fix the exception of update null point of workflow instance due to no… (#4459)

* fix the exception of update null point of workflow instance due to not add global parameter when create workflow definition

* optimization of the leading package

Co-authored-by: yaoshui <huangqitao@accesscorporate.com.cn>

dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/service/ProcessInstanceService.java

@@ -66,11 +66,13 @@ import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 import java.text.ParseException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.stream.Collectors;
 
 import org.slf4j.Logger;
@@ -449,7 +451,7 @@ public class ProcessInstanceService extends BaseService {
 
             originDefParams = JSONUtils.toJsonString(processData.getGlobalParams());
             List<Property> globalParamList = processData.getGlobalParams();
-            Map<String, String> globalParamMap = globalParamList.stream().collect(Collectors.toMap(Property::getProp, Property::getValue));
+            Map<String, String> globalParamMap = Optional.ofNullable(globalParamList).orElse(Collections.emptyList()).stream().collect(Collectors.toMap(Property::getProp, Property::getValue));
             globalParams = ParameterUtils.curingGlobalParams(globalParamMap, globalParamList,
                     processInstance.getCmdTypeIfComplement(), schedule);
             timeout = processData.getTimeout();