Add support for Java 8.

Support for java -source 1.8
Also change Travis to use 3x3 test matrix (jdk x nvm).

.travis.yml

@@ -1,8 +1,18 @@
-language: node_js
-node_js:
-  - "0.11"
-  - "0.10"
-  - "0.8"
+language: java
+jdk:
+  - oraclejdk8
+  - oraclejdk7
+  - openjdk6
+env:
+  - NODE_VERSION="0.11"
+  - NODE_VERSION="0.10"
+  - NODE_VERSION="0.8"
+before_install:
+  - nvm install $NODE_VERSION
+before_script:
+  - npm install
+script:
+  - npm test
 notifications:
   email:
     on_success: "never"

README.md

@@ -58,6 +58,20 @@ npm test
 
 _NOTE: You will need node-gyp installed using "npm install -g node-gyp"_
 
+### Java 1.8 support
+
+Manual compilation for Java 1.8 support requires additional steps:
+
+```bash
+./compile-java-code.sh
+./compile-java8-code.sh
+node-gyp configure build
+npm test
+npm test8
+```
+
+Java 1.8 language features can be used in Java classes only if a Java 1.8 JRE is available. The script compile-java8-code.sh is used only to compile java classes used in the 'test8' unit tests, but these classes are checked into the test8/ directory. Note that unit tests in the test8/ directory will pass (by design) if run against a Java 1.6 or 1.7 JRE, provided that a java.lang.UnsupportedClassVersionError is caught with the message 'Unsupported major.minor version 52.0' (the expected behavior when Java 1.8 language features are used in an older JRE).
+
 ## Installation node-webkit
 
 ```bash
@@ -208,7 +222,7 @@ __Example__
     var Test = java.import('Test');
     Test.someStaticMethodSync(5);
     console.log(Test.someStaticField);
-    
+
     var value1 = Test.NestedEnum.Value1;
 
     var test = new Test();

compile-java8-code.sh

@@ -0,0 +1,14 @@
+#!/bin/bash -e
+
+# This script must be run on a Mac due to its reliance on /usr/libexec/java_home
+# to find a JDK 1.8 installation. Note that this script will work correctly on
+# a mac with JDK 1.8 installed, even if JAVA_HOME currently points to a 1.7
+# or earlier JDK.
+# This script is run manually by maintainers of this project, who add the
+# the generated .class files to source control.
+
+JAVA_VERSION=1.8
+JDK8_HOME=$(/usr/libexec/java_home -v ${JAVA_VERSION})
+
+cd test8
+${JDK8_HOME}/bin/javac -source ${JAVA_VERSION} *.java

package.json

@@ -35,7 +35,7 @@
     "nodeunit": "0.9.0"
   },
   "scripts": {
-    "test": "nodeunit test",
+    "test": "nodeunit test test8",
     "postinstall": "node postInstall.js"
   },
   "main": "./index.js"

src/java.cpp

@@ -161,7 +161,7 @@ v8::Local<v8::Value> Java::createJVM(JavaVM** jvm, JNIEnv** env) {
   }
 
   JNI_GetDefaultJavaVMInitArgs(&args);
-  args.version = JNI_VERSION_1_6;
+  args.version = JNI_BEST_VERSION;
   args.ignoreUnrecognized = false;
   args.options = vmOptions;
   args.nOptions = vmOptionsCount;
@@ -1050,6 +1050,12 @@ NAN_METHOD(Java::instanceOf) {
 void EIO_CallJs(uv_work_t* req) {
 }
 
+static std::string int_to_string(int i) {
+  char buf[32];
+  snprintf(buf, sizeof(buf), "%d", i);
+  return std::string(buf);
+}
+
 #if NODE_MINOR_VERSION >= 10
 void EIO_AfterCallJs(uv_work_t* req, int status) {
 #else
@@ -1062,10 +1068,10 @@ void EIO_AfterCallJs(uv_work_t* req) {
   dynamicProxyData->result = NULL;
 
   JNIEnv* env;
-  int ret = dynamicProxyData->java->getJvm()->GetEnv((void**)&env, JNI_VERSION_1_6);
+  int ret = dynamicProxyData->java->getJvm()->GetEnv((void**)&env, JNI_BEST_VERSION);
   if (ret != JNI_OK) {
     dynamicProxyData->throwableClass = "java/lang/IllegalStateException";
-    dynamicProxyData->throwableMessage = "Could not retrieve JNIEnv: jvm->GetEnv returned " + ret;
+    dynamicProxyData->throwableMessage = "Could not retrieve JNIEnv: jvm->GetEnv returned " + int_to_string(ret);
     dynamicProxyData->done = DYNAMIC_PROXY_JS_ERROR;
     return;
   }

src/java.h

@@ -8,6 +8,12 @@
 #include <string>
 #include <nan.h>
 
+#ifdef JNI_VERSION_1_8
+#define JNI_BEST_VERSION JNI_VERSION_1_8
+#else
+#define JNI_BEST_VERSION JNI_VERSION_1_6
+#endif
+
 class Java : public node::ObjectWrap {
 public:
   static void Init(v8::Handle<v8::Object> target);

src/utils.cpp

@@ -127,11 +127,11 @@ std::string javaMethodCallToString(JNIEnv *env, jobject obj, jmethodID methodId,
 
 JNIEnv* javaGetEnv(JavaVM* jvm, jobject classLoader) {
   JNIEnv *env = NULL;
-  int ret = jvm->GetEnv((void**)&env, JNI_VERSION_1_6);
+  int ret = jvm->GetEnv((void**)&env, JNI_BEST_VERSION);
 
   if (ret == JNI_EDETACHED) {
     JavaVMAttachArgs attachArgs;
-    attachArgs.version = JNI_VERSION_1_6;
+    attachArgs.version = JNI_BEST_VERSION;
     attachArgs.name = NULL;
     attachArgs.group = NULL;
     jvm->AttachCurrentThread((void**)&env, &attachArgs);

test8/TestLambda.java

@@ -0,0 +1,18 @@
+class TestLambda
+{
+    public TestLambda() {}
+
+    interface IntegerMath {
+        int op(int a, int b);
+    }
+
+    public int testLambdaAddition(Integer x, Integer y) {
+        IntegerMath addition = (a, b) -> a + b;
+        return addition.op(x, y);
+    }
+
+    public int testLambdaSubtraction(Integer x, Integer y) {
+        IntegerMath subtraction = (a, b) -> a - b;
+        return subtraction.op(x, y);
+    }
+}

test8/testLambda.js

@@ -0,0 +1,27 @@
+var java = require("../testHelpers").java;
+
+var nodeunit = require("nodeunit");
+var util = require("util");
+
+exports['Java8'] = nodeunit.testCase({
+  "call methods of a class that uses lambda expressions": function(test) {
+    try {
+      var TestLambda = java.import('TestLambda');
+      var lambda = new TestLambda();
+      var sum = lambda.testLambdaAdditionSync(23, 42);
+      test.equal(sum, 65);
+      var diff = lambda.testLambdaSubtractionSync(23, 42);
+      test.equal(diff, -19);
+    }
+    catch (err) {
+      var unsupportedVersion = err.toString().match(/Unsupported major.minor version 52.0/)
+      test.ok(unsupportedVersion);
+      if (unsupportedVersion)
+        console.log('JRE 1.8 not available');
+      else
+        console.error('Java8 test failed with unknown error:', err);
+    }
+    test.done();
+  }
+});
+

testHelpers.js

@@ -5,5 +5,6 @@ java.options.push("-Djava.awt.headless=true");
 
 java.classpath.push("test/");
 java.classpath.push("test/commons-lang3-3.1.jar");
+java.classpath.push("test8/");
 
 module.exports.java = java;