/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

2047          ; disallowed_STD3_mapped ; 003F 003F     # 3.2  DOUBLE QUESTION MARK
2048          ; disallowed_STD3_mapped ; 003F 0021     # 3.0  QUESTION EXCLAMATION MARK
2049          ; disallowed_STD3_mapped ; 0021 003F     # 3.0  EXCLAMATION QUESTION MARK
204A..204D    ; valid                  ;      ; NV8    # 3.0  TIRONIAN SIGN ET..BLACK RIGHTWARDS BULLET

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

这些状态码都具有便于识别的关联名称，但是重要的还是数字。

简言之：

* `100` 及以上的状态码用于返回**信息**。这类状态码很少直接使用。具有这些状态码的响应不能包含响应体
* **`200`** 及以上的状态码用于表示**成功**。这些状态码是最常用的
    * `200` 是默认状态代码，表示一切**正常**
    * `201` 表示**已创建**，通常在数据库中创建新记录后使用
    * `204` 是一种特殊的例子，表示**无内容**。该响应在没有为客户端返回内容时使用，因此，该响应不能包含响应体
* **`300`** 及以上的状态码用于**重定向**。具有这些状态码的响应不一定包含响应体，但 `304`**未修改**是个例外，该响应不得包含响应体
* **`400`** 及以上的状态码用于表示**客户端错误**。这些可能是第二常用的类型
    * `404`，用于**未找到**响应
    * 对于来自客户端的一般错误，可以只使用 `400`