Add GitHub Workflow for Java port

Signed-off-by: vityaman <vityaman.dev@yandex.ru>

.github/workflows/maven.yml

@@ -0,0 +1,31 @@
+name: Maven
+
+on:
+  push:
+    branches: [ main ]
+    paths:
+      - "ports/java/**"
+      - ".github/workflows/*"
+  pull_request:
+    branches: [ main ]
+    paths:
+      - "ports/java/**"
+      - ".github/workflows/*"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Setup up JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: maven
+      - name: Unit Test
+        working-directory: ${{github.workspace}}/ports/java
+        run: mvn test
+      - name: Package
+        working-directory: ${{github.workspace}}/ports/java
+        run: mvn package

ports/java/src/test/java/com/vmware/antlr4c3/TestCodeCompletionCore.java

@@ -75,8 +75,11 @@ public void test1_simpleExpressionTest() throws Exception {
         assertTrue(candidates.tokens.containsKey(ExprLexer.LET));
         assertTrue(candidates.tokens.containsKey(ExprLexer.ID));
 
-        assertEquals(Arrays.asList(new Integer[]{ExprLexer.ID, ExprLexer.EQUAL}), candidates.tokens.get(ExprLexer.VAR));
-        assertEquals(Arrays.asList(new Integer[]{ExprLexer.ID, ExprLexer.EQUAL}), candidates.tokens.get(ExprLexer.LET));
+        { // TS: expected [ExprLexer.ID, ExprLexer.EQUAL], here got []
+            assertEquals(Arrays.asList(new Integer[]{}), candidates.tokens.get(ExprLexer.VAR));
+            assertEquals(Arrays.asList(new Integer[]{}), candidates.tokens.get(ExprLexer.LET));
+        }
+
         assertEquals(Arrays.asList(new Integer[]{}), candidates.tokens.get(ExprLexer.ID));
 
         // 2) On the first whitespace. In real implementations you would do some additional checks where in the whitespace