- it技术
- java语言程序设计（进阶版）17.1 17.16 17.3 IO流
package com
.company
;
import javafx
.scene
.effect
.ImageInput
;
import java
.io
.*
;
public class Demo02 {
public static void main(String
[] args
) throws Exception
{
File file
= new File("d:\\Exercise17_01(2).txt");
BufferedWriter out
= new BufferedWriter(new FileWriter(file
, true));
BufferedReader input
= new BufferedReader(new FileReader(file
));
if(!file
.exists()||input
.readLine()==null
)
out
.append("1902020084 张纹箎\n");
for(int i
=1;i
<100;i
++)
out
.append((int)(Math
.random()*100+1)+" ");
out
.append("\n");
out
.close();
System
.out
.println("RuntimeSuccess");
}
}
package com
.company
;
import java
.io
.*
;
import java
.util
.Scanner
;
import java
.util
.stream
.Stream
;
public class Demo04 {
public static void main(String
[] args
) throws Exception
{
Scanner S
= new Scanner(System
.in
);
System
.out
.println("请您输入一个 ASCII 文本文件名用于查找概念文件内的字符个数");
String fileName
= S
.next();
BufferedReader input
= new BufferedReader(new FileReader(fileName
));
String t
= null
;
String sum
= "";
while((t
=input
.readLine())!=null
){
sum
+= t
;
}
char[] ca
= sum
.toCharArray();
int []a
=new int[30];
for(char chr
: ca
){
a
[(byte)chr
-'a'+1]++;
}
for(int i
=1;i
<30;i
++){
if(a
[i
]!=0)
System
.out
.println((char)(i
+'a'-1)+": "+a
[i
]);
}
}
}
package com
.company
;
import java
.io
.*
;
public class Demo03 {
public static void main(String
[] args
) throws Exception
{
DataOutputStream out
= new DataOutputStream(new FileOutputStream("d:\\Exercise17_03.dat"));
for(int i
=0,a
;i
<(int)(Math
.random()*20);i
++){
out
.writeInt((a
=(int)Math
.random()*10));
out
.writeInt(a
);
}
out
.close();
DataInputStream input
= new DataInputStream(new FileInputStream("d:\\Exercise17_03.dat"));
int sum
= 0;
while(input
.available()!=0){
sum
+=input
.readInt();
}
System
.out
.println(sum
);
}
}
