.length无法解析或不是字段

Question

我已经尝试过很难用之前的类似答案来解决这个问题,但我仍然无法看到我的问题,希望你能提供帮助.我的代码看起来像这样:

String MyContent =" ";
String nextline = " ";

InputStream in = new FileInputStream(f);

BufferedInputStream bin = new BufferedInputStream(in);

DataInputStream din = new DataInputStream(bin);

    while(din.available()>1)
    {
    nextline = din.readLine();

    //Filter out XML headers which are not browser compliant
    if (nextline.length > 4)
        {
        if (nextline.substring(1,5) != "<?xml")
            {
            MyContent=MyContent+ nextline;
            }
        }   
    }

    out.print (MyContent);

in.close();
bin.close();
din.close();

我收到一个错误:

An error occurred at line: 25 in the jsp file: /MaxiSunReports/DisplayXMLFile.jsp
nextline.length cannot be resolved or is not a field
22:     nextline = din.readLine();
23:     nextline = "THISISATEST";
24:     //Filter out XML headers which are not browser compliant
25:     if (nextline.length > 4)
26:         {
27:         if (nextline.substring(1,5) != "<?xml")

Answer 1

首先,该方法readLine()中DataInputStream已过时.

其次,这个方法返回一个String,它没有field length.它只有方法length().length是数组的属性.