--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Supporting services for the FFI with Java
+#
+# This modules relies on `Sys::jvm`, `Sys::jni_env` and
+# `Sys::create_default_jvm` to get a handle on a JVM. You can adapt the
+# behavior of the FFI and services in this module by redefing
+# `Sys::create_default_jvm` and supply your own JVM object. You can manage
+# multiple java thread by switching the current environment in a redef
+# of `Sys::jni_env`, and multiple JVM using `Sys::jvm`.
+module base is
+ cflags "-I $(JAVA_HOME)/include/ -I $(JAVA_HOME)/include/linux/"
+ ldflags "-L $(JNI_LIB_PATH) -ljvm"
+ new_annotation extra_java_files
+end
+
+import jvm
+
+redef class Sys
+ private var jvm_cache: nullable JavaVM = null
+ private var jni_env_cache: nullable JniEnv = null
+
+ # Default Java Virtual Machine to use (will be instantiated using
+ # `create_default_jvm` if not already set)
+ fun jvm: JavaVM
+ do
+ if jvm_cache == null then create_default_jvm
+ return jvm_cache.as(not null)
+ end
+
+ # Sets the current default Java Virtual Machine (use with `jni_env=`)
+ fun jvm=(jvm: JavaVM) do jvm_cache = jvm
+
+ # Current main `JniEnv`
+ fun jni_env: JniEnv
+ do
+ if jni_env_cache == null then create_default_jvm
+ return jni_env_cache.as(not null)
+ end
+
+ # Sets the current default JNI env (use with `jvm=`)
+ fun jni_env=(jni_env: JniEnv) do jni_env_cache = jni_env
+
+ # Called by `jvm` and `jni_env` to instantiate a Java Virtual Machine.
+ # Used mostly for the FFI with Java.
+ protected fun create_default_jvm
+ do
+ var builder = new JavaVMBuilder
+
+ # By default, look for Java classes in a jar file the same directory as the executable
+ builder.options.add "-Djava.class.path={sys.program_name}.jar"
+
+ var jvm = builder.create_jvm
+ assert jvm != null else print "JVM creation failed"
+
+ self.jvm = jvm
+ self.jni_env = builder.jni_env.as(not null)
+ end
+
+ # Get a Java class by its name from the current `jni_env`
+ fun load_jclass(name: NativeString): JClass import jni_env `{
+ JNIEnv *nit_ffi_jni_env = Sys_jni_env(self);
+
+ // retrieve the implementation Java class
+ jclass java_class = (*nit_ffi_jni_env)->FindClass(nit_ffi_jni_env, name);
+ if (java_class == NULL) {
+ fprintf(stderr, "Nit FFI with Java error: failed to load class.\\n");
+ (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
+ exit(1);
+ }
+
+ return java_class;
+ `}
+end
+
+# A standard Java string `java.lang.String`
+#
+# Converted to a Nit string using `to_s`, or to a C string with `to_cstring`.
+# Created using `String::to_java_string` or `NativeString::to_java_string`.
+extern class JavaString in "Java" `{ java.lang.String `}
+ super JavaObject
+
+ # Get the string from Java and copy it to Nit memory
+ fun to_cstring: NativeString import sys, Sys.jni_env `{
+ Sys sys = JavaString_sys(self);
+ JNIEnv *env = Sys_jni_env(sys);
+
+ // Get the data from Java
+ const char *java_cstr = (*env)->GetStringUTFChars(env, self, NULL);
+ jsize len = (*env)->GetStringUTFLength(env, self);
+
+ // Copy it in control of Nit
+ char *nit_cstr = (char*)malloc(len+1);
+ memcpy(nit_cstr, java_cstr, len);
+ nit_cstr[len] = '\0';
+
+ // Free JNI ref and return
+ (*env)->ReleaseStringUTFChars(env, self, java_cstr);
+ return nit_cstr;
+ `}
+
+ redef fun to_s do return to_cstring.to_s
+end
+
+redef class NativeString
+ # Get a Java string from this C string
+ #
+ # This instance is only valid until the next execution of Java code.
+ # You can use `new_local_ref` to keep it longer.
+ fun to_java_string: JavaString import sys, Sys.jni_env `{
+ Sys sys = JavaString_sys(self);
+ JNIEnv *env = Sys_jni_env(sys);
+ return (*env)->NewStringUTF(env, self);
+ `}
+end
+
+redef class Text
+ # Get `self` as a `JavaString`
+ fun to_java_string: JavaString do return to_cstring.to_java_string
+end
+
+redef extern class JavaObject
+
+ # Returns a global reference to the Java object behind this reference
+ #
+ # You must use a global reference when keeping a Java object
+ # across execution of Java code, per JNI specification.
+ fun new_global_ref: SELF import sys, Sys.jni_env `{
+ Sys sys = JavaObject_sys(self);
+ JNIEnv *env = Sys_jni_env(sys);
+ return (*env)->NewGlobalRef(env, self);
+ `}
+
+ # Delete this global reference
+ fun delete_global_ref import sys, Sys.jni_env `{
+ Sys sys = JavaObject_sys(self);
+ JNIEnv *env = Sys_jni_env(sys);
+ (*env)->DeleteGlobalRef(env, self);
+ `}
+
+ # Delete this local reference
+ fun delete_local_ref import sys, Sys.jni_env `{
+ Sys sys = JavaObject_sys(self);
+ JNIEnv *env = Sys_jni_env(sys);
+ (*env)->DeleteLocalRef(env, self);
+ `}
+
+ # Pops the current local reference frame and return a valid reference to self
+ #
+ # Similar to `JavaVM::pop_local_frame` but returns a value.
+ fun pop_from_local_frame: SELF
+ do
+ var jni_env = sys.jni_env
+ return pop_from_local_frame_with_env(jni_env)
+ end
+
+ # Java implementation of `pop_from_local_frame`
+ protected fun pop_from_local_frame_with_env(jni_env: JniEnv): SELF `{
+ return (*jni_env)->PopLocalFrame(jni_env, self);
+ `}
+
+ # Is `self` null in Java?
+ #
+ # Since Java type system doesn't have the same `nullable` concept as Nit's,
+ # the two systems are not directly compatible. Any Nit instances of
+ # `JavaObject` may hold a Java null.
+ #
+ # To benefit from the safer type system of Nit, it is recommended to check
+ # the return of all extern methods implemented in Java to ensure the value
+ # is not a Java null. In case it is, you should replace it by a normal Nit
+ # `null`.
+ fun is_java_null: Bool in "Java" `{ return self == null; `}
+
+ # `JavaString` representation of `self` using Java's `toString`
+ fun to_java_string: JavaString in "Java" `{ return self.toString(); `}
+
+ # Use Java's `toString` for any `JavaObject`
+ redef fun to_s
+ do
+ if is_java_null then return super
+ return to_java_string.to_s
+ end
+end
# This file is part of NIT ( http://www.nitlanguage.org ).
#
-# Copyright 2014 Alexis Laferrière <alexis.laf@xymus.net>
-#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# The module `jvm` gives more control over the JVM instances and wraps
# most of JNI functions. You can use it to further customize the behavior
# of your code.
-module java is
- cflags "-I $(JAVA_HOME)/include/ -I $(JAVA_HOME)/include/linux/"
- ldflags "-L $(JNI_LIB_PATH) -ljvm"
- new_annotation extra_java_files
-end
-
-import jvm
-
-redef class Sys
- private var jvm_cache: nullable JavaVM = null
- private var jni_env_cache: nullable JniEnv = null
-
- # Default Java Virtual Machine to use (will be instantiated using
- # `create_default_jvm` if not already set)
- fun jvm: JavaVM
- do
- if jvm_cache == null then create_default_jvm
- return jvm_cache.as(not null)
- end
-
- # Sets the current default Java Virtual Machine (use with `jni_env=`)
- fun jvm=(jvm: JavaVM) do jvm_cache = jvm
-
- # Current main `JniEnv`
- fun jni_env: JniEnv
- do
- if jni_env_cache == null then create_default_jvm
- return jni_env_cache.as(not null)
- end
-
- # Sets the current default JNI env (use with `jvm=`)
- fun jni_env=(jni_env: JniEnv) do jni_env_cache = jni_env
-
- # Called by `jvm` and `jni_env` to instantiate a Java Virtual Machine.
- # Used mostly for the FFI with Java.
- protected fun create_default_jvm
- do
- var builder = new JavaVMBuilder
-
- # By default, look for Java classes in a jar file the same directory as the executable
- builder.options.add "-Djava.class.path={sys.program_name}.jar"
-
- var jvm = builder.create_jvm
- assert jvm != null else print "JVM creation failed"
-
- self.jvm = jvm
- self.jni_env = builder.jni_env.as(not null)
- end
-
- # Get a Java class by its name from the current `jni_env`
- fun load_jclass(name: NativeString): JClass import jni_env `{
- JNIEnv *nit_ffi_jni_env = Sys_jni_env(self);
-
- // retrieve the implementation Java class
- jclass java_class = (*nit_ffi_jni_env)->FindClass(nit_ffi_jni_env, name);
- if (java_class == NULL) {
- fprintf(stderr, "Nit FFI with Java error: failed to load class.\\n");
- (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
- exit(1);
- }
-
- return java_class;
- `}
-end
-
-# A standard Java string `java.lang.String`
-#
-# Converted to a Nit string using `to_s`, or to a C string with `to_cstring`.
-# Created using `String::to_java_string` or `NativeString::to_java_string`.
-extern class JavaString in "Java" `{ java.lang.String `}
- super JavaObject
-
- # Get the string from Java and copy it to Nit memory
- fun to_cstring: NativeString import sys, Sys.jni_env `{
- Sys sys = JavaString_sys(self);
- JNIEnv *env = Sys_jni_env(sys);
-
- // Get the data from Java
- const char *java_cstr = (*env)->GetStringUTFChars(env, self, NULL);
- jsize len = (*env)->GetStringUTFLength(env, self);
-
- // Copy it in control of Nit
- char *nit_cstr = (char*)malloc(len+1);
- memcpy(nit_cstr, java_cstr, len);
- nit_cstr[len] = '\0';
-
- // Free JNI ref and return
- (*env)->ReleaseStringUTFChars(env, self, java_cstr);
- return nit_cstr;
- `}
-
- redef fun to_s do return to_cstring.to_s
-end
-
-redef class NativeString
- # Get a Java string from this C string
- #
- # This instance is only valid until the next execution of Java code.
- # You can use `new_local_ref` to keep it longer.
- fun to_java_string: JavaString import sys, Sys.jni_env `{
- Sys sys = JavaString_sys(self);
- JNIEnv *env = Sys_jni_env(sys);
- return (*env)->NewStringUTF(env, self);
- `}
-end
-
-redef class Text
- # Get `self` as a `JavaString`
- fun to_java_string: JavaString do return to_cstring.to_java_string
-end
-
-redef extern class JavaObject
-
- # Returns a global reference to the Java object behind this reference
- #
- # You must use a global reference when keeping a Java object
- # across execution of Java code, per JNI specification.
- fun new_global_ref: SELF import sys, Sys.jni_env `{
- Sys sys = JavaObject_sys(self);
- JNIEnv *env = Sys_jni_env(sys);
- return (*env)->NewGlobalRef(env, self);
- `}
-
- # Delete this global reference
- fun delete_global_ref import sys, Sys.jni_env `{
- Sys sys = JavaObject_sys(self);
- JNIEnv *env = Sys_jni_env(sys);
- (*env)->DeleteGlobalRef(env, self);
- `}
-
- # Delete this local reference
- fun delete_local_ref import sys, Sys.jni_env `{
- Sys sys = JavaObject_sys(self);
- JNIEnv *env = Sys_jni_env(sys);
- (*env)->DeleteLocalRef(env, self);
- `}
-
- # Pops the current local reference frame and return a valid reference to self
- #
- # Similar to `JavaVM::pop_local_frame` but returns a value.
- fun pop_from_local_frame: SELF
- do
- var jni_env = sys.jni_env
- return pop_from_local_frame_with_env(jni_env)
- end
-
- # Java implementation of `pop_from_local_frame`
- protected fun pop_from_local_frame_with_env(jni_env: JniEnv): SELF `{
- return (*jni_env)->PopLocalFrame(jni_env, self);
- `}
-
- # Is `self` null in Java?
- #
- # Since Java type system doesn't have the same `nullable` concept as Nit's,
- # the two systems are not directly compatible. Any Nit instances of
- # `JavaObject` may hold a Java null.
- #
- # To benefit from the safer type system of Nit, it is recommended to check
- # the return of all extern methods implemented in Java to ensure the value
- # is not a Java null. In case it is, you should replace it by a normal Nit
- # `null`.
- fun is_java_null: Bool in "Java" `{ return self == null; `}
-
- # `JavaString` representation of `self` using Java's `toString`
- fun to_java_string: JavaString in "Java" `{ return self.toString(); `}
+module java
- # Use Java's `toString` for any `JavaObject`
- redef fun to_s
- do
- if is_java_null then return super
- return to_java_string.to_s
- end
-end
+import base
+import collections
nitlanguage / nit.git / commitdiff