org.springframework.http.client.MultipartBodyBuilder Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or authors.
*
* 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.springframework.http.client;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.function.Consumer;
import org.reactivestreams.Publisher;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.core.ResolvableType;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
/**
* A mutable builder for multipart form bodies. For example:
*
*
* MultipartBodyBuilder builder = new MultipartBodyBuilder();
* builder.part("form field", "form value");
*
* Resource image = new ClassPathResource("image.jpg");
* builder.part("image", image).header("Baz", "Qux");
*
* MultiValueMap<String, HttpEntity<?>> multipartBody = builder.build();
* // use multipartBody with RestTemplate or WebClient
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @since 5.0.2
* @see RFC 7578
*/
public final class MultipartBodyBuilder {
private final LinkedMultiValueMap parts = new LinkedMultiValueMap<>();
/**
* Creates a new, empty instance of the {@code MultipartBodyBuilder}.
*/
public MultipartBodyBuilder() {
}
/**
* Add a part from an Object.
* @param name the name of the part to add
* @param part the part data
* @return builder that allows for further customization of part headers
*/
public PartBuilder part(String name, Object part) {
return part(name, part, null);
}
/**
* Variant of {@link #part(String, Object)} that also accepts a MediaType
* which is used to determine how to encode the part.
* @param name the name of the part to add
* @param part the part data
* @param contentType the media type for the part
* @return builder that allows for further customization of part headers
*/
public PartBuilder part(String name, Object part, @Nullable MediaType contentType) {
Assert.hasLength(name, "'name' must not be empty");
Assert.notNull(part, "'part' must not be null");
if (part instanceof Publisher) {
throw new IllegalArgumentException("Use publisher(String, Publisher, Class) or " +
"publisher(String, Publisher, ParameterizedTypeReference) for adding Publisher parts");
}
if (part instanceof PublisherEntity) {
PublisherPartBuilder builder = new PublisherPartBuilder<>((PublisherEntity) part);
this.parts.add(name, builder);
return builder;
}
Object partBody;
HttpHeaders partHeaders = new HttpHeaders();
if (part instanceof HttpEntity) {
HttpEntity httpEntity = (HttpEntity) part;
partBody = httpEntity.getBody();
partHeaders.addAll(httpEntity.getHeaders());
}
else {
partBody = part;
}
if (contentType != null) {
partHeaders.setContentType(contentType);
}
DefaultPartBuilder builder = new DefaultPartBuilder(partHeaders, partBody);
this.parts.add(name, builder);
return builder;
}
/**
* Add an asynchronous part with {@link Publisher}-based content.
* @param name the name of the part to add
* @param publisher the part contents
* @param elementClass the type of elements contained in the publisher
* @return builder that allows for further customization of part headers
*/
public > PartBuilder asyncPart(String name, P publisher, Class elementClass) {
Assert.hasLength(name, "'name' must not be empty");
Assert.notNull(publisher, "'publisher' must not be null");
Assert.notNull(elementClass, "'elementClass' must not be null");
HttpHeaders headers = new HttpHeaders();
PublisherPartBuilder builder = new PublisherPartBuilder<>(headers, publisher, elementClass);
this.parts.add(name, builder);
return builder;
}
/**
* Variant of {@link #asyncPart(String, Publisher, Class)} that accepts a
* {@link ParameterizedTypeReference} for the element type, which allows
* specifying generic type information.
* @param name the name of the part to add
* @param publisher the part contents
* @param typeReference the type of elements contained in the publisher
* @return builder that allows for further customization of part headers
*/
public > PartBuilder asyncPart(
String name, P publisher, ParameterizedTypeReference typeReference) {
Assert.hasLength(name, "'name' must not be empty");
Assert.notNull(publisher, "'publisher' must not be null");
Assert.notNull(typeReference, "'typeReference' must not be null");
HttpHeaders headers = new HttpHeaders();
PublisherPartBuilder builder = new PublisherPartBuilder<>(headers, publisher, typeReference);
this.parts.add(name, builder);
return builder;
}
/**
* Return a {@code MultiValueMap} with the configured parts.
*/
public MultiValueMap> build() {
MultiValueMap> result = new LinkedMultiValueMap<>(this.parts.size());
for (Map.Entry> entry : this.parts.entrySet()) {
for (DefaultPartBuilder builder : entry.getValue()) {
HttpEntity entity = builder.build();
result.add(entry.getKey(), entity);
}
}
return result;
}
/**
* Builder that allows for further customization of part headers.
*/
public interface PartBuilder {
/**
* Add part header values.
* @param headerName the part header name
* @param headerValues the part header value(s)
* @return this builder
* @see HttpHeaders#addAll(String, List)
*/
PartBuilder header(String headerName, String... headerValues);
/**
* Manipulate the part headers through the given consumer.
* @param headersConsumer consumer to manipulate the part headers with
* @return this builder
*/
PartBuilder headers(Consumer headersConsumer);
}
private static class DefaultPartBuilder implements PartBuilder {
protected final HttpHeaders headers;
@Nullable
protected final Object body;
public DefaultPartBuilder(HttpHeaders headers, @Nullable Object body) {
this.headers = headers;
this.body = body;
}
@Override
public PartBuilder header(String headerName, String... headerValues) {
this.headers.addAll(headerName, Arrays.asList(headerValues));
return this;
}
@Override
public PartBuilder headers(Consumer headersConsumer) {
headersConsumer.accept(this.headers);
return this;
}
public HttpEntity build() {
return new HttpEntity<>(this.body, this.headers);
}
}
private static class PublisherPartBuilder> extends DefaultPartBuilder {
private final ResolvableType resolvableType;
public PublisherPartBuilder(HttpHeaders headers, P body, Class elementClass) {
super(headers, body);
this.resolvableType = ResolvableType.forClass(elementClass);
}
public PublisherPartBuilder(HttpHeaders headers, P body, ParameterizedTypeReference typeReference) {
super(headers, body);
this.resolvableType = ResolvableType.forType(typeReference);
}
public PublisherPartBuilder(PublisherEntity other) {
super(other.getHeaders(), other.getBody());
this.resolvableType = other.getResolvableType();
}
@Override
@SuppressWarnings("unchecked")
public HttpEntity build() {
P publisher = (P) this.body;
Assert.state(publisher != null, "Publisher must not be null");
return new PublisherEntity<>(this.headers, publisher, this.resolvableType);
}
}
/**
* Specialization of {@link HttpEntity} for use with a
* {@link Publisher}-based body, for which we also need to keep track of
* the element type.
* @param the type contained in the publisher
* @param the publisher
*/
public static final class PublisherEntity> extends HttpEntity {
private final ResolvableType resolvableType;
private PublisherEntity(@Nullable MultiValueMap headers, P publisher,
ResolvableType resolvableType) {
super(publisher, headers);
Assert.notNull(publisher, "'publisher' must not be null");
Assert.notNull(resolvableType, "'resolvableType' must not be null");
this.resolvableType = resolvableType;
}
/**
* Return the element type for the {@code Publisher} body.
*/
public ResolvableType getResolvableType() {
return this.resolvableType;
}
}
}