Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF 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. */ package org.jclouds.http; import static com.google.common.base.Preconditions.checkNotNull; import java.io.File; import java.io.InputStream; import java.util.Collection; import org.jclouds.functions.ToLowerCase; import org.jclouds.http.internal.PayloadEnclosingImpl; import org.jclouds.io.Payload; import org.jclouds.io.Payloads; import org.jclouds.javax.annotation.Nullable; import org.jclouds.util.Multimaps2; import com.google.common.base.Objects; import com.google.common.base.Objects.ToStringHelper; import com.google.common.collect.ImmutableMultimap; import com.google.common.collect.Multimap; /** * Represents a request that can be executed within {@link HttpCommandExecutorService} * * @author Adrian Cole */ public class HttpMessage extends PayloadEnclosingImpl { public static Builder<?> builder() { return new ConcreteBuilder(); } public Builder<?> toBuilder() { return new ConcreteBuilder().fromHttpMessage(this); } public abstract static class Builder<T extends Builder<T>> { protected abstract T self(); protected ImmutableMultimap.Builder<String, String> headers = ImmutableMultimap.<String, String>builder(); protected Payload payload; /** * @see HttpMessage#getPayload() */ public T payload(Payload payload) { this.payload = payload; return self(); } /** * @see HttpMessage#getPayload() */ public T payload(byte[] payload) { this.payload = Payloads.newByteArrayPayload(checkNotNull(payload, "payload")); return self(); } /** * @see HttpMessage#getPayload() */ public T payload(File payload) { this.payload = Payloads.newFilePayload(checkNotNull(payload, "payload")); return self(); } /** * @see HttpMessage#getPayload() */ public T payload(InputStream payload) { this.payload = Payloads.newInputStreamPayload(checkNotNull(payload, "payload")); return self(); } /** * @see HttpMessage#getPayload() */ public T payload(String payload) { this.payload = Payloads.newStringPayload(checkNotNull(payload, "payload")); return self(); } /** * replaces all headers with the the supplied multimap. * * @see HttpMessage#getHeaders() */ public T headers(Multimap<String, String> headers) { this.headers = ImmutableMultimap.<String, String>builder(); this.headers.putAll(checkNotNull(headers, "headers")); return self(); } /** * replace all headers that have the same keys as the input multimap * * @see HttpMessage#getHeaders() */ public T replaceHeaders(Multimap<String, String> headers) { checkNotNull(headers, "headers"); Multimap<String, String> oldHeaders = this.headers.build(); this.headers = ImmutableMultimap.<String, String>builder(); this.headers.putAll(Multimaps2.replaceEntries(oldHeaders, headers)); return self(); } /** * replace all headers that have the same keys as the input multimap * * @see HttpMessage#getHeaders() */ public T removeHeader(String name) { checkNotNull(name, "name"); Multimap<String, String> oldHeaders = this.headers.build(); this.headers = ImmutableMultimap.<String, String>builder(); this.headers.putAll(Multimaps2.withoutKey(oldHeaders, name)); return self(); } /** * Note that if there's an existing header of the same name, this will only add the new value, * not replace it. * * @see HttpMessage#getHeaders() */ public T addHeader(String name, String... values) { this.headers.putAll(checkNotNull(name, "name"), checkNotNull(values, "values of %s", name)); return self(); } /** * Replace header. * * @see HttpMessage#getHeaders() */ public T replaceHeader(String name, String... values) { checkNotNull(name, "name"); checkNotNull(values, "values of %s", name); return replaceHeaders(ImmutableMultimap.<String, String>builder().putAll(name, values).build()); } public HttpMessage build() { return new HttpMessage(headers.build(), payload); } public T fromHttpMessage(HttpMessage in) { return this.headers(in.getHeaders()).payload(in.getPayload()); } } private static class ConcreteBuilder extends Builder<ConcreteBuilder> { @Override protected ConcreteBuilder self() { return this; } } protected final Multimap<String, String> headers; protected HttpMessage(Multimap<String, String> headers, @Nullable Payload payload) { super(payload); this.headers = ImmutableMultimap.copyOf(checkNotNull(headers, "headers")); } public Multimap<String, String> getHeaders() { return headers; } /** * try to get the value, then try as lowercase. */ public String getFirstHeaderOrNull(String string) { Collection<String> values = headers.get(string); if (values.size() == 0) { Multimap<String, String> lowerCaseHeaders = Multimaps2.transformKeys(getHeaders(), new ToLowerCase()); values = lowerCaseHeaders.get(string.toLowerCase()); } return (values.size() >= 1) ? values.iterator().next() : null; } @Override public int hashCode() { return Objects.hashCode(headers, payload); } @Override public boolean equals(Object obj) { if (this == obj) return true; // testing equals by value, not by type if (!(obj instanceof HttpMessage)) return false; HttpMessage that = HttpMessage.class.cast(obj); return Objects.equal(this.headers, that.headers) && Objects.equal(this.payload, that.payload); } protected ToStringHelper string() { return Objects.toStringHelper("").omitNullValues().add("headers", headers).add("payload", payload); } @Override public String toString() { return string().toString(); } }