org.hawkular.inventory.json.TenantlessPathSerializer Maven / Gradle / Ivy
/*
* Copyright 2014-2017 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* 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 org.hawkular.inventory.json;
import java.io.IOException;
import org.hawkular.inventory.paths.Path;
import org.hawkular.inventory.paths.RelativePath;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
/**
* Used to strip the tenant from the canonical path when serializing it.
*
* Note that while the stripping can be done using a custom serializer statelessly, the re-introduction of the tenant
* id to the paths needs manual intervention because the resolution is contextual - it depends on the tenant ID as well
* as the intended type of the target entity and the path that the path is relative against (if the path is relative).
* That's why the {@link DetypedPathDeserializer} contains a couple of static methods to inject this context into it.
*
*
So while this serializer is universally usable, the deserializer is not. It can only be used in places that can
* reliably inject the necessary state before the deserialization occurs.
*
*
To use this path serializer to serialize canonical (and relative) paths, you need to configure Jackson for example
* by providing a mixin class with custom annotations.
*
* @author Lukas Krejci
* @see com.fasterxml.jackson.databind.ObjectMapper#addMixInAnnotations(Class, Class)
* @since 0.2.0
*/
public final class TenantlessPathSerializer extends JsonSerializer {
@Override
public void serialize(Path value, JsonGenerator jgen, SerializerProvider provider) throws IOException {
//this is easy for relative paths - just use its string representation
if (value instanceof RelativePath) {
jgen.writeString(value.toString());
return;
}
//strip the tenant from the canonical path so that it appears to users it doesn't even exist. They don't
//need to provide it in their paths and the API doesn't show it to them either.
String output = value.toString();
int firstDelimIdx = output.indexOf(Path.PATH_DELIM);
int secondDelim = output.indexOf(Path.PATH_DELIM, firstDelimIdx + 1);
if (secondDelim < 0) {
jgen.writeString(output);
} else {
jgen.writeString(output.substring(secondDelim));
}
}
}