allow to get settings as delimited string

src/main/java/org/elasticsearch/common/settings/ImmutableSettings.java

@@ -324,6 +324,15 @@ public class ImmutableSettings implements Settings {
         }
     }
 
+    @Override
+    public String toDelimitedString(char delimiter) {
+        StringBuilder sb = new StringBuilder();
+        for (Map.Entry<String, String> entry : settings.entrySet()) {
+            sb.append(entry.getKey()).append("=").append(entry.getValue()).append(delimiter);
+        }
+        return sb.toString();
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

src/main/java/org/elasticsearch/common/settings/Settings.java

@@ -245,6 +245,11 @@ public interface Settings {
      */
     Version getAsVersion(String setting, Version defaultVersion) throws SettingsException;
 
+    /**
+     * Returns the settings as delimited string.
+     */
+    String toDelimitedString(char delimiter);
+
     /**
      * A settings builder interface.
      */

src/test/java/org/elasticsearch/test/unit/common/settings/ImmutableSettingsTests.java

@@ -70,6 +70,7 @@ public class ImmutableSettingsTests {
         assertThat(settings.get("key1"), equalTo("value1"));
         assertThat(settings.get("key2"), equalTo("value2"));
         assertThat(settings.getAsMap().size(), equalTo(2));
+        assertThat(settings.toDelimitedString(';'), equalTo("key1=value1;key2=value2;"));
 
         settings = settingsBuilder()
                 .loadFromDelimitedString("key1=value1;key2=value2;", ';')
@@ -77,6 +78,7 @@ public class ImmutableSettingsTests {
         assertThat(settings.get("key1"), equalTo("value1"));
         assertThat(settings.get("key2"), equalTo("value2"));
         assertThat(settings.getAsMap().size(), equalTo(2));
+        assertThat(settings.toDelimitedString(';'), equalTo("key1=value1;key2=value2;"));
     }
 
 }