Improvement the exception type of MasterConfig throws

[ykgarfield]

Motivation MasterConfig load configs of master.ini, parse and check.If has problems, almost of them throws NullPointerException or IllegalArgumentException.But in some cases, throw NullPointerException probably inappropriate.For example:

• code snippet 1:

try {
    this.hostName = masterConf.get("hostName").trim();
    AddressUtils.validLocalIp(this.hostName);
} catch (Throwable e) {
    throw new NullPointerException(new StringBuilder(256)
            .append("Illegal hostName value in ").append(SECT_TOKEN_MASTER)
            .append(" section!").toString());
}

• code snippet 2:

  if (!this.startConsumeAuthenticate && this.startConsumeAuthorize) {
  throw new NullPointerException(
          "startConsumeAuthenticate must set true if startConsumeAuthorize is true!");
  }

IllegalArgumentException may more reasonable or use cusutom exception(for example: ConfigException).

In addition, the following exception message not clear enough:

String tmpAuthToken = masterConf.get("confModAuthToken").trim();
if (tmpAuthToken.length() > TServerConstants.CFG_MODAUTHTOKEN_MAX_LENGTH) {
    throw new IllegalArgumentException(
            "Invalid value: confModAuthToken's value > " + TServerConstants.CFG_MODAUTHTOKEN_MAX_LENGTH);
}

Here is the string length illegal, the more detail exception message should be:

"Invalid value: the length of confModAuthToken's value > " + TServerConstants.CFG_MODAUTHTOKEN_MAX_LENGTH);

(optional) Design

(optional) Example snippet

[gosonzhang]

@ykgarfield, this is a question. Can you contribute a PR?

[gosonzhang]

see https://github.com/Tencent/TubeMQ/pull/53

[gosonzhang]

Thanks @ykgarfield