net.logstash.logback.composite.JsonWritingUtils Maven / Gradle / Ivy
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/*
* Copyright 2013-2022 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
*
* http://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 net.logstash.logback.composite;
import java.io.IOException;
import java.util.Map;
import net.logstash.logback.fieldnames.LogstashCommonFieldNames;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonMappingException;
/**
* Utilities for writing JSON
*
* Note: This class is for internal use only and subject to backward incompatible change
* at any time.
*/
public class JsonWritingUtils {
/**
* Writes entries of the map as fields.
*
* @param generator the {@link JsonGenerator} to produce JSON content
* @param map map whose entries are written as JSON field/values
*
* @throws IOException if an I/O error occurs
* @throws JsonMappingException when problem to convert map values of type Object into JSON
*/
public static void writeMapEntries(JsonGenerator generator, Map map) throws IOException, JsonMappingException {
if (map != null) {
for (Map.Entry entry : map.entrySet()) {
if (entry.getKey() != null && entry.getValue() != null) {
generator.writeFieldName(entry.getKey().toString());
generator.writeObject(entry.getValue());
}
}
}
}
/**
* Writes a map as String fields to the generator if and only if the {@code fieldName}
* and values are not {@code null}.
*
* @param generator the {@link JsonGenerator} to produce JSON content
* @param fieldName name of the JSON property to write the map content under
* @param map map whose entries are written as JSON field/values
*
* @throws IOException if an I/O error occurs
* @throws JsonMappingException when problem to convert map values of type Object into JSON
*/
public static void writeMapStringFields(JsonGenerator generator, String fieldName, Map map) throws IOException, JsonMappingException {
writeMapStringFields(generator, fieldName, map, false);
}
/**
* Writes a map as String fields to the generator if and only if the {@code fieldName}
* and values are not {@code null}.
*
* @param generator the {@link JsonGenerator} to produce JSON content
* @param fieldName name of the JSON property to write the map content under
* @param map map whose entries are written as JSON field/values
* @param lowerCaseKeys when true, the map keys will be written in lower case.
*
* @throws IOException if an I/O error occurs
* @throws JsonMappingException when problem to convert map values of type Object into JSON
*/
public static void writeMapStringFields(JsonGenerator generator, String fieldName, Map map, boolean lowerCaseKeys) throws IOException, JsonMappingException {
if (shouldWriteField(fieldName) && map != null && !map.isEmpty()) {
generator.writeObjectFieldStart(fieldName);
for (Map.Entry entry : map.entrySet()) {
String key = entry.getKey() != null && lowerCaseKeys
? entry.getKey().toLowerCase()
: entry.getKey();
writeStringField(generator, key, entry.getValue());
}
generator.writeEndObject();
}
}
/**
* Writes an array of strings to the generator if and only if the {@code fieldName}
* and values are not {@code null}.
*
* @param generator the {@link JsonGenerator} to produce JSON content
* @param fieldName the field name
* @param fieldValues the field values
*
* @throws IOException if an I/O error occurs
*/
public static void writeStringArrayField(JsonGenerator generator, String fieldName, String[] fieldValues) throws IOException {
if (shouldWriteField(fieldName) && fieldValues != null && fieldValues.length > 0) {
generator.writeArrayFieldStart(fieldName);
for (String fieldValue : fieldValues) {
generator.writeString(fieldValue);
}
generator.writeEndArray();
}
}
/**
* Writes the field to the generator if and only if the {@code fieldName} and
* {@code fieldValue} are not {@code null}.
*
* @param generator the {@link JsonGenerator} to produce JSON content
* @param fieldName the field name
* @param fieldValue the field value
*
* @throws IOException if an I/O error occurs
*/
public static void writeStringField(JsonGenerator generator, String fieldName, String fieldValue) throws IOException {
if (shouldWriteField(fieldName) && fieldValue != null) {
generator.writeStringField(fieldName, fieldValue);
}
}
/**
* Writes the field to the generator if and only if the {@code fieldName} is not {@code null}.
*
* @param generator the {@link JsonGenerator} to produce JSON content
* @param fieldName the field name
* @param fieldValue the field value
*
* @throws IOException if an I/O error occurs
*/
public static void writeNumberField(JsonGenerator generator, String fieldName, int fieldValue) throws IOException {
if (shouldWriteField(fieldName)) {
generator.writeNumberField(fieldName, fieldValue);
}
}
/**
* Writes the field to the generator if and only if the {@code fieldName} is not {@code null}.
*
* @param generator the {@link JsonGenerator} to produce JSON content
* @param fieldName the field name
* @param fieldValue the field value
*
* @throws IOException if an I/O error occurs
*/
public static void writeNumberField(JsonGenerator generator, String fieldName, long fieldValue) throws IOException {
if (shouldWriteField(fieldName)) {
generator.writeNumberField(fieldName, fieldValue);
}
}
/**
* Indicates whether the given field name must be written or not.
* A field should be written if its name is not null and not ignored.
*
* @param fieldName the field name
* @return {@code true} if the field should be written, {@code false} otherwise
*
* @see LogstashCommonFieldNames#IGNORE_FIELD_INDICATOR
*/
public static boolean shouldWriteField(String fieldName) {
return fieldName != null && !fieldName.equals(LogstashCommonFieldNames.IGNORE_FIELD_INDICATOR);
}
}