Java第十八天-IO流，其他流

//打印流
FileOutputStream fos = null;
try {
	fos = new FileOutputStream(new File("D:\\IO\\text.txt"));
} catch (FileNotFoundException e) {
	e.printStackTrace();
}
PrintStream ps = new PrintStream(fos,true);//创建打印输出流,设置为自动刷新模式(写入换行符或字节 '\n' 时都会刷新输出缓冲区)
if (ps != null) {	
	System.setOut(ps);}// 把标准输出流(控制台输出)改成文件，改变程序输出的位置
for (int i = 0; i <= 255; i++) {  //输出ASCII字符
	System.out.print((char)i);
	if (i % 50 == 0) {   //每50个数据一行
		System.out.println(); // 换行
	}  }
ps.close();

输入输出流

		/*
		 * 标准的输入输出流： 输入流：System.in 输出流: System.out
		 */
		// 从键盘输入，让小写的字母转换为大写的字母

		BufferedReader br = null;
		try {
			InputStream is = System.in;
			InputStreamReader isr = new InputStreamReader(is);// 将输入的字节转换为字符
			br = new BufferedReader(isr);
			String str;// 用str接受输入的字符串
			while (true) {
				System.out.println("请输入字符串");
				str = br.readLine();
				if (str.equalsIgnoreCase("e") || str.equalsIgnoreCase("exit")) {
					break;
				}
				String str1 = str.toUpperCase();//用str1接收转化后的str字符串
				System.out.println(str1);
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(br!=null){
				try {
					br.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				
			}
		}

转换流

用法与缓冲流一样

对象流

/*

• 要实现序列化的类：1.要求此类时可序列化的：实现Serializable接口
• 2.要求类的属性也要实现Serializable接口
• 3.提供一个版本号：pirvate static final long serialVersionID
• 4.使用static或transient修饰的属性不可序列化

*/

	//对象的反序列化过程：将硬盘种的文件通过ObjectInputStream转换为相应的对象
	@Test
	public void testObjectIntputStream(){
		ObjectInputStream ois = null;
		try{
			ois = new ObjectInputStream(new FileInputStream("person.txt"));
			Person p1 = (Person)ois.readObject();
			System.out.println(p1);
			Person p2 = (Person)ois.readObject();
			System.out.println(p2);		
		}catch (Exception e){
			e.printStackTrace();
		}finally{
			if(ois!=null){
				try {
					ois.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}
	// 对象的序列化过程：将内存中的对象通过ObjectOutputStream转换为二进制流，存储在硬盘中
	@Test
	public void testObjectOutputStream() {
		Person p1 = new Person("天天", 23);
		Person p2 = new Person("鸣人", 24);

		ObjectOutputStream oos = null;
		try {
			oos = new ObjectOutputStream(new FileOutputStream(
					"person.txt"));
			
			oos.writeObject(p1);
			oos.flush();
			oos.writeObject(p2);
			oos.flush();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(oos!= null){
				try {
					oos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				
			}
		}
		

	}
}


class Person implements Serializable {
	private String name;
	private Integer age;

	public Person(String name, Integer age) {
		super();
		this.name = name;
		this.age = age;
	}

	@Override
	public String toString() {
		return "Person [name=" + name + ", age=" + age + "]";
	}

}