java 不允许默认构造_Java错误：默认的构造函数不能处理异常类型FileNotFound异常...

无论是在你的子类抛出FileNotFoundException声明一个显式构造：

public MySubClass() throws FileNotFoundException {

}

或环绕有try-catch块在基类中的代码，而不是抛出一个FileNotFoundException异常：

public MyBaseClass() {

FileInputStream fstream = null;

try {

File inFile = new File("textfile.txt");

fstream = new FileInputStream(inFile);

// Get the object of DataInputStream

DataInputStream in = new DataInputStream(fstream);

BufferedReader br = new BufferedReader(new InputStreamReader(in));

// Do something with the stream

} catch (FileNotFoundException ex) {

Logger.getLogger(this.getClass().getName()).log(Level.SEVERE, null, ex);

} finally {

try {

// If you don't need the stream open after the constructor

// else, remove that block but don't forget to close the

// stream after you are done with it

fstream.close();

} catch (IOException ex) {

Logger.getLogger(this.getClass().getName()).log(Level.SEVERE, null, ex);

}

}

}

无关，但是由于您正在编写Java小程序，请记住您需要sign it才能执行IO操作。