我们有如下要求
- 集成系统需要调用我们的服务
- 我们的服务需要调用 FlipKart 服务并在请求中附加令牌
- 将响应返回到集成系统
上面应该可以无缝地用于 GET 和 PUT 请求。
我在 Eclipse 中开发了一个 REST 项目，并且能够将 GET 和 PUT 响应返回到 Integration。
不过问题很少
- 在 Get Requests 中，我们显式设置标头并为 appication/json 生成注释。我们如何为所有类型的请求设置它？
- 在 Post Response 中，我们没有得到完整的响应，并且我们无法在响应中设置应用程序类型（不确定如何！）
- 如果应用程序类型是 pdf、img 等，所有这些请求都会失败。
有人可以帮忙吗？
到目前为止实现的代码：
@GET
@Path("{pathvalue : (.+)?}")
@Produces("{application/json;application/octet-stream}")
public String getFlipKartResponse(@Context UriInfo uriInfo, @PathParam("pathvalue") String pathValue, @Context HttpServletRequest request) throws ClassNotFoundException,IOException {
String methodName = "getFlipKartResponse";
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.entering(CLASSNAME, methodName);
}
MultivaluedMap<String, String> queryParams = uriInfo.getQueryParameters();
//if(null == flipkartUrl || flipkartUrl.isEmpty())
flipkartUrl = config.getProperty(ServiceConstants.FLIPKART_URL);
String queryParam = new String();
Iterator<String> iterator = queryParams.keySet().iterator();
while (iterator.hasNext()) {
String parameter = iterator.next();
queryParam = queryParam.concat(parameter + ServiceConstants.EQUALS + queryParams.getFirst(parameter) + ServiceConstants.AMPERSAND);
}
String modifiedflipkartUrl = flipkartUrl.concat(pathValue).concat(ServiceConstants.QUESTION).concat(queryParam);
if (modifiedflipkartUrl.endsWith(ServiceConstants.QUESTION) || modifiedflipkartUrl.endsWith(ServiceConstants.AMPERSAND)) {
modifiedflipkartUrl = modifiedflipkartUrl.substring(0, modifiedflipkartUrl.length()-1);
}
LOGGER.log(Level.INFO, "Flipkart URL framed : "+ modifiedflipkartUrl);
url = new URL(modifiedflipkartUrl);
connection = (HttpsURLConnection) url.openConnection();
setHeadersInConnectionObject(url, connection, request.getMethod());
return handleInvalidToken(connection.getResponseCode(), request);
}
private String handleInvalidToken(int responseCode, HttpServletRequest request){
try {
if (connection.getResponseCode() == 401) {
LOGGER.log(Level.INFO, "ResponseCode " + connection.getResponseCode());
connection.disconnect();
regenerateAccessToken();
connection = (HttpsURLConnection) url.openConnection();
setHeadersInConnectionObject(url, connection, request.getMethod());
inputLine = new BufferedReader(new InputStreamReader(connection.getInputStream()));
} else if (connection.getResponseCode() == 200) {
inputLine = new BufferedReader(new InputStreamReader(connection.getInputStream()));
} else {
inputLine = new BufferedReader(new InputStreamReader(connection.getErrorStream()));
}
String responseInputLine;
String responseMessage = "";
while (null != (responseInputLine = inputLine.readLine())) {
responseMessage = responseMessage + responseInputLine;
}
inputLine.close();
connection.disconnect();
return responseMessage;
} catch (Exception e) {
LOGGER.log(Level.SEVERE,"Exception occured while calling service.Please try again after sometime : ", e);
return this.handleErrorResponse("Exception occured while calling service.Please try again after sometime.");
}
}
private void regenerateAccessToken() throws ClassNotFoundException, IOException, SQLException{
TokenGenerator tokenGenerator = new TokenGenerator();
accessToken= tokenGenerator.getAccessToken();
}
@POST
@Path("{pathvalue : (.+)?}")
@Produces({"application/json;application/octet-stream"})
public String getFlipKartPostResponse(@Context UriInfo uriInfo, @PathParam("pathvalue") String pathValue,@Context HttpServletRequest requestBody) throws ClassNotFoundException,IOException, SQLException {
String methodName = "getFlipKartPostResponse";
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.entering(CLASSNAME, methodName);
}
//if(null == flipkartUrl || flipkartUrl.isEmpty())
flipkartUrl = config.getProperty(ServiceConstants.FLIPKART_URL);
String modifiedflipkartUrl = flipkartUrl + pathValue;
url = new URL(modifiedflipkartUrl);
LOGGER.log(Level.INFO, "Flipkart URL framed : "+ flipkartUrl);
connection = (HttpsURLConnection) url.openConnection();
setHeadersInConnectionObject(url, connection, requestBody.getMethod());
InputStream requestInputStream = requestBody.getInputStream();
String reqBody = getStringFromInputStream(requestBody.getInputStream());
OutputStream outputStream = connection.getOutputStream();
outputStream.write(reqBody.getBytes());
outputStream.flush();
if(connection.getResponseCode() == 401) {
connection.disconnect();
regenerateAccessToken();
connection = (HttpsURLConnection) url.openConnection();
setHeadersInConnectionObject(url, connection, requestBody.getMethod());
outputStream = connection.getOutputStream();
outputStream.write(reqBody.getBytes());
outputStream.flush();
}
String output = getStringFromInputStream (connection.getInputStream());
connection.disconnect();
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.exiting(CLASSNAME, methodName);
}
return output;
}
private static String getStringFromInputStream(InputStream is) {
String methodName = "getStringFromInputStream";
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.entering(CLASSNAME, methodName);
}
BufferedReader br = null;
StringBuilder sb = new StringBuilder();
String line;
try {
br = new BufferedReader(new InputStreamReader(is));
while ((line = br.readLine()) != null) {
sb.append(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.exiting(CLASSNAME, methodName);
}
return sb.toString();
}
/**
* Method to generate the access token
* @return String - Access token
* @throws IOException
*/
private String getAccessToken() throws IOException {
if (null != accessToken) {
return accessToken;
} else {
url = getClass().getResource(ServiceConstants.ACCESS_TOKEN_CONFIG_PATH);
file = new File(url.getPath());
reader = new BufferedReader (new InputStreamReader (new FileInputStream (file), ServiceConstants.UTF_ENCODING));
accessToken = reader.readLine();
reader.close();
return accessToken;
}
}
/**
* Method to construct error response for exception scenario
* @param errorMessage
* @return
*/
private String handleErrorResponse(String errorMessage) {
String methodName = "handleErrorResponse";
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.entering(CLASSNAME, methodName);
}
JSONObject errorResponse = new JSONObject();
JSONArray errorMsg = new JSONArray();
errorResponse.put(ServiceConstants.STATUS, ServiceConstants.STATUS_FAILED);
errorResponse.put(ServiceConstants.ERROR_MESSAGE, errorMessage);
errorMsg.add(errorResponse);
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.exiting(CLASSNAME, methodName);
}
return errorResponse.toString();
}
/**
* Method to form the connection object
* @param url
* @param connection
* @param requestType
* @throws IOException
*/
private void setHeadersInConnectionObject(URL url, HttpsURLConnection connection, String requestType) throws IOException {
String methodName = "setHeadersInConnectionObject";
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.entering(CLASSNAME, methodName);
}
if (null == accessToken) {
getAccessToken();
}
connection.setRequestMethod(requestType);
connection.setRequestProperty(ServiceConstants.AUTHORIZATION, ServiceConstants.BEARER + accessToken);
connection.setDoOutput(true);
if (requestType.equals(ServiceConstants.REQUEST_TYPE_GET)) {
connection.setRequestProperty(ServiceConstants.ACCEPT_HEADER, ServiceConstants.ACCEPT_ALL);
//connection.setRequestProperty(ServiceConstants.ACCEPT_HEADER, ServiceConstants.APPLICATION_JSON);
}
if (requestType.equals(ServiceConstants.REQUEST_TYPE_POST)) {
connection.setRequestProperty(ServiceConstants.ACCEPT_HEADER, ServiceConstants.APPLICATION_JSON);
connection.setRequestProperty(ServiceConstants.CONTENT_TYPE_HEADER, ServiceConstants.APPLICATION_JSON);
//connection.setDoInput(true);
}
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.exiting(CLASSNAME, methodName);
}
}