(JavaSE 学习记录) IO之文件字节流 FileInputStream、FileOutputStream，利用文件字节流拷贝文件

文件字节流

FileInputStream：字节方式读取文件（适合读取所有类型文件）
FileOutputStream：字节方式输出到文件中

IO基本步骤：
1、创建源
2、选择流
3、操作
4、关闭流

FileInputStream

        //创建源File src = new File("Garden.txt");//选择流InputStream is = null;//操作try {
    is = new FileInputStream(src);byte[] flush = new byte[1024];int len;	//实际长度//read(byte[]);返回读到的数据的长度//read();返回char，一个一个读//此处为纯文本，将其打印出来while((len = is.read(flush))!=-1){
    String temp = new String(flush,0,len);System.out.println(temp);}} catch (FileNotFoundException e) {
    e.printStackTrace();} catch (IOException e) {
    e.printStackTrace();}finally {
    //关闭流//null的判断不要忘try {
    if (null!=is) {
    is.close();}} catch (IOException e) {
    e.printStackTrace();}}

FileOutputStream

        File dest = new File("dest02.txt");OutputStream os = null;try {
    os = new FileOutputStream(dest,true);//操作的是字节，需要将内容转化为字节数组String str = "Upsy Daisy";byte[] flush = str.getBytes();os.write(flush,0,str.length());os.flush();	//记得flush} catch (FileNotFoundException e) {
    e.printStackTrace();} catch (IOException e) {
    e.printStackTrace();}finally {
    try {
    if (null!=os) {
    os.close();}} catch (IOException e) {
    e.printStackTrace();}}

利用文件字节流拷贝文件

注意先开的流后关闭，且要分别关闭。

        File src = new File("Garden.txt");File dest = new File("GardenCopy.txt");InputStream is = null;OutputStream os = null;try {
    is = new FileInputStream(src);os = new FileOutputStream(dest);byte[] flush = new byte[1024];int len;//读、写while ((len = is.read(flush))!=-1){
    os.write(flush,0,len);os.flush();}} catch (FileNotFoundException e) {
    e.printStackTrace();} catch (IOException e) {
    e.printStackTrace();}finally {
    try {
    if (null!=os) {
    os.close();}} catch (IOException e) {
    e.printStackTrace();}try {
    if (null!=is) {
    is.close();}} catch (IOException e) {
    e.printStackTrace();}}