ref(logging): improve filter matching logic in ElasticsearchBackendClient

Signed-off-by: Johnny Hujol <itudoben@users.noreply.github.com>

Author: itudoben

src/main/java/io/github/delirius325/jmeter/backendlistener/elasticsearch/ElasticsearchBackendClient.java

@@ -317,11 +317,13 @@ private boolean validateSample(BackendListenerContext context, SampleResult sr)
 
     if (!this.filters.isEmpty()) {
       for (String filter : filters) {
-        Pattern pattern = Pattern.compile(filter);
+        Pattern pattern = Pattern.compile(String.format(".*%s.*", filter));
         Matcher matcher = pattern.matcher(sampleLabel);
 
-        if (!sampleLabel.startsWith("!!") && (sampleLabel.contains(filter) || matcher.find())) {
-          valid = true;
+        if (matcher.find()) {
+          // README.md#Features*Filters
+          // You can also choose to exclude certain samplers; `!!exclude_this;filter1;filter2`
+          valid = !sampleLabel.startsWith("!!");
           break;
         }
         else {