> For the complete documentation index, see [llms.txt](https://gwt.dontcareabout.us/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gwt.dontcareabout.us/gwt/sdm.md).

# Super Dev Mode

> ## Super Dev Mode \#

修改 gwt.xml，目前測試結果是一定得要重開 SDM。（DevMode 好像可以不用）

`Dev Mode On` bookmark 內容主要是把現在的頁面卡一段 `<script src="http://localhost:9876/dev_mode_on.js" />`， 所以 code server 的 IP / port 號改變的話 bookmark 就得重拉一次。

### RPC 突發異常的解法

如果時常發生 GWT RPC 無法運作，JSP container 炸出來的錯誤訊息大意是：

1. 找不到 `UNIQUE_ID.gwt.rpc` 這個檔案
2. `FOO_POJO` 沒有繼承 `IsSerializable`，沒辦法 serialize

那麼在 JSP container 啟動的參數加上 `-Dgwt.codeserver.port=PORT_NUMBER`（預設值是 9876）， 基本上就可以正常運作。

背後的原理在於 `RemoteServiceServlet` 有針對 SDM 作特製， 會試圖嘗試從 code server（`http://localhost:PORT_NUMBER/policies/UNIQUE_ID.gwt.prc`）取得 RPC policy 相關檔案。

Reference：

* 官方解釋：<https://code.google.com/p/google-web-toolkit/issues/detail?id=7522#c12>
* RemoteServiceServlet commit：<https://gwt.googlesource.com/gwt/+/9faa03e06112984dd4ac5ff100a2515c2d3f74f8/user/src/com/google/gwt/user/server/rpc/RemoteServiceServlet.java>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://gwt.dontcareabout.us/gwt/sdm.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.