feat: REST Gapic (REGAPIC) Support

build.gradle

@@ -132,6 +132,8 @@ subprojects {
       'maven.io_grpc_grpc_protobuf': "io.grpc:grpc-protobuf:${libraries['version.io_grpc']}",
       'maven.io_grpc_grpc_netty_shaded': "io.grpc:grpc-netty-shaded:${libraries['version.io_grpc']}",
       'maven.io_grpc_grpc_alts': "io.grpc:grpc-alts:${libraries['version.io_grpc']}",
+      'maven.com_google_protobuf': "com.google.protobuf:protobuf-java:${libraries['version.com_google_protobuf']}",
+      'maven.com_google_protobuf_java_util': "com.google.protobuf:protobuf-java-util:${libraries['version.com_google_protobuf']}"
     ])
   }
 

gax-httpjson/BUILD.bazel

@@ -19,6 +19,8 @@ _COMPILE_DEPS = [
     "@com_google_auto_value_auto_value//jar",
     "@com_google_http_client_google_http_client_jackson2//jar",
     "@javax_annotation_javax_annotation_api//jar",
+    "@com_google_protobuf//:protobuf_java",
+    "@com_google_protobuf_java_util//jar",
     "//gax:gax",
 ]
 

gax-httpjson/build.gradle

@@ -5,6 +5,8 @@ project.version = "0.75.3-SNAPSHOT" // {x-version-update:gax-httpjson:current}
 
 dependencies {
   compile project(':gax'),
+    libraries['maven.com_google_protobuf'],
+    libraries['maven.com_google_protobuf_java_util'],
     libraries['maven.com_google_code_gson_gson'],
     libraries['maven.com_google_guava_guava'],
     libraries['maven.com_google_code_findbugs_jsr305'],

gax-httpjson/src/main/java/com/google/api/gax/httpjson/FieldsExtractor.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google LLC nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.google.api.gax.httpjson;
+
+public interface FieldsExtractor<RequestT, ParamsT> {
+  ParamsT extract(RequestT request);
+}

gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpRequestRunnable.java

@@ -103,7 +103,8 @@ HttpRequest createHttpRequest() throws IOException {
     }
 
     // Populate URL path and query parameters.
-    GenericUrl url = new GenericUrl(getEndpoint() + requestFormatter.getPath(getRequest()));
+    String endpoint = normalizeEndpoint(getEndpoint());
+    GenericUrl url = new GenericUrl(endpoint + requestFormatter.getPath(getRequest()));
     Map<String, List<String>> queryParams = requestFormatter.getQueryParamNames(getRequest());
     for (Entry<String, List<String>> queryParam : queryParams.entrySet()) {
       if (queryParam.getValue() != null) {
@@ -120,6 +121,21 @@ HttpRequest createHttpRequest() throws IOException {
     return httpRequest;
   }
 
+  // This will be frequently executed, so avoiding using regexps if not necessary.
+  private String normalizeEndpoint(String endpoint) {
+    String normalized = endpoint;
+    // Set protocol as https by default if not set explicitly
+    if (!normalized.contains("://")) {
+      normalized = "https://" + normalized;
+    }
+
+    if (normalized.charAt(normalized.length() - 1) != '/') {
+      normalized += '/';
+    }
+
+    return normalized;
+  }
+
   @Override
   public void run() {
     try {

gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageRequestFormatter.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google LLC nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.google.api.gax.httpjson;
+
+import com.google.api.pathtemplate.PathTemplate;
+import com.google.protobuf.Message;
+import java.util.List;
+import java.util.Map;
+
+public class ProtoMessageRequestFormatter<RequestT extends Message>
+    implements HttpRequestFormatter<RequestT> {
+
+  private final FieldsExtractor<RequestT, String> requestBodyExtractor;
+  private final FieldsExtractor<RequestT, Map<String, List<String>>> queryParamsExtractor;
+  private final PathTemplate pathTemplate;
+  private final FieldsExtractor<RequestT, Map<String, String>> pathVarsExtractor;
+
+  private ProtoMessageRequestFormatter(
+      FieldsExtractor<RequestT, String> requestBodyExtractor,
+      FieldsExtractor<RequestT, Map<String, List<String>>> queryParamsExtractor,
+      PathTemplate pathTemplate,
+      FieldsExtractor<RequestT, Map<String, String>> pathVarsExtractor) {
+    this.requestBodyExtractor = requestBodyExtractor;
+    this.queryParamsExtractor = queryParamsExtractor;
+    this.pathTemplate = pathTemplate;
+    this.pathVarsExtractor = pathVarsExtractor;
+  }
+
+  public static <RequestT extends Message>
+      ProtoMessageRequestFormatter.Builder<RequestT> newBuilder() {
+    return new Builder<>();
+  }
+
+  @Override
+  public Map<String, List<String>> getQueryParamNames(RequestT apiMessage) {
+    return queryParamsExtractor.extract(apiMessage);
+  }
+
+  @Override
+  public String getRequestBody(RequestT apiMessage) {
+    return requestBodyExtractor.extract(apiMessage);
+  }
+
+  @Override
+  public String getPath(RequestT apiMessage) {
+    return pathTemplate.instantiate(pathVarsExtractor.extract(apiMessage));
+  }
+
+  @Override
+  public PathTemplate getPathTemplate() {
+    return pathTemplate;
+  }
+
+  public static class Builder<RequestT extends Message> {
+    private FieldsExtractor<RequestT, String> requestBodyExtractor;
+    private FieldsExtractor<RequestT, Map<String, List<String>>> queryParamsExtractor;
+    private String path;
+    private FieldsExtractor<RequestT, Map<String, String>> pathVarsExtractor;
+
+    public Builder<RequestT> setRequestBodyExtractor(
+        FieldsExtractor<RequestT, String> requestBodyExtractor) {
+      this.requestBodyExtractor = requestBodyExtractor;
+      return this;
+    }
+
+    public Builder<RequestT> setQueryParamsExtractor(
+        FieldsExtractor<RequestT, Map<String, List<String>>> queryParamsExtractor) {
+      this.queryParamsExtractor = queryParamsExtractor;
+      return this;
+    }
+
+    public Builder<RequestT> setPath(
+        String path, FieldsExtractor<RequestT, Map<String, String>> pathVarsExtractor) {
+      this.path = path;
+      this.pathVarsExtractor = pathVarsExtractor;
+      return this;
+    }
+
+    public ProtoMessageRequestFormatter<RequestT> build() {
+      return new ProtoMessageRequestFormatter<>(
+          requestBodyExtractor, queryParamsExtractor, PathTemplate.create(path), pathVarsExtractor);
+    }
+  }
+}

gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageResponseParser.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google LLC nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.google.api.gax.httpjson;
+
+import com.google.protobuf.Message;
+import java.io.InputStream;
+
+public class ProtoMessageResponseParser<ResponseT extends Message>
+    implements HttpResponseParser<ResponseT> {
+
+  private final ResponseT defaultInstance;
+
+  private ProtoMessageResponseParser(ResponseT defaultInstance) {
+    this.defaultInstance = defaultInstance;
+  }
+
+  public static <RequestT extends Message>
+      ProtoMessageResponseParser.Builder<RequestT> newBuilder() {
+    return new ProtoMessageResponseParser.Builder<>();
+  }
+
+  @Override
+  public ResponseT parse(InputStream httpContent) {
+    return ProtoRestSerializer.<ResponseT>create()
+        .fromJson(httpContent, defaultInstance.newBuilderForType());
+  }
+
+  @Override
+  public String serialize(ResponseT response) {
+    return ProtoRestSerializer.create().toJson(response);
+  }
+
+  public static class Builder<ResponseT extends Message> {
+    private ResponseT defaultInstance;
+
+    public Builder<ResponseT> setDefaultInstance(ResponseT defaultInstance) {
+      this.defaultInstance = defaultInstance;
+      return this;
+    }
+
+    public ProtoMessageResponseParser<ResponseT> build() {
+      return new ProtoMessageResponseParser<>(defaultInstance);
+    }
+  }
+}

gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoRestSerializer.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google LLC nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.google.api.gax.httpjson;
+
+import com.google.common.collect.ImmutableList;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.Message;
+import com.google.protobuf.util.JsonFormat;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.List;
+import java.util.Map;
+
+public class ProtoRestSerializer<RequestT extends Message> {
+  private ProtoRestSerializer() {}
+
+  public static <RequestT extends Message> ProtoRestSerializer<RequestT> create() {
+    return new ProtoRestSerializer<>();
+  }
+
+  public String toJson(RequestT message) {
+    try {
+      return JsonFormat.printer().print(message);
+    } catch (InvalidProtocolBufferException e) {
+      throw new RuntimeException("Failed to serialize message to JSON", e);
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  public RequestT fromJson(InputStream message, Message.Builder builder) {
+    try (Reader json = new InputStreamReader(message)) {
+      JsonFormat.parser().ignoringUnknownFields().merge(json, builder);
+      return (RequestT) builder.build();
+    } catch (IOException e) {
+      throw new RuntimeException("Failed to parse response message", e);
+    }
+  }
+
+  public void toPathParam(Map<String, String> fields, String fieldName, Object fieldValue) {
+    if (isDefaultValue(fieldName, fieldValue)) {
+      return;
+    }
+    fields.put(fieldName, String.valueOf(fieldValue));
+  }
+
+  public void toQueryParam(Map<String, List<String>> fields, String fieldName, Object fieldValue) {
+    if (isDefaultValue(fieldName, fieldValue)) {
+      return;
+    }
+
+    ImmutableList.Builder<String> paramValueList = ImmutableList.builder();
+    if (fieldValue instanceof List<?>) {
+      for (Object fieldValueItem : (List<?>) fieldValue) {
+        paramValueList.add(String.valueOf(fieldValueItem));
+      }
+    } else {
+      paramValueList.add(String.valueOf(fieldValue));
+    }
+
+    fields.put(fieldName, paramValueList.build());
+  }
+
+  public String toBody(String fieldName, RequestT fieldValue) {
+    return toJson(fieldValue);
+  }
+
+  private boolean isDefaultValue(String fieldName, Object fieldValue) {
+    if (fieldValue instanceof Number) {
+      return ((Number) fieldValue).longValue() == 0L;
+    } else if (fieldValue instanceof String) {
+      return ((String) fieldValue).isEmpty();
+    }
+
+    return false;
+  }
+}