update 初始化流程变量，确保默认值为 HashMap，简化变量获取逻辑

ruoyi-modules/ruoyi-workflow/src/main/java/org/dromara/workflow/domain/bo/BackProcessBo.java

@@ -57,13 +57,6 @@ public class BackProcessBo implements Serializable {
     /**
      * 流程变量
      */
-    private Map<String, Object> variables;
+    private Map<String, Object> variables = new HashMap<>();
 
-    public Map<String, Object> getVariables() {
-        if (variables == null) {
-            return new HashMap<>(16);
-        }
-        variables.entrySet().removeIf(entry -> Objects.isNull(entry.getValue()));
-        return variables;
-    }
 }

ruoyi-modules/ruoyi-workflow/src/main/java/org/dromara/workflow/domain/bo/CompleteTaskBo.java

@@ -9,7 +9,6 @@ import java.io.Serializable;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 
 /**
  * 办理任务请求对象
@@ -61,7 +60,7 @@ public class CompleteTaskBo implements Serializable {
     /**
      * 流程变量
      */
-    private Map<String, Object> variables;
+    private Map<String, Object> variables = new HashMap<>();
 
     /**
      * 弹窗选择的办理人
@@ -73,13 +72,4 @@ public class CompleteTaskBo implements Serializable {
      */
     private String ext;
 
-    public Map<String, Object> getVariables() {
-        if (variables == null) {
-            variables = new HashMap<>(16);
-            return variables;
-        }
-        variables.entrySet().removeIf(entry -> Objects.isNull(entry.getValue()));
-        return variables;
-    }
-
 }

ruoyi-modules/ruoyi-workflow/src/main/java/org/dromara/workflow/domain/bo/FlowNextNodeBo.java

@@ -6,7 +6,6 @@ import java.io.Serial;
 import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Objects;
 
 /**
  * 下一节点信息
@@ -26,13 +25,6 @@ public class FlowNextNodeBo implements Serializable {
     /**
      * 流程变量
      */
-    private Map<String, Object> variables;
+    private Map<String, Object> variables = new HashMap<>();
 
-    public Map<String, Object> getVariables() {
-        if (variables == null) {
-            return new HashMap<>(16);
-        }
-        variables.entrySet().removeIf(entry -> Objects.isNull(entry.getValue()));
-        return variables;
-    }
 }

ruoyi-modules/ruoyi-workflow/src/main/java/org/dromara/workflow/domain/bo/StartProcessBo.java

@@ -1,7 +1,6 @@
 package org.dromara.workflow.domain.bo;
 
 
-import cn.hutool.core.util.ObjectUtil;
 import jakarta.validation.constraints.NotBlank;
 import lombok.Data;
 import org.dromara.common.core.validate.AddGroup;
@@ -11,7 +10,6 @@ import java.io.Serial;
 import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Objects;
 
 /**
  * 启动流程对象
@@ -44,25 +42,11 @@ public class StartProcessBo implements Serializable {
     /**
      * 流程变量，前端会提交一个元素{'entity': {业务详情数据对象}}
      */
-    private Map<String, Object> variables;
+    private Map<String, Object> variables = new HashMap<>();
 
     /**
      * 流程业务扩展信息
      */
-    private FlowInstanceBizExt bizExt;
+    private FlowInstanceBizExt bizExt = new FlowInstanceBizExt();
 
-    public Map<String, Object> getVariables() {
-        if (variables == null) {
-            return new HashMap<>(16);
-        }
-        variables.entrySet().removeIf(entry -> Objects.isNull(entry.getValue()));
-        return variables;
-    }
-
-    public FlowInstanceBizExt getBizExt() {
-        if (ObjectUtil.isNull(bizExt)) {
-            bizExt = new FlowInstanceBizExt();
-        }
-        return bizExt;
-    }
 }

ruoyi-modules/ruoyi-workflow/src/main/java/org/dromara/workflow/domain/vo/NodeExtVo.java

@@ -4,6 +4,7 @@ import lombok.Data;
 
 import java.io.Serial;
 import java.io.Serializable;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -40,6 +41,6 @@ public class NodeExtVo implements Serializable {
      * <p>
      * 根据扩展属性中 VariablesEnum 类型的数据生成，存储 key=value 格式的自定义参数
      */
-    private Map<String, String> variables;
+    private Map<String, String> variables = new HashMap<>();
 
 }