0822 Java io操作2

一、File类

        File f1=new File("C:/java/iodemo/out10.txt");
File f2=new File("C:/java/iodemo","out10.txt");
File parent=new File("C:/java/iodemo");
File f3=new File(parent,"out10.txt");

二、文件创建与删除

                //创建文件
File file=new File("C:/java/iodemo/dir");

                //创建文件夹
File file1=new File("C:/java/iodemo/dir1");
File file2=new File(file1,"dir2");
if(file1.mkdir()){
file2.mkdir();
System.out.println("文件夹创建成功！");
}else{
System.out.println("文件夹创建失败！");
}
//递归创建文件夹
File file3=new File("C:/java/iodemo/d1/d2/d3");
System.out.println(file3.mkdirs());

三、字节转为字符流

                FileInputStream fis=null;
InputStreamReader isr=null;
BufferedReader br=null;
try {
fis=new FileInputStream("C:/java/iodemo/ch01.txt");
isr=new InputStreamReader(fis);
br=new BufferedReader(isr);
StringBuffer sb=new StringBuffer();
String str=null;
while((str=br.readLine())!=null){
sb.append(str+"\r\n");
}
System.out.println(sb.toString());

四、字符输出流FileWriter

                        fw=new FileWriter("C:/java/iodemo/fw.txt");
fw.write("啊啊啊啊啊\r\n");
fw.write("恢复光华大道");
System.out.println("写入成功！");

五、字符输出流BufferedWriter

                        bw=new BufferedWriter(new FileWriter("C:/java/iodemo/bw.txt"));
bw.write("vwnytjyu");
//实现换行
bw.newLine();
bw.write("tyjuynf");
System.out.println("写入成功！");

六、序列化：将对象转换为二进制文件

关键字Serializable

对象输出流：ObjectOutputStream

oos=new ObjectOutputStream(new FileOutputStream("C:/java/iodemo/oos.txt"));
//实现序列化
oos.writeObject(book);
System.out.println("序列化成功！");

七、反序列化：二进制文件转换为对象

读取：ObjectInputStream

ois=new ObjectInputStream(new FileInputStream("C:/java/iodemo/oos.txt"));
   book=(Book) ois.readObject();

八、写入Writer

九、读取Reader