在千峰第32天
“只有用汗水磨砺,天赋才会绽放出耀眼的光”
中国加油,武汉加油,千峰加油,我自己加油。
1、
ABC
2、
file=new File(“hello.txt”);
if(file.exist()){
System.out.println(file.getAbsolutePath());
}
10、
A:能将字符写入输出流,默认编码
B:可以换行,默认编码
C:可以改变编码方式
11、
Ⅰ字符流
Ⅱ字符流
Ⅲ字符流
Ⅳ字节流
Ⅴ字节流
12、
1:1357
2:1467
3:17
4:17
5:13
6:14
7:24679
8:14679
9:278
14、
public class TEST14 {
public static void main(String[] args) throws IOException {
InputStream is = new FileInputStream("test.txt");
InputStreamReader isr = new InputStreamReader(is,"UTF-8");
BufferedReader br = new BufferedReader(isr);
OutputStream os = new FileOutputStream("test2.txt");
OutputStreamWriter osw = new OutputStreamWriter(os,"UTF-8");
PrintWriter pw = new PrintWriter(osw);
while(true){
String s = br.readLine();
if(s == null){
break;
}
pw.println(s);
}
pw.flush();
br.close();
pw.close();
}
}
17、
import java.io.*;
import java.util.Scanner;
public class TEST17{
public static void main(String[] args) throws IOException {
InputStream is = new FileInputStream("worldcup.txt");
InputStreamReader isr = new InputStreamReader(is,"UTF-8");
BufferedReader br = new BufferedReader(isr);
System.out.println("请输入一个年份:");
Scanner sc = new Scanner(System.in);
String str = sc.next();
while(true){
String s = br.readLine();
if(s.contains(str)){
char[] chr = s.toCharArray();
for(int i = s.indexOf("/") + 1 ; i < s.length(); i++){
System.out.print(chr[i]);
}
}else{
System.out.println("没有举办世界杯");
}
}
}
}
18、
public class TEST18 {
public static void main(String[] args) throws IOException {
Scanner sc= new Scanner(System.in);
System.out.println("请输入文件名:");
String s = sc.next();
File file = new File(s);
if(file.exists()){
InputStream is = new FileInputStream(s);
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
OutputStream os = new FileOutputStream("copy_" + file.getName());
OutputStreamWriter osw = new OutputStreamWriter(os);
PrintWriter pw = new PrintWriter(osw);
while(true){
String s1 = br.readLine();
if(s1 == null){
break;
}
pw.println(s1);
}
pw.flush();
br.close();
pw.close();
}else{
System.out.println("该文件不存在");
}
}
}