importjava.io.BufferedInputStream;importjava.io.BufferedOutputStream;importjava.io.File;importjava.io.FileInputStream;importjava.io.FileNotFoundException;importjava.io.FileOutputStream;importjava.io.IOException;public classCopyFileDemo {public static voidmain(String[] args) {
copyFile("c:\\a.txt","d:\\b.txt");
}private static final int OUTPUT_FILE_BUFFER_SIZE = 4*1024;private static booleancopyFile(String srcdir,String desdir){//文件流
FileInputStream fileInputStream = null;
FileOutputStream fileOutputStream= null;//使用缓存
BufferedInputStream bis;
BufferedOutputStream bos;//每次读取的长度
int readLength = 0;//当前位置
int position = 0;//打印信息
System.out.println("copyFile srcdir: " + srcdir + " desdir:" +desdir);//目标文件
File disFileInfo = null;//源文件信息
File fileInfo = newFile(srcdir);if(!fileInfo.exists()){
System.out.println("源文件不存在 返回false");return false;
}//定义缓存大小
byte[] buffer = new byte[OUTPUT_FILE_BUFFER_SIZE];try{
fileInputStream= newFileInputStream(fileInfo);
}catch(FileNotFoundException e) {
e.printStackTrace();return false;
}//缓冲的输入流
bis = new BufferedInputStream(fileInputStream, 0x4000);//检测目标文件是否存在 创建文件
disFileInfo = newFile(desdir);if(!disFileInfo.exists()){try{
disFileInfo.createNewFile();
}catch(IOException e) {
e.printStackTrace();return false;
}
}try{
fileOutputStream= newFileOutputStream(disFileInfo);
}catch(FileNotFoundException e) {
e.printStackTrace();return false;
}//缓冲的输出流
bos = new BufferedOutputStream(fileOutputStream, 0x10000);while(position !=fileInfo.length())
{if(position !=fileInfo.length()){try{//{@
/*核心代码*/
//从此字节输入流中给定偏移量处开始将各字节读取到指定的 byte数组中buffer
readLength = bis.read(buffer, 0, OUTPUT_FILE_BUFFER_SIZE);//将指定 byte数组buffer中从偏移量 off开始的 len个字节写入此缓冲的输出流
bos.write(buffer, 0, readLength);
position+=readLength;//@}
} catch(IOException e) {
e.printStackTrace();return false;
}
}
}//依次关闭流
if(bis != null){try{
bis.close();
}catch(IOException e) {
e.printStackTrace();return false;
}
}if(bos != null){try{
bos.close();
}catch(IOException e) {
e.printStackTrace();return false;
}
}if(position ==fileInfo.length()){
System.out.println("copyFile success !!");return true;
}return false;
}
}