org.opensearch.rest.DeprecationRestHandler Maven / Gradle / Ivy
Show all versions of opensearch Show documentation
/*
* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*/
package org.opensearch.rest;
import org.opensearch.client.node.NodeClient;
import org.opensearch.common.logging.DeprecationLogger;
import org.opensearch.core.common.Strings;
import java.util.Objects;
/**
* {@code DeprecationRestHandler} provides a proxy for any existing {@link RestHandler} so that usage of the handler can be
* logged using the {@link DeprecationLogger}.
*
* @opensearch.api
*/
public class DeprecationRestHandler implements RestHandler {
private final RestHandler handler;
private final String deprecationMessage;
private final DeprecationLogger deprecationLogger;
/**
* Create a {@link DeprecationRestHandler} that encapsulates the {@code handler} using the {@code deprecationLogger} to log
* deprecation {@code warning}.
*
* @param handler The rest handler to deprecate (it's possible that the handler is reused with a different name!)
* @param deprecationMessage The message to warn users with when they use the {@code handler}
* @param deprecationLogger The deprecation logger
* @throws NullPointerException if any parameter except {@code deprecationMessage} is {@code null}
* @throws IllegalArgumentException if {@code deprecationMessage} is not a valid header
*/
public DeprecationRestHandler(RestHandler handler, String deprecationMessage, DeprecationLogger deprecationLogger) {
this.handler = Objects.requireNonNull(handler);
this.deprecationMessage = requireValidHeader(deprecationMessage);
this.deprecationLogger = Objects.requireNonNull(deprecationLogger);
}
/**
* {@inheritDoc}
*
* Usage is logged via the {@link DeprecationLogger} so that the actual response can be notified of deprecation as well.
*/
@Override
public void handleRequest(RestRequest request, RestChannel channel, NodeClient client) throws Exception {
deprecationLogger.deprecate("deprecated_route", deprecationMessage);
handler.handleRequest(request, channel, client);
}
@Override
public boolean supportsContentStream() {
return handler.supportsContentStream();
}
/**
* This does a very basic pass at validating that a header's value contains only expected characters according to RFC-5987, and those
* that it references.
*
* https://tools.ietf.org/html/rfc5987
*
* This is only expected to be used for assertions. The idea is that only readable US-ASCII characters are expected; the rest must be
* encoded with percent encoding, which makes checking for a valid character range very simple.
*
* @param value The header value to check
* @return {@code true} if the {@code value} is not obviously wrong.
*/
public static boolean validHeaderValue(String value) {
if (Strings.hasText(value) == false) {
return false;
}
for (int i = 0; i < value.length(); i++) {
char c = value.charAt(i);
// 32 = ' ' (31 = unit separator); 126 = '~' (127 = DEL)
if (c < 32 || c > 126) {
return false;
}
}
return true;
}
/**
* Throw an exception if the {@code value} is not a {@link #validHeaderValue(String) valid header}.
*
* @param value The header value to check
* @return Always {@code value}.
* @throws IllegalArgumentException if {@code value} is not a {@link #validHeaderValue(String) valid header}.
*/
public static String requireValidHeader(String value) {
if (validHeaderValue(value) == false) {
throw new IllegalArgumentException("header value must contain only US ASCII text");
}
return value;
}
}