自己定义 了一个ReadTxtFile类，在主程序引用时，显示方法未定义

Question

自己定义 了一个ReadTxtFile类，在主程序引用时，显示方法未定义 ，怎么解决呀：
下面是ReadTxtFile类：

package test;
import java.io.*;

public class ReadTxtFile {
    public readTxt(String filePath) {
          
          try {
            File file = new File(filePath);
            if(file.isFile() && file.exists()) {
              InputStreamReader isr = new InputStreamReader(new FileInputStream(file), "utf-8");
              BufferedReader br = new BufferedReader(isr);
              String lineTxt = null;
              while ((lineTxt = br.readLine()) != null) {
                System.out.println(lineTxt);
              }
              br.close();
            } else {
              System.out.println("no exit");
            }
          } catch (Exception e) {
            System.out.println("wrong doing");
          }
          
          }
}

下面是主程序 ：

package test;
import test.ReadTxtFile;
public class Read {
      public static void main(String[] args) {
            String filePath = "F:\\javawork\\readtxtfile\\mdata.txt";
            ReadTxtFile f = new ReadTxtFile();
            f.readTxt(filePath);
          }

}

下面是结果 显示：

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 
    The method readTxt(String) is undefined for the type ReadTxtFile

    at test/test.Read.main(Read.java:7)

Answer 1

你的 ReadTxtFile 的readTxt 都没有 返回值，你应该这样写

package test;
import java.io.*;
 
public class ReadTxtFile {
    public void readTxt(String filePath) {
          
          try {
            File file = new File(filePath);
            if(file.isFile() && file.exists()) {
              InputStreamReader isr = new InputStreamReader(new FileInputStream(file), "utf-8");
              BufferedReader br = new BufferedReader(isr);
              String lineTxt = null;
              while ((lineTxt = br.readLine()) != null) {
                System.out.println(lineTxt);
              }
              br.close();
            } else {
              System.out.println("no exit");
            }
          } catch (Exception e) {
            System.out.println("wrong doing");
          }
          
      }
}