Android httpUrlConnection POST 文件上传

conn.setrequestproperty("content-length", string.valueof(info.getbytes().length));

出现错误的代码为：conn.setrequestproperty("content-length", string.valueof(info.length()));

这个应该先将内容转换成bytes再计算它的长度length。改成下面的即可：

conn.setrequestproperty("content-length", string.valueof(info.getbytes().length));

conn.setrequestproperty("content-length", string.valueof(info.getbytes().length));