javagen

package
v0.0.8 Latest Latest
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 Go to latest Published: Mar 29, 2026 License: CC0-1.0 Imports: 10 Imported by: 0

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Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func BuildCallbackDispatch 

func BuildCallbackDispatch(cb *MergedCallback) string

BuildCallbackDispatch generates the Go code for a callback's switch/case dispatch inside a jni.NewProxy handler.

func BuildCallbackType 

func BuildCallbackType(cb *MergedCallback) string

BuildCallbackType generates the Go struct type definition with function fields for a callback interface.

func Generate 

func Generate(
	specPath string,
	overlayPath string,
	templatesDir string,
	outputDir string,
	goModule string,
) error

Generate is the main entry point. It loads spec + overlay, merges them, renders templates, and writes output files.

The goModule parameter is the Go module path (e.g. "github.com/AndroidGoLab/jni"). Output directories and Go package names are derived from the spec's go_import field by stripping the module prefix.

func GoImportToRelDir 

func GoImportToRelDir(goImport, goModule string) string

GoImportToRelDir strips the Go module prefix from a go_import path to produce the relative output directory. e.g. GoImportToRelDir("github.com/foo/bar/hw/cam", "github.com/foo/bar") → "hw/cam"

func IsManager 

func IsManager(cls *MergedClass) bool

IsManager returns true if the class is obtained via system service.

func JNISignature 

func JNISignature(params []Param, returnType string) string

JNISignature computes the JNI method signature from parameter types and return type.

func JNITypeSignature 

func JNITypeSignature(javaType string) string

JNITypeSignature converts a single Java type to its JNI type signature. Generic type parameters are stripped because JNI uses erased types.

func JavaClassToSlash 

func JavaClassToSlash(className string) string

JavaClassToSlash converts a dotted Java class name to slash-separated JNI format. Handles inner classes: "android.app.AlarmManager.AlarmClockInfo" becomes "android/app/AlarmManager$AlarmClockInfo".

func ParamConversionCode 

func ParamConversionCode(p MergedParam) string

ParamConversionCode generates Go code to convert a Go parameter to its JNI representation before a JNI call.

Types

type AbstractCallback added in v0.0.8 

type AbstractCallback struct {
	JavaClass string                   `yaml:"java_class"`
	GoType    string                   `yaml:"go_type"`
	Methods   []AbstractCallbackMethod `yaml:"methods"`
}

AbstractCallback describes an abstract Java class whose abstract methods are delegated to Go via GoAbstractDispatch.

type AbstractCallbackMethod added in v0.0.8 

type AbstractCallbackMethod struct {
	JavaMethod string   `yaml:"java_method"`
	Params     []string `yaml:"params"`
	Returns    string   `yaml:"returns"`
	GoField    string   `yaml:"go_field"`
}

AbstractCallbackMethod describes a single abstract method in an abstract callback class.

type Callback 

type Callback struct {
	JavaInterface string           `yaml:"java_interface"`
	GoType        string           `yaml:"go_type"`
	Methods       []CallbackMethod `yaml:"methods"`
}

Callback describes a Java callback interface to bridge to Go.

type CallbackMethod 

type CallbackMethod struct {
	JavaMethod string   `yaml:"java_method"`
	Params     []string `yaml:"params"`
	GoField    string   `yaml:"go_field"`
}

CallbackMethod describes a single method in a callback interface.

type Class 

type Class struct {
	JavaClass         string        `yaml:"java_class"`
	GoType            string        `yaml:"go_type"`
	Obtain            string        `yaml:"obtain"`
	ServiceName       string        `yaml:"service_name"`
	Kind              string        `yaml:"kind"`
	Close             bool          `yaml:"close"`
	ConstructorParams []Param       `yaml:"constructor_params"`
	Methods           []Method      `yaml:"methods"`
	StaticMethods     []Method      `yaml:"static_methods"`
	Fields            []Field       `yaml:"fields"`
	StaticFields      []StaticField `yaml:"static_fields"`
	IntentExtras      []IntentExtra `yaml:"intent_extras"`
}

Class describes a Java class to wrap.

func (Class) AllMethods 

func (c Class) AllMethods() []Method

AllMethods returns both instance and static methods. Static methods have their Static field set to true.

type Constant 

type Constant struct {
	GoName       string `yaml:"go_name"`
	Value        string `yaml:"value"`
	GoType       string `yaml:"go_type"`
	GoUnderlying string `yaml:"go_underlying"`
}

Constant describes a named constant value.

type ConstructorOverride added in v0.0.8 

type ConstructorOverride struct {
	Params []Param `yaml:"params"`
}

ConstructorOverride customizes the constructor for a specific Java class. Keyed by Java class name (e.g. "android.graphics.Canvas") in the overlay's constructor_overrides map.

type ConversionOverride 

type ConversionOverride struct {
	ToGo   string `yaml:"to_go"`
	ToJava string `yaml:"to_java"`
}

ConversionOverride specifies custom type conversion expressions.

type Field 

type Field struct {
	JavaMethod string `yaml:"java_method"`
	JavaField  string `yaml:"java_field"`
	Returns    string `yaml:"returns"`
	GoName     string `yaml:"go_name"`
	GoType     string `yaml:"go_type"`
}

Field describes a getter method on a data class. Supports both java_method (getter) and java_field (direct field access).

func (Field) GetterName 

func (f Field) GetterName() string

GetterName returns the Java getter method name for this field. If java_method is set, it is used directly. If java_field is set, it is converted to a getter name (e.g., "packageName" -> "getPackageName").

type IntentExtra 

type IntentExtra struct {
	JavaExtra string `yaml:"java_extra"`
	JavaType  string `yaml:"java_type"`
	GoName    string `yaml:"go_name"`
	GoType    string `yaml:"go_type"`
}

IntentExtra describes a value extracted from a sticky broadcast intent.

type ManagerData 

type ManagerData struct {
	GoType      string
	ServiceName string
	HasClose    bool
}

ManagerData holds template data for generating a system service manager constructor.

func ManagerConstructorData 

func ManagerConstructorData(cls *MergedClass) ManagerData

ManagerConstructorData returns template data for the NewManager constructor.

type MergedAbstractCallback added in v0.0.8 

type MergedAbstractCallback struct {
	JavaClass      string
	JavaClassSlash string
	GoType         string
	Methods        []MergedAbstractCallbackMethod
}

MergedAbstractCallback is a resolved abstract callback class.

func (*MergedAbstractCallback) AdapterClassName added in v0.0.8 

func (m *MergedAbstractCallback) AdapterClassName() string

AdapterClassName returns the Java adapter class name for this abstract callback. The name uses the Java simple class name (not the Go type) with an "Adapter" suffix, matching the naming convention that tryAbstractAdapter in proxy.go searches for (e.g. "ScanCallbackAdapter" for "android.bluetooth.le.ScanCallback").

func (*MergedAbstractCallback) JavaPackage added in v0.0.8 

func (m *MergedAbstractCallback) JavaPackage() string

JavaPackage returns the Java package of the abstract class (e.g. "android.bluetooth.le" from "android.bluetooth.le.ScanCallback").

func (*MergedAbstractCallback) JavaSimpleName added in v0.0.8 

func (m *MergedAbstractCallback) JavaSimpleName() string

JavaSimpleName returns the simple (unqualified) Java class name (e.g. "ScanCallback" from "android.bluetooth.le.ScanCallback").

type MergedAbstractCallbackMethod added in v0.0.8 

type MergedAbstractCallbackMethod struct {
	JavaMethod string
	GoField    string
	Params     []MergedParam
	GoParams   string
	Returns    string
}

MergedAbstractCallbackMethod is a resolved method in an abstract callback class.

func (*MergedAbstractCallbackMethod) HasReturn added in v0.0.8 

func (m *MergedAbstractCallbackMethod) HasReturn() bool

HasReturn reports whether this method returns a value (non-void).

func (*MergedAbstractCallbackMethod) JavaArgList added in v0.0.8 

func (m *MergedAbstractCallbackMethod) JavaArgList() string

JavaArgList returns the argument names for passing to GoAbstractDispatch.invoke (e.g. "arg0, arg1"). Primitives are autoboxed via valueOf wrappers.

func (*MergedAbstractCallbackMethod) JavaCastReturn added in v0.0.8 

func (m *MergedAbstractCallbackMethod) JavaCastReturn() string

JavaCastReturn returns the Java cast expression needed to convert the Object return from GoAbstractDispatch.invoke to the method's return type.

func (*MergedAbstractCallbackMethod) JavaParamList added in v0.0.8 

func (m *MergedAbstractCallbackMethod) JavaParamList() string

JavaParamList returns the Java parameter declaration list for the adapter method (e.g. "int arg0, android.bluetooth.le.ScanResult arg1").

func (*MergedAbstractCallbackMethod) JavaReturnType added in v0.0.8 

func (m *MergedAbstractCallbackMethod) JavaReturnType() string

JavaReturnType returns the Java return type for use in the adapter template.

func (*MergedAbstractCallbackMethod) JavaUnboxReturn added in v0.0.8 

func (m *MergedAbstractCallbackMethod) JavaUnboxReturn() string

JavaUnboxReturn returns the Java unboxing method call for primitive return types, or empty string for object/void returns.

type MergedCallback 

type MergedCallback struct {
	JavaInterface string
	GoType        string
	Methods       []MergedCallbackMethod
}

MergedCallback is a resolved callback interface.

type MergedCallbackMethod 

type MergedCallbackMethod struct {
	JavaMethod string
	GoField    string
	Params     []MergedParam
	GoParams   string
}

MergedCallbackMethod is a resolved callback method.

type MergedClass 

type MergedClass struct {
	JavaClass         string
	JavaClassSlash    string
	GoType            string
	Obtain            string
	ServiceName       string
	Kind              string
	Close             bool
	ConstructorParams []MergedParam
	ConstructorJNISig string
	Methods           []MergedMethod
}

MergedClass is a resolved Java class wrapper.

type MergedConstant 

type MergedConstant struct {
	GoName string
	Value  string
	// IsVar is true when the value cannot be a Go compile-time constant
	// (e.g. NaN, Infinity) and must be declared as a var instead.
	IsVar bool
}

MergedConstant is a resolved constant value.

type MergedConstantGroup 

type MergedConstantGroup struct {
	GoType   string
	BaseType string
	Values   []MergedConstant
}

MergedConstantGroup groups constants by their Go type.

func (MergedConstantGroup) ConstValues added in v0.0.6 

func (g MergedConstantGroup) ConstValues() []MergedConstant

ConstValues returns only the values that can be Go constants.

func (MergedConstantGroup) HasVars added in v0.0.6 

func (g MergedConstantGroup) HasVars() bool

HasVars reports whether this group contains any var-only values (e.g. NaN, Infinity).

func (MergedConstantGroup) NeedsMathImport added in v0.0.6 

func (g MergedConstantGroup) NeedsMathImport() bool

NeedsMathImport reports whether any value in the group uses math package functions (e.g. math.NaN(), math.Inf()).

func (MergedConstantGroup) VarValues added in v0.0.6 

func (g MergedConstantGroup) VarValues() []MergedConstant

VarValues returns only the values that must be Go vars (NaN, Infinity).

type MergedDataClass 

type MergedDataClass struct {
	JavaClass      string
	JavaClassSlash string
	GoType         string
	Fields         []MergedField
}

MergedDataClass is a resolved data class (getter extraction).

type MergedField 

type MergedField struct {
	JavaMethod string // getter method name (for java_method fields)
	JavaName   string // raw field name (for java_field direct access)
	GoName     string
	GoType     string
	JNISig     string
	CallSuffix string
	IsField    bool // true = use GetFieldID/Get*Field, false = use GetMethodID/Call*Method
}

MergedField is a resolved field getter on a data class.

type MergedMethod 

type MergedMethod struct {
	JavaMethod string
	GoName     string
	Static     bool
	Params     []MergedParam
	Returns    string
	GoReturn   string
	JNISig     string
	CallSuffix string
	ReturnKind ReturnKind

	GoParamList          string
	GoParamListMultiLine string
	GoReturnList         string
	GoReturnVars         string
	GoReturnValues       string
	JNIArgs              string
	HasError             bool
}

MergedMethod is a resolved method with all computed helpers.

type MergedParam 

type MergedParam struct {
	JavaType       string
	GoName         string
	GoType         string
	ConversionCode string
	IsString       bool
	IsBool         bool
	IsObject       bool
}

MergedParam is a resolved parameter.

type MergedSpec 

type MergedSpec struct {
	Package         string
	GoImport        string
	JavaPackageDesc string

	Classes           []MergedClass
	DataClasses       []MergedDataClass
	Callbacks         []MergedCallback
	AbstractCallbacks []MergedAbstractCallback
	ConstantGroups    []MergedConstantGroup
}

MergedSpec is the fully resolved specification ready for template rendering.

func Merge 

func Merge(spec *Spec, overlay *Overlay) (*MergedSpec, error)

Merge combines a Spec and Overlay into a fully resolved MergedSpec.

type Method 

type Method struct {
	JavaMethod string  `yaml:"java_method"`
	GoName     string  `yaml:"go_name"`
	Static     bool    `yaml:"static"`
	Params     []Param `yaml:"params"`
	Returns    string  `yaml:"returns"`
	Error      bool    `yaml:"error"`
}

Method describes a Java method to generate a Go wrapper for.

type Overlay 

type Overlay struct {
	GoNameOverrides      map[string]string              `yaml:"go_name_overrides"`
	MethodGrouping       map[string][]string            `yaml:"method_grouping"`
	ExtraMethods         []Method                       `yaml:"extra_methods"`
	TypeOverrides        map[string]string              `yaml:"type_overrides"`
	ConversionFuncs      map[string]ConversionOverride  `yaml:"conversion_funcs"`
	ConstructorOverrides map[string]ConstructorOverride `yaml:"constructor_overrides"`
}

Overlay provides per-package customization applied on top of a Spec.

func LoadOverlay 

func LoadOverlay(path string) (*Overlay, error)

LoadOverlay reads an overlay YAML file. If the file does not exist, an empty Overlay is returned without error.

func ParseOverlay added in v0.0.5 

func ParseOverlay(data []byte) (*Overlay, error)

ParseOverlay parses an overlay from YAML data.

type Param 

type Param struct {
	JavaType string `yaml:"java_type"`
	GoName   string `yaml:"go_name"`
	GoType   string `yaml:"go_type"`
}

Param describes a method parameter.

type ReturnKind 

type ReturnKind string

ReturnKind classifies how a method's return value should be handled in the generated code. 

const (
	ReturnVoid      ReturnKind = "void"
	ReturnString    ReturnKind = "string"
	ReturnBool      ReturnKind = "bool"
	ReturnObject    ReturnKind = "object"
	ReturnPrimitive ReturnKind = "primitive"
)

type Spec 

type Spec struct {
	Package           string             `yaml:"package"`
	GoImport          string             `yaml:"go_import"`
	Classes           []Class            `yaml:"classes"`
	Callbacks         []Callback         `yaml:"callbacks"`
	AbstractCallbacks []AbstractCallback `yaml:"abstract_callbacks"`
	Constants         []Constant         `yaml:"constants"`
	IntentExtras      []IntentExtra      `yaml:"intent_extras"`
}

Spec represents a per-package Java API specification loaded from YAML.

func LoadSpec 

func LoadSpec(path string) (*Spec, error)

LoadSpec reads and validates a Java API spec from a YAML file.

func ParseSpec added in v0.0.5 

func ParseSpec(data []byte) (*Spec, error)

ParseSpec validates and parses a Java API spec from YAML data.

type StaticField 

type StaticField struct {
	JavaField string `yaml:"java_field"`
	Returns   string `yaml:"returns"`
	GoName    string `yaml:"go_name"`
	GoType    string `yaml:"go_type"`
}

StaticField describes a Java static field to read.

type TypeConv 

type TypeConv struct {
	GoType     string
	JNISig     string
	CallSuffix string
	IsObject   bool
}

TypeConv holds the Go and JNI type information for a Java type.

func ResolveType 

func ResolveType(javaType string) TypeConv

ResolveType maps a Java type string to its TypeConv. Generic type parameters are stripped because JNI uses erased types.

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