Java Proto Names

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.
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";

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

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

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

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.

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.