Java Proto Names

This topic covers the names that are generated by the immutable API.

This document contains information on what the fully-qualified Java name of a proto is, based on the different proto options. This name corresponds to the package you need to import to use that message.

Immutable API Message Names

The names for protos generated by the immutable API (java_proto_library BUILD target) are listed in the following table.

java_api_version	java_multiple_files	java_alt_api_package	java_package	java_outer_classname	Generated full message name
1	true	Defined	-		`$java_alt_api_package.$message`
1	true	Not defined	Not defined		`com.google.protos.$package.proto2api.$message`
1	true	Not defined	Defined		`$java_package.proto2api.$message`
1	false	Defined	-	Not defined	`$java_alt_api_package.$derived_outer_class.$message`
1	false	Defined	-	Defined	`$java_alt_api_package.$java_outer_classname.$message`
1	false	Not defined	Not defined	Not defined	`com.google.protos.$package.proto2api.$derived_outer_class.$message`
1	false	Not defined	Not defined	Defined	`com.google.protos.$package.proto2api.$java_outer_classname.$message`
1	false	Not defined	Defined	Not defined	`$java_package.proto2api.$derived_outer_class.$message`
1	false	Not defined	Defined	Defined	`$java_package.proto2api.$java_outer_classname.$message`
2	true	-	Not defined	-	`com.google.protos.$package.$message`
2	true	-	Defined	-	`$java_package.$message`
2	false	-	Not defined	Not defined	`com.google.protos.$package.$derived_outer_class.$message`
2	false	-	Not defined	Defined	`com.google.protos.$package.$java_outer_classname.$message`
2	false	-	Defined	Not defined	`$java_package.$derived_outer_class.$message`
2	false	-	Defined	Defined	`$java_package.$java_outer_classname.$message`

Legend

- means either setting or not setting the option will not change the generated full message name.
$message is the actual name of the proto message.
$package is the name of the proto package. This is the name specified by the package directive in the proto file, which is usually at the top of the file.
$derived_outer_class is a name generated from the proto file name. Generally it’s computed by removing punctuation from the file name and converting it to CamelCase. For example, if the proto is foo_bar.proto, the $derived_outer_class value is FooBar.
If the generated class name would be the same as one of the messages defined in the proto file, derived_outer_class has OuterClass appended to it. For example, if the proto is foo_bar.proto and contains a FooBar message, the $derived_outer_class value is FooBarOuterClass. The same is true when using the v1 API, whether or not the class name would be the same as one of the messages defined.
All other $names are the values of the corresponding proto2 file options defined in the proto file.

The recommended set of options is:

option java_multiple_files = true;
option java_outer_classname = "{UpperCamelCaseFilename}Proto";

Mutable API Message Names

The names for protos generated by the mutable API are outlined in the following sections.

Note

Java mutable API names will be generated only when the java_mutable_proto_library target is built.

Generated Proto API Version

Warning

Java proto1 is deprecated. Avoid any settings that will generate that version.

java_api_version	java_mutable_api	java_enable_dual_generate_mutable_api	API version
-	-	true	proto1, proto2 mutable
1	-	false	proto1
2	true	false	proto2 mutable
2	false	false	proto1

Proto2 Message Names

java_api_version	(java_multiple_files, java_multiple_files_mutable_package)	java_package	java_outer_classname	java_alt_api_package	Proto2 Mutable message name
-	(true, defined)	-	-	-	`$java_multiple_files_mutable_package.$message`
1	!(true, defined)	Undefined	Undefined	Undefined	`com.google.protos.$package.proto2api.Mutable$Filename.$message`
1	!(true, defined)	Undefined	Undefined	Defined	`$java_alt_api_package.Mutable$Filename.$message`
1	!(true, defined)	Undefined	Defined	Undefined	`com.google.protos.$package.proto2api.Mutable$java_outer_classname.$message`
1	!(true, defined)	Undefined	Defined	Defined	`$java_alt_api_package.Mutable$java_outer_classname.$message`
1	!(true, defined)	Defined	Undefined	Undefined	`$java_package.proto2api.Mutable$Filename.$message`
1	!(true, defined)	Defined	Undefined	Defined	`$java_alt_api_package.Mutable$Filename.$message`
1	!(true, defined)	Defined	Defined	Undefined	`$java_package.proto2api.Mutable$java_outer_classname.$message`
1	!(true, defined)	Defined	Defined	Defined	`$java_alt_api_package.Mutable$java_outer_classname.$message`
2	!(true, defined)	Undefined	Undefined	-	`com.google.protos.$package.Mutable$Filename.$message`
2	!(true, defined)	Undefined	Defined	-	`com.google.protos.$package..Mutable$java_outer_classname.$message`
2	!(true, defined)	Defined	Undefined	-	`$java_package.Mutable$Filename.$message`
2	!(true, defined)	Defined	Defined	-	`$java_package.Mutable$java_outer_classname.$message`

Legend

- means either setting or not setting the option will not change the generated full message name.
$message is the actual name of the proto message.
All other $names are the values of the corresponding proto2 file options defined in the proto file.

Proto1 Message Names

Warning

Java proto1 is deprecated. The following table is provided for informational purposes only.

java_api_version	java_multiple_files	java_package	java_outer_classname	java_alt_api_package	Proto1 message name
1	true	Undefined	-	-	`com.google.protos.$package.$message`
1	true	Defined	-	-	`$java_package.$message`
1	false	Undefined	Defined	-	`com.google.protos.$package.$java_outer_class.$message`
1	false	Undefined	Undefined	-	`com.google.protos.$package.$message`
1	false	Defined	Defined	-	`$java_package.$java_outer_class.$message`
1	false	Defined	Undefined	-	`$java_package.$message`
2	true	Undefined	-	Undefined	`com.google.protos.$package.proto1api.$message`
2	true	Defined	-	Undefined	`$java_package.proto1api.$message`
2	false	Undefined	Defined	Undefined	`com.google.protos.$package.proto1api.$java_outer_class.$message`
2	false	Undefined	Undefined	Undefined	`com.google.protos.$package.proto1api.$message`
2	false	Defined	Defined	Undefined	`$java_package.proto1api.$java_outer_class.$message`
2	false	Defined	Undefined	Undefined	`$java_package.proto1api.$message`
2	true	Undefined	-	Defined	`com.google.protos.$package.$java_alt_api_package.$message`
2	true	Defined	-	Defined	`$java_package.$java_alt_api_package.$message`
2	false	Undefined	Defined	Defined	`com.google.protos.$package.$java_alt_api_package.$java_outer_class.$message`
2	false	Undefined	Undefined	Defined	`com.google.protos.$package.$java_alt_api_package.$message`
2	false	Defined	Defined	Defined	`$java_package.$java_alt_api_package.$java_outer_class.$message`
2	false	Defined	Undefined	Defined	`$java_package.$java_alt_api_package.$message`

Legend

- means either setting or not setting the option will not change the generated full message name.
$message is the actual name of the proto message.
All other $names are the values of the corresponding proto2 file options defined in the proto file.