package IODemo;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class CopyFileDemo {
 /**
 * @param args
 * @throws IOException 
 */
 public static void main(String[] args) throws IOException {
 FileReader fr=new FileReader("Demo.txt");
 FileWriter fw=new FileWriter("Demo1.txt");
 int ch=0;
 while((ch=fr.read())!=-1){//單個字符進行讀取
 fw.write(ch);//單個字符進行寫入操作
 }
 fw.close();
 fr.close();
 }
}

package IODemo;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class CopyFileDemo2 {
 private static final int BUFFER_SIZE = 1024;
 /**
 * @param args
 */
 public static void main(String[] args) {
 FileReader fr = null;
 FileWriter fw = null;
 try {
 fr = new FileReader("Demo.txt");//工程所在目錄
 fw = new FileWriter("Demo2.txt");
 char buf[] = new char[BUFFER_SIZE];
 int len = 0;
 while ((len = fr.read(buf)) != -1) {
 fw.write(buf, 0, len);
 }
 } catch (Exception e) {
 // TODO: handle exception
 } finally {
 if (fr != null) {
 try {
 fr.close();
 } catch (IOException e) {
 System.out.println("讀寫失敗");
 }
 }
 if (fw != null) {
 try {
 fw.close();
 } catch (IOException e) {
 System.out.println("讀寫失敗");
 }
 }
 }
 }
}