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How do I send nested json POST request in java using jersey?

I am using a document converter api called cloudconvert. They don't have an official java library, but a third party java option. I needed a little customization so I cloned the github project and added it to my project. I am sending cloudconvert a .epub file and getting a .pdf file in return. If I use the default settings it works without issue and properly converts my .epub to a .pdf. Here is the code that makes it happen.
Here is what triggers the conversion:
// Create service object
CloudConvertService service = new CloudConvertService("api-key");
// Create conversion process
ConvertProcess process = service.startProcess(convertFrom, convertTo);
// Perform conversion
//convertFromFile is a File object with a .epub extension
process.startConversion(convertFromFile);
// Wait for result
ProcessStatus status;
waitLoop:
while (true) {
status = process.getStatus();
switch (status.step) {
case FINISHED:
break waitLoop;
case ERROR:
throw new RuntimeException(status.message);
}
// Be gentle
Thread.sleep(200);
}
//Download result
service.download(status.output.url, convertToFile);
//lean up
process.delete();
startConversion() calls:
public void startConversion(File file) throws ParseException, FileNotFoundException, IOException {
if (!file.exists()) {
throw new FileNotFoundException("File not found: " + file);
}
startConversion(new FileDataBodyPart("file", file));
}
Which calls this to actually send the POST request using jersey:
private void startConversion(BodyPart bodyPart) {
if (args == null) {
throw new IllegalStateException("No conversion arguments set.");
}
MultiPart multipart = new FormDataMultiPart()
.field("input", "upload")
.field("outputformat", args.outputformat)
.bodyPart(bodyPart);
//root is a class level WebTarget object
root.request(MediaType.APPLICATION_JSON).post(Entity.entity(multipart, multipart.getMediaType()));
}
Up to this point everything is working. My problem is that the when the conversion happens the .pdf that returns has very small margins. cloudconvert provides a way to change those margins. You can send in an optional json param converteroptions and set the margins manually. I have tested this out using postman and it works without issue, I was able to get a properly formatted margin document. So know this is possible. Here is the POSTMAN info I used:
#POST : https://host123d1qo.cloudconvert.com/process/WDK9Yq0z1xso6ETgvpVQ
Headers: 'Content-Type' : 'application/json'
Body:
{
"input": "base64",
"file": "0AwAAIhMAAAAA", //base64 file string that is much longer than this
"outputformat": "pdf",
"converteroptions": {
"margin_bottom": 75,
"margin_top": 75,
"margin_right": 50,
"margin_left": 50
}
}
Here are my attempts at getting the POST request formatted properly, I'm just not very experienced with jersey and the couple of answers I did find on stackoverflow didn't work for me.
Attempt 1, I tried adding the json string as a Multipart.field. It didn't give me any errors and still returned a converted .pdf file, but the margins didn't get changed so I must not be sending it back right.
private void startConversion(BodyPart bodyPart) {
String jsonString = "{\"margin_bottom\":75,\"margin_top\":75,\"margin_right\":50,\"margin_left\":50}";
MultiPart multipart = new FormDataMultiPart()
.field("input", "upload")
.field("outputformat", args.outputformat)
.field("converteroptions", jsonString)
.bodyPart(bodyPart);
root.request(MediaType.APPLICATION_JSON).post(Entity.entity(multipart, multipart.getMediaType()));
}
Attempt 2, when I had it working in POSTMAN it was using the 'input' type as 'base64' so I tried changing it to that but it this time it doesn't return anything at all, no request errors, just a timeout error at the 5 minute mark.
//I pass in a File object rather than the bodypart object.
private void startConversion(File file) {
byte[] encoded1 = Base64.getEncoder().encode(FileUtils.readFileToByteArray(file));
String encoded64 = new String(encoded1, StandardCharsets.US_ASCII);
String jsonString = "{\"margin_bottom\":75,\"margin_top\":75,\"margin_right\":50,\"margin_left\":50}";
MultiPart multipart = new FormDataMultiPart()
.field("input", "base64")
.field("outputformat", args.outputformat)
.field("file", encoded64)
.field("converteroptions", jsonString);
root.request(MediaType.APPLICATION_JSON).post(Entity.entity(multipart, multipart.getMediaType()));
}
Attempt 3, after some googling on how to properly send jersey json post requests I changed the format. This time it returned a 400 bad request error.
private void startConversionPDF(File file) throws IOException {
byte[] encoded1 = Base64.getEncoder().encode(FileUtils.readFileToByteArray(file));
String encoded64 = new String(encoded1, StandardCharsets.US_ASCII);
String jsonString = "{\"input\":\"base64\",\"file\":\"" + encoded64 + "\",\"outputformat\":\"pdf\",\"converteroptions\":{\"margin_bottom\":75,\"margin_top\":75,\"margin_right\":50,\"margin_left\":50}}";
root.request(MediaType.APPLICATION_JSON).post(Entity.json(jsonString));
}
Attempt 4, Someone said you don't need to manually use a jsonString you should use serializable java beans. So I created the corresponding classes and made the request like shown below. Same 400 bad request error.
#XmlRootElement
public class PDFConvert implements Serializable {
private String input;
private String file;
private String outputformat;
private ConverterOptions converteroptions;
//with the a default constructor and getters/setters for all
}
#XmlRootElement
public class ConverterOptions implements Serializable {
private int margin_bottom;
private int margin_top;
private int margin_left;
private int margin_right;
//with the a default constructor and getters/setters for all
}
private void startConversionPDF(File file) throws IOException {
byte[] encoded1 = Base64.getEncoder().encode(FileUtils.readFileToByteArray(file));
String encoded64 = new String(encoded1, StandardCharsets.US_ASCII);
PDFConvert data = new PDFConvert();
data.setInput("base64");
data.setFile(encoded64);
data.setOutputformat("pdf");
ConverterOptions converteroptions = new ConverterOptions();
converteroptions.setMargin_top(75);
converteroptions.setMargin_bottom(75);
converteroptions.setMargin_left(50);
converteroptions.setMargin_right(50);
data.setConverteroptions(converteroptions);
root.request(MediaType.APPLICATION_JSON).post(Entity.json(data));
}
I know this is quite the wall of text, but I wanted to show all the different things I tried so that I wouldn't waste anyone's time. Thank you for any help or ideas you might have to make this work. I really want to make it work with jersey because I have several other conversions I do that work perfectly, they just don't need any converteroptions. Also I know its possible because it works when manually running the process through POSTMAN.
Cloudconvert api documentation for starting a conversion
Github repo with the recommended 3rd party java library I am using/modifying

I finally figured it out. Hours of trial and error. Here is the code that did it:
private void startConversionPDF(File file) throws IOException {
if (args == null) {
throw new IllegalStateException("No conversion arguments set.");
}
PDFConvert data = new PDFConvert();
data.setInput("upload");
data.setOutputformat("pdf");
ConverterOptions converteroptions = new ConverterOptions();
converteroptions.setMargin_top(60);
converteroptions.setMargin_bottom(60);
converteroptions.setMargin_left(30);
converteroptions.setMargin_right(30);
data.setConverteroptions(converteroptions);
MultiPart multipart = new FormDataMultiPart()
.bodyPart(new FormDataBodyPart("json", data, MediaType.APPLICATION_JSON_TYPE))
.bodyPart(new FileDataBodyPart("file", file));
root.request(MediaType.APPLICATION_JSON).post(Entity.entity(multipart, multipart.getMediaType()));
}

Mocking/Testing HTTP Get Request

I'm trying to write unit tests for my program and use mock data. I'm a little confused on how to intercept an HTTP Get request to a URL.
My program calls a URL to our API and it is returned a simple XML file. I would like the test to instead of getting the XML file from the API online to receive a predetermined XML file from me so that I can compare the output to the expected output and determine if everything is working correctly.
I was pointed to Mockito and have been seeing many different examples such as this SO post, How to use mockito for testing a REST service? but it's not becoming clear to me how to set it all up and how to mock the data (i.e., return my own xml file whenever the call to the URL is made).
The only thing I can think of is having another program made that's running locally on Tomcat and in my test pass a special URL that calls the locally running program on Tomcat and then return the xml file that I want to test with. But that just seems like overkill and I don't think that would be acceptable. Could someone please point me in the right direction.
private static InputStream getContent(String uri) {
HttpURLConnection connection = null;
try {
URL url = new URL(uri);
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setRequestProperty("Accept", "application/xml");
return connection.getInputStream();
} catch (MalformedURLException e) {
LOGGER.error("internal error", e);
} catch (IOException e) {
LOGGER.error("internal error", e);
} finally {
if (connection != null) {
connection.disconnect();
}
}
return null;
}
I am using Spring Boot and other parts of the Spring Framework if that helps.

Part of the problem is that you're not breaking things down into interfaces. You need to wrap getContent into an interface and provide a concrete class implementing the interface. This concrete class will then
need to be passed into any class that uses the original getContent. (This is essentially dependency inversion.) Your code will end up looking something like this.
public interface IUrlStreamSource {
InputStream getContent(String uri)
}
public class SimpleUrlStreamSource implements IUrlStreamSource {
protected final Logger LOGGER;
public SimpleUrlStreamSource(Logger LOGGER) {
this.LOGGER = LOGGER;
}
// pulled out to allow test classes to provide
// a version that returns mock objects
protected URL stringToUrl(String uri) throws MalformedURLException {
return new URL(uri);
}
public InputStream getContent(String uri) {
HttpURLConnection connection = null;
try {
Url url = stringToUrl(uri);
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setRequestProperty("Accept", "application/xml");
return connection.getInputStream();
} catch (MalformedURLException e) {
LOGGER.error("internal error", e);
} catch (IOException e) {
LOGGER.error("internal error", e);
} finally {
if (connection != null) {
connection.disconnect();
}
}
return null;
}
}
Now code that was using the static getContent should go through a IUrlStreamSource instances getContent(). You then provide to the object that you want to test a mocked IUrlStreamSource rather than a SimpleUrlStreamSource.
If you want to test SimpleUrlStreamSource (but there's not much to test), then you can create a derived class that provides an implementation of stringToUrl that returns a mock (or throws an exception).

The other answers in here advise you to refactor your code to using a sort of provider which you can replace during your tests - which is the better approach.
If that isn't a possibility for whatever reason you can install a custom URLStreamHandlerFactory that intercepts the URLs you want to "mock" and falls back to the standard implementation for URLs that shouldn't be intercepted.
Note that this is irreversible, so you can't remove the InterceptingUrlStreamHandlerFactory once it's installed - the only way to get rid of it is to restart the JVM. You could implement a flag in it to disable it and return null for all lookups - which would produce the same results.
URLInterceptionDemo.java:
public class URLInterceptionDemo {
private static final String INTERCEPT_HOST = "dummy-host.com";
public static void main(String[] args) throws IOException {
// Install our own stream handler factory
URL.setURLStreamHandlerFactory(new InterceptingUrlStreamHandlerFactory());
// Fetch an intercepted URL
printUrlContents(new URL("http://dummy-host.com/message.txt"));
// Fetch another URL that shouldn't be intercepted
printUrlContents(new URL("http://httpbin.org/user-agent"));
}
private static void printUrlContents(URL url) throws IOException {
try(InputStream stream = url.openStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(stream))) {
String line;
while((line = reader.readLine()) != null) {
System.out.println(line);
}
}
}
private static class InterceptingUrlStreamHandlerFactory implements URLStreamHandlerFactory {
#Override
public URLStreamHandler createURLStreamHandler(final String protocol) {
if("http".equalsIgnoreCase(protocol)) {
// Intercept HTTP requests
return new InterceptingHttpUrlStreamHandler();
}
return null;
}
}
private static class InterceptingHttpUrlStreamHandler extends URLStreamHandler {
#Override
protected URLConnection openConnection(final URL u) throws IOException {
if(INTERCEPT_HOST.equals(u.getHost())) {
// This URL should be intercepted, return the file from the classpath
return URLInterceptionDemo.class.getResource(u.getHost() + "/" + u.getPath()).openConnection();
}
// Fall back to the default handler, by passing the default handler here we won't end up
// in the factory again - which would trigger infinite recursion
return new URL(null, u.toString(), new sun.net.www.protocol.http.Handler()).openConnection();
}
}
}
dummy-host.com/message.txt:
Hello World!
When run, this app will output:
Hello World!
{
"user-agent": "Java/1.8.0_45"
}
It's pretty easy to change the criteria of how you decide which URLs to intercept and what you return instead.

The answer depends on what you are testing.
If you need to test the processing of the InputStream
If getContent() is called by some code that processes the data returned by the InputStream, and you want to test how the processing code handles specific sets of input, then you need to create a seam to enable testing. I would simply move getContent() into a new class, and inject that class into the class that does the processing:
public interface ContentSource {
InputStream getContent(String uri);
}
You could create a HttpContentSource that uses URL.openConnection() (or, better yet, the Apache HttpClientcode).
Then you would inject the ContentSource into the processor:
public class Processor {
private final ContentSource contentSource;
#Inject
public Processor(ContentSource contentSource) {
this.contentSource = contentSource;
}
...
}
The code in Processor could be tested with a mock ContentSource.
If you need to test the fetching of the content
If you want to make sure that getContent() works, you could create a test that starts a lightweight in-memory HTTP server that serves the expected content, and have getContent() talk to that server. That does seem overkill.
If you need to test a large subset of the system with fake data
If you want to make sure things work end to end, write an end to end system test. Since you indicated you use Spring, you can use Spring to wire together parts of the system (or to wire the entire system, but with different properties). You have two choices
Have the system test start a local HTTP server, and when you have your test create your system, configure it to talk to that server. See the answers to this question for ways to start the HTTP server.
Configure spring to use a fake implementation of ContentSource. This gets you slightly less confidence that everything works end-to-end, but it will be faster and less flaky.

Java : Using Spring remoting for getting objects from server

I am working on a JavaSE application in which I would like to connect to a Spring-MVC based server to get List of objects, Objects itself. I looked up on net, and came upon JSON. While I agree that it is working, but it is very inefficient as I have to go through the 2 while loops and seems not so sophisticated. For this reason I researched and found out I can use Spring remoting to achieve the task.
One thing I would like to do is to send over objects directly, instead of converting them by JSON, and sending.
I am pasting my code below for what I have with JSON, I would appreciate if I know this seems more better or is Spring remoting more sophisticated in long term too. A replacement code for the client side would be nice. Thanks.
Client code :
public void getCanvas(){
JsonFactory jsonFactory = new JsonFactory();
String canvas = "";
try {
JsonParser jsonParser = jsonFactory.createJsonParser(new URL(canvasURL));
JsonToken token = jsonParser.nextToken();
while (token!=JsonToken.START_ARRAY && token!=null){
token = jsonParser.nextToken();
if(token==null){break;}
System.out.println("Token is "+jsonParser.getText());
}
while (token!=JsonToken.END_ARRAY){
token = jsonParser.nextToken();
if(token == JsonToken.START_OBJECT){
canvas = jsonParser.toString();
System.out.println("Canvas is "+canvas);
}
}
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("Canvas is "+canvas);
}
Server code :
#RequestMapping(value = "/getcanvas",method = RequestMethod.GET)
public #ResponseBody String getCanvasforFX(){
System.out.println("Canvas was requested");
Canvas canvas = this.canvasService.getCanvasById(10650);
canvas.setCanvasimage(null);
ObjectMapper objectMapper = new ObjectMapper();
try {
System.out.println("Canvas value is "+objectMapper.writeValueAsString(canvas));
return objectMapper.writeValueAsString(canvas);
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
In the client-code I am getting the information, but again I have to read the fields, set them in object and update the UI, even though I am programming the server also, I want to directly receive an object, and cut out the middle-man(JSON). Thanks.

Java Webdav File Synchronization

I have a cloud storage at strato namely hidrive. It uses the webdav protocol. Note that it's based on HTTP. The client application they provide is poor and buggy so I tried various other tools for synchronization but none just worked the way I need it.
I'm therefore trying to implement it in Java using the Sardine project. Is there any code for hard-copying a local source folder to an external cloud folder? I haven't found anything in that direction.
The following code is supposed to upload the file...
Sardine sardine = SardineFactory.begin("username", "password");
InputStream fis = new FileInputStream(new File("some/file/test.txt"));
sardine.put("https://webdav.hidrive.strato.com/users/username/Backup", fis);
... but throws an exception instead:
Exception in thread "main" com.github.sardine.impl.SardineException: Unexpected response (301 Moved Permanently)
at com.github.sardine.impl.handler.ValidatingResponseHandler.validateResponse(ValidatingResponseHandler.java:48)
at com.github.sardine.impl.handler.VoidResponseHandler.handleResponse(VoidResponseHandler.java:34)
at com.github.sardine.impl.handler.VoidResponseHandler.handleResponse(VoidResponseHandler.java:1)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:218)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:160)
at com.github.sardine.impl.SardineImpl.execute(SardineImpl.java:828)
at com.github.sardine.impl.SardineImpl.put(SardineImpl.java:755)
at com.github.sardine.impl.SardineImpl.put(SardineImpl.java:738)
at com.github.sardine.impl.SardineImpl.put(SardineImpl.java:726)
at com.github.sardine.impl.SardineImpl.put(SardineImpl.java:696)
at com.github.sardine.impl.SardineImpl.put(SardineImpl.java:689)
at com.github.sardine.impl.SardineImpl.put(SardineImpl.java:682)
at com.github.sardine.impl.SardineImpl.put(SardineImpl.java:676)
Printing out the folders in that directory works so the connection/ authentication did succeed:
List<DavResource> resources = sardine.list("https://webdav.hidrive.strato.com/users/username/Backup");
for (DavResource res : resources)
{
System.out.println(res);
}
Please either help me fix my code or link me to some file synchronization library that works for my purpose.

Sardine uses (internally) HttpClient. There is similar question here where you can find an answer Httpclient 4, error 302. How to redirect?.

Try converting the InputStream obj into byte array before you call put(). Something like the below,
byte[] fisByte = IOUtils.toByteArray(fis);
sardine.put("https://webdav.hidrive.strato.com/users/username/Backup", fisByte);
It worked for me. Let me know.

I had to extend the "org.apache.http.impl.client.LaxRedirectStrategy" and also the getRedirect() Method of org.apache.http.impl.client.DefaultRedirectStrategy with a treatment of the needed methods: PUT, MKOL, etc. . By default only GET is redirected.
It looks like this:
private static final String[] REDIRECT_METHODS = new String[] { HttpGet.METHOD_NAME, HttpPost.METHOD_NAME, HttpHead.METHOD_NAME, HttpPut.METHOD_NAME, HttpDelete.METHOD_NAME, HttpMkCol.METHOD_NAME };
isRedirectable-Method
for (final String m : REDIRECT_METHODS) {
if (m.equalsIgnoreCase(method)) {
System.out.println("isRedirectable true");
return true;
}
}
return method.equalsIgnoreCase(HttpPropFind.METHOD_NAME);
getRedirect-Method:
final URI uri = getLocationURI(request, response, context);
final String method = request.getRequestLine().getMethod();
if (method.equalsIgnoreCase(HttpHead.METHOD_NAME)) {
return new HttpHead(uri);
} else if (method.equalsIgnoreCase(HttpGet.METHOD_NAME)) {
return new HttpGet(uri);
} else if (method.equalsIgnoreCase(HttpPut.METHOD_NAME)) {
HttpPut httpPut = new HttpPut(uri);
httpPut.setEntity(((HttpEntityEnclosingRequest) request).getEntity());
return httpPut;
} else if (method.equalsIgnoreCase("MKCOL")) {
return new HttpMkCol(uri);
} else if (method.equalsIgnoreCase("DELETE")) {
return new HttpDelete(uri);
} else {
final int status = response.getStatusLine().getStatusCode();
if (status == HttpStatus.SC_TEMPORARY_REDIRECT) {
return RequestBuilder.copy(request).setUri(uri).build();
} else {
return new HttpGet(uri);
}
}
That worked for me.

URLConnection created through OkHttp has useCache set to false

I am using the Kohsuke GitHub-API to connect to the GitHub from my Java (server-side) application and I wanted to use the OkHttp's ability to cache responses from the GitHub. This worked perfectly when I wrote a test for it, but it doesn't work in the application itself and I don't have a clue why that is. I have managed to trace the problem back to the creation of the URLConnection object that is created with its useCache variable set to false, but I cannot figure out why. Does it maybe have something to do with the server configuration or something like that?
I would appreciate any ideas or even a nudge in any direction, because frankly I don't have any ideas left... Thanks
Provider:
public class GitHubProvider implements Provider<GitHub> {
#Override
public GitHub get() {
GitHub gitHub = null;
HttpResponseCache cache = null;
OkHttpClient okHttpClient = new OkHttpClient();
File cacheDir = new File(System.getProperty("java.io.tmpdir"), UUID.randomUUID().toString());
try {
cache = new HttpResponseCache(cacheDir, 10L * 1024 * 1024);
} catch (IOException e) {
// NOTHING
}
okHttpClient.setResponseCache(cache);
try {
gitHub = GitHub.connectUsingPassword("user", "password");
} catch (Exception e) {
// NOTHING
}
gitHub.setConnector(new OkHttpConnector(okHttpClient));
return gitHub;
}
}
Test (works):
#RunWith(JukitoRunner.class)
public class SoftwareComponentServiceTest {
public static class Module extends TestModule {
#Override
protected void configureTest() {
bind(GitHub.class).toProvider(GitHubProvider.class);
}
}
#Inject
GitHub gitHub;
#Test
public void testInjectedGitHubResponseCache() {
try {
GHUser ghUser = gitHub.getUser("user");
GHRepository repository = ghUser.getRepository("repository");
int limit = gitHub.getRateLimit().remaining;
repository.getFileContent("README.md");
assertEquals(limit - 1, gitHub.getRateLimit().remaining);
repository.getFileContent("README.md");
assertEquals(limit - 1, gitHub.getRateLimit().remaining);
} catch (IOException e) {
e.printStackTrace();
}
}
}
Service that is used in the application (doesn't work):
#Singleton
#RequiresAuthentication
public class SoftwareComponentService {
#Inject
GitHub gitHub;
public List<SoftwareComponent> findAll() {
List<SoftwareComponent> softwareComponentList = new ArrayList<SoftwareComponent>();
try {
GHUser ghUser = gitHub.getUser("user");
List<GHRepository> repositories = ghUser.listRepositories().asList();
for (int i = 0; i < repositories.size(); i++) {
GHRepository repository = repositories.get(i);
if (!repository.getName().startsWith("sc_")) {
continue;
}
softwareComponentList.add(new SoftwareComponent(repository.getName(), repository.getDescription()));
}
} catch (IOException e) {
// NOTHING
}
return softwareComponentList;
}
}

The reason
The URLConnection object is created with its useCache variable set to false because its defaultUseCaches variable is also set to false by the Tomcat server at the time of initialization. Tomcat does this through its JreMemoryLeakPreventionListener class because reading resources from JAR files using java.net.URLConnections can sometimes result in the JAR file being locked (urlCacheProtection variable). The workaround they implemented to solve this problem was to disable URLConnection caching by default (!?!?).
The solution
The workaround to this workaround is to create a dummy URLConnection and use its setDefaultUseCaches() method to change the default value of every subsequently created URLConnection (as suggested by Jesse Wilson).
URL url = new URL("jar:file://dummy.jar!/");
URLConnection uConn = url.openConnection();
uConn.setDefaultUseCaches(true);
Big thanks to Jesse Wilson for pointing me in the right direction!

There's an insane method called URLConnection.setDefaultUseCaches() that could be doing it globally. That's an instance method that works like a static method: it sets the property for everyone.