rest-assured/src/main/java/io/restassured/config/EncoderConfig.java
public EncoderConfig defaultContentCharset(Charset charset) {
        String charsetAsString = notNull(charset, Charset.class).toString();
        return new EncoderConfig(charsetAsString, defaultQueryParameterCharset, shouldAppendDefaultContentCharsetToContentTypeIfUndefined, contentEncoders, contentTypeToDefaultCharset, true);
    }
public EncoderConfig defaultContentCharset(Charset charset) {
        String charsetAsString = notNull(charset, Charset.class).toString();
        return new EncoderConfig(charsetAsString, defaultQueryParameterCharset, shouldAppendDefaultContentCharsetToContentTypeIfUndefined, contentEncoders, contentTypeToDefaultCharset, true);
    }
Specify the default charset for the body/content in the request specification

@param charset The charset to use.
@return A new instance of {@link EncoderConfig}