org.apache.flink.runtime.rest.handler.util.HandlerRequestUtils Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
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* 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,
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*/
package org.apache.flink.runtime.rest.handler.util;
import org.apache.flink.runtime.rest.handler.HandlerRequest;
import org.apache.flink.runtime.rest.handler.RestHandlerException;
import org.apache.flink.runtime.rest.messages.MessageParameters;
import org.apache.flink.runtime.rest.messages.MessageQueryParameter;
import org.apache.flink.runtime.rest.messages.RequestBody;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
import java.util.List;
/**
* Utils for getting query parameters from {@link HandlerRequest}.
*/
public class HandlerRequestUtils {
/**
* Returns the value of a query parameter, or {@code null} if the query parameter is not set.
* @throws RestHandlerException If the query parameter is repeated.
*/
public static , R extends RequestBody, M extends MessageParameters> X getQueryParameter(
final HandlerRequest request,
final Class queryParameterClass) throws RestHandlerException {
return getQueryParameter(request, queryParameterClass, null);
}
public static , R extends RequestBody, M extends MessageParameters> X getQueryParameter(
final HandlerRequest request,
final Class queryParameterClass,
final X defaultValue) throws RestHandlerException {
final List values = request.getQueryParameter(queryParameterClass);
final X value;
if (values.size() > 1) {
throw new RestHandlerException(
String.format("Expected only one value %s.", values),
HttpResponseStatus.BAD_REQUEST);
} else if (values.size() == 1) {
value = values.get(0);
} else {
value = defaultValue;
}
return value;
}
}