io.helidon.http.media.ReadableEntity Maven / Gradle / Ivy
/*
* Copyright (c) 2022, 2024 Oracle and/or its affiliates.
*
* 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 io.helidon.http.media;
import java.io.IOException;
import java.io.InputStream;
import java.io.UncheckedIOException;
import java.util.Optional;
import io.helidon.common.GenericType;
/**
* Readable HTTP entity.
* This may be server request entity, or client response entity.
*/
public interface ReadableEntity {
/**
* Input stream to read bytes of the entity.
* Cannot be combined with methods {@link #as(Class)} or {@link #as(io.helidon.common.GenericType)}
* If there is no entity, returns input stream on empty byte array.
*
* @return input stream to entity bytes
*/
InputStream inputStream();
/**
* Get the entity as a specific class.
* The entity will use {@link MediaContext} to find correct media mapper.
*
* @param type class of the entity
* @param type of the entity
* @return entity correctly typed
* @throws IllegalArgumentException in case the entity type is not supported
* @throws java.lang.IllegalStateException in case there is no entity
* @throws java.io.UncheckedIOException in case I/O fails
*/
default T as(Class type) {
return as(GenericType.create(type));
}
/**
* Get the entity as a specific class (optional).
* The entity will use {@link MediaContext} to find correct media mapper.
*
* @param type class of the entity
* @param type of the entity
* @return entity correctly typed, or an empty optional if entity is not present
* @throws IllegalArgumentException in case the entity type is not supported
* @throws java.io.UncheckedIOException in case I/O fails
*/
default Optional asOptional(Class type) {
return asOptional(GenericType.create(type));
}
/**
* Get the entity as a specific type.
* The entity will use {@link MediaContext} to find correct media mapper.
*
* @param type generic type of the entity
* @param type of the entity
* @return entity correctly typed
* @throws IllegalArgumentException in case the entity type is not supported
* @throws java.lang.IllegalStateException in case there is no entity
* @throws java.io.UncheckedIOException in case I/O fails
*/
T as(GenericType type);
/**
* Get the entity as a specific type (optional).
* The entity will use {@link MediaContext} to find correct media mapper.
*
* @param type generic type of the entity
* @param type of the entity
* @return entity correctly typed, or an empty optional if entity is not present
* @throws IllegalArgumentException in case the entity type is not supported
* @throws java.io.UncheckedIOException in case I/O fails
*/
Optional asOptional(GenericType type);
/**
* Whether an entity actually exists.
*
* @return {@code true} if an entity exists and can be read
*/
boolean hasEntity();
/**
* Whether this entity has been consumed already.
*
* @return {@code true} if the entity is already consumed; a consumed entity cannot be consumed again
*/
boolean consumed();
/**
* Copy this entity and add a new runnable to be executed after this entity is consumed.
*
* @param entityProcessedRunnable runnable to execute on consumed entity
* @return a new entity delegating to this entity
*/
ReadableEntity copy(Runnable entityProcessedRunnable);
/**
* Consume the entity if not yet consumed.
* Reads all bytes from the entity and discards them. If entity is larger than allowed, appropriate HTTP exception is thrown.
* If entity is already consumed, this is a no-op.
*/
default void consume() {
if (consumed()) {
return;
}
try (InputStream inputStream = inputStream()) {
byte[] buffer = new byte[2048];
while (inputStream.read(buffer) > 0) {
// ignore
}
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
}