final String template = """
                {"source":{"index":"__SOURCE_INDEX__","size":__SIZE__},"dest":{"index":"__DEST_INDEX__"}}
                """;
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String source = template //
                .replace("__SOURCE_INDEX__", fromIndex)//
                .replace("__SIZE__", fessConfig.getIndexReindexSize())//
                .replace("__DEST_INDEX__", toIndex);

image/x-icon=ico\n\
image/x-icon=ico\n\
image/png=png\n\
image/svg+xml=svg\n\
image/tiff=tiff\n\
image/jpeg=jpg\n\

index.reindex.size=100
index.reindex.body={"source":{"index":"__SOURCE_INDEX__","size":__SIZE__},"dest":{"index":"__DEST_INDEX__"},"script":{"source":"__SCRIPT_SOURCE__"}}
index.reindex.requests_per_second=adaptive
index.reindex.refresh=false
index.reindex.timeout=1m
index.reindex.scroll=5m
index.reindex.max_docs=

    /** The key of the configuration. e.g. 100 */
    String INDEX_REINDEX_SIZE = "index.reindex.size";

    /** The key of the configuration. e.g. {"source":{"index":"__SOURCE_INDEX__","size":__SIZE__},"dest":{"index":"__DEST_INDEX__"},"script":{"source":"__SCRIPT_SOURCE__"}} */
    String INDEX_REINDEX_BODY = "index.reindex.body";

    /** The key of the configuration. e.g. adaptive */