玩转java之io的键盘录入和文件拷贝

很简洁，具体操作请看API，代码如下：

package file;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.BufferedWriter;import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;public class FileDemo {/** * @param args * @throws IOException */public static void main(String[] args) throws IOException {//TODO Auto-generated method stubkeyboardInput();fileCopy();}/** * 文件拷贝 * @throws FileNotFoundException * @throws IOException */public static void fileCopy() throws FileNotFoundException, IOException {int charsum =0;    int charlong = 0;File file2  = new File("F:\\copy.txt");//如果文件存在if(file2.exists()){//输入流，用于读文件FileReader fr =  new FileReader(new File("F:\\filetest\\test.txt"));//输出流，用于写入FileWriter fw =  new FileWriter(file2);char[] cbuf =  new char[1024];//2k的大小//如没有到文件的结尾继续while( (charlong = fr.read(cbuf)) !=-1){fw.write(cbuf,0,charlong);}//关闭流fr.close();fw.close();}else{//如果不存则创建file2.createNewFile();}FileReader fr =  new FileReader(new File("F:\\filetest\\test.txt"));FileWriter fw =  new FileWriter(file2);char[] cbuf =  new char[1024];while( (charlong = fr.read(cbuf)) !=-1){System.out.println(charlong);fw.write(cbuf,0,charlong);}fr.close();fw.close();} /** * 键盘录入  * @throws IOException * @throws FileNotFoundException */public static void keyboardInput() throws IOException,FileNotFoundException {File file = new File("F:\\filetest\\test.txt");if(file.exists()){}else{file.createNewFile();}BufferedInputStream bis  = new BufferedInputStream(System.in);    FileOutputStream fos = new FileOutputStream(file);byte[] str = new byte[1024];if(str.length != 0){bis.read(str);     fos.write(str);}bis.close();fos.close();}}