java - 分割后读取内容

Question

我的问题是我有一个代码，但我在修复“找不到符号”错误时遇到问题。这是代码。

public static void writer() throws IOException {
    FileReader in = null;
    FileWriter out = null;
    BufferedReader br = null;
    BufferedWriter bw = null;
    try {
        in = new FileReader("Student.txt");
        out = new FileWriter("StudentAvg.txt");
        br = new BufferedReader(in);
        bw = new BufferedWriter(out);
        String[] line = new String[28];
        line = in.split("\t");

错误指向拆分过程。我的变量有问题吗？

Answer 1

问题是，您还没有读过任何行。

br = new BufferedReader(in);
bw = new BufferedWriter(out);
String[] line = new String[28];
line = in.split("\t"); // <-- this is your input file reader.

我想你想要

br = new BufferedReader(in);
bw = new BufferedWriter(out);
String fromFile;
while ((fromFile = br.readLine()) != null) {
    String[] line = fromFile.split("\t");

您也可以使用try-with-resources和类似的东西

try (BufferedReader br = new BufferedReader(//
        new FileReader("Student.txt"));
        BufferedWriter bw = new BufferedWriter(//
                new FileWriter("StudentAvg.txt"))) {
    String fromFile;
    while ((fromFile = br.readLine()) != null) {
        String[] line = fromFile.split("\t");
    }
}