Example usage for com.google.gson.stream JsonReader JsonReader

Introduction

In this page you can find the example usage for com.google.gson.stream JsonReader JsonReader.

Prototype

public JsonReader(Reader in)

Source Link

Document

Creates a new instance that reads a JSON-encoded stream from in .

Usage

From source file:com.example.endpoints.Echo.java

License:Apache License

public static void echo(MessageTranslator translator, HttpServletRequest req, HttpServletResponse resp)
        throws IOException {
    resp.addHeader("Content-Encoding", "application/json");

    try {/*from  www.  j  a v  a 2 s. co m*/
        JsonReader jsonReader = new JsonReader(req.getReader());
        Message message = translator.fromExternalToInternal(new Gson().fromJson(jsonReader, Map.class));
        performTask(message);
        new Gson().toJson(translator.fromInternalToExternal(message), resp.getWriter());
    } catch (JsonParseException je) {
        resp.setStatus(HttpServletResponse.SC_BAD_REQUEST);
        JsonObject error = new JsonObject();
        error.addProperty("code", HttpServletResponse.SC_BAD_REQUEST);
        error.addProperty("message", "Body was not valid JSON.");
        new Gson().toJson(error, resp.getWriter());
    }
}

From source file:com.example.endpoints.EchoServlet.java

License:Open Source License

@Override
public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
    resp.addHeader("Content-Encoding", "application/json");

    Object responseBody;/*from   w  w w  .  j  a  va 2s.com*/
    try {
        JsonReader jsonReader = new JsonReader(req.getReader());
        responseBody = new Gson().fromJson(jsonReader, Map.class);
    } catch (JsonParseException je) {
        resp.setStatus(HttpServletResponse.SC_BAD_REQUEST);
        JsonObject error = new JsonObject();
        error.addProperty("code", HttpServletResponse.SC_BAD_REQUEST);
        error.addProperty("message", "Body was not valid JSON.");
        responseBody = error;
    }

    new Gson().toJson(responseBody, resp.getWriter());
}

From source file:com.facebook.buck.httpserver.TracesHelper.java

License:Apache License

private Optional<String> parseCommandFrom(Path pathToTrace) {
    try (InputStream input = projectFilesystem.newFileInputStream(pathToTrace);
            JsonReader jsonReader = new JsonReader(new InputStreamReader(input))) {
        jsonReader.beginArray();/*from  www  .j  a v a2s .  c om*/
        Gson gson = new Gson();

        // Look through the first few elements to see if one matches the schema for an event that
        // contains the command that the user ran.
        for (int i = 0; i < 4; i++) {
            // If END_ARRAY is the next token, then there are no more elements in the array.
            if (jsonReader.peek().equals(JsonToken.END_ARRAY)) {
                break;
            }

            JsonObject json = gson.fromJson(jsonReader, JsonObject.class);
            Optional<String> command = tryToFindCommand(json);
            if (command.isPresent()) {
                return command;
            }
        }

        // Oh well, we tried.
        return Optional.absent();
    } catch (IOException e) {
        logger.error(e);
        return Optional.absent();
    }
}

From source file:com.facebook.buck.json.BuildFileToJsonParser.java

License:Apache License

/**
 * @param jsonReader That contains the JSON data.
 *///from ww  w . ja  va2  s.c o m
public BuildFileToJsonParser(Reader jsonReader) {
    this.gson = new Gson();
    this.reader = new JsonReader(jsonReader);

    // This is used to read one line at a time.
    reader.setLenient(true);
}

From source file:com.facebook.buck.json.RawParser.java

License:Apache License

/**
 * Consumes the next JSON map from the reader, parses it as a Java {@link Map} to return, and then
 * closes the reader.//ww  w.j  a  v a  2s .c om
 * <p>
 * <strong>Warning:</strong> This method closes the reader.
 */
@SuppressWarnings("unchecked")
public static Map<String, Object> parseFromReader(Reader reader) throws IOException {
    JsonReader jsonReader = new JsonReader(reader);
    try {
        JsonObject json = new Gson().fromJson(reader, JsonObject.class);
        Map<String, Object> map = (Map<String, Object>) toRawTypes(json);
        return Preconditions.checkNotNull(map);
    } finally {
        jsonReader.close();
    }
}

From source file:com.facebook.buck.shell.WorkerProcess.java

License:Apache License

public synchronized void ensureLaunchAndHandshake() throws IOException {
    if (handshakePerformed) {
        return;//w w w  .  ja  v a  2s.  c om
    }
    LOG.debug("Starting up process %d using command: \'%s\'", this.hashCode(),
            Joiner.on(' ').join(processParams.getCommand()));
    launchedProcess = executor.launchProcess(processParams);
    JsonWriter processStdinWriter = new JsonWriter(
            new BufferedWriter(new OutputStreamWriter(launchedProcess.getOutputStream())));
    JsonReader processStdoutReader = new JsonReader(
            new BufferedReader(new InputStreamReader(launchedProcess.getInputStream())));
    protocol = new WorkerProcessProtocolZero(executor, launchedProcess, processStdinWriter, processStdoutReader,
            stdErr);

    int messageID = currentMessageID.getAndAdd(1);
    LOG.debug("Sending handshake to process %d", this.hashCode());
    protocol.sendHandshake(messageID);
    LOG.debug("Receiving handshake from process %d", this.hashCode());
    protocol.receiveHandshake(messageID);
    handshakePerformed = true;
}

From source file:com.facebook.buck.util.trace.ChromeTraceParser.java

License:Apache License

/**
 * Parses a Chrome trace and stops parsing once all of the specified matchers have been
 * satisfied. This method parses only one Chrome trace event at a time, which avoids loading the
 * entire trace into memory.//w w w . j  a  va  2s  .  co  m
 * @param pathToTrace is a relative path [to the ProjectFilesystem] to a Chrome trace in the
 *     "JSON Array Format."
 * @param chromeTraceEventMatchers set of matchers this invocation of {@code parse()} is trying to
 *     satisfy. Once a matcher finds a match, it will not consider any other events in the trace.
 * @return a {@code Map} where every matcher that found a match will have an entry whose key is
 *     the matcher and whose value is the one returned by
 *     {@link ChromeTraceEventMatcher#test(JsonObject, String)} without the {@link Optional}
 *     wrapper.
 */
public Map<ChromeTraceEventMatcher<?>, Object> parse(Path pathToTrace,
        Set<ChromeTraceEventMatcher<?>> chromeTraceEventMatchers) throws IOException {
    Set<ChromeTraceEventMatcher<?>> unmatchedMatchers = new HashSet<>(chromeTraceEventMatchers);
    Preconditions.checkArgument(!unmatchedMatchers.isEmpty(), "Must specify at least one matcher");
    Map<ChromeTraceEventMatcher<?>, Object> results = new HashMap<>();

    try (InputStream input = projectFilesystem.newFileInputStream(pathToTrace);
            JsonReader jsonReader = new JsonReader(new InputStreamReader(input))) {
        jsonReader.beginArray();
        Gson gson = new Gson();

        featureSearch: while (true) {
            // If END_ARRAY is the next token, then there are no more elements in the array.
            if (jsonReader.peek().equals(JsonToken.END_ARRAY)) {
                break;
            }

            // Verify and extract the name property before invoking any of the matchers.
            JsonObject event = gson.fromJson(jsonReader, JsonObject.class);
            JsonElement nameEl = event.get("name");
            if (nameEl == null || !nameEl.isJsonPrimitive()) {
                continue;
            }
            String name = nameEl.getAsString();

            // Prefer Iterator to Iterable+foreach so we can use remove().
            for (Iterator<ChromeTraceEventMatcher<?>> iter = unmatchedMatchers.iterator(); iter.hasNext();) {
                ChromeTraceEventMatcher<?> chromeTraceEventMatcher = iter.next();
                Optional<?> result = chromeTraceEventMatcher.test(event, name);
                if (result.isPresent()) {
                    iter.remove();
                    results.put(chromeTraceEventMatcher, result.get());

                    if (unmatchedMatchers.isEmpty()) {
                        break featureSearch;
                    }
                }
            }
        }
    }

    // We could throw if !unmatchedMatchers.isEmpty(), but that might be overbearing.
    return results;
}

From source file:com.fb.resttest.AuthorListReader.java

@Override
public List<Author> readFrom(Class<List<Author>> type, Type genericType, Annotation[] annotations,
        MediaType mediaType, MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
        throws IOException, WebApplicationException {
    final Author[] authors = new Gson().fromJson(new JsonReader(new InputStreamReader(entityStream)),
            Author[].class);
    return Arrays.asList(authors);
}

From source file:com.fb.resttest.BookListReader.java

@Override
public List<Book> readFrom(Class<List<Book>> type, Type genericType, Annotation[] annotations,
        MediaType mediaType, MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
        throws IOException, WebApplicationException {
    final Book[] books = new Gson().fromJson(new JsonReader(new InputStreamReader(entityStream)), Book[].class);
    return Arrays.asList(books);
}

From source file:com.fb.resttest.BookReader.java

@Override
public Book readFrom(Class<Book> type, Type genericType, Annotation[] annotations, MediaType mediaType,
        MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
        throws IOException, WebApplicationException {
    return new Gson().fromJson(new JsonReader(new InputStreamReader(entityStream)), Book.class);
}