Put in a LogEvent abstraction

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/json/CommonJsonFormats.java

@@ -0,0 +1,161 @@
+/*
+ * Copyright 2012-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.logging.json;
+
+import java.time.OffsetDateTime;
+import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+
+import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
+import org.springframework.util.ObjectUtils;
+
+/**
+ * Common JSON formats.
+ *
+ * @author Moritz Halbritter
+ * @since 3.4.0
+ */
+public final class CommonJsonFormats {
+
+	private static final Map<String, JsonFormat> FORMATS = Map.of("ecs", new EcsJsonFormat(), "logstash",
+			new LogstashJsonFormat());
+
+	private CommonJsonFormats() {
+	}
+
+	public static Set<String> getSupportedFormats() {
+		return FORMATS.keySet();
+	}
+
+	/**
+	 * Returns the requested {@link JsonFormat}. Returns {@code null} if the format isn't
+	 * known.
+	 * @param format the requested format
+	 * @return the requested format or{@code null} if the format isn't known.
+	 */
+	public static JsonFormat get(String format) {
+		Assert.notNull(format, "Format must not be null");
+		return FORMATS.get(format.toLowerCase(Locale.ENGLISH));
+	}
+
+	/**
+	 * <a href="https://www.elastic.co/guide/en/ecs/current/ecs-log.html">ECS logging
+	 * format</a>.
+	 */
+	private static final class EcsJsonFormat implements JsonFormat {
+
+		@Override
+		public void write(LogEvent event, JsonBuilder builder) {
+			builder.attribute("@timestamp", event.getTimestamp().toString());
+			builder.attribute("log.level", event.getLevel());
+			if (event.getPid() != null) {
+				builder.attribute("process.pid", event.getPid());
+			}
+			builder.attribute("process.thread.name", event.getThreadName());
+			if (event.getServiceName() != null) {
+				builder.attribute("service.name", event.getServiceName());
+			}
+			if (event.getServiceVersion() != null) {
+				builder.attribute("service.version", event.getServiceVersion());
+			}
+			if (event.getServiceEnvironment() != null) {
+				builder.attribute("service.environment", event.getServiceEnvironment());
+			}
+			if (event.getServiceNodeName() != null) {
+				builder.attribute("service.node.name", event.getServiceNodeName());
+			}
+			builder.attribute("log.logger", event.getLoggerName());
+			builder.attribute("message", event.getFormattedMessage());
+			addMdc(event, builder);
+			addKeyValuePairs(event, builder);
+			if (event.hasThrowable()) {
+				builder.attribute("error.type", event.getThrowableClassName());
+				builder.attribute("error.message", event.getThrowableMessage());
+				builder.attribute("error.stack_trace", event.getThrowableStackTraceAsString());
+			}
+			builder.attribute("ecs.version", "8.11");
+		}
+
+		private void addKeyValuePairs(LogEvent event, JsonBuilder builder) {
+			Map<String, Object> keyValuePairs = event.getKeyValuePairs();
+			if (CollectionUtils.isEmpty(keyValuePairs)) {
+				return;
+			}
+			keyValuePairs.forEach((key, value) -> builder.attribute(key, ObjectUtils.nullSafeToString(value)));
+		}
+
+		private static void addMdc(LogEvent event, JsonBuilder builder) {
+			Map<String, String> mdc = event.getMdc();
+			if (CollectionUtils.isEmpty(mdc)) {
+				return;
+			}
+			mdc.forEach(builder::attribute);
+		}
+
+	}
+
+	private static final class LogstashJsonFormat implements JsonFormat {
+
+		@Override
+		public void write(LogEvent event, JsonBuilder builder) {
+			OffsetDateTime time = OffsetDateTime.ofInstant(event.getTimestamp(), ZoneId.systemDefault());
+			builder.attribute("@timestamp", DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(time));
+			builder.attribute("@version", "1");
+			builder.attribute("message", event.getFormattedMessage());
+			builder.attribute("logger_name", event.getLoggerName());
+			builder.attribute("thread_name", event.getThreadName());
+			builder.attribute("level", event.getLevel());
+			builder.attribute("level_value", event.getLevelValue());
+			addMdc(event, builder);
+			addKeyValuePairs(event, builder);
+			addMarkers(event, builder);
+			if (event.hasThrowable()) {
+				builder.attribute("stack_trace", event.getThrowableStackTraceAsString());
+			}
+		}
+
+		private void addMarkers(LogEvent event, JsonBuilder builder) {
+			Set<String> markers = event.getMarkers();
+			if (CollectionUtils.isEmpty(markers)) {
+				return;
+			}
+			builder.attribute("tags", markers);
+		}
+
+		private void addKeyValuePairs(LogEvent event, JsonBuilder builder) {
+			Map<String, Object> keyValuePairs = event.getKeyValuePairs();
+			if (CollectionUtils.isEmpty(keyValuePairs)) {
+				return;
+			}
+			keyValuePairs.forEach((key, value) -> builder.attribute(key, ObjectUtils.nullSafeToString(value)));
+		}
+
+		private static void addMdc(LogEvent event, JsonBuilder builder) {
+			Map<String, String> mdc = event.getMdc();
+			if (CollectionUtils.isEmpty(mdc)) {
+				return;
+			}
+			mdc.forEach(builder::attribute);
+		}
+
+	}
+
+}