IO总结

package com.mi.demo;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class IOTEST {

public static void main(String[] args) {
byte[] buffer = new byte[1024];
int numberRead = 0;

FileInputStream fis = null;
FileOutputStream fos = null;
try {

File file1 = new File("C:/Users/admin/Desktop/CSXY.txt");
File file2 = new File("C:/Users/admin/Desktop/copy.txt");
System.out.println(file1.getTotalSpace()/(1024*1024*1024)+"G");
System.out.println(file1.getFreeSpace()/(1024*1024*1024)+"G");
System.out.println(file1.getUsableSpace()/(1024*1024*1024)+"G");
System.out.println(file1.getName());
System.out.println(file1.getParent());
System.out.println(file1.getPath());
System.out.println(file1.getCanonicalPath());
System.out.println(file1.getParentFile());
System.out.println(file1.getAbsolutePath());

fis = new FileInputStream(file1);
fos = new FileOutputStream(file2);

while((numberRead=fis.read(buffer))!=-1){
fos.write(buffer, 0, numberRead);
}

} catch (Exception e) {
e.printStackTrace();
}finally {
try {
fis.close();
fos.close();
} catch (IOException e) {
e.printStackTrace();
}

}

}
}

package com.mi.demo;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class IOTEST {

public static void main(String[] args) throws IOException {
Random r = new Random();
int i=r.nextInt(1000001);
FileOutputStream foStream = new FileOutputStream(new File("D:/a.txt"));
OutputStreamWriter pw=new OutputStreamWriter(foStream);
BufferedWriter bufferedWriter  = new BufferedWriter(pw);
for (int j = 0; j <i; j++) {
bufferedWriter.newLine();
bufferedWriter.write(r.nextInt(1000001));
}
pw.close();

FileReader reader=new FileReader(new File("D:/a.txt"));
ArrayList<Integer> n=new ArrayList<Integer>();
int count=1;
BufferedReader br = new BufferedReader (reader);
String s;
Scanner sc = new Scanner(System.in);
s=sc.nextLine();
if(IOTEST.valueOfCheck(s)){
String number;
while ((number = br.readLine() )!=null) {

if(number.equals(s)){
n.add(count);
}
count++;
}
System.out.println(n.size());
for (Integer integer : n) {
System.out.println(integer);
}
}
else System.out.println("输入的不是数字");
reader.close();

}

public static boolean valueOfCheck(String s){
try {
int num=Integer.valueOf(s);//把字符串强制转换为数字
return true;//如果是数字，返回True
} catch (Exception e) {
return false;
}
}

}