javaIO-学习笔记

 

 

 

 

package IOTest;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.RandomAccessFile;

public class IOMain {

    public static void main(String[] args) throws IOException {
        
        /*
         * 1
         */
//        try (FileReader fr = new FileReader("E:/Workspase/MyEclipse 2015 CI/Shulie/src/A2.java")) {
//            char[] cbuf = new char[32];
//            int hasRead = 0;
//            while((hasRead = fr.read(cbuf))>0){
//                System.out.println(new String(cbuf, 0, hasRead));
//            }
//            
//        } catch (FileNotFoundException e) {
//            // TODO Auto-generated catch block
//            e.printStackTrace();
//        }
        
        
        /*
         * 2 节点流
         */
//        File f = new File("newfile.txt");
//        
//        try(
//                FileInputStream fis = new FileInputStream("E:/Workspase/MyEclipse 2015 CI/Shulie/src/A2.java");
//                FileOutputStream fos = new FileOutputStream(f))
//        {
//            byte[] buf = new byte[1024];
//            int hasRead = 0;
//            while((hasRead = fis.read(buf))>0){
//                fos.write(buf, 0, hasRead);
//            }
//            
//        }catch(Exception e){
//            e.printStackTrace();
//        }
        
        
        /*
         * 3  转换流
         */
//        try (InputStreamReader reader = new InputStreamReader(System.in);
//            BufferedReader bf = new BufferedReader(reader)    ){        
//            String line = null;
//            while((line = bf.readLine()) !=null){
//                if("exit".equals(line)){
//                    System.exit(1);
//                }
//                System.out.println(line);
//            }
//        } catch (Exception e) {
//            // TODO Auto-generated catch block
//            e.printStackTrace();
//        }
        
        /*
         * 4 重定向输出
         */
//        try (PrintStream ps = new PrintStream(new FileOutputStream("out.txt"))) {
//            
//            System.setOut(ps);
//            System.out.println(new Scanner(System.in).next());
//            System.out.print(new IOMain());
//        } catch (Exception e) {
//            // TODO Auto-generated catch block
//            e.printStackTrace();
//        }
//        
//        
        
        
        /*
         * 5 RandomAccessFile
         */
//        
//        try (RandomAccessFile raf = new RandomAccessFile("newfile.txt", "rw");) {
//            System.out.println("指针初始位置："+raf.getFilePointer());
//            raf.seek(300);
//            byte[] bbuff = new byte[1024];
//            int hasRead = 0;
//            while((hasRead = raf.read(bbuff)) > 0){
//                System.out.println(new String(bbuff, 0, hasRead));
//            }
//            raf.seek(raf.length());
//            raf.write("\r\n追加的内容!\r\n".getBytes());
//        } catch (Exception e) {
//            // TODO Auto-generated catch block
//            e.printStackTrace();
//        }
//        
//        
//        insert("out.txt", 3, "\r\n插入的内容\r\n");
//        FileInputStream fis = new FileInputStream(new File("out.txt"));
//        byte[] bbuff = new byte[1024];
//        int hasRead = 0;
//        while((hasRead = fis.read(bbuff)) > 0){
//            System.out.println(new String(bbuff, 0, hasRead));
//        }
//        
//        
        /*
         * 6  序列化
         */
        
    
//        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("object.txt"));) {
//            Person p1 = new Person("Jeff", 23);
//            oos.writeObject(p1);
//        } catch (Exception e) {
//            // TODO Auto-generated catch block
//            e.printStackTrace();
//        }
        
        try (ObjectInputStream oip = new ObjectInputStream(new FileInputStream("object.txt"));) {
            Person p2 = (Person) oip.readObject();
            System.out.println("name:"+p2.getName()+"\n"+"age:"+p2.getAge());
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        
        
        
        

    }
    public static void insert(String fileName, long pos, String insertContent) throws IOException{
        File temp = File.createTempFile("temp", null);
        temp.deleteOnExit();
        try (
        RandomAccessFile raf = new RandomAccessFile(fileName, "rw");
        FileOutputStream fos = new FileOutputStream(temp);
        FileInputStream fis = new FileInputStream(temp);) {
            raf.seek(pos);
            byte[] buff = new byte[64];
            int hasRead = 0;
            while((hasRead = raf.read(buff))>0){
                fos.write(buff, 0, hasRead);
            }
            raf.seek(pos);
            raf.write(insertContent.getBytes());
            while((hasRead = fis.read(buff))>0){
                raf.write(buff, 0, hasRead);
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}
class Person implements java.io.Serializable{
    private String name;
    private int age;
    public Person(String name, int age){
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    
}
class PersonNew implements java.io.Externalizable{
    private String name;
    private int age;
    public PersonNew(String name, int age){
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    @Override
    public void writeExternal(ObjectOutput out) throws IOException {
        out.writeObject(new StringBuffer(name).reverse());
        out.writeInt(age);
        
    }
    @Override
    public void readExternal(ObjectInput in) throws IOException,
            ClassNotFoundException {
        this.name = ((StringBuffer)in.readObject()).reverse().toString();
        this.age = in.readInt();
    }
    
}