More granular steps in the Makefile, can help with running all or single Java tests (and with ASAN build - https://github.com/facebook/rocksdb/wiki/JNI-Debugging) (#1237)

Makefile

@@ -1378,6 +1378,12 @@ rocksdbjava: $(java_libobjects)
 jclean:
 	cd java;$(MAKE) clean;
 
+jtest_compile: rocksdbjava
+	cd java;$(MAKE) java_test
+
+jtest_run:
+	cd java;$(MAKE) run_test
+
 jtest: rocksdbjava
 	cd java;$(MAKE) sample;$(MAKE) test;
 

java/Makefile

@@ -181,7 +181,9 @@ java_test: resolve_test_deps
 		$(TEST_SRC)/org/rocksdb/*.java
 	$(AM_V_at)javah -cp $(MAIN_CLASSES):$(TEST_CLASSES) -d $(NATIVE_INCLUDE) -jni $(NATIVE_JAVA_TEST_CLASSES)
 
-test: java resolve_test_deps java_test
+test: java resolve_test_deps java_test run_test
+
+run_test:
 	java -ea -Xcheck:jni -Djava.library.path=target -cp "$(MAIN_CLASSES):$(TEST_CLASSES):$(JAVA_TESTCLASSPATH):target/*" org.rocksdb.test.RocksJunitRunner $(JAVA_TESTS)
 
 db_bench: java