diff --git a/src/main/java/io/github/simplex/luck/FeelingLucky.java b/src/main/java/io/github/simplex/luck/FeelingLucky.java index 015f639..d200197 100644 --- a/src/main/java/io/github/simplex/luck/FeelingLucky.java +++ b/src/main/java/io/github/simplex/luck/FeelingLucky.java @@ -5,12 +5,12 @@ import io.github.simplex.luck.player.PlayerConfig; import io.github.simplex.luck.player.PlayerHandler; import io.github.simplex.luck.util.LuckCMD; import io.github.simplex.luck.util.SneakyWorker; +import io.github.simplex.metrics.Metrics; import org.bukkit.plugin.java.JavaPlugin; import org.jetbrains.annotations.NotNull; import java.io.File; import java.io.IOException; -import java.lang.reflect.InvocationTargetException; import java.util.Arrays; import java.util.HashMap; import java.util.Map; @@ -28,7 +28,9 @@ public final class FeelingLucky extends JavaPlugin { @Override public void onEnable() { - getLogger().info("Initializing the PlayerHandler..."); + getLogger().info("Initializing metrics..."); + new Metrics(this, 15054); + getLogger().info("Metrics loaded. Initializing the PlayerHandler..."); handler = new PlayerHandler(this); getLogger().info("Initialization complete! Attempting to register the Listeners..."); registerListeners(); diff --git a/src/main/java/io/github/simplex/metrics/Metrics.java b/src/main/java/io/github/simplex/metrics/Metrics.java new file mode 100644 index 0000000..ecf70f2 --- /dev/null +++ b/src/main/java/io/github/simplex/metrics/Metrics.java @@ -0,0 +1,863 @@ +/* + * This Metrics class was auto-generated and can be copied into your project if you are + * not using a build tool like Gradle or Maven for dependency management. + * + * IMPORTANT: You are not allowed to modify this class, except changing the package. + * + * Unallowed modifications include but are not limited to: + * - Remove the option for users to opt-out + * - Change the frequency for data submission + * - Obfuscate the code (every obfucator should allow you to make an exception for specific files) + * - Reformat the code (if you use a linter, add an exception) + * + * Violations will result in a ban of your plugin and account from bStats. + */ +package io.github.simplex.metrics; + +import java.io.BufferedReader; +import java.io.ByteArrayOutputStream; +import java.io.DataOutputStream; +import java.io.File; +import java.io.IOException; +import java.io.InputStreamReader; +import java.lang.reflect.Method; +import java.net.URL; +import java.nio.charset.StandardCharsets; +import java.util.Arrays; +import java.util.Collection; +import java.util.HashSet; +import java.util.Map; +import java.util.Objects; +import java.util.Set; +import java.util.UUID; +import java.util.concurrent.Callable; +import java.util.concurrent.Executors; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.TimeUnit; +import java.util.function.BiConsumer; +import java.util.function.Consumer; +import java.util.function.Supplier; +import java.util.logging.Level; +import java.util.stream.Collectors; +import java.util.zip.GZIPOutputStream; +import javax.net.ssl.HttpsURLConnection; +import org.bukkit.Bukkit; +import org.bukkit.configuration.file.YamlConfiguration; +import org.bukkit.entity.Player; +import org.bukkit.plugin.Plugin; +import org.bukkit.plugin.java.JavaPlugin; + +public class Metrics { + + private final Plugin plugin; + + private final MetricsBase metricsBase; + + /** + * Creates a new Metrics instance. + * + * @param plugin Your plugin instance. + * @param serviceId The id of the service. It can be found at What is my plugin id? + */ + public Metrics(JavaPlugin plugin, int serviceId) { + this.plugin = plugin; + // Get the config file + File bStatsFolder = new File(plugin.getDataFolder().getParentFile(), "bStats"); + File configFile = new File(bStatsFolder, "config.yml"); + YamlConfiguration config = YamlConfiguration.loadConfiguration(configFile); + if (!config.isSet("serverUuid")) { + config.addDefault("enabled", true); + config.addDefault("serverUuid", UUID.randomUUID().toString()); + config.addDefault("logFailedRequests", false); + config.addDefault("logSentData", false); + config.addDefault("logResponseStatusText", false); + // Inform the server owners about bStats + config + .options() + .header( + "bStats (https://bStats.org) collects some basic information for plugin authors, like how\n" + + "many people use their plugin and their total player count. It's recommended to keep bStats\n" + + "enabled, but if you're not comfortable with this, you can turn this setting off. There is no\n" + + "performance penalty associated with having metrics enabled, and data sent to bStats is fully\n" + + "anonymous.") + .copyDefaults(true); + try { + config.save(configFile); + } catch (IOException ignored) { + } + } + // Load the data + boolean enabled = config.getBoolean("enabled", true); + String serverUUID = config.getString("serverUuid"); + boolean logErrors = config.getBoolean("logFailedRequests", false); + boolean logSentData = config.getBoolean("logSentData", false); + boolean logResponseStatusText = config.getBoolean("logResponseStatusText", false); + metricsBase = + new MetricsBase( + "bukkit", + serverUUID, + serviceId, + enabled, + this::appendPlatformData, + this::appendServiceData, + submitDataTask -> Bukkit.getScheduler().runTask(plugin, submitDataTask), + plugin::isEnabled, + (message, error) -> this.plugin.getLogger().log(Level.WARNING, message, error), + (message) -> this.plugin.getLogger().log(Level.INFO, message), + logErrors, + logSentData, + logResponseStatusText); + } + + /** + * Adds a custom chart. + * + * @param chart The chart to add. + */ + public void addCustomChart(CustomChart chart) { + metricsBase.addCustomChart(chart); + } + + private void appendPlatformData(JsonObjectBuilder builder) { + builder.appendField("playerAmount", getPlayerAmount()); + builder.appendField("onlineMode", Bukkit.getOnlineMode() ? 1 : 0); + builder.appendField("bukkitVersion", Bukkit.getVersion()); + builder.appendField("bukkitName", Bukkit.getName()); + builder.appendField("javaVersion", System.getProperty("java.version")); + builder.appendField("osName", System.getProperty("os.name")); + builder.appendField("osArch", System.getProperty("os.arch")); + builder.appendField("osVersion", System.getProperty("os.version")); + builder.appendField("coreCount", Runtime.getRuntime().availableProcessors()); + } + + private void appendServiceData(JsonObjectBuilder builder) { + builder.appendField("pluginVersion", plugin.getDescription().getVersion()); + } + + private int getPlayerAmount() { + try { + // Around MC 1.8 the return type was changed from an array to a collection, + // This fixes java.lang.NoSuchMethodError: + // org.bukkit.Bukkit.getOnlinePlayers()Ljava/util/Collection; + Method onlinePlayersMethod = Class.forName("org.bukkit.Server").getMethod("getOnlinePlayers"); + return onlinePlayersMethod.getReturnType().equals(Collection.class) + ? ((Collection) onlinePlayersMethod.invoke(Bukkit.getServer())).size() + : ((Player[]) onlinePlayersMethod.invoke(Bukkit.getServer())).length; + } catch (Exception e) { + // Just use the new method if the reflection failed + return Bukkit.getOnlinePlayers().size(); + } + } + + public static class MetricsBase { + + /** The version of the Metrics class. */ + public static final String METRICS_VERSION = "3.0.0"; + + private static final ScheduledExecutorService scheduler = + Executors.newScheduledThreadPool(1, task -> new Thread(task, "bStats-Metrics")); + + private static final String REPORT_URL = "https://bStats.org/api/v2/data/%s"; + + private final String platform; + + private final String serverUuid; + + private final int serviceId; + + private final Consumer appendPlatformDataConsumer; + + private final Consumer appendServiceDataConsumer; + + private final Consumer submitTaskConsumer; + + private final Supplier checkServiceEnabledSupplier; + + private final BiConsumer errorLogger; + + private final Consumer infoLogger; + + private final boolean logErrors; + + private final boolean logSentData; + + private final boolean logResponseStatusText; + + private final Set customCharts = new HashSet<>(); + + private final boolean enabled; + + /** + * Creates a new MetricsBase class instance. + * + * @param platform The platform of the service. + * @param serviceId The id of the service. + * @param serverUuid The server uuid. + * @param enabled Whether or not data sending is enabled. + * @param appendPlatformDataConsumer A consumer that receives a {@code JsonObjectBuilder} and + * appends all platform-specific data. + * @param appendServiceDataConsumer A consumer that receives a {@code JsonObjectBuilder} and + * appends all service-specific data. + * @param submitTaskConsumer A consumer that takes a runnable with the submit task. This can be + * used to delegate the data collection to a another thread to prevent errors caused by + * concurrency. Can be {@code null}. + * @param checkServiceEnabledSupplier A supplier to check if the service is still enabled. + * @param errorLogger A consumer that accepts log message and an error. + * @param infoLogger A consumer that accepts info log messages. + * @param logErrors Whether or not errors should be logged. + * @param logSentData Whether or not the sent data should be logged. + * @param logResponseStatusText Whether or not the response status text should be logged. + */ + public MetricsBase( + String platform, + String serverUuid, + int serviceId, + boolean enabled, + Consumer appendPlatformDataConsumer, + Consumer appendServiceDataConsumer, + Consumer submitTaskConsumer, + Supplier checkServiceEnabledSupplier, + BiConsumer errorLogger, + Consumer infoLogger, + boolean logErrors, + boolean logSentData, + boolean logResponseStatusText) { + this.platform = platform; + this.serverUuid = serverUuid; + this.serviceId = serviceId; + this.enabled = enabled; + this.appendPlatformDataConsumer = appendPlatformDataConsumer; + this.appendServiceDataConsumer = appendServiceDataConsumer; + this.submitTaskConsumer = submitTaskConsumer; + this.checkServiceEnabledSupplier = checkServiceEnabledSupplier; + this.errorLogger = errorLogger; + this.infoLogger = infoLogger; + this.logErrors = logErrors; + this.logSentData = logSentData; + this.logResponseStatusText = logResponseStatusText; + checkRelocation(); + if (enabled) { + // WARNING: Removing the option to opt-out will get your plugin banned from bStats + startSubmitting(); + } + } + + public void addCustomChart(CustomChart chart) { + this.customCharts.add(chart); + } + + private void startSubmitting() { + final Runnable submitTask = + () -> { + if (!enabled || !checkServiceEnabledSupplier.get()) { + // Submitting data or service is disabled + scheduler.shutdown(); + return; + } + if (submitTaskConsumer != null) { + submitTaskConsumer.accept(this::submitData); + } else { + this.submitData(); + } + }; + // Many servers tend to restart at a fixed time at xx:00 which causes an uneven distribution + // of requests on the + // bStats backend. To circumvent this problem, we introduce some randomness into the initial + // and second delay. + // WARNING: You must not modify and part of this Metrics class, including the submit delay or + // frequency! + // WARNING: Modifying this code will get your plugin banned on bStats. Just don't do it! + long initialDelay = (long) (1000 * 60 * (3 + Math.random() * 3)); + long secondDelay = (long) (1000 * 60 * (Math.random() * 30)); + scheduler.schedule(submitTask, initialDelay, TimeUnit.MILLISECONDS); + scheduler.scheduleAtFixedRate( + submitTask, initialDelay + secondDelay, 1000 * 60 * 30, TimeUnit.MILLISECONDS); + } + + private void submitData() { + final JsonObjectBuilder baseJsonBuilder = new JsonObjectBuilder(); + appendPlatformDataConsumer.accept(baseJsonBuilder); + final JsonObjectBuilder serviceJsonBuilder = new JsonObjectBuilder(); + appendServiceDataConsumer.accept(serviceJsonBuilder); + JsonObjectBuilder.JsonObject[] chartData = + customCharts.stream() + .map(customChart -> customChart.getRequestJsonObject(errorLogger, logErrors)) + .filter(Objects::nonNull) + .toArray(JsonObjectBuilder.JsonObject[]::new); + serviceJsonBuilder.appendField("id", serviceId); + serviceJsonBuilder.appendField("customCharts", chartData); + baseJsonBuilder.appendField("service", serviceJsonBuilder.build()); + baseJsonBuilder.appendField("serverUUID", serverUuid); + baseJsonBuilder.appendField("metricsVersion", METRICS_VERSION); + JsonObjectBuilder.JsonObject data = baseJsonBuilder.build(); + scheduler.execute( + () -> { + try { + // Send the data + sendData(data); + } catch (Exception e) { + // Something went wrong! :( + if (logErrors) { + errorLogger.accept("Could not submit bStats metrics data", e); + } + } + }); + } + + private void sendData(JsonObjectBuilder.JsonObject data) throws Exception { + if (logSentData) { + infoLogger.accept("Sent bStats metrics data: " + data.toString()); + } + String url = String.format(REPORT_URL, platform); + HttpsURLConnection connection = (HttpsURLConnection) new URL(url).openConnection(); + // Compress the data to save bandwidth + byte[] compressedData = compress(data.toString()); + connection.setRequestMethod("POST"); + connection.addRequestProperty("Accept", "application/json"); + connection.addRequestProperty("Connection", "close"); + connection.addRequestProperty("Content-Encoding", "gzip"); + connection.addRequestProperty("Content-Length", String.valueOf(compressedData.length)); + connection.setRequestProperty("Content-Type", "application/json"); + connection.setRequestProperty("User-Agent", "Metrics-Service/1"); + connection.setDoOutput(true); + try (DataOutputStream outputStream = new DataOutputStream(connection.getOutputStream())) { + outputStream.write(compressedData); + } + StringBuilder builder = new StringBuilder(); + try (BufferedReader bufferedReader = + new BufferedReader(new InputStreamReader(connection.getInputStream()))) { + String line; + while ((line = bufferedReader.readLine()) != null) { + builder.append(line); + } + } + if (logResponseStatusText) { + infoLogger.accept("Sent data to bStats and received response: " + builder); + } + } + + /** Checks that the class was properly relocated. */ + private void checkRelocation() { + // You can use the property to disable the check in your test environment + if (System.getProperty("bstats.relocatecheck") == null + || !System.getProperty("bstats.relocatecheck").equals("false")) { + // Maven's Relocate is clever and changes strings, too. So we have to use this little + // "trick" ... :D + final String defaultPackage = + new String(new byte[] {'o', 'r', 'g', '.', 'b', 's', 't', 'a', 't', 's'}); + final String examplePackage = + new String(new byte[] {'y', 'o', 'u', 'r', '.', 'p', 'a', 'c', 'k', 'a', 'g', 'e'}); + // We want to make sure no one just copy & pastes the example and uses the wrong package + // names + if (MetricsBase.class.getPackage().getName().startsWith(defaultPackage) + || MetricsBase.class.getPackage().getName().startsWith(examplePackage)) { + throw new IllegalStateException("bStats Metrics class has not been relocated correctly!"); + } + } + } + + /** + * Gzips the given string. + * + * @param str The string to gzip. + * @return The gzipped string. + */ + private static byte[] compress(final String str) throws IOException { + if (str == null) { + return null; + } + ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); + try (GZIPOutputStream gzip = new GZIPOutputStream(outputStream)) { + gzip.write(str.getBytes(StandardCharsets.UTF_8)); + } + return outputStream.toByteArray(); + } + } + + public static class DrilldownPie extends CustomChart { + + private final Callable>> callable; + + /** + * Class constructor. + * + * @param chartId The id of the chart. + * @param callable The callable which is used to request the chart data. + */ + public DrilldownPie(String chartId, Callable>> callable) { + super(chartId); + this.callable = callable; + } + + @Override + public JsonObjectBuilder.JsonObject getChartData() throws Exception { + JsonObjectBuilder valuesBuilder = new JsonObjectBuilder(); + Map> map = callable.call(); + if (map == null || map.isEmpty()) { + // Null = skip the chart + return null; + } + boolean reallyAllSkipped = true; + for (Map.Entry> entryValues : map.entrySet()) { + JsonObjectBuilder valueBuilder = new JsonObjectBuilder(); + boolean allSkipped = true; + for (Map.Entry valueEntry : map.get(entryValues.getKey()).entrySet()) { + valueBuilder.appendField(valueEntry.getKey(), valueEntry.getValue()); + allSkipped = false; + } + if (!allSkipped) { + reallyAllSkipped = false; + valuesBuilder.appendField(entryValues.getKey(), valueBuilder.build()); + } + } + if (reallyAllSkipped) { + // Null = skip the chart + return null; + } + return new JsonObjectBuilder().appendField("values", valuesBuilder.build()).build(); + } + } + + public static class AdvancedPie extends CustomChart { + + private final Callable> callable; + + /** + * Class constructor. + * + * @param chartId The id of the chart. + * @param callable The callable which is used to request the chart data. + */ + public AdvancedPie(String chartId, Callable> callable) { + super(chartId); + this.callable = callable; + } + + @Override + protected JsonObjectBuilder.JsonObject getChartData() throws Exception { + JsonObjectBuilder valuesBuilder = new JsonObjectBuilder(); + Map map = callable.call(); + if (map == null || map.isEmpty()) { + // Null = skip the chart + return null; + } + boolean allSkipped = true; + for (Map.Entry entry : map.entrySet()) { + if (entry.getValue() == 0) { + // Skip this invalid + continue; + } + allSkipped = false; + valuesBuilder.appendField(entry.getKey(), entry.getValue()); + } + if (allSkipped) { + // Null = skip the chart + return null; + } + return new JsonObjectBuilder().appendField("values", valuesBuilder.build()).build(); + } + } + + public static class MultiLineChart extends CustomChart { + + private final Callable> callable; + + /** + * Class constructor. + * + * @param chartId The id of the chart. + * @param callable The callable which is used to request the chart data. + */ + public MultiLineChart(String chartId, Callable> callable) { + super(chartId); + this.callable = callable; + } + + @Override + protected JsonObjectBuilder.JsonObject getChartData() throws Exception { + JsonObjectBuilder valuesBuilder = new JsonObjectBuilder(); + Map map = callable.call(); + if (map == null || map.isEmpty()) { + // Null = skip the chart + return null; + } + boolean allSkipped = true; + for (Map.Entry entry : map.entrySet()) { + if (entry.getValue() == 0) { + // Skip this invalid + continue; + } + allSkipped = false; + valuesBuilder.appendField(entry.getKey(), entry.getValue()); + } + if (allSkipped) { + // Null = skip the chart + return null; + } + return new JsonObjectBuilder().appendField("values", valuesBuilder.build()).build(); + } + } + + public static class SimpleBarChart extends CustomChart { + + private final Callable> callable; + + /** + * Class constructor. + * + * @param chartId The id of the chart. + * @param callable The callable which is used to request the chart data. + */ + public SimpleBarChart(String chartId, Callable> callable) { + super(chartId); + this.callable = callable; + } + + @Override + protected JsonObjectBuilder.JsonObject getChartData() throws Exception { + JsonObjectBuilder valuesBuilder = new JsonObjectBuilder(); + Map map = callable.call(); + if (map == null || map.isEmpty()) { + // Null = skip the chart + return null; + } + for (Map.Entry entry : map.entrySet()) { + valuesBuilder.appendField(entry.getKey(), new int[] {entry.getValue()}); + } + return new JsonObjectBuilder().appendField("values", valuesBuilder.build()).build(); + } + } + + public abstract static class CustomChart { + + private final String chartId; + + protected CustomChart(String chartId) { + if (chartId == null) { + throw new IllegalArgumentException("chartId must not be null"); + } + this.chartId = chartId; + } + + public JsonObjectBuilder.JsonObject getRequestJsonObject( + BiConsumer errorLogger, boolean logErrors) { + JsonObjectBuilder builder = new JsonObjectBuilder(); + builder.appendField("chartId", chartId); + try { + JsonObjectBuilder.JsonObject data = getChartData(); + if (data == null) { + // If the data is null we don't send the chart. + return null; + } + builder.appendField("data", data); + } catch (Throwable t) { + if (logErrors) { + errorLogger.accept("Failed to get data for custom chart with id " + chartId, t); + } + return null; + } + return builder.build(); + } + + protected abstract JsonObjectBuilder.JsonObject getChartData() throws Exception; + } + + public static class SimplePie extends CustomChart { + + private final Callable callable; + + /** + * Class constructor. + * + * @param chartId The id of the chart. + * @param callable The callable which is used to request the chart data. + */ + public SimplePie(String chartId, Callable callable) { + super(chartId); + this.callable = callable; + } + + @Override + protected JsonObjectBuilder.JsonObject getChartData() throws Exception { + String value = callable.call(); + if (value == null || value.isEmpty()) { + // Null = skip the chart + return null; + } + return new JsonObjectBuilder().appendField("value", value).build(); + } + } + + public static class AdvancedBarChart extends CustomChart { + + private final Callable> callable; + + /** + * Class constructor. + * + * @param chartId The id of the chart. + * @param callable The callable which is used to request the chart data. + */ + public AdvancedBarChart(String chartId, Callable> callable) { + super(chartId); + this.callable = callable; + } + + @Override + protected JsonObjectBuilder.JsonObject getChartData() throws Exception { + JsonObjectBuilder valuesBuilder = new JsonObjectBuilder(); + Map map = callable.call(); + if (map == null || map.isEmpty()) { + // Null = skip the chart + return null; + } + boolean allSkipped = true; + for (Map.Entry entry : map.entrySet()) { + if (entry.getValue().length == 0) { + // Skip this invalid + continue; + } + allSkipped = false; + valuesBuilder.appendField(entry.getKey(), entry.getValue()); + } + if (allSkipped) { + // Null = skip the chart + return null; + } + return new JsonObjectBuilder().appendField("values", valuesBuilder.build()).build(); + } + } + + public static class SingleLineChart extends CustomChart { + + private final Callable callable; + + /** + * Class constructor. + * + * @param chartId The id of the chart. + * @param callable The callable which is used to request the chart data. + */ + public SingleLineChart(String chartId, Callable callable) { + super(chartId); + this.callable = callable; + } + + @Override + protected JsonObjectBuilder.JsonObject getChartData() throws Exception { + int value = callable.call(); + if (value == 0) { + // Null = skip the chart + return null; + } + return new JsonObjectBuilder().appendField("value", value).build(); + } + } + + /** + * An extremely simple JSON builder. + * + *

While this class is neither feature-rich nor the most performant one, it's sufficient enough + * for its use-case. + */ + public static class JsonObjectBuilder { + + private StringBuilder builder = new StringBuilder(); + + private boolean hasAtLeastOneField = false; + + public JsonObjectBuilder() { + builder.append("{"); + } + + /** + * Appends a null field to the JSON. + * + * @param key The key of the field. + * @return A reference to this object. + */ + public JsonObjectBuilder appendNull(String key) { + appendFieldUnescaped(key, "null"); + return this; + } + + /** + * Appends a string field to the JSON. + * + * @param key The key of the field. + * @param value The value of the field. + * @return A reference to this object. + */ + public JsonObjectBuilder appendField(String key, String value) { + if (value == null) { + throw new IllegalArgumentException("JSON value must not be null"); + } + appendFieldUnescaped(key, "\"" + escape(value) + "\""); + return this; + } + + /** + * Appends an integer field to the JSON. + * + * @param key The key of the field. + * @param value The value of the field. + * @return A reference to this object. + */ + public JsonObjectBuilder appendField(String key, int value) { + appendFieldUnescaped(key, String.valueOf(value)); + return this; + } + + /** + * Appends an object to the JSON. + * + * @param key The key of the field. + * @param object The object. + * @return A reference to this object. + */ + public JsonObjectBuilder appendField(String key, JsonObject object) { + if (object == null) { + throw new IllegalArgumentException("JSON object must not be null"); + } + appendFieldUnescaped(key, object.toString()); + return this; + } + + /** + * Appends a string array to the JSON. + * + * @param key The key of the field. + * @param values The string array. + * @return A reference to this object. + */ + public JsonObjectBuilder appendField(String key, String[] values) { + if (values == null) { + throw new IllegalArgumentException("JSON values must not be null"); + } + String escapedValues = + Arrays.stream(values) + .map(value -> "\"" + escape(value) + "\"") + .collect(Collectors.joining(",")); + appendFieldUnescaped(key, "[" + escapedValues + "]"); + return this; + } + + /** + * Appends an integer array to the JSON. + * + * @param key The key of the field. + * @param values The integer array. + * @return A reference to this object. + */ + public JsonObjectBuilder appendField(String key, int[] values) { + if (values == null) { + throw new IllegalArgumentException("JSON values must not be null"); + } + String escapedValues = + Arrays.stream(values).mapToObj(String::valueOf).collect(Collectors.joining(",")); + appendFieldUnescaped(key, "[" + escapedValues + "]"); + return this; + } + + /** + * Appends an object array to the JSON. + * + * @param key The key of the field. + * @param values The integer array. + * @return A reference to this object. + */ + public JsonObjectBuilder appendField(String key, JsonObject[] values) { + if (values == null) { + throw new IllegalArgumentException("JSON values must not be null"); + } + String escapedValues = + Arrays.stream(values).map(JsonObject::toString).collect(Collectors.joining(",")); + appendFieldUnescaped(key, "[" + escapedValues + "]"); + return this; + } + + /** + * Appends a field to the object. + * + * @param key The key of the field. + * @param escapedValue The escaped value of the field. + */ + private void appendFieldUnescaped(String key, String escapedValue) { + if (builder == null) { + throw new IllegalStateException("JSON has already been built"); + } + if (key == null) { + throw new IllegalArgumentException("JSON key must not be null"); + } + if (hasAtLeastOneField) { + builder.append(","); + } + builder.append("\"").append(escape(key)).append("\":").append(escapedValue); + hasAtLeastOneField = true; + } + + /** + * Builds the JSON string and invalidates this builder. + * + * @return The built JSON string. + */ + public JsonObject build() { + if (builder == null) { + throw new IllegalStateException("JSON has already been built"); + } + JsonObject object = new JsonObject(builder.append("}").toString()); + builder = null; + return object; + } + + /** + * Escapes the given string like stated in https://www.ietf.org/rfc/rfc4627.txt. + * + *

This method escapes only the necessary characters '"', '\'. and '\u0000' - '\u001F'. + * Compact escapes are not used (e.g., '\n' is escaped as "\u000a" and not as "\n"). + * + * @param value The value to escape. + * @return The escaped value. + */ + private static String escape(String value) { + final StringBuilder builder = new StringBuilder(); + for (int i = 0; i < value.length(); i++) { + char c = value.charAt(i); + if (c == '"') { + builder.append("\\\""); + } else if (c == '\\') { + builder.append("\\\\"); + } else if (c <= '\u000F') { + builder.append("\\u000").append(Integer.toHexString(c)); + } else if (c <= '\u001F') { + builder.append("\\u00").append(Integer.toHexString(c)); + } else { + builder.append(c); + } + } + return builder.toString(); + } + + /** + * A super simple representation of a JSON object. + * + *

This class only exists to make methods of the {@link JsonObjectBuilder} type-safe and not + * allow a raw string inputs for methods like {@link JsonObjectBuilder#appendField(String, + * JsonObject)}. + */ + public static class JsonObject { + + private final String value; + + private JsonObject(String value) { + this.value = value; + } + + @Override + public String toString() { + return value; + } + } + } +} \ No newline at end of file