打印流的主要功能是用于输出,在整个IO包中打印流分为两种类型:
字节打印流:PrintStream
字符打印流:PrintWriter
打印流可以很方便的进行输出
public class PrintStreamDemo { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub byteStreamOut(); charStreamOut(); } //PrintStream public static void byteStreamOut(){ try { OutputStream out=new FileOutputStream("G:\\hhb.txt"); BufferedOutputStream bos=new BufferedOutputStream(out); PrintStream ps=new PrintStream(bos);//更加方便的输出 //bos.write("hhhhh".getBytes()); ps.println(123); ps.close(); bos.close(); out.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } //PrintWriter public static void charStreamOut(){ try { Writer w=new FileWriter("G:\\hhh.txt"); BufferedWriter bw=new BufferedWriter(w); PrintWriter pw=new PrintWriter(bw); pw.println(343); pw.println("lll"); //bw.write("我爱你!"); pw.close(); bw.close(); w.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
对象流
对象序列化
对象序列化就是指将一个对象转化为二进制的byte流。
两种情况:
将对象保存在文件上的操作称为对象的序列化操作
将对象从文件之中恢复称为反序列化的操作
使用ObjectOutputStream类实现对象的序列化,使用ObjectInputStream类实现反序列。
被序列化的对象所在的类必须实现java.io.Serializable接口
public class Cat implements Serializable{ private String name; private int age; private transient String color;//关键字transient,表示不用序列化 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; } public Cat(String name, int age) { super(); this.name = name; this.age = age; } @Override public String toString() { return "Cat [name=" + name + ", age=" + age + "]"; } public Cat() { super(); // TODO Auto-generated constructor stub } }
public class ObjectStreamDemo { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub objectOut(); objectIn(); } //实现对象的序列化 public static void objectOut(){ Cat cat=new Cat("mimi",3); try { OutputStream out=new FileOutputStream("G://555.kds"); ObjectOutputStream oos=new ObjectOutputStream(out); oos.writeObject(cat); oos.close(); out.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } //实现反序列化 public static void objectIn(){ try { InputStream in=new FileInputStream("G://555.kds"); ObjectInputStream ois=new ObjectInputStream(in); Cat cat=(Cat)ois.readObject(); System.out.println(cat); ois.close(); in.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
原文:http://www.cnblogs.com/shenhainixin/p/5118037.html