Java Code Examples for org.codehaus.jackson.JsonGenerator#writeStringField()

@Override
public void serialize(List<Map<Term, String>> value, JsonGenerator jgen, SerializerProvider provider)
  throws IOException {
  if ((value == null || value.isEmpty()) && provider.getConfig().isEnabled(Feature.WRITE_EMPTY_JSON_ARRAYS)) {
    jgen.writeStartArray();
    jgen.writeEndArray();
  } else {
    jgen.writeStartArray();
    for (Map<Term, String> extension : value) {
      jgen.writeStartObject();
      for (Entry<Term, String> entry : extension.entrySet()) {
        jgen.writeStringField(entry.getKey().qualifiedName(), entry.getValue());
      }
      jgen.writeEndObject();
    }
    jgen.writeEndArray();
  }
}
 

@Override
public void writeTo(Collection<Language> detected, Class<?> type, Type genericType, Annotation[] annotations,
        MediaType mediaType, MultivaluedMap<String,Object> httpHeaders, OutputStream entityStream)
        throws IOException, WebApplicationException {
    JsonGenerator jg = getJsonFactory().createJsonGenerator(entityStream);
    jg.writeStartArray();
    for(Language lang : detected){
        jg.writeStartObject();
        jg.writeStringField("lang", lang.getLang());
        if(lang.getProb() > 0){
            jg.writeNumberField("prob", lang.getProb());
        }
        jg.writeEndObject();
    }
    jg.writeEndArray();
    jg.close();
}
 

/**
 * Return String representation of enums as a JSON list.
 *
 * @param values the enums
 * @return String representation of enums as a JSON list
 * @throws IOException if parsing or writing fails
 */
public static String toJsonList(Enum[]... values) throws IOException {
  StringWriter sw = new StringWriter();
  JsonGenerator json = new JsonFactory().createJsonGenerator(sw).useDefaultPrettyPrinter();
  try {
    json.writeStartObject();
    for (int i = 0; i < values.length; i++) {
      Enum[] enumList = values[i];
      json.writeArrayFieldStart("Possibilities " + (i + 1));
      for (Enum value : enumList) {
        if (value != null) {
          json.writeStartObject();
          json.writeStringField("Name", value.name());
          json.writeEndObject();
        }
      }
      json.writeEndArray();
    }
    json.writeEndObject();
  } finally {
    IOUtils.closeStream(json);
  }
  return sw.toString();
}
 

/**
 * PATCH repo only accepts description and label updates, name is needed for URL creation, because of the special
 * ignore and property structure of the RepositoryDetails class this method just uses a json generator to write
 * the update json.
 */
public static String getUpdateJson(RepositoryDetails repositoryDetails) throws IOException {
    StringWriter writer = new StringWriter();
    JsonGenerator jGen = ObjectMapperHelper.get().getJsonFactory().createJsonGenerator(writer);
    jGen.writeStartObject();
    jGen.writeStringField("name", repositoryDetails.getName());
    jGen.writeStringField("desc", repositoryDetails.getDescription());
    if (repositoryDetails.getLabels().size() > 0) {
        jGen.writeArrayFieldStart("labels");
        for (String label : repositoryDetails.getLabels()) {
            jGen.writeString(label);
        }
        jGen.writeEndArray();
    }
    jGen.writeEndObject();
    jGen.close();
    writer.close();
    return writer.toString();
}
 

@Override
public void serialize(
    PropertyInfo propertyInfo, JsonGenerator jgen, SerializerProvider provider)
  throws IOException, JsonProcessingException
{
  if (provideDescription) {
    jgen.writeStartObject();
    jgen.writeStringField("value", propertyInfo.value);
    jgen.writeStringField("description", propertyInfo.description);
    jgen.writeEndObject();
  } else {
    jgen.writeString(propertyInfo.value);
  }
}
 

/**
 *  Writes out all the parameters and their properties (final and resource) to
 *  the given {@link Writer}
 *  The format of the output would be
 *  { "properties" : [ {key1,value1,key1.isFinal,key1.resource}, {key2,value2,
 *  key2.isFinal,key2.resource}... ] }
 *  It does not output the parameters of the configuration object which is
 *  loaded from an input stream.
 * @param out the Writer to write to
 * @throws IOException
 */
public static void dumpConfiguration(Configuration config,
    Writer out) throws IOException {
  JsonFactory dumpFactory = new JsonFactory();
  JsonGenerator dumpGenerator = dumpFactory.createJsonGenerator(out);
  dumpGenerator.writeStartObject();
  dumpGenerator.writeFieldName("properties");
  dumpGenerator.writeStartArray();
  dumpGenerator.flush();
  synchronized (config) {
    for (Entry<Object,Object> item: config.getProps().entrySet()) {
      dumpGenerator.writeStartObject();
      dumpGenerator.writeStringField("key", (String) item.getKey());
      dumpGenerator.writeStringField("value",
                                     config.get((String) item.getKey()));
      dumpGenerator.writeBooleanField("isFinal",
                                      config.finalParameters.contains(item.getKey()));
      String[] resources = config.updatingResource.get(item.getKey());
      String resource = UNKNOWN_RESOURCE;
      if(resources != null && resources.length > 0) {
        resource = resources[0];
      }
      dumpGenerator.writeStringField("resource", resource);
      dumpGenerator.writeEndObject();
    }
  }
  dumpGenerator.writeEndArray();
  dumpGenerator.writeEndObject();
  dumpGenerator.flush();
}
 

/**
 *  Writes out all the parameters and their properties (final and resource) to
 *  the given {@link Writer}
 *  The format of the output would be
 *  { "properties" : [ {key1,value1,key1.isFinal,key1.resource}, {key2,value2,
 *  key2.isFinal,key2.resource}... ] }
 *  It does not output the parameters of the configuration object which is
 *  loaded from an input stream.
 * @param out the Writer to write to
 * @throws IOException
 */
public static void dumpConfiguration(Configuration config,
    Writer out) throws IOException {
  JsonFactory dumpFactory = new JsonFactory();
  JsonGenerator dumpGenerator = dumpFactory.createJsonGenerator(out);
  dumpGenerator.writeStartObject();
  dumpGenerator.writeFieldName("properties");
  dumpGenerator.writeStartArray();
  dumpGenerator.flush();
  synchronized (config) {
    for (Entry<Object,Object> item: config.getProps().entrySet()) {
      dumpGenerator.writeStartObject();
      dumpGenerator.writeStringField("key", (String) item.getKey());
      dumpGenerator.writeStringField("value",
                                     config.get((String) item.getKey()));
      dumpGenerator.writeBooleanField("isFinal",
                                      config.finalParameters.contains(item.getKey()));
      String[] resources = config.updatingResource.get(item.getKey());
      String resource = UNKNOWN_RESOURCE;
      if(resources != null && resources.length > 0) {
        resource = resources[0];
      }
      dumpGenerator.writeStringField("resource", resource);
      dumpGenerator.writeEndObject();
    }
  }
  dumpGenerator.writeEndArray();
  dumpGenerator.writeEndObject();
  dumpGenerator.flush();
}
 

@Override
public void serialize(
    PropertyInfo propertyInfo, JsonGenerator jgen, SerializerProvider provider)
  throws IOException, JsonProcessingException
{
  if (provideDescription) {
    jgen.writeStartObject();
    jgen.writeStringField("value", propertyInfo.value);
    jgen.writeStringField("description", propertyInfo.description);
    jgen.writeEndObject();
  } else {
    jgen.writeString(propertyInfo.value);
  }
}
 

/**
 * Build a JSON entry from the parameters. This is public for testing.
 *
 * @param writer destination
 * @param loggerName logger name
 * @param timeStamp time_t value
 * @param level level string
 * @param threadName name of the thread
 * @param message rendered message
 * @param ti nullable thrown information
 * @return the writer
 * @throws IOException on any problem
 */
public Writer toJson(final Writer writer,
                     final String loggerName,
                     final long timeStamp,
                     final String level,
                     final String threadName,
                     final String message,
                     final ThrowableInformation ti) throws IOException {
  JsonGenerator json = factory.createJsonGenerator(writer);
  json.writeStartObject();
  json.writeStringField(NAME, loggerName);
  json.writeNumberField(TIME, timeStamp);
  Date date = new Date(timeStamp);
  json.writeStringField(DATE, dateFormat.format(date));
  json.writeStringField(LEVEL, level);
  json.writeStringField(THREAD, threadName);
  json.writeStringField(MESSAGE, message);
  if (ti != null) {
    //there is some throwable info, but if the log event has been sent over the wire,
    //there may not be a throwable inside it, just a summary.
    Throwable thrown = ti.getThrowable();
    String eclass = (thrown != null) ?
        thrown.getClass().getName()
        : "";
    json.writeStringField(EXCEPTION_CLASS, eclass);
    String[] stackTrace = ti.getThrowableStrRep();
    json.writeArrayFieldStart(STACK);
    for (String row : stackTrace) {
      json.writeString(row);
    }
    json.writeEndArray();
  }
  json.writeEndObject();
  json.flush();
  json.close();
  return writer;
}
 

private void writeHeaders(RecordWithMetadata<?> inputRecord, JsonGenerator generator)
    throws IOException {
  generator.writeStringField("mId", inputRecord.getMetadata().getGlobalMetadata().getId());

  if (!inputRecord.getMetadata().getRecordMetadata().isEmpty()) {
    generator.writeObjectField("rMd", inputRecord.getMetadata().getRecordMetadata());
  }
}
 

/**
 *  Writes out all the parameters and their properties (final and resource) to
 *  the given {@link Writer}
 *  The format of the output would be 
 *  { "properties" : [ {key1,value1,key1.isFinal,key1.resource}, {key2,value2,
 *  key2.isFinal,key2.resource}... ] } 
 *  It does not output the parameters of the configuration object which is 
 *  loaded from an input stream.
 * @param out the Writer to write to
 * @throws IOException
 */
public static void dumpConfiguration(Configuration config,
    Writer out) throws IOException {
  JsonFactory dumpFactory = new JsonFactory();
  JsonGenerator dumpGenerator = dumpFactory.createJsonGenerator(out);
  dumpGenerator.writeStartObject();
  dumpGenerator.writeFieldName("properties");
  dumpGenerator.writeStartArray();
  dumpGenerator.flush();
  synchronized (config) {
    for (Map.Entry<Object,Object> item: config.getProps().entrySet()) {
      dumpGenerator.writeStartObject();
      dumpGenerator.writeStringField("key", (String) item.getKey());
      dumpGenerator.writeStringField("value", 
                                     config.get((String) item.getKey()));
      dumpGenerator.writeBooleanField("isFinal",
                                      config.finalParameters.contains(item.getKey()));
      String[] resources = config.updatingResource.get(item.getKey());
      String resource = UNKNOWN_RESOURCE;
      if(resources != null && resources.length > 0) {
        resource = resources[0];
      }
      dumpGenerator.writeStringField("resource", resource);
      dumpGenerator.writeEndObject();
    }
  }
  dumpGenerator.writeEndArray();
  dumpGenerator.writeEndObject();
  dumpGenerator.flush();
}
 

protected void toJsonUtf8(JsonGenerator generator) throws IOException {
  generator.writeStartObject();
  generator.writeStringField("id", getId());
  bodyToJsonUtf8(generator);
  generator.writeEndObject();
  generator.flush();
}
 

static String toJson(Metrics commandMetrics) throws IOException {
    StringWriter jsonString = new StringWriter();
    JsonGenerator json = jsonFactory.createJsonGenerator(jsonString);

    json.writeStartObject();
    json.writeStringField("type", "HystrixCommand"); // act as this as we are hijacking Hystrix for the dashboard
    json.writeStringField("name", commandMetrics.getName());
    json.writeStringField("group", "");
    json.writeNumberField("currentTime", System.currentTimeMillis());

    json.writeBooleanField("isCircuitBreakerOpen", false);

    long errors = commandMetrics.getRollingNumber().getRollingSum(Metrics.EventType.FAILURE);
    long success = commandMetrics.getRollingNumber().getRollingSum(Metrics.EventType.SUCCESS);
    long requests = success + errors;
    int errorPercentage = (int) ((double) errors / requests * 100);

    json.writeNumberField("errorPercentage", errorPercentage);
    json.writeNumberField("errorCount", errors);
    json.writeNumberField("requestCount", requests);

    // rolling counters
    json.writeNumberField("rollingCountCollapsedRequests", 0);
    json.writeNumberField("rollingCountExceptionsThrown", commandMetrics.getRollingNumber().getRollingSum(Metrics.EventType.EXCEPTION_THROWN));
    json.writeNumberField("rollingCountFailure", errors);
    json.writeNumberField("rollingCountFallbackFailure", 0);
    json.writeNumberField("rollingCountFallbackRejection", 0);
    json.writeNumberField("rollingCountFallbackSuccess", 0);
    json.writeNumberField("rollingCountResponsesFromCache", 0);
    json.writeNumberField("rollingCountSemaphoreRejected", 0);
    json.writeNumberField("rollingCountShortCircuited", 0);
    json.writeNumberField("rollingCountSuccess", success);
    json.writeNumberField("rollingCountThreadPoolRejected", 0);
    json.writeNumberField("rollingCountTimeout", 0);

    json.writeNumberField("currentConcurrentExecutionCount", commandMetrics.getRollingNumber().getRollingMaxValue(Metrics.EventType.CONCURRENCY_MAX_ACTIVE));

    // latency percentiles
    json.writeNumberField("latencyExecute_mean", commandMetrics.getRollingPercentile().getMean());
    json.writeObjectFieldStart("latencyExecute");
    json.writeNumberField("0", commandMetrics.getRollingPercentile().getPercentile(0));
    json.writeNumberField("25", commandMetrics.getRollingPercentile().getPercentile(25));
    json.writeNumberField("50", commandMetrics.getRollingPercentile().getPercentile(50));
    json.writeNumberField("75", commandMetrics.getRollingPercentile().getPercentile(75));
    json.writeNumberField("90", commandMetrics.getRollingPercentile().getPercentile(90));
    json.writeNumberField("95", commandMetrics.getRollingPercentile().getPercentile(95));
    json.writeNumberField("99", commandMetrics.getRollingPercentile().getPercentile(99));
    json.writeNumberField("99.5", commandMetrics.getRollingPercentile().getPercentile(99.5));
    json.writeNumberField("100", commandMetrics.getRollingPercentile().getPercentile(100));
    json.writeEndObject();

    json.writeNumberField("latencyTotal_mean", commandMetrics.getRollingPercentile().getMean());
    json.writeObjectFieldStart("latencyTotal");
    json.writeNumberField("0", commandMetrics.getRollingPercentile().getPercentile(0));
    json.writeNumberField("25", commandMetrics.getRollingPercentile().getPercentile(25));
    json.writeNumberField("50", commandMetrics.getRollingPercentile().getPercentile(50));
    json.writeNumberField("75", commandMetrics.getRollingPercentile().getPercentile(75));
    json.writeNumberField("90", commandMetrics.getRollingPercentile().getPercentile(90));
    json.writeNumberField("95", commandMetrics.getRollingPercentile().getPercentile(95));
    json.writeNumberField("99", commandMetrics.getRollingPercentile().getPercentile(99));
    json.writeNumberField("99.5", commandMetrics.getRollingPercentile().getPercentile(99.5));
    json.writeNumberField("100", commandMetrics.getRollingPercentile().getPercentile(100));
    json.writeEndObject();
    
    json.writeNumberField("propertyValue_circuitBreakerRequestVolumeThreshold", 0);
    json.writeNumberField("propertyValue_circuitBreakerSleepWindowInMilliseconds", 0);
    json.writeNumberField("propertyValue_circuitBreakerErrorThresholdPercentage", 0);
    json.writeBooleanField("propertyValue_circuitBreakerForceOpen", false);
    json.writeBooleanField("propertyValue_circuitBreakerForceClosed", false);
    json.writeBooleanField("propertyValue_circuitBreakerEnabled", false);

    json.writeStringField("propertyValue_executionIsolationStrategy", "");
    json.writeNumberField("propertyValue_executionIsolationThreadTimeoutInMilliseconds", 0);
    json.writeBooleanField("propertyValue_executionIsolationThreadInterruptOnTimeout", false);
    json.writeStringField("propertyValue_executionIsolationThreadPoolKeyOverride", "");
    json.writeNumberField("propertyValue_executionIsolationSemaphoreMaxConcurrentRequests", 0);
    json.writeNumberField("propertyValue_fallbackIsolationSemaphoreMaxConcurrentRequests", 0);

    json.writeNumberField("propertyValue_metricsRollingStatisticalWindowInMilliseconds", 10000);

    json.writeBooleanField("propertyValue_requestCacheEnabled", false);
    json.writeBooleanField("propertyValue_requestLogEnabled", false);

    
    json.writeNumberField("reportingHosts", 1); // this will get summed across all instances in a cluster

    json.writeEndObject();
    json.close();

    return jsonString.getBuffer().toString();
}
 

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
    throws IOException {
  resp.setContentType("application/json; charset=UTF-8");
  StartupProgress prog = NameNodeHttpServer.getStartupProgressFromContext(
    getServletContext());
  StartupProgressView view = prog.createView();
  JsonGenerator json = new JsonFactory().createJsonGenerator(resp.getWriter());
  try {
    json.writeStartObject();
    json.writeNumberField(ELAPSED_TIME, view.getElapsedTime());
    json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete());
    json.writeArrayFieldStart(PHASES);

    for (Phase phase: view.getPhases()) {
      json.writeStartObject();
      json.writeStringField(NAME, phase.getName());
      json.writeStringField(DESC, phase.getDescription());
      json.writeStringField(STATUS, view.getStatus(phase).toString());
      json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete(phase));
      json.writeNumberField(ELAPSED_TIME, view.getElapsedTime(phase));
      writeStringFieldIfNotNull(json, FILE, view.getFile(phase));
      writeNumberFieldIfDefined(json, SIZE, view.getSize(phase));
      json.writeArrayFieldStart(STEPS);

      for (Step step: view.getSteps(phase)) {
        json.writeStartObject();
        StepType type = step.getType();
        if (type != null) {
          json.writeStringField(NAME, type.getName());
          json.writeStringField(DESC, type.getDescription());
        }
        json.writeNumberField(COUNT, view.getCount(phase, step));
        writeStringFieldIfNotNull(json, FILE, step.getFile());
        writeNumberFieldIfDefined(json, SIZE, step.getSize());
        json.writeNumberField(TOTAL, view.getTotal(phase, step));
        json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete(phase,
          step));
        json.writeNumberField(ELAPSED_TIME, view.getElapsedTime(phase, step));
        json.writeEndObject();
      }

      json.writeEndArray();
      json.writeEndObject();
    }

    json.writeEndArray();
    json.writeEndObject();
  } finally {
    IOUtils.cleanup(LOG, json);
  }
}
 

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
    throws IOException {
  resp.setContentType("application/json; charset=UTF-8");
  StartupProgress prog = NameNodeHttpServer.getStartupProgressFromContext(
    getServletContext());
  StartupProgressView view = prog.createView();
  JsonGenerator json = new JsonFactory().createJsonGenerator(resp.getWriter());
  try {
    json.writeStartObject();
    json.writeNumberField(ELAPSED_TIME, view.getElapsedTime());
    json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete());
    json.writeArrayFieldStart(PHASES);

    for (Phase phase: view.getPhases()) {
      json.writeStartObject();
      json.writeStringField(NAME, phase.getName());
      json.writeStringField(DESC, phase.getDescription());
      json.writeStringField(STATUS, view.getStatus(phase).toString());
      json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete(phase));
      json.writeNumberField(ELAPSED_TIME, view.getElapsedTime(phase));
      writeStringFieldIfNotNull(json, FILE, view.getFile(phase));
      writeNumberFieldIfDefined(json, SIZE, view.getSize(phase));
      json.writeArrayFieldStart(STEPS);

      for (Step step: view.getSteps(phase)) {
        json.writeStartObject();
        StepType type = step.getType();
        if (type != null) {
          json.writeStringField(NAME, type.getName());
          json.writeStringField(DESC, type.getDescription());
        }
        json.writeNumberField(COUNT, view.getCount(phase, step));
        writeStringFieldIfNotNull(json, FILE, step.getFile());
        writeNumberFieldIfDefined(json, SIZE, step.getSize());
        json.writeNumberField(TOTAL, view.getTotal(phase, step));
        json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete(phase,
          step));
        json.writeNumberField(ELAPSED_TIME, view.getElapsedTime(phase, step));
        json.writeEndObject();
      }

      json.writeEndArray();
      json.writeEndObject();
    }

    json.writeEndArray();
    json.writeEndObject();
  } finally {
    IOUtils.cleanup(LOG, json);
  }
}
 

/**
 * method to perform depth-first search and write the parameters of every 
 * queue in JSON format.
 * @param dumpGenerator JsonGenerator object which takes the dump and flushes
 *  to a writer object
 * @param rootQueues the top-level queues
 * @throws JsonGenerationException
 * @throws IOException
 */
private static void dumpConfiguration(JsonGenerator dumpGenerator,
    Set<Queue> rootQueues) throws JsonGenerationException, IOException {
  for (Queue queue : rootQueues) {
    dumpGenerator.writeStartObject();
    dumpGenerator.writeStringField("name", queue.getName());
    dumpGenerator.writeStringField("state", queue.getState().toString());
    AccessControlList submitJobList = null;
    AccessControlList administerJobsList = null;
    if (queue.getAcls() != null) {
      submitJobList =
        queue.getAcls().get(toFullPropertyName(queue.getName(),
            QueueACL.SUBMIT_JOB.getAclName()));
      administerJobsList =
        queue.getAcls().get(toFullPropertyName(queue.getName(),
            QueueACL.ADMINISTER_JOBS.getAclName()));
    }
    String aclsSubmitJobValue = " ";
    if (submitJobList != null ) {
      aclsSubmitJobValue = submitJobList.getAclString();
    }
    dumpGenerator.writeStringField("acl_submit_job", aclsSubmitJobValue);
    String aclsAdministerValue = " ";
    if (administerJobsList != null) {
      aclsAdministerValue = administerJobsList.getAclString();
    }
    dumpGenerator.writeStringField("acl_administer_jobs",
        aclsAdministerValue);
    dumpGenerator.writeFieldName("properties");
    dumpGenerator.writeStartArray();
    if (queue.getProperties() != null) {
      for (Map.Entry<Object, Object>property :
        queue.getProperties().entrySet()) {
        dumpGenerator.writeStartObject();
        dumpGenerator.writeStringField("key", (String)property.getKey());
        dumpGenerator.writeStringField("value", (String)property.getValue());
        dumpGenerator.writeEndObject();
      }
    }
    dumpGenerator.writeEndArray();
    Set<Queue> childQueues = queue.getChildren();
    dumpGenerator.writeFieldName("children");
    dumpGenerator.writeStartArray();
    if (childQueues != null && childQueues.size() > 0) {
      dumpConfiguration(dumpGenerator, childQueues);
    }
    dumpGenerator.writeEndArray();
    dumpGenerator.writeEndObject();
  }
}
 

private void writeStringFieldIfNotNull(JsonGenerator json, String key, String value)
    throws IOException {
  if (value != null) {
    json.writeStringField(key, value);
  }
}
 

/**
 * Sends the loading status as JSON to the parameter HTTP response. Copied from NameNode.
 *
 * @param resp the HTTP response
 * @throws IOException error in fetching loading status
 */
public void sendLoadingStatus(HttpServletResponse resp) throws IOException {
  String count = "count";
  String elapsedTime = "elapsedTime";
  String file = "file";
  String name = "name";
  String desc = "desc";
  String percentComplete = "percentComplete";
  String phases = "phases";
  String size = "size";
  String status = "status";
  String steps = "steps";
  String total = "total";

  StartupProgressView view = NameNode.getStartupProgress().createView();
  JsonGenerator json =
      new JsonFactory().createJsonGenerator(resp.getWriter()).useDefaultPrettyPrinter();

  try {
    json.writeStartObject();
    json.writeNumberField(elapsedTime, view.getElapsedTime());
    json.writeNumberField(percentComplete, view.getPercentComplete());
    json.writeArrayFieldStart(phases);

    for (Phase phase : view.getPhases()) {
      json.writeStartObject();
      json.writeStringField(name, phase.getName());
      json.writeStringField(desc, phase.getDescription());
      json.writeStringField(status, view.getStatus(phase).toString());
      json.writeNumberField(percentComplete, view.getPercentComplete(phase));
      json.writeNumberField(elapsedTime, view.getElapsedTime(phase));
      writeStringFieldIfNotNull(json, file, view.getFile(phase));
      writeNumberFieldIfDefined(json, size, view.getSize(phase));
      json.writeArrayFieldStart(steps);

      for (Step step : view.getSteps(phase)) {
        json.writeStartObject();
        StepType stepType = step.getType();
        if (stepType != null) {
          json.writeStringField(name, stepType.getName());
          json.writeStringField(desc, stepType.getDescription());
        }
        json.writeNumberField(count, view.getCount(phase, step));
        writeStringFieldIfNotNull(json, file, step.getFile());
        writeNumberFieldIfDefined(json, size, step.getSize());
        json.writeNumberField(total, view.getTotal(phase, step));
        json.writeNumberField(percentComplete, view.getPercentComplete(phase, step));
        json.writeNumberField(elapsedTime, view.getElapsedTime(phase, step));
        json.writeEndObject();
      }

      json.writeEndArray();
      json.writeEndObject();
    }

    json.writeEndArray();
    json.writeEndObject();
  } finally {
    IOUtils.closeStream(json);
  }
}
 

/**
 * Writes a JSON string field only if the value is non-null.
 * 
 * @param json JsonGenerator to receive output
 * @param key String key to put
 * @param value String value to put
 * @throws IOException if there is an I/O error
 */
private static void writeStringFieldIfNotNull(JsonGenerator json, String key,
    String value) throws IOException {
  if (value != null) {
    json.writeStringField(key, value);
  }
}
 

/**
 * Writes a JSON string field only if the value is non-null.
 * 
 * @param json JsonGenerator to receive output
 * @param key String key to put
 * @param value String value to put
 * @throws IOException if there is an I/O error
 */
private static void writeStringFieldIfNotNull(JsonGenerator json, String key,
    String value) throws IOException {
  if (value != null) {
    json.writeStringField(key, value);
  }
}