Introduce high level client (#25086)

The high level client supports the following apis: ping, info, index, bulk, get, delete, update, search, search scroll and clear scroll. Also, the BulkProcessor has been updated so that it can be used with the high level client as well.

Author: javanna

buildSrc/src/main/resources/forbidden/http-signatures.txt

@@ -0,0 +1,45 @@
+# 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.
+
+@defaultMessage Explicitly specify the ContentType of HTTP entities when creating
+org.apache.http.entity.StringEntity#<init>(java.lang.String)
+org.apache.http.entity.StringEntity#<init>(java.lang.String,java.lang.String)
+org.apache.http.entity.StringEntity#<init>(java.lang.String,java.nio.charset.Charset)
+org.apache.http.entity.ByteArrayEntity#<init>(byte[])
+org.apache.http.entity.ByteArrayEntity#<init>(byte[],int,int)
+org.apache.http.entity.FileEntity#<init>(java.io.File)
+org.apache.http.entity.InputStreamEntity#<init>(java.io.InputStream)
+org.apache.http.entity.InputStreamEntity#<init>(java.io.InputStream,long)
+org.apache.http.nio.entity.NByteArrayEntity#<init>(byte[])
+org.apache.http.nio.entity.NByteArrayEntity#<init>(byte[],int,int)
+org.apache.http.nio.entity.NFileEntity#<init>(java.io.File)
+org.apache.http.nio.entity.NStringEntity#<init>(java.lang.String)
+org.apache.http.nio.entity.NStringEntity#<init>(java.lang.String,java.lang.String)
+
+@defaultMessage Use non-deprecated constructors
+org.apache.http.nio.entity.NFileEntity#<init>(java.io.File,java.lang.String)
+org.apache.http.nio.entity.NFileEntity#<init>(java.io.File,java.lang.String,boolean)
+org.apache.http.entity.FileEntity#<init>(java.io.File,java.lang.String)
+org.apache.http.entity.StringEntity#<init>(java.lang.String,java.lang.String,java.lang.String)
+
+@defaultMessage BasicEntity is easy to mess up and forget to set content type
+org.apache.http.entity.BasicHttpEntity#<init>()
+
+@defaultMessage EntityTemplate is easy to mess up and forget to set content type
+org.apache.http.entity.EntityTemplate#<init>(org.apache.http.entity.ContentProducer)
+
+@defaultMessage SerializableEntity uses java serialization and makes it easy to forget to set content type
+org.apache.http.entity.SerializableEntity#<init>(java.io.Serializable)

client/rest-high-level/build.gradle

@@ -0,0 +1,51 @@
+import org.elasticsearch.gradle.precommit.PrecommitTasks
+
+/*
+ * 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.
+ */
+apply plugin: 'elasticsearch.build'
+apply plugin: 'elasticsearch.rest-test'
+
+group = 'org.elasticsearch.client'
+
+dependencies {
+  compile "org.elasticsearch:elasticsearch:${version}"
+  compile "org.elasticsearch.client:rest:${version}"
+  compile "org.elasticsearch.plugin:parent-join-client:${version}"
+  compile "org.elasticsearch.plugin:aggs-matrix-stats-client:${version}"
+
+  testCompile "org.elasticsearch.client:test:${version}"
+  testCompile "org.elasticsearch.test:framework:${version}"
+  testCompile "com.carrotsearch.randomizedtesting:randomizedtesting-runner:${versions.randomizedrunner}"
+  testCompile "junit:junit:${versions.junit}"
+  testCompile "org.hamcrest:hamcrest-all:${versions.hamcrest}"
+}
+
+dependencyLicenses {
+  // Don't check licenses for dependency that are part of the elasticsearch project
+  // But any other dependency should have its license/notice/sha1
+  dependencies = project.configurations.runtime.fileCollection {
+    it.group.startsWith('org.elasticsearch') == false
+  }
+}
+
+forbiddenApisMain {
+  // core does not depend on the httpclient for compile so we add the signatures here. We don't add them for test as they are already
+  // specified
+  signaturesURLs += [PrecommitTasks.getResource('/forbidden/http-signatures.txt')]
+}