java 文件的读取与写入（简单操作）

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;

public class FileIo {
public static void main(String[] args){
try {
//字节流
//			FileInputStream input = new FileInputStream("F:/123156.txt");
//			int a;
//			FileOutputStream out = new FileOutputStream("E:/123.txt");
//			while((a=input.read())!=-1){
//			System.out.println((char)a);
//			out.write(a);
//		}
//		input.close();
//		out.close();

//字符流
//			FileReader input1= new FileReader("F:/123156.txt");
//			FileWriter out1 = new FileWriter("E:/123.txt");
//
//			int a;
//			while((a=input1.read())!=-1){
//				System.out.println((char)a);
//				out1.write(a);
//			}
//			input1.close();
//			out1.close();

//单行读取字符流
FileReader input= new FileReader("D:/123156.txt");
FileWriter out = new FileWriter("D:/123.txt");

BufferedReader input1 = new BufferedReader(input);
BufferedWriter out1 = new BufferedWriter(out);
String temp;
while((temp=input1.readLine())!=null){
System.out.println(temp);
out1.write(temp);
}

input1.close();
out1.close();
input.close();
out.close();

} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

使用Sanner 进行扫描

public static void main(String[] args) {
File file = new File("D:/123.txt");
File file2 = new File("D:/1234.txt");
try {
Scanner input = new Scanner(file);
FileWriter f1 = new FileWriter(file2);
BufferedWriter out = new BufferedWriter(f1);
while(input.hasNextLine()){
String temp = input.nextLine();
System.out.println(temp);
out.write(temp);

}

input.close();
out.close();

} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}