drivers: implement streaming exec for executor based drivers

These simply delegate call to backend executor.

drivers/java/driver.go

@@ -554,6 +554,25 @@ func (d *Driver) ExecTask(taskID string, cmd []string, timeout time.Duration) (*
 	}, nil
 }
 
+var _ drivers.ExecTaskStreamingRawDriver = (*Driver)(nil)
+
+func (d *Driver) ExecTaskStreamingRaw(ctx context.Context,
+	taskID string,
+	command []string,
+	tty bool,
+	stream drivers.ExecTaskStream) error {
+
+	if len(command) == 0 {
+		return fmt.Errorf("error cmd must have atleast one value")
+	}
+	handle, ok := d.tasks.Get(taskID)
+	if !ok {
+		return drivers.ErrTaskNotFound
+	}
+
+	return handle.exec.ExecStreaming(ctx, command, tty, stream)
+}
+
 // GetAbsolutePath returns the absolute path of the passed binary by resolving
 // it in the path and following symlinks.
 func GetAbsolutePath(bin string) (string, error) {

drivers/java/driver_test.go

@@ -243,6 +243,35 @@ func TestJavaCmdArgs(t *testing.T) {
 	}
 }
 
+func TestJavaDriver_ExecTaskStreaming(t *testing.T) {
+	javaCompatible(t)
+	if !testutil.IsCI() {
+		t.Parallel()
+	}
+
+	require := require.New(t)
+	d := NewDriver(testlog.HCLogger(t))
+	harness := dtestutil.NewDriverHarness(t, d)
+	defer harness.Kill()
+
+	tc := &TaskConfig{
+		Class: "Hello",
+		Args:  []string{"900"},
+	}
+	task := basicTask(t, "demo-app", tc)
+
+	cleanup := harness.MkAllocDir(task, true)
+	defer cleanup()
+
+	copyFile("./test-resources/Hello.class", filepath.Join(task.TaskDir().Dir, "Hello.class"), t)
+
+	_, _, err := harness.StartTask(task)
+	require.NoError(err)
+	defer d.DestroyTask(task.ID, true)
+
+	dtestutil.ExecTaskStreamingConformanceTests(t, harness, task.ID)
+
+}
 func basicTask(t *testing.T, name string, taskConfig *TaskConfig) *drivers.TaskConfig {
 	t.Helper()