修改AFNetworking源文件可接收text/plain和text/html的方法

 在使用AFNetworking的时候可能会碰到下面的错误：

    { status code: 200, headers {

    "Content-Length" = 14;

    "Content-Type" = "text/plain;charset=utf-8";

    Date = "Thu, 22 May 2014 10:37:50 GMT";

    Server = "Apache-Coyote/1.1";

    "Set-Cookie" ="JSESSIONID=C0DFED60A154557F8386E62AB2A066CE; Path=/FHJRDT";

    } }, NSLocalizedDescription=Request failed:unacceptable content-type: text/plain}

    此时需要修改AFNetworking可接收的Content-Type，前往AFNetworking源代码目录找到AFURLResponseSerialization.m文件将里面的代码：

    self.acceptableContentTypes =[NSSetsetWithObjects:@"application/json",@"text/json",@"text/javascript",nil];

    修改为：

    self.acceptableContentTypes =[NSSetsetWithObjects:@"application/json",@"text/json",@"text/javascript",@"text/html",nil];

    self.acceptableContentTypes =[NSSetsetWithObjects:@"application/json",@"text/json", @"text/javascript" ,@"text/plain" , nil];