Promisify three async methods of Java module.

jimlloyd · jimlloyd · commit d6aef41226ed · 2015-01-14T10:46:00.000-08:00
Joe, I implemented an onJvmCreated callback so I could do the promisification
from javascript instead of C++. Let me know if you have reservations about
this approach.
diff --git a/lib/nodeJavaBridge.js b/lib/nodeJavaBridge.js
@@ -11,6 +11,19 @@ java.classpath.push(path.resolve(__dirname, "../commons-lang3-node-java.jar"));
 java.classpath.push(path.resolve(__dirname, __dirname, "../src-java"));
 java.nativeBindingLocation = binaryPath;
 
+java.onJvmCreated = function() {
+  if (java.asyncOptions) {
+    var suffix = java.asyncOptions.promiseSuffix;
+    var promisify = java.asyncOptions.promisify;
+    if (typeof suffix === 'string' && typeof promisify === 'function') {
+      var methods = ['newInstance', 'callMethod', 'callStaticMethod'];
+      methods.forEach(function (name) {
+        java[name + suffix] = promisify(java[name]);
+      });
+    }
+  }
+}
+
 var MODIFIER_PUBLIC = 1;
 var MODIFIER_STATIC = 8;
 
diff --git a/src/java.cpp b/src/java.cpp
@@ -185,11 +185,20 @@ v8::Local<v8::Value> Java::createJVM(JavaVM** jvm, JNIEnv** env) {
 
   m_classLoader = getSystemClassLoader(*env);
 
+  v8::Local<v8::Value> onJvmCreated = NanObjectWrapHandle(this)->Get(NanNew<v8::String>("onJvmCreated"));
+
   // TODO: this handles sets put doesn't prevent modifing the underlying data. So java.classpath.push will still work which is invalid.
   NanObjectWrapHandle(this)->SetAccessor(NanNew<v8::String>("classpath"), AccessorProhibitsOverwritingGetter, AccessorProhibitsOverwritingSetter);
   NanObjectWrapHandle(this)->SetAccessor(NanNew<v8::String>("options"), AccessorProhibitsOverwritingGetter, AccessorProhibitsOverwritingSetter);
   NanObjectWrapHandle(this)->SetAccessor(NanNew<v8::String>("nativeBindingLocation"), AccessorProhibitsOverwritingGetter, AccessorProhibitsOverwritingSetter);
   NanObjectWrapHandle(this)->SetAccessor(NanNew<v8::String>("asyncOptions"), AccessorProhibitsOverwritingGetter, AccessorProhibitsOverwritingSetter);
+  NanObjectWrapHandle(this)->SetAccessor(NanNew<v8::String>("onJvmCreated"), AccessorProhibitsOverwritingGetter, AccessorProhibitsOverwritingSetter);
+
+  if (onJvmCreated->IsFunction()) {
+    v8::Local<v8::Function> onJvmCreatedFunc = onJvmCreated.As<v8::Function>();
+    v8::Local<v8::Object> context = NanNew<v8::Object>();
+    onJvmCreatedFunc->Call(context, 0, NULL);
+  }
 
   return NanNull();
 }
@@ -206,6 +215,8 @@ NAN_GETTER(Java::AccessorProhibitsOverwritingGetter) {
     NanReturnValue(NanNew<v8::String>(Java::s_nativeBindingLocation.c_str()));
   } else if(!strcmp("asyncOptions", *nameStr)) {
     NanReturnValue(self->m_asyncOptions);
+  } else if(!strcmp("onJvmCreated", *nameStr)) {
+    // There is no good reason to get onJvmCreated, so just fall through to error below.
   }
 
   std::ostringstream errStr;
diff --git a/src/javaObject.cpp b/src/javaObject.cpp
@@ -69,7 +69,7 @@
       funcTemplate->PrototypeTemplate()->Set(methodNameSync, methodCallSyncTemplate->GetFunction());
 
       if (promisifying) {
-        v8::Local<v8::Object> recv = asyncOptions; // just a dummy receiver
+        v8::Local<v8::Object> recv = NanNew<v8::Object>();
         v8::Local<v8::Value> argv[] = { methodCallTemplate->GetFunction() };
         v8::Local<v8::Value> result = promisify->Call(recv, 1, argv);
         if (!result->IsFunction()) {
diff --git a/test/promises-test.js b/test/promises-test.js
@@ -3,31 +3,27 @@ var java = require("../testHelpers").java;
 var nodeunit = require("nodeunit");
 var util = require("util");
 
-
 exports['Promises'] = nodeunit.testCase({
-
   "create an instance of a class and call methods (getClassPromise & getNamePromise)": function(test) {
     // Adapted from a test in simple-test.js
     java.newInstance("java.util.ArrayList", function(err, list) {
-      if (err) {
-        console.log(err);
-        return;
-      }
+      test.ifError(err);
       test.ok(list);
-      if (list) {
-        list.getClassPromise()
-          .then(function(clazz) { return clazz.getNamePromise(); })
-          .then(function(name) {
-            test.equal(name, "java.util.ArrayList");
-          })
-          .catch(function(err) {
-            test.ifError(err);
-          })
-          .then(function() {
-            test.expect(2);
-            test.done();
-          });
-      }
+      list.getClassPromise()
+        .then(function(clazz) {
+          test.ok(clazz);
+          return clazz.getNamePromise();
+        })
+        .then(function(name) {
+          test.equal(name, "java.util.ArrayList");
+        })
+        .catch(function(err) {
+          test.ifError(err);
+        })
+        .then(function() {
+          test.expect(4);
+          test.done();
+        });
     });
   },
 
@@ -44,6 +40,28 @@ exports['Promises'] = nodeunit.testCase({
         test.expect(1);
         test.done();
       });
+  },
+
+  "run promisified method of Java module (newInstancePromise)": function (test) {
+    java.newInstancePromise("java.util.ArrayList")
+      .then(function(list) {
+        test.ok(list);
+        return list.getClassPromise();
+      })
+      .then(function(clazz) {
+        test.ok(clazz);
+        return clazz.getNamePromise();
+      })
+      .then(function(name) {
+        test.equal(name, "java.util.ArrayList");
+      })
+      .catch(function(err) {
+        test.ifError(err);
+      })
+      .then(function() {
+        test.expect(3);
+        test.done();
+      });
   }
 });
 
