java IO使用Demo

public class ReadByteStream {

    public static void main(String[] args) {
        //stream 字节流
        //reader,writer 字符流
        //input 读取外部东西，
        //output 输出
        try { //read byte stream,mytext.txt is exits
            FileInputStream inputStream=new FileInputStream("mytext.txt");
            byte []in=new byte[60];
            inputStream.read(in);//把字节读入数组中
            
            //String str=new String(in);默认是GBK
            String str=new String(in,"UTF-8");//是乱码
            System.out.println(str);
            
            
            
        } catch (FileNotFoundException e) {
            
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        

    }

}

public class WriteByteStream {

    public static void main(String[] args) {
        
        try {
            FileOutputStream fileOutputStream=new FileOutputStream("mytext1.txt");
            String str="hello ,jack...";
            byte []out=str.getBytes();
            try {
                fileOutputStream.write(out);
            } catch (IOException e) {
                
                e.printStackTrace();
            }
            
        } catch (FileNotFoundException e) {
            
            e.printStackTrace();
        }
        
        
    }

}

public class CopyByByteStream {

    public static void main(String[] args) {
        
        try {
            FileInputStream inputStream=new FileInputStream("water.jpg");
            FileOutputStream outputStream=new FileOutputStream("newwater.jpg");
            
            byte []in=new byte[50]; //现在只是读取了50个字节,不能读取完整的图片
                    
        //    inputStream.read(in);  //不能读取完整的图片
        //    outputStream.write(in);
            
         //    inputStream.read(in);返回int类型，如果返回-1表示没有数据了
            
            while(inputStream.read(in)!=-1)//表示还有数据，就写入
            {
                outputStream.write(in); 
            }
            
            inputStream.close();
            outputStream.close();
    
        } catch (FileNotFoundException e) {
            
            e.printStackTrace();
        } catch (IOException e) {
        
            e.printStackTrace();
        }
        
    }

}

public class FileReaderAndFileWriter {

    public static void main(String[] args) {

        try {
            //文件写入读取
            FileReader fileReader=new FileReader("java.txt");
            BufferedReader bufferedReader=new BufferedReader(fileReader);
            //字符流包装为缓冲流
            FileWriter fileWriter=new FileWriter("java_new_1");
            BufferedWriter bufferedWriter=new BufferedWriter(fileWriter);
            String len;
            while ((len=bufferedReader.readLine())!=null) {

                bufferedWriter.write(len+"\n");
            }
            bufferedWriter.flush();//注意writer有关的都要flush()
            bufferedWriter.close();
            bufferedReader.close();
            fileReader.close();
            fileWriter.close();
            System.out.println("Done");
        } catch (FileNotFoundException e) {

            e.printStackTrace();
        } catch (IOException e) {

            e.printStackTrace();
        }

    }

}

public class BufferReader {


    public static void main(String[] args) {
        try {
            FileInputStream fileInputStream=new FileInputStream("java.txt");
            InputStreamReader isr=new InputStreamReader(fileInputStream);//字节流转化为字符流
    
            BufferedReader reader=new BufferedReader(isr);
                        
            FileOutputStream fileOutputStream=new FileOutputStream("java_new_buffered.txt");
            OutputStreamWriter osw=new OutputStreamWriter(fileOutputStream);
            BufferedWriter writer=new BufferedWriter(osw);
            
            String len;
            while ((len=reader.readLine())!=null) {
                writer.write(len);
            }
            writer.flush();
            writer.close();
            osw.close();
            fileInputStream.close();
            fileOutputStream.close();
            System.out.println("done");

            
        } catch (FileNotFoundException e) {
        
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        

    }

}

public class ReadBufferByStream {


    public static void main(String[] args) {
    
        try {
            FileInputStream fileInputStream=new FileInputStream("vidio.wmv");
            BufferedInputStream bufferedInputStream=new BufferedInputStream(fileInputStream);
            
            FileOutputStream fileOutputStream=new FileOutputStream("E://TextVidio.wmv");
            BufferedOutputStream bufferedOutputStream=new BufferedOutputStream(fileOutputStream);
            
            byte []by=new byte[100];
            while (    bufferedInputStream.read(by)!=-1) {
                bufferedOutputStream.write(by);
                
            }
        
            bufferedInputStream.close();
            bufferedOutputStream.close();
            fileInputStream.close();
            fileOutputStream.close();
            System.out.println("vidio create sucess....");
            
        } catch (FileNotFoundException e) {
            
            e.printStackTrace();
        } catch (IOException e) {
        
            e.printStackTrace();
        }
        

    }

}