package com.imooc_io;
public class CodeTest {public static void main(String[] args) throws Exception{       String s = "慕课ABC";byte[] bytes1 = s.getBytes();//转换成字节序列用的是项目默认的编码for(byte b:bytes1){//把字节转换成了int以16进制的方式显示System.out.print(Integer.toHexString(b & 0xff)+" ");}System.out.println();//gbk编码中文占用两个字节，英文占用一个字节byte[] bytes2 = s.getBytes("utf-8");//utf-8编码中文占用3个字节，英文占用一个字节for(byte b:bytes2){System.out.print(Integer.toHexString(b & 0xff)+" ");}System.out.println();//java是双字节编码utf-16bebyte[] bytes3 = s.getBytes("utf-16be");//utf-16be编码中文占用2个字节，英文占用2个字节for(byte b:bytes3){System.out.print(Integer.toHexString(b & 0xff)+" ");}System.out.println();String str1 = new String(bytes3);//乱码String str2 = new String(bytes3,"utf-16be");System.out.println(str1);System.out.println(str2);}}

package com.imooc_io;
import java.io.File;
import java.io.IOException;
public class FileDemo {public static void main(String[] args) {File file = new File("D:\\imooc\\jsp");System.out.println(file.exists());if(!file.exists()){file.mkdir();}else{file.delete();}System.out.println(file.isDirectory());System.out.println(file.isFile());File file2 = new File("D:\\imooc\\1.txt");//File file2 = new File("D:\\imooc","1.txt");if(!file2.exists()){try {file2.createNewFile();} catch (IOException e) {// TODO Auto-generated catch block
                e.printStackTrace();}}else{file2.delete();}//常用的File对象方法
        System.out.println(file.getAbsolutePath());System.out.println(file.getName());System.out.println(file.getParent());System.out.println(file.getParentFile().getAbsolutePath());}}

package com.imooc_io;
import java.io.*;
public class FileUtils {/*** 列出指定目录下（包括其子目录）的所有文件* @throws IllegalAccessException */public static void listDirectory(File dir)throws IOException, IllegalAccessException{if(!dir.exists()){throw new IllegalAccessException("目录："+dir+"不存在");}if(!dir.isDirectory()){throw new IllegalAccessException(dir+"不是目录");}//直接子的名称，不包含子目录下的文件/**String[] filenames = dir.list();for(String string : filenames){System.out.println(dir+"\\"+string);}*///如果要遍历子目录下的内容就需要构造File对象做递归操作File[] files = dir.listFiles();//返回的是直接子目录（文件）的抽象
//        for(File file:files){
//            System.out.println(file);
//        }if(files!=null&&files.length>0){for(File file:files){if(file.isDirectory()){listDirectory(file);}else{System.out.println(file);}}}}
}

package com.imooc_io;import java.io.*;
import java.lang.reflect.Array;
import java.util.Arrays;public class RafDemo {public static void main(String[] args) throws IOException {File demo = new File("demo");if(!demo.exists()){demo.mkdir();}File file = new File(demo,"raf.dat");if(!file.exists()){file.createNewFile();}RandomAccessFile raf = new RandomAccessFile(file, "rw");//指针的位置
        System.out.println(raf.getFilePointer());raf.write('A');//只写一个字节int i = 0x7fffffff;//java最大整数//如果要把i写进去写4次raf.write(i>>>24);//高8位raf.write(i>>>16);raf.write(i>>>8);raf.write(i);System.out.println(raf.getFilePointer());//可以直接写一个int
        raf.writeInt(i);//读文件，必须把指针移到头部raf.seek(0);//一次性读取，把文件的内容都读到字节数组中byte[] buf = new byte[(int) raf.length()];raf.read(buf);System.out.println(Arrays.toString(buf));}}

package com.imooc_io;import java.io.FileInputStream;
import java.io.IOException;public class IOUtil {/*** 读取指定文件内容，按照16进制输出到控制台* 并且没输出10个byte换行* @throws IOException */public static void printHex(String fileName) throws IOException{//把文件作为字节流进行操作FileInputStream in = new FileInputStream(fileName);int b ;int i= 1;while ((b=in.read())!=-1) {if(b<=0xf){//b小于1位数//单位数前面补0System.out.print("0");}//将整型b转换为16进制表示的字符串System.out.print(Integer.toHexString(b)+" ");if(i++%10==0){System.out.println();}}in.close();}public static void printHexByByteArray(String fileName) throws IOException{FileInputStream in = new FileInputStream(fileName);byte[] buf = new byte[20*1024];int bytes = in.read(buf, 0, buf.length);int j = 1;for(int i =0;i<bytes;i++){if(buf[i]<=0xf){System.out.print("0");}System.out.print(Integer.toHexString(buf[i])+" ");if(j++%10==0){System.out.println();}}in.close();}}

public static void copyFile(File srcFile,File destFile) throws IOException{if(!srcFile.exists()){throw new IllegalArgumentException("文件"+srcFile+"不存在");}if(!srcFile.isFile()){throw new IllegalArgumentException(srcFile+"不是文件");}FileInputStream in = new FileInputStream(srcFile);FileOutputStream out = new FileOutputStream(destFile);byte[] buf = new byte[8*1024];int b ;while((b=in.read(buf, 0, buf.length))!=-1){out.write(buf, 0, b);out.flush();}in.close();out.close();}

public static void copyFileByBuffer(File srcFile,File destFile)throws IOException{if(!srcFile.exists()){throw new IllegalArgumentException("文件"+srcFile+"不存在");}if(!srcFile.isFile()){throw new IllegalArgumentException(srcFile+"不是文件");}BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcFile));BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destFile));int c;while((c=bis.read())!=-1){bos.write(c);bos.flush();}bis.close();bos.close();}

public static void main(String[] args) throws IOException {FileInputStream in =new FileInputStream("D:\\Java open source\\API\\javascript\\JavaScript方法大全.txt");InputStreamReader isr = new InputStreamReader(in,"UTF-8");FileOutputStream out = new FileOutputStream("D:\\Java open source\\API\\javascript\\JavaScript方法大全2.txt");OutputStreamWriter osw = new OutputStreamWriter(out,"UTF-8");//        int c;
//        while((c = isr.read())!=-1){
//            System.out.print((char)c);
//        }char[] buf = new char[8*1024];int c;//批量读取，放入buffer这个字符数组，从第0个位置开始的位置，最多放buf.length//返回的是读到字符的个数while ((c = isr.read(buf,0,buf.length))!=-1) {String s = new String(buf,0,c);System.out.print(s);osw.write(buf, 0, c);}in.close();out.close();isr.close();osw.close();}

public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream("D:\\Java open source\\API\\javascript\\1.txt")));
//        BufferedWriter bw = new BufferedWriter(
//                new OutputStreamWriter(
//                        new FileOutputStream("D:\\Java open source\\API\\javascript\\2.txt")));PrintWriter pw = new PrintWriter("D:\\Java open source\\API\\javascript\\3.txt");String line;while((line = br.readLine())!=null){System.out.println(line);//一次读一行，并不能识别换行
//            bw.write(line);
//            //单独写出换行
//            bw.newLine();
//            bw.flush();
            pw.println(line);pw.flush();}br.close();
//        bw.close();
        pw.close();}

public class Student implements Serializable{private static final long serialVersionUID = 1L;public static void main(String[] args) throws IOException{String file="demo/obj.dat";//对象序列化ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(file));Student stu = new Student("100001","zhangsan","20");oos.writeObject(stu);oos.flush();oos.close();

　　　　　　ObjectInputStream ois = new ObjectInputStream(
　　　　　　　　　　new FileInputStream(file));
　　　　　　Student stu1 = (Student) ois.readObject();
　　　　　　ois.close();

    }

package com.imooc_io;import java.io.FileInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;public class ObjectserialDemo {public static void main(String[] args) throws IOException, Exception{
//        ObjectOutputStream oos = new ObjectOutputStream(
//                new FileOutputStream("demo/obj1.dat"));
//        Foo2 foo2 = new Foo2();
//        oos.writeObject(foo2);
//        oos.flush();
//        oos.close();//反序列化是否递归调用父类的构造函数ObjectInputStream ois = new ObjectInputStream(new FileInputStream("demo/obj1.dat"));Foo2 foo2 = (Foo2) ois.readObject();//发现没有调用构造函数，只是打印了这个对象
        System.out.println(foo2);ois.close();}
}
/**
*一个类实现了序列化接口，那么其子类都可以进行序列化
*对子类对象进行反序列化操作时，如果其父类没有实现序列化接口，
*那么其父类的构造函数会被调用
*序列化了，构造函数不会被调用
*/
class Foo implements Serializable{public Foo(){System.out.println("foo...");}
}
class Foo1 extends Foo{public Foo1(){System.out.println("foo1...");}
}class Foo2 extends Foo1{public Foo2(){System.out.println("foo2...");}
}