrs.api.context.Context;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.openmrs.module.webservices.rest.SimpleObject;
import org.openmrs.module.webservices.rest.web.RestConstants;
import org.openmrs.module.webservices.rest.web.RestUtil;
import org.openmrs.module.webservices.validation.ValidationException;
import org.springframework.stereotype.Controller;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;

/**
 * Resource controllers should extend this base class to have standard exception handling done
 * automatically. (This is necessary to send error messages as HTTP statuses rather than just as
 * html content, as the core web application does.)
 */
@Controller
@RequestMapping(value = "/rest/**")
public class BaseRestController {

    private final int DEFAULT_ERROR_CODE = HttpServletResponse.SC_INTERNAL_SERVER_ERROR;

    private static final String DISABLE_WWW_AUTH_HEADER_NAME = "Disable-WWW-Authenticate";

    private final String DEFAULT_ERROR_DETAIL = "";

    private final Log log = LogFactory.getLog(getClass());

    /**
     * @should return unauthorized if not logged in
     * @should return forbidden if logged in
     */
    @ExceptionHandler(APIAuthenticationException.class)
    @ResponseBody
    public SimpleObject apiAuthenticationExceptionHandler(Exception ex, HttpServletRequest request,
            HttpServletResponse response) throws Exception {
        int errorCode;
        String errorDetail;
        if (Context.isAuthenticated()) {
            // user is logged in but doesn't have the relevant privilege -> 403 FORBIDDEN
            errorCode = HttpServletResponse.SC_FORBIDDEN;
            errorDetail = "User is logged in but doesn't have the relevant privilege";
        } else {
            // user is not logged in -> 401 UNAUTHORIZED
            errorCode = HttpServletResponse.SC_UNAUTHORIZED;
            errorDetail = "User is not logged in";
            if (shouldAddWWWAuthHeader(request)) {
                response.addHeader("WWW-Authenticate",
                        "Basic realm=\"OpenMRS at " + RestConstants.URI_PREFIX + "\"");
            }
        }
        response.setStatus(errorCode);
        return RestUtil.wrapErrorResponse(ex, errorDetail);
    }

    @ExceptionHandler(ValidationException.class)
    @ResponseBody
    public SimpleObject validationExceptionHandler(ValidationException validationException,
            HttpServletRequest request, HttpServletResponse response) {
        response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
        return RestUtil.wrapValidationErrorResponse(validationException);
    }

    @ExceptionHandler(Exception.class)
    @ResponseBody
    public SimpleObject handleException(Exception ex, HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        log.error(ex.getMessage(), ex);
        int errorCode = DEFAULT_ERROR_CODE;
        String errorDetail = DEFAULT_ERROR_DETAIL;
        ResponseStatus ann = ex.getClass().getAnnotation(ResponseStatus.class);
        if (ann != null) {
            errorCode = ann.value().value();
            if (StringUtils.isNotEmpty(ann.reason())) {
                errorDetail = ann.reason();
            }

        } else if (RestUtil.hasCause(ex, APIAuthenticationException.class)) {
            return apiAuthenticationExceptionHandler(ex, request, response);
        } else if (ex.getClass() == HttpRequestMethodNotSupportedException.class) {
            errorCode = HttpServletResponse.SC_METHOD_NOT_ALLOWED;
        }
        response.setStatus(errorCode);
        return RestUtil.wrapErrorResponse(ex, errorDetail);
    }

    private boolean shouldAddWWWAuthHeader(HttpServletRequest request) {
        return request.getHeader(DISABLE_WWW_AUTH_HEADER_NAME) == null
                || !request.getHeader(DISABLE_WWW_AUTH_HEADER_NAME).equals("true");
    }

    /**
     * It should be overridden if you want to expose resources under a different URL than /rest/v1.
     * 
     * @return the namespace
     */
    public String getNamespace() {
        return RestConstants.VERSION_1;
    }

    public String buildResourceName(String resource) {
        String namespace = getNamespace();

        if (StringUtils.isBlank(namespace)) {
            return resource;
        } else {
            if (namespace.startsWith("/")) {
                namespace = namespace.substring(1);
            }
            if (!namespace.endsWith("/")) {
                namespace += "/";
            }
            return namespace + resource;
        }
    }

}