增加String转换

flowable-core/src/main/java/com/lanyuanxiaoyao/flowable/core/model/FlowableMetadata.java

@@ -37,6 +37,10 @@ public class FlowableMetadata implements Serializable {
     return clazz.cast(metadata.get(key));
   }
 
+  public String getString(String key) {
+    return get(key, String.class);
+  }
+
   public Integer getInt(String key) {
     return get(key, Integer.class);
   }
@@ -81,6 +85,10 @@ public class FlowableMetadata implements Serializable {
     return clazz.cast(metadata.getOrDefault(key, defaultValue));
   }
 
+  public String getStringOrDefault(String key, String defaultValue) {
+    return getOrDefault(key, String.class, defaultValue);
+  }
+
   public Integer getIntOrDefault(String key, Integer defaultValue) {
     return getOrDefault(key, Integer.class, defaultValue);
   }