标签:NPU source space 数据 int exception gre color for
1、概述
1.1 JDK提供了Scanner类,用来获取键盘输入;
1.2 Scanner类是 一个基于正则表达式的文本扫描器,可以从文件、输入流、字符串中解析出基本类型值、字符串值;
1.3 Scanner类提供了多个不同的构造器,可接受文件,输入流,字符串作为数据源,用于从文件、输入流、字符串中解析数据;
public final class Scanner implements Iterator<String>, Closeable {
=====构造器
private Scanner(Readable source, Pattern pattern) {
assert source != null : "source should not be null";
assert pattern != null : "pattern should not be null";
this.source = source;
delimPattern = pattern;
buf = CharBuffer.allocate(BUFFER_SIZE);
buf.limit(0);
matcher = delimPattern.matcher(buf);
matcher.useTransparentBounds(true);
matcher.useAnchoringBounds(false);
useLocale(Locale.getDefault(Locale.Category.FORMAT));
}
public Scanner(File source) throws FileNotFoundException {
this((ReadableByteChannel)(new FileInputStream(source).getChannel()));
}
public Scanner(String source) {
this(new StringReader(source), WHITESPACE_PATTERN);
}
public Scanner(InputStream source) {
this(new InputStreamReader(source), WHITESPACE_PATTERN);
}
}
1.4 Scanner类提供的方法:
hasNextXX():是否还有下一项;
nextXX():获取下一项;
import java.util.Scanner;
public class TestScanner {
public static void main(String[] args){
boolean flag=true;
while (flag){
//System.in标准输入,即键盘输入
Scanner scanner=new Scanner(System.in);
String inputContent=scanner.next();
if (inputContent.equals("exit")){
flag=false;
}
System.out.println(inputContent);
}
}
}
hasNextLine():是否有下一行;
nextLine():获取下一行;
标签:NPU source space 数据 int exception gre color for
原文地址:https://www.cnblogs.com/anpeiyong/p/11357153.html