Multipart上传filename乱码

使用httpClient上传文件，文件名是中文，需要设置http为兼容模式，否则会使用mime默认的编码（US-ASCII），中文文件名就乱码了，源码分析如下。

HttpBrowserCompatibleMultipart
浏览器兼容模式 （设置的charset）（UTF-8），文件名正常

编码过程如下：

    private static void writeBytes(            final String s, final Charset charset, final OutputStream out) throws IOException {        final ByteArrayBuffer b = encode(charset, s);        writeBytes(b, out);    }    protected static void writeField(            final MinimalField field, final Charset charset, final OutputStream out) throws IOException {        writeBytes(field.getName(), charset, out);        writeBytes(FIELD_SEP, out);        writeBytes(field.getBody(), charset, out);        writeBytes(CR_LF, out);    }

结果：


--mFDXEYYXySUoUuFmPQ2yjojbK0_qgR8Z4V
Content-Disposition: form-data; name="uploadFile2"; filename="中文.mp4"
Content-Type: video/mp4


HttpStrictMultipart
浏览器严格模式 MIME.DEFAULT_CHARSET  （US-ASCII），文件名乱码了
编码过程如下：

    private static void writeBytes(            final String s, final OutputStream out) throws IOException {        final ByteArrayBuffer b = encode(MIME.DEFAULT_CHARSET, s); // US-ASCII        writeBytes(b, out);    }    protected static void writeField(            final MinimalField field, final OutputStream out) throws IOException {        writeBytes(field.getName(), out);        writeBytes(FIELD_SEP, out);        writeBytes(field.getBody(), out);        writeBytes(CR_LF, out);    }

结果

--k8ni5k102LlgW3Ez5ktsImNa3lMr5tB8FPe_e
Content-Disposition: form-data; name="uploadFile2"; filename="??.mp4"
Content-Type: video/mp4
Content-Transfer-Encoding: binary

设置方法：

MultipartEntityBuilder builder = MultipartEntityBuilder.create();builder.setCharset(Charset.forName("UTF-8"));builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);