java - 如何用Java搜索文件并返回值？

Question

我需要一些有关以下代码的帮助。
我想做的是从文件中的行中读取数据。我想到的方法是使用 while 循环来迭代各行，尝试找到特定的“x_y_z”并使用 indexOf() 方法查看它是否存在。所以基本上我想运行循环直到得到一个不是 -1 的值，然后中断循环并返回该值。我在返回值时遇到问题...我似乎无法将其从循环中取出。有人可以帮我吗？

import java.io.InputStreamReader;
import org.bukkit.entity.Player;

/**
 *
 * @author Tim
 */
public class ReadIn {

    public static int read(String path, int x, int y, int z, Player player) {
        try {
            FileInputStream fstream = new FileInputStream(path);
            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String strLine;

            //Read File Line By Line
            int index = -1;
            while ((strLine = br.readLine()) != null && index == -1) {
                index = strLine.indexOf(x + "_" + y + "_" + z);
                if (index != -1) {
                    int value = index;
                    break;
                }
            }

            //Close the input stream
            in.close();

        } catch (Exception exception) {//Catch exception if any
            exception.printStackTrace();
        }
    }
}

非常感谢，
蒂姆

Answer 1

您的代码无法编译，该方法不返回任何值!改为这样做:

    public static int read(String path, int x, int y, int z, Player player) {
        int value = -1;
        try {
            FileInputStream fstream = new FileInputStream(path);
            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String strLine = "";       
            //Read File Line By Line
            int index = -1;
            while ((strLine = br.readLine()) != null) {
                index = strLine.indexOf(x + "_" + y + "_" + z);
                if (index != -1) {
                    value = index;
                    break;
                }
            }
            //Close the input stream
            in.close();
        } catch (Exception exception) {//Catch exception if any
            exception.printStackTrace();
        }
        return value;
    }

值现在将包含正确的索引，否则为 -1。