org.apache.pulsar.client.impl.schema.JSONSchema Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.pulsar.client.impl.schema;
import static org.apache.pulsar.client.impl.schema.util.SchemaUtil.parseSchemaInfo;
import com.fasterxml.jackson.annotation.JsonInclude;
import org.apache.pulsar.shade.com.fasterxml.jackson.core.JsonProcessingException;
import org.apache.pulsar.shade.com.fasterxml.jackson.databind.DeserializationFeature;
import org.apache.pulsar.shade.com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.pulsar.shade.com.fasterxml.jackson.databind.ObjectWriter;
import org.apache.pulsar.shade.com.fasterxml.jackson.module.jsonSchema.JsonSchema;
import org.apache.pulsar.shade.com.fasterxml.jackson.module.jsonSchema.JsonSchemaGenerator;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;
import lombok.extern.slf4j.Slf4j;
import org.apache.pulsar.client.api.schema.SchemaDefinition;
import org.apache.pulsar.client.api.schema.SchemaReader;
import org.apache.pulsar.client.api.schema.SchemaWriter;
import org.apache.pulsar.client.impl.schema.reader.JacksonJsonReader;
import org.apache.pulsar.client.impl.schema.writer.JacksonJsonWriter;
import org.apache.pulsar.common.schema.SchemaInfo;
import org.apache.pulsar.common.schema.SchemaType;
import org.apache.pulsar.common.util.ObjectMapperFactory;
/**
* A schema implementation to deal with json data.
*/
@Slf4j
public class JSONSchema extends AvroBaseStructSchema {
private static final AtomicReference JSON_MAPPER = new AtomicReference<>(createObjectMapper());
private static ObjectMapper createObjectMapper() {
ObjectMapper mapper = ObjectMapperFactory.create();
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
// keep backwards compatibility, don't accept unknown enum values
mapper.configure(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL, false);
mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
return mapper;
}
private static ObjectMapper jsonMapper() {
return JSON_MAPPER.get();
}
private final Class pojo;
private JSONSchema(SchemaInfo schemaInfo, Class pojo, SchemaReader reader, SchemaWriter writer) {
super(schemaInfo);
this.pojo = pojo;
setWriter(writer);
setReader(reader);
}
/**
* Implemented for backwards compatibility reasons.
* since the original schema generated by JSONSchema was based off the json schema standard
* since then we have standardized on Avro
*
* @return
*/
public SchemaInfo getBackwardsCompatibleJsonSchemaInfo() {
SchemaInfo backwardsCompatibleSchemaInfo;
try {
ObjectWriter objectWriter = ObjectMapperFactory.getMapperWithIncludeAlways().writer();
JsonSchemaGenerator schemaGen = new JsonSchemaGenerator(objectWriter);
JsonSchema jsonBackwardsCompatibleSchema = schemaGen.generateSchema(pojo);
backwardsCompatibleSchemaInfo = SchemaInfoImpl.builder()
.name("")
.properties(schemaInfo.getProperties())
.type(SchemaType.JSON)
.schema(objectWriter.writeValueAsBytes(jsonBackwardsCompatibleSchema))
.build();
} catch (JsonProcessingException ex) {
throw new RuntimeException(ex);
}
return backwardsCompatibleSchemaInfo;
}
public static JSONSchema of(SchemaDefinition schemaDefinition) {
SchemaReader reader = schemaDefinition.getSchemaReaderOpt()
.orElseGet(() -> new JacksonJsonReader<>(jsonMapper(), schemaDefinition.getPojo()));
SchemaWriter writer = schemaDefinition.getSchemaWriterOpt()
.orElseGet(() -> new JacksonJsonWriter<>(jsonMapper()));
return new JSONSchema<>(parseSchemaInfo(schemaDefinition, SchemaType.JSON), schemaDefinition.getPojo(),
reader, writer);
}
public static JSONSchema of(Class pojo) {
return JSONSchema.of(SchemaDefinition.builder().withPojo(pojo).build());
}
public static JSONSchema of(Class pojo, Map properties) {
return JSONSchema.of(SchemaDefinition.builder().withPojo(pojo).withProperties(properties).build());
}
/**
* Clears the caches tied to the ObjectMapper instances and replaces the singleton ObjectMapper instance.
*
* This can be used in tests to ensure that classloaders and class references don't leak across tests.
*/
public static void clearCaches() {
jsonMapper().getTypeFactory().clearCache();
replaceSingletonInstance();
}
private static void replaceSingletonInstance() {
// recycle the singleton instance to release remaining caches
JSON_MAPPER.set(createObjectMapper());
}
}