键盘输入
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Main {
public static void main(String[] args) throws Exception{
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
boolean flag = true;
while (flag){
String str = bufferedReader.readLine();
if(str.matches("\\d+")){
System.out.println(Integer.parseInt(str));
bufferedReader.close();
flag = false;
}else {
System.out.println("Error");
}
}
}
}
读取文件
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
public class Main {
public static void main(String[] args) throws Exception {
File file = new File("/Users/yuzhen/File/testA.txt");
BufferedReader bufferedReader = new BufferedReader(new FileReader(file));
String str = null;
while((str = bufferedReader.readLine()) != null){
System.out.println(str);
}
bufferedReader.close();
}
}