java 输入输出流1 FileInputStrem&&FileOutStream

时间:2021-12-19 12:05:08

通过文件输入流读取问价

package unit6;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.channels.FileLockInterruptionException; public class mytype { public static void main(String[] args) {
try{
FileInputStream fin= new FileInputStream(args[0]);
int ch=fin.read();
while(ch!=-1){
System.out.println((char )ch);
ch=fin.read();
}
}catch (ArrayIndexOutOfBoundsException e) {
System.out.println("use the right style: java mytype filename");
System.exit(0); }catch (FileNotFoundException e2) { System.out.println("file does not find");
}catch (IOException e3) { System.out.println("input stream error!");
}
}
}

通过文件输入输出流复制文件

package unit6;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream; import org.xml.sax.InputSource; public class copy { public static void main(String[] args) {
int numberRead=0;
InputStream in = null;
OutputStream out = null;
byte buf[] = new byte[512];
if(args.length!=2){
System.out.println("Usage: java copy sourcefile destfile");
System.exit(0);
}
try{
in=new FileInputStream(args[0]);
out= new FileOutputStream(args[1]);
while((numberRead=in.read(buf))!=-1){
out.write(buf,0,numberRead);
}
}catch (FileNotFoundException e1) { System.out.println(args[0]+" not found");
System.exit(0);
}catch (IOException e2) { System.out.println("Error reading/writing file.");
}finally{
try{
in.close();
out.close();
}catch (Exception e) { e.printStackTrace();
}
}
System.out.println("1 file copyed");
}
}

按文件读入字符,并且对文件进行加密,保存为新的文件

package unit6;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException; public class jmcopy { public static void main(String[] args) {
int ch;
FileInputStream fin = null;
FileOutputStream fout =null;
try{
fin=new FileInputStream(args[0]);
fout=new FileOutputStream(args[1]);
int key=args[2].length();
ch=fin.read();
while(ch!=-1){
fout.write(ch^key);
ch=fin.read();
}
fin.close();fout.close();
}catch (ArrayIndexOutOfBoundsException e1) { System.out.println("fomat error,type: java jmcopy sourcefile destfile key");
System.exit(0);
}catch (FileNotFoundException e2) { System.out.println("file not found");
}catch (IOException e3) { System.out.println("strem error!");
}
}
}