无法将数组中的String复制到String变量

Question

我正在做一个相对简单的文件读取,并且我在输入值和从平面文件读取并存储在数组中的数据值之间的验证中遇到了异常.我已经将错误追踪到了firstName现场.我将此字段定义为等于array[0].While array[0]在我的输出中完美显示,fieldName不...它是空白或空.

这是我的代码,带有输出样本.

我不确定Stringbuilder这里是否最适合使用？或者其中一个深层String方法？我试过的一切似乎都没有用.我错过了什么...我知道这是我看不见的明显的东西.

public class DisplaySelectedNumbers
{
    public static void main(String[] args)
    {
        final String FN = "            ";
        final String LN = "            ";
        final String PHONE = "0000000000";
        String delimiter = ",";
        String s = FN + delimiter + LN + delimiter + PHONE + System.getProperty("line.separator");
        final int RECSIZE = s.length();
        String[] array = new String[3];
        Scanner kb = new Scanner(System.in);
        Path file = Paths.get("PhoneList.txt");
        String fName = JOptionPane.showInputDialog(null,"Enter first name to search");
        try
        {
            InputStream iStream=new BufferedInputStream(Files.newInputStream(file));
            BufferedReader reader=new BufferedReader(new InputStreamReader(iStream));
            while ((s = reader.readLine()) != null)
            {
                array = s.split(delimiter);
                String dispString = array[0]+" "+array[1]+" "+array[2]+"\n";
                System.out.println("array[0]="+array[0]);
                System.out.println("array[1]="+array[1]);
                System.out.println("array[2]="+array[2]);
                String firstName = array[0];
                System.out.println("firstName=");
                    s=reader.readLine();
            }
        }
        catch(Exception e)
        {
            System.out.println("Message: " + e);
        }
    }
}


array[0]=D
array[1]=JJ
array[2]=0123450000
firstName=
array[0]=B
array[1]=EE
array[2]=1111111111
firstName=
array[0]=D
array[1]=GG
array[2]=0033333333
firstName=

Answer 1

你忘了实际打印firstName变量:

System.out.println("firstName="); 

你需要:

System.out.println("firstName=" + firstName);