# Android - Protobuf Samples

###### tags: `Android` `Protobuf`

# Reference

### [Language Guide (proto3)](https://developers.google.com/protocol-buffers/docs/proto3)

### [How to add a int array in protobuf message](https://stackoverflow.com/questions/7408203/how-to-add-a-int-array-in-protobuf-message)

### [Repeated fields for lists and arrays](https://docs.microsoft.com/en-us/dotnet/architecture/grpc-for-wcf-developers/protobuf-repeated)

C#

You specify lists in Protocol Buffer (Protobuf)
by using the ``repeated`` prefix keyword.
The following example shows how to create a list:

message Person {
    // Other fields elided
    repeated string aliases = 8;
}

In the generated code, ``repeated`` fields are represented by
__read-only properties__ of the ``Google.Protobuf.Collections.RepeatedField<T>`` type
rather than any of the built-in .NET collection types.
This type implements all the standard .NET collection interfaces,
such as ``IList<T>`` and ``IEnumerable<T>``.
So you can use __LINQ queries__ or __convert it to an array or a list easily__.

The ``RepeatedField<T>`` type includes the code required
to serialize and deserialize the list to the binary wire format.

---

# 1. Sample1 - Nested enum

syntax = "proto3";

option java_package = "com.shalu.android.datastore";
option java_multiple_files = true;

message UserSettings {

  enum BgColor {
    COLOR_WHITE = 0;
    COLOR_BLACK = 1;
  }
  BgColor bgColor = 1;
}

public final class UserSettings extends
        com.google.protobuf.GeneratedMessageLite<UserSettings, UserSettings.Builder>
        implements
        // @@protoc_insertion_point(message_implements:UserSettings)
        UserSettingsOrBuilder {

    private UserSettings() {}

    public enum BgColor implements com.google.protobuf.Internal.EnumLite {
        /**
         * <code>COLOR_WHITE = 0;</code>
         */
        COLOR_WHITE(0),
        /**
         * <code>COLOR_BLACK = 1;</code>
         */
        COLOR_BLACK(1),
        UNRECOGNIZED(-1),
        ;

        private final int value;

        private BgColor(int value) {
            this.value = value;
        }
    }

    public static final int BGCOLOR_FIELD_NUMBER = 1;
    private int bgColor_;

    /**
     * <code>.UserSettings.BgColor bgColor = 1;</code>
     * @return The enum numeric value on the wire for bgColor.
     */
    @java.lang.Override
    public int getBgColorValue() {
        return bgColor_;
    }

    /**
     * <code>.UserSettings.BgColor bgColor = 1;</code>
     * @param value The enum numeric value on the wire for bgColor to set.
     */
    private void setBgColorValue(int value) {
        bgColor_ = value;
    }
    /**
     * <code>.UserSettings.BgColor bgColor = 1;</code>
     * @param value The bgColor to set.
     */
    private void setBgColor(com.shalu.android.datastore.UserSettings.BgColor value) {
        bgColor_ = value.getNumber();
    }
    /**
     * <code>.UserSettings.BgColor bgColor = 1;</code>
     */
    private void clearBgColor() {
        bgColor_ = 0;
    }

    
    public static final class Builder extends
            com.google.protobuf.GeneratedMessageLite.Builder<com.shalu.android.datastore.UserSettings, Builder>
            implements
            // @@protoc_insertion_point(builder_implements:UserSettings)
            com.shalu.android.datastore.UserSettingsOrBuilder {

        // Construct using com.shalu.android.datastore.UserSettings.newBuilder()

        private Builder() {
            super(DEFAULT_INSTANCE);
        }

        /**
         * <code>.UserSettings.BgColor bgColor = 1;</code>
         * @return The enum numeric value on the wire for bgColor.
         */
        @java.lang.Override
        public int getBgColorValue() {
            return instance.getBgColorValue();
        }
        /**
         * <code>.UserSettings.BgColor bgColor = 1;</code>
         * @param value The bgColor to set.
         * @return This builder for chaining.
         */
        public Builder setBgColorValue(int value) {
            copyOnWrite();
            instance.setBgColorValue(value);
            return this;
        }
        /**
         * <code>.UserSettings.BgColor bgColor = 1;</code>
         * @return The bgColor.
         */
        @java.lang.Override
        public com.shalu.android.datastore.UserSettings.BgColor getBgColor() {
            return instance.getBgColor();
        }
        /**
         * <code>.UserSettings.BgColor bgColor = 1;</code>
         * @param value The enum numeric value on the wire for bgColor to set.
         * @return This builder for chaining.
         */
        public Builder setBgColor(com.shalu.android.datastore.UserSettings.BgColor value) {
            copyOnWrite();
            instance.setBgColor(value);
            return this;
        }
        /**
         * <code>.UserSettings.BgColor bgColor = 1;</code>
         * @return This builder for chaining.
         */
        public Builder clearBgColor() {
            copyOnWrite();
            instance.clearBgColor();
            return this;
        }
    }
}

---

# 2. Sample2 - Two classes

syntax = "proto3";

//package tutorial;
option java_package = "com.elyeproj.demosimpleprotobuf.tutorial";
option java_multiple_files = true; // seems to need the setting, but i don't know why?

message Person {
    string name = 1;
    int32 id = 2;
    string email = 3;
    string phone = 4;
}

// ===
//option java_package = "com.vladsonkin.protodatastore.proto";
//option java_multiple_files = true;

message FilterPreference {
    string serial = 1;
    string color = 2;
    string manufacturer = 3;
    string type = 4;
    string stolenLocation = 5;
}

public final class Person extends com.google.protobuf.GeneratedMessageLite<Person, Person.Builder>
        implements
        // @@protoc_insertion_point(message_implements:Person)
        PersonOrBuilder {

    private Person() {
        name_ = "";
        email_ = "";
        phone_ = "";
    }

    public static final int NAME_FIELD_NUMBER = 1;
    private java.lang.String name_;

    /**
     * <code>string name = 1;</code>
     * @return The name.
     */
    @java.lang.Override
    public java.lang.String getName() {
        return name_;
    }

    /**
     * <code>string name = 1;</code>
     * @param value The name to set.
     */
    private void setName(java.lang.String value) {
        value.getClass();
        name_ = value;
    }

    public static final int ID_FIELD_NUMBER = 2;
    private int id_;

    /**
     * <code>int32 id = 2;</code>
     * @return The id.
     */
    @java.lang.Override
    public int getId() {
        return id_;
    }

    /**
     * <code>int32 id = 2;</code>
     * @param value The id to set.
     */
    private void setId(int value) {
        id_ = value;
    }

    public static final int EMAIL_FIELD_NUMBER = 3;
    private java.lang.String email_;

    /**
     * <code>string email = 3;</code>
     * @return The email.
     */
    @java.lang.Override
    public java.lang.String getEmail() {
        return email_;
    }

    /**
     * <code>string email = 3;</code>
     * @param value The email to set.
     */
    private void setEmail(java.lang.String value) {
        value.getClass();
        email_ = value;
    }

    public static final int PHONE_FIELD_NUMBER = 4;
    private java.lang.String phone_;

    /**
     * <code>string phone = 4;</code>
     * @return The phone.
     */
    @java.lang.Override
    public java.lang.String getPhone() {
        return phone_;
    }

    /**
     * <code>string phone = 4;</code>
     * @param value The phone to set.
     */
    private void setPhone(java.lang.String value) {
        value.getClass();
        phone_ = value;
    }

    public static final class Builder extends com.google.protobuf.GeneratedMessageLite.Builder<com.elyeproj.demosimpleprotobuf.tutorial.Person, Builder> 	implements
            // @@protoc_insertion_point(builder_implements:Person)
            com.elyeproj.demosimpleprotobuf.tutorial.PersonOrBuilder {

    }
}

public final class FilterPreference 
        extends com.google.protobuf.GeneratedMessageLite<FilterPreference, FilterPreference.Builder> 
        implements
        // @@protoc_insertion_point(message_implements:FilterPreference)
        FilterPreferenceOrBuilder {

    private FilterPreference() {
        serial_ = "";
        color_ = "";
        manufacturer_ = "";
        type_ = "";
        stolenLocation_ = "";
    }

    public static final int SERIAL_FIELD_NUMBER = 1;
    private java.lang.String serial_;

    /**
     * <code>string serial = 1;</code>
     *
     * @return The serial.
     */
    @java.lang.Override
    public java.lang.String getSerial() {
        return serial_;
    }

    /**
     * <code>string serial = 1;</code>
     *
     * @param value The serial to set.
     */
    private void setSerial(java.lang.String value) {
        value.getClass();
        serial_ = value;
    }

    public static final int COLOR_FIELD_NUMBER = 2;
    private java.lang.String color_;

    /**
     * <code>string color = 2;</code>
     *
     * @return The color.
     */
    @java.lang.Override
    public java.lang.String getColor() {
        return color_;
    }

    /**
     * <code>string color = 2;</code>
     *
     * @param value The color to set.
     */
    private void setColor(java.lang.String value) {
        value.getClass();
        color_ = value;
    }

    public static final int MANUFACTURER_FIELD_NUMBER = 3;
    private java.lang.String manufacturer_;

    /**
     * <code>string manufacturer = 3;</code>
     *
     * @return The manufacturer.
     */
    @java.lang.Override
    public java.lang.String getManufacturer() {
        return manufacturer_;
    }

    /**
     * <code>string manufacturer = 3;</code>
     *
     * @param value The manufacturer to set.
     */
    private void setManufacturer(java.lang.String value) {
        value.getClass();
        manufacturer_ = value;
    }

    public static final int TYPE_FIELD_NUMBER = 4;
    private java.lang.String type_;

    /**
     * <code>string type = 4;</code>
     *
     * @return The type.
     */
    @java.lang.Override
    public java.lang.String getType() {
        return type_;
    }

    /**
     * <code>string type = 4;</code>
     *
     * @param value The type to set.
     */
    private void setType(java.lang.String value) {
        value.getClass();
        type_ = value;
    }

    public static final int STOLENLOCATION_FIELD_NUMBER = 5;
    private java.lang.String stolenLocation_;

    /**
     * <code>string stolenLocation = 5;</code>
     *
     * @return The stolenLocation.
     */
    @java.lang.Override
    public java.lang.String getStolenLocation() {
        return stolenLocation_;
    }

    /**
     * <code>string stolenLocation = 5;</code>
     *
     * @param value The stolenLocation to set.
     */
    private void setStolenLocation(java.lang.String value) {
        value.getClass();
        stolenLocation_ = value;
    }

    public static final class Builder 
            extends com.google.protobuf.GeneratedMessageLite.Builder<com.elyeproj.demosimpleprotobuf.tutorial.FilterPreference, Builder> 
            implements
            // @@protoc_insertion_point(builder_implements:FilterPreference)
            com.elyeproj.demosimpleprotobuf.tutorial.FilterPreferenceOrBuilder {
        
        // Construct using com.elyeproj.demosimpleprotobuf.tutorial.FilterPreference.newBuilder()
        private Builder() {
            super(DEFAULT_INSTANCE);
        }
    }
}

---

# 3. Sample3 - Nested classes with ``List``

syntax = "proto3";

option java_package = "com.shalu.android.datastore";
option java_multiple_files = true;

message SearchResponse {
  message Result {
    string url = 1;
    string title = 2;
    repeated string snippets = 3;
  }
  repeated Result results = 1;
}

``repeated`` is used to define a ``List`` of some types!!

public final class SearchResponse 
        extends com.google.protobuf.GeneratedMessageLite<SearchResponse, SearchResponse.Builder> 
        // @@protoc_insertion_point(message_implements:SearchResponse)
        implements SearchResponseOrBuilder {
    
    private SearchResponse() { results_ = emptyProtobufList(); }

    public static final int RESULTS_FIELD_NUMBER = 1;
    private com.google.protobuf.Internal.ProtobufList<com.shalu.android.datastore.SearchResponse.Result> results_;
    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    @java.lang.Override
    public java.util.List<com.shalu.android.datastore.SearchResponse.Result> getResultsList() { return results_; }

    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    @java.lang.Override
    public int getResultsCount() { return results_.size(); }
    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    @java.lang.Override
    public com.shalu.android.datastore.SearchResponse.Result getResults(int index) { return results_.get(index); }

    private void ensureResultsIsMutable() {
        com.google.protobuf.Internal.ProtobufList<com.shalu.android.datastore.SearchResponse.Result> tmp = results_;
        if (!tmp.isModifiable()) {
            results_ =
                    com.google.protobuf.GeneratedMessageLite.mutableCopy(tmp);
        }
    }

    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    private void setResults(int index, com.shalu.android.datastore.SearchResponse.Result value) {
        value.getClass();
        ensureResultsIsMutable();
        results_.set(index, value);
    }
    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    private void addResults(com.shalu.android.datastore.SearchResponse.Result value) {
        value.getClass();
        ensureResultsIsMutable();
        results_.add(value);
    }
    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    private void addResults(int index, com.shalu.android.datastore.SearchResponse.Result value) {
        value.getClass();
        ensureResultsIsMutable();
        results_.add(index, value);
    }
    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    private void addAllResults(java.lang.Iterable<? extends com.shalu.android.datastore.SearchResponse.Result> values) {
        ensureResultsIsMutable();
        com.google.protobuf.AbstractMessageLite.addAll(values, results_);
    }
    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    private void clearResults() { results_ = emptyProtobufList(); }
    /**
     * <code>repeated .SearchResponse.Result results = 1;</code>
     */
    private void removeResults(int index) {
        ensureResultsIsMutable();
        results_.remove(index);
    }
    
    ///

    public static final class Result 
            extends com.google.protobuf.GeneratedMessageLite<Result, Result.Builder>          
            // @@protoc_insertion_point(message_implements:SearchResponse.Result)
            implements ResultOrBuilder {
        
        private Result() {
            url_ = "";
            title_ = "";
            snippets_ = com.google.protobuf.GeneratedMessageLite.emptyProtobufList();
        }
        
        public static final int URL_FIELD_NUMBER = 1;
        private java.lang.String url_;
        /**
         * <code>string url = 1;</code>
         * @return The url.
         */
        @java.lang.Override
        public java.lang.String getUrl() { return url_; }

        /**
         * <code>string url = 1;</code>
         * @param value The url to set.
         */
        private void setUrl(java.lang.String value) {
            value.getClass();
            url_ = value;
        }

        public static final int TITLE_FIELD_NUMBER = 2;
        private java.lang.String title_;
        /**
         * <code>string title = 2;</code>
         * @return The title.
         */
        @java.lang.Override
        public java.lang.String getTitle() { return title_; }

        /**
         * <code>string title = 2;</code>
         * @param value The title to set.
         */
        private void setTitle(java.lang.String value) {
            value.getClass();
            title_ = value;
        }

        public static final int SNIPPETS_FIELD_NUMBER = 3;
        private com.google.protobuf.Internal.ProtobufList<java.lang.String> snippets_;
        /**
         * <code>repeated string snippets = 3;</code>
         * @return A list containing the snippets.
         */
        @java.lang.Override
        public java.util.List<java.lang.String> getSnippetsList() { return snippets_; }

        /**
         * <code>repeated string snippets = 3;</code>
         * @return The count of snippets.
         */
        @java.lang.Override
        public int getSnippetsCount() { return snippets_.size(); }
        /**
         * <code>repeated string snippets = 3;</code>
         * @param index The index of the element to return.
         * @return The snippets at the given index.
         */
        @java.lang.Override
        public java.lang.String getSnippets(int index) { return snippets_.get(index); }

        private void ensureSnippetsIsMutable() {
            com.google.protobuf.Internal.ProtobufList<java.lang.String> tmp = snippets_;
            if (!tmp.isModifiable()) {
                snippets_ = com.google.protobuf.GeneratedMessageLite.mutableCopy(tmp);
            }
        }
        
        /**
         * <code>repeated string snippets = 3;</code>
         * @param index The index to set the value at.
         * @param value The snippets to set.
         */
        private void setSnippets(int index, java.lang.String value) {
            value.getClass();
            ensureSnippetsIsMutable();
            snippets_.set(index, value);
        }
        /**
         * <code>repeated string snippets = 3;</code>
         * @param value The snippets to add.
         */
        private void addSnippets(java.lang.String value) {
            value.getClass();
            ensureSnippetsIsMutable();
            snippets_.add(value);
        }
        /**
         * <code>repeated string snippets = 3;</code>
         * @param values The snippets to add.
         */
        private void addAllSnippets(java.lang.Iterable<java.lang.String> values) {
            ensureSnippetsIsMutable();
            com.google.protobuf.AbstractMessageLite.addAll(values, snippets_);
        }
        /**
         * <code>repeated string snippets = 3;</code>
         */
        private void clearSnippets() {
            snippets_ = com.google.protobuf.GeneratedMessageLite.emptyProtobufList();
        }
    }
}