Cloning properties in order to safely iterate over them

Author: neugartf

api/all/src/main/java/io/opentelemetry/api/internal/ConfigUtil.java

@@ -8,6 +8,7 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Properties;
 import javax.annotation.Nullable;
 
 /**
@@ -35,13 +36,16 @@ private ConfigUtil() {}
  public static String getString(String key, String defaultValue) {
  String normalizedKey = normalizePropertyKey(key);
 
+ // Cloning in order to avoid ConcurrentModificationException
+ // see https://github.com/open-telemetry/opentelemetry-java/issues/6732
  String systemProperty =
- System.getProperties().stringPropertyNames().stream()
- .filter(propertyName -> normalizedKey.equals(normalizePropertyKey(propertyName)))
- .map(System::getProperty)
- .filter(Objects::nonNull)
- .findFirst()
- .orElse(null);
+ ((Properties) System.getProperties().clone())
+ .stringPropertyNames().stream()
+ .filter(propertyName -> normalizedKey.equals(normalizePropertyKey(propertyName)))
+ .map(System::getProperty)
+ .filter(Objects::nonNull)
+ .findFirst()
+ .orElse(null);
  if (systemProperty != null) {
  return systemProperty;
  }