Java快读快写

Posted 2022-03-19 敲代码的xiaolang

每读一个数据就要用一次 nextToken（）方法。这个方法是我们每次读入数据之前必须要写的，也就是我们读入一个数据之前就要写一个这个方法才行。

import java.io.*;
public class test 
	public static void main(String args[]) throws IOException
		StreamTokenizer st = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in))); 
		st.nextToken();
		String str = st.sval;//读取String类型数据
		st.nextToken();
		double num1 =  st.nval;//读取double类型数据
		st.nextToken();
		int num2 = (int)st.nval;//读取int类型数据
		st.nextToken();
		long num3 = (long)st.nval;//读取long类型数据
	

当只想读入字符串的时候

import java.io.*;
public class test 
	public static void main(String args[]) throws IOException
//		StreamTokenizer re = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
		BufferedReader re = new BufferedReader(new InputStreamReader(System.in));
		String x = re.readLine();
		System.out.println(x);
	

PrintWriter类最后要加flush

import java.io.*;
public class test 
	public static void main(String args[])
		PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
		pw.print();//不换行输出
		pw.println();//换行输出
		pw.printf();//格式化输出
		pw.flush();//关闭输出流
	

参考文章：Java算法必备（背）之快读快输出.