Java tutorial
package com.inductiveautomation.ignition.examples.reporting.datasource.common; import java.io.IOException; import java.io.Serializable; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.Map; import com.google.common.collect.Iterators; import com.inductiveautomation.ignition.examples.reporting.datasource.common.gateway.GatewayHook; import com.inductiveautomation.ignition.common.BasicDataset; import com.inductiveautomation.ignition.common.Dataset; import com.inductiveautomation.ignition.common.TypeUtilities; import com.inductiveautomation.ignition.common.licensing.LicenseState; import com.inductiveautomation.ignition.common.util.DatasetBuilder; import com.inductiveautomation.reporting.common.resource.DataSourceConfig; import com.inductiveautomation.ignition.examples.reporting.datasource.common.utils.JsonUtils; import com.inductiveautomation.reporting.gateway.api.GatewayDataSourceRegistry; import com.inductiveautomation.reporting.gateway.api.ReportDataSource; import com.inductiveautomation.reporting.gateway.api.ReportExecutionContext; import com.inductiveautomation.reporting.gateway.api.ReportExecutionContext.ReportLoggerEx; import com.inductiveautomation.rm.base.RMKey; import com.squareup.okhttp.Headers; import com.squareup.okhttp.MediaType; import com.squareup.okhttp.OkHttpClient; import com.squareup.okhttp.Request; import com.squareup.okhttp.Response; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; /** * This class provides the Gateway scoped functionality for the example Datasource. By implementing {@link ReportDataSource} * and registering it in the {@link GatewayHook#startup(LicenseState)} * through {@link GatewayDataSourceRegistry}. * @author Perry Arellano-Jones */ public class RestJsonDataSource implements ReportDataSource { public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8"); /* * ReportLoggerEx is a wrapper around LoggerEx that adds WARN and ERROR level log messages to the data collection * error popup that is displayed in the Report Design/Preview panels as well as the Report Viewer component in * Vision windows. */ ReportLoggerEx log; /** * This method is where data can be added to the data map. We utilitize the * {@link ReportExecutionContext} to get the data map, and simple inject our data as an additional * entry. * @param reportExecutionContext provides * @param _configObject is the configuration object we defined in Common scope. It's information originates from * the Designer's {@link DataSourceConfig} panel. * @param extraConfigs Extra info the datasource may need. The key is the datasource ID. */ @Override public void gatherData(ReportExecutionContext reportExecutionContext, Serializable _configObject, Map<String, Object> extraConfigs) { log = reportExecutionContext.getLog(); /* Collect information from the config object and add to the data map with the proper ID. */ Map<String, Object> data = reportExecutionContext.getExecutionData().getData(); RestJsonDataObject configObject = (RestJsonDataObject) _configObject; // verify the user entered a valid datakey if (configObject != null && RMKey.isKey(configObject.getKey())) { String key = configObject.getKey(); String url; // get the url if (!TypeUtilities.isNullOrEmpty(configObject.getUrl())) { url = configObject.getUrl(); } else { log.warnf("Url field of REST JSON Datasource %s requires a URL to attempt data collection.", key); return; } log.tracef("Attempting to collect data from '%s' for %s Datakey.", configObject.getUrl(), configObject.getKey()); try { //collect the data as a String String jsonString = collectData(url); if (!TypeUtilities.isNullOrEmpty(jsonString)) { try { log.tracef("Attempting to build JSON Object from data string."); // map our simple string to a reporting-engine friendly map JSONObject jsonObject = new JSONObject(jsonString); Map<String, Object> mappedJSON = JsonUtils.toMap(jsonObject); if (mappedJSON != null) { data.put(configObject.getKey(), mappedJSON); } } catch (JSONException jse) { // may have an array of json objects, so we try to build a data set out of them log.tracef("Failed to create single JSON object from data, attempting JSONArray from data.", jse); try { JSONArray jsonArray = new JSONArray(jsonString); Dataset dataset = createDatasetFromJSONArray(jsonArray); if (dataset != null) { data.put(configObject.getKey(), dataset); } log.tracef("Dataset created from Json Array and added to map."); } catch (Exception e) { log.warnf("Could not parse JSONArray from \'%s\'.", configObject.getUrl(), e); } } } else { log.warnf("No Json data could be found at \'%s\'", configObject.getUrl()); } } catch (Exception e) { log.warnf("Could not create usable data from \'%s\'", configObject.getUrl(), e); } } } /** * Looks through the {@link JSONArray}, evaluating each {@link JSONObject} to determine which has the largest * set of keys. This process is useful because not all JSON objects in an array may have the same key set. There * are some assumptions made that the largest keyset will contain all the keys available in those of lower sets. * This is far from true, but this assumption is allowed for the sake of simplicity for this example. * @param jsonArray a {@link JSONArray} * @return a JSONObject containing the most keys found in the array. May be empty. */ private JSONObject findReferenceObjectIndex(JSONArray jsonArray) throws JSONException { JSONObject reference = null; if (jsonArray != null && jsonArray.length() > 0) { reference = jsonArray.getJSONObject(0); for (int i = 0; i < jsonArray.length(); i++) { JSONObject jo = jsonArray.getJSONObject(i); if (Iterators.size(jo.keys()) > Iterators.size(reference.keys())) { reference = jo; } } } return reference == null ? new JSONObject() : reference; } /** * Creates and returns {@link Dataset} with String column types from a {@link JSONArray}. Returns empty if no data * was found and an exception was not thrown. */ private Dataset createDatasetFromJSONArray(JSONArray jsonArray) throws JSONException { Dataset ds = null; if (jsonArray.length() >= 1) { // JSON objects in an array may not have values for each key, so make sure we // get the full keyset JSONObject reference = findReferenceObjectIndex(jsonArray); // get column names from the reference object List<String> colNames = new ArrayList<>(); Iterator keys = reference.keys(); while (keys.hasNext()) { colNames.add(keys.next().toString()); } // now start building dataset to pass into report engine DatasetBuilder builder = new DatasetBuilder(); builder.colNames(colNames.toArray(new String[0])); // set the column types. We're using all strings in this example, but we could be // checking for numeric types and setting different column types to enable calculations Class[] types = new Class[colNames.size()]; for (int i = 0; i < types.length; i++) { types[i] = String.class; } builder.colTypes(types); // now create rows for each json list value for (int row = 0; row < jsonArray.length(); row++) { String[] rowData = new String[colNames.size()]; for (int col = 0; col < colNames.size(); col++) { try { rowData[col] = jsonArray.getJSONObject(row).get(colNames.get(col)).toString(); } catch (JSONException e) { // ignore because it just means this object didn't have our key } } builder.addRow(rowData); } ds = builder.build(); } return ds != null ? ds : new BasicDataset(); } public String getId() { return RestJsonDataObject.ID; } /** * Attempts to connect to a Url using {@link OkHttpClient} and return the body of the reply as a String, if it is * JSON mime type. * @param url String specifying the * @return the body of the http response received from the specified Url */ private String collectData(String url) throws IOException { OkHttpClient client = new OkHttpClient(); Request request = new Request.Builder().url(url).build(); Response response = client.newCall(request).execute(); // get headers to check the content type out of Headers headers = null; if (response != null) { headers = response.headers(); } // at least try to make sure we have JSON data. boolean isJSON = false; if (headers != null) { isJSON = MediaType.parse(headers.get("Content-Type")).equals(JSON); } return isJSON ? response.body().string() : ""; } }