change to a better method

Signed-off-by: xinyual <xinyual@amazon.com>

Author: xinyual

plugin/src/main/java/org/opensearch/ml/action/models/DeleteModelTransportAction.java

@@ -52,6 +52,8 @@
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.common.xcontent.XContentHelper;
+import org.opensearch.common.xcontent.json.JsonXContent;
 import org.opensearch.commons.authuser.User;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.rest.RestStatus;
@@ -68,7 +70,6 @@
 import org.opensearch.ml.common.transport.model.MLModelDeleteAction;
 import org.opensearch.ml.common.transport.model.MLModelDeleteRequest;
 import org.opensearch.ml.common.transport.model.MLModelGetRequest;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.ml.engine.utils.AgentModelsSearcher;
 import org.opensearch.ml.helper.ModelAccessControlHelper;
 import org.opensearch.ml.utils.RestActionUtils;
@@ -305,7 +306,7 @@ private void checkPipelineBeforeDeleteModel(
     ) {
         ActionRequest request = requestSupplier.get();
         client.execute(actionType, request, ActionListener.wrap(pipelineResponse -> {
-            Map<String, Object> allConfigMap = StringUtils.fromJson(pipelineResponse.toString(), "");
+            Map<String, Object> allConfigMap = XContentHelper.convertToMap(JsonXContent.jsonXContent, pipelineResponse.toString(), true);
             List<String> allDependentPipelineIds = findDependentPipelinesEasy(allConfigMap, modelId);
             if (allDependentPipelineIds.isEmpty()) {
                 actionListener.onResponse(true);

plugin/src/test/java/org/opensearch/ml/action/models/DeleteModelTransportActionTests.java

@@ -302,7 +302,7 @@ public void testDeleteModel_BlockedByIngestPipeline() throws IOException {
     public void testDeleteModel_BlockedByAgent() throws IOException {
         XContentBuilder content = XContentBuilder.builder(XContentType.JSON.xContent());
         content.startObject();
-        content.field(MLAgent.IS_HIDDEN_FIELD, "false");
+        content.field(MLAgent.IS_HIDDEN_FIELD, false);
         content.endObject();
         SearchHit hit = new SearchHit(1, "1", null, null).sourceRef(BytesReference.bytes(content));
         SearchHits searchHits = new SearchHits(new SearchHit[] { hit }, new TotalHits(1, TotalHits.Relation.EQUAL_TO), 1.0f);