corejava学习8(io)

tanzhengping11

 
Vector     的方法都是synchronized的
 
Arraylist   快   不安全
I/O
 
输入/输出    方向
 
字节/字符    单位
 
FileInputStream    读文件
 
Read（）返回及一个整数，表示的你读出的字节的值，
当读了返回－1
 
Read（int b［］）读满一个字节数组
fileOutputStream    写文件
 
 
 
 
import java.io.*;
public class TestOutputStream {
    public static void main(String[] args){
           OutputStream os=null;
           try {
                  os=new FileOutputStream("2.txt");
                  String str="Hello Kettas";
                  byte[] bs=str.getBytes();//将字符串数组转换成字节数组
                  os.write(bs);
           } catch (FileNotFoundException e) {
                  e.printStackTrace();
           } catch (IOException e) {
                  e.printStackTrace();
           }finally{
                  try {
                         if (os!=null) os.close();
                  } catch (IOException e) {
                         e.printStackTrace();
                  }
           }
    }
}
 
 
import java.io.*;
public class TestListFiles {
    public static void main(String[] args) {
           File dir=new File("D:\\0804corejava");
           print(dir);
    }
    static void print(File dir){
           File[] fs=dir.listFiles();
           for(int i=0;i<fs.length;i++){
                  if (fs.isFile()) //判断是否是一个文件
                         System.out.println(fs.getAbsolutePath());
                  else print(fs);
           }
    }
}
 
 
 
import java.io.*;
public class TestPipedStream {
    public static void main(String[] args) throws Exception{
           PipedInputStream fis=new PipedInputStream();
           PipedOutputStream fos=new PipedOutputStream();
           fis.connect(fos);//连接
          
           Thread t=new ThreadA(fos);
           t.start();
          
           System.out.println(fis.read());
          
           fis.close();
    }
}
class ThreadA extends Thread{
    PipedOutputStream pos;
    public ThreadA(PipedOutputStream pos) {
           super();
           this.pos = pos;
    }
 
    public void run(){
           int result=0;
           try {
                  for(int i=1;i<=10;i++){
                         result+=i;
                         Thread.sleep(500);
                  }
                  pos.write(result);
                  pos.close();
           } catch (InterruptedException e) {
                  e.printStackTrace();
           } catch (IOException e) {
                  e.printStackTrace();
           }
          
    }
}
 
 
import java.io.*;
public class TestDataStream {
    public static void main(String[] args) throws Exception{
           long l=1234567890123456L;
           FileOutputStream fos=new FileOutputStream("1.dat");
           DataOutputStream out=new DataOutputStream(fos);
           out.writeLong(l);
           out.close();
          
           FileInputStream fis=new FileInputStream("1.dat");
           DataInputStream in=new DataInputStream(fis);
           long l2=in.readLong();
           in.close();关闭外层就可以
          
           System.out.println(l2);
    }
 
}
 
 
import java.io.*;
public class TestBufferedStream {
    public static void main(String[] args) throws Exception{
           String str="Hello Kettas";
           byte[] bs=str.getBytes();
           FileOutputStream fos=new FileOutputStream("kettas.txt");
           BufferedOutputStream out=new BufferedOutputStream(fos);
           //DataOutputStream dout=new DataOutputStream(out);
           out.write(bs);
           out.flush();//刷新输出流
    }
}
 
 
 
原子操作   synchronzined
 
 
ObjectOutputStream   能读八种基本的数据，带在缓冲。
序列化必须，Serializable
 
Transient   修辞的属性是临时属性，不参加序列化。
 
 
import java.io.*;
public class TestObjectStream {
    public static void main(String[] args) throws Exception{
           Student s1=new Student("Liucy",30,80);
           Student s2=new Student("Huxz",18,100);
          
           FileOutputStream fos=new FileOutputStream("students.dat");
           ObjectOutputStream out=new ObjectOutputStream(fos);
           out.writeObject(s1);
           out.writeObject(s2);
           out.close();
          
           FileInputStream fis=new FileInputStream("students.dat");
           ObjectInputStream in=new ObjectInputStream(fis);
           Object o1=in.readObject();
           Object o2=in.readObject();
           in.close();
          
           System.out.println(o1);
           System.out.println(o2);
    }
}
实现Serializable,序列化
class Student implements Serializable{
    String name;
    int age;
    transient double score;//临时属性
    public Student(String name, int age, double score) {
           super();
           this.name = name;
           this.age = age;
           this.score = score;
    }
    public String toString(){
           return "Student name="+name+" age="+age+" score="+score;
    }
}
 
 
import java.io.*;
import java.util.*;
public class TestPoemInverse {
    public static void main(String[] args) throws Exception{
           Stack s=new Stack();
          
           FileInputStream fis=new FileInputStream("1.txt");
           InputStreamReader ir=new InputStreamReader(fis);// 创建一个使用默认字符集的InputStreamReader
           BufferedReader in=new BufferedReader(ir);
           String str;
     //readLine()读取一个文本行。
           while((str=in.readLine())!=null){
                  s.push(str);
           }
           in.close();
          
           FileOutputStream fos=new FileOutputStream("2.txt");
           PrintWriter out=new PrintWriter(fos);
           int size=s.size();
           for(int i=0;i<size;i++){
                  str=s.pop();
                  out.println(str);
           }
           out.close();
          
    }
}
class Stack {
    private LinkedList list=new LinkedList();
    public void push(String str){
           list.addFirst(str);
    }
    public String pop(){
           return (String)list.removeFirst();
    }
    public int size(){
           return list.size();
    }
}
 
 
import java.io.*;
public class TestReaderWriter {
    public static void main(String[] args) throws Exception{
           FileOutputStream fos=new FileOutputStream("poem.txt");
           //Writer ow=new OutputStreamWriter(fos,"GBK");
           //PrintWriter out=new PrintWriter(ow);
           PrintWriter out=new PrintWriter(fos);
           out.println("葡萄美酒夜光杯");
           out.println("欲饮琵琶马上催");
           out.println("醉卧沙场君莫笑");
           out.println("我是流氓我怕谁");
           out.close();          
          
           FileInputStream fis=new FileInputStream("poem.txt");
           Reader ir=new InputStreamReader(fis,"Big5");
           BufferedReader in=new BufferedReader(ir);
           String str;
           while((str=in.readLine())!=null){
                  System.out.println(str);
           }
           in.close();
          
    }
}
 
 
public class TestString {
    public static void main(String[] args) throws Exception{
           String str="1232131 ";
           byte[] bs1=str.getBytes("GBK");//编码
           String str2=new String(bs1,"Big5");//解码
           System.out.println(str);
           System.out.println(str2);
          
           byte[] bs2=str2.getBytes("Big5");
           String str3=new String(bs2,"GBK");
           System.out.println(str3);

<span style="font-size: 12pt;"><span style="font-family: Times New Roman;"><