打印流和数据流

1 打印流：字节流：PrintStream 字符流: PrintWriter

package lianxi1;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;

import org.junit.Test;

public class TestOtherStream {
@Test
  public void test1(){
     FileOutputStream fos = null;
     try {
        fos = new FileOutputStream(new File("Tangshan"));
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
    PrintStream ps = new PrintStream(fos,true);
    if(ps!=null){
    System.setOut(ps);
    }
    for(int i=1;i<=300;i++){
        System.out.print((char)i);
        if(i%50==0){
            System.out.println();
        }
    }
    try {
        fos.close();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
}

2 数据流：用来处理基本数据类型、String、字节数组的数据：DateInputStream,DateOutputStream

package lianxi1;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;

import org.junit.Test;

public class TestOtherStream {
@Test
   public void test2(){
    DataOutputStream dos = null;
    DataInputStream dis = null;
      try {
          FileOutputStream fos = new FileOutputStream("data");
          dos = new DataOutputStream(fos);
          dos.writeDouble(32.23);
          dos.writeUTF("我是年轻人");
          dos.writeInt(3234);
          FileInputStream fis = new FileInputStream("data");
          dis = new DataInputStream(fis);
          double d1 = dis.readDouble();
          System.out.println(d1);
          String s1 = dis.readUTF();
          System.out.println(s1);
          int i1 = dis.readInt();
          System.out.println(i1);
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }finally{
        try {
            dos.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    }
@Test
  public void test1(){
     FileOutputStream fos = null;
     try {
        fos = new FileOutputStream(new File("Tangshan"));
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
    PrintStream ps = new PrintStream(fos,true);
    if(ps!=null){
    System.setOut(ps);
    }
    for(int i=1;i<=300;i++){
        System.out.print((char)i);
        if(i%50==0){
            System.out.println();
        }
    }
    try {
        fos.close();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
}

3 对象流：

对象的序列化过程：用ObjectOutputStream类将一个java对象写入IO流中

  反序列化过程： 用ObjectInputStream类从IO流中恢复该Java对象

  要实现序列化的类：1 要求此类是序列化的，实现Serializable接口

  2 要求类的属性同样要实现Serializable接口

  3 提供一个版本号： private static final long serialVersionUID

  4 使用static或transient修饰的属性，不可实现序列化