_119_Java_打印流与数据流

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• 打印流： 

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

import org.junit.Test;

public class _001_PrintStream {

	//字节流：PrintStream;字符流：PrintWriter;(输出流)
	@Test
	public void test() {
		FileOutputStream fos=null;
		
		try {
			fos=new FileOutputStream(new File("print.txt"));
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		PrintStream ps = new PrintStream(fos, true);
		
		//创建打印输出流，设置为自动刷新（写入换行符或者字节'\n'时都会刷新输出缓冲区）
		if(ps!=null) {
			System.setOut(ps);
		}
		
		for(int i=0;i<=255;i++) {
			System.out.print((char)i);
			if(i%50==0) {
				System.out.println();
			}
		}
		ps.close();
	}
}

• 数据流

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

import org.junit.Test;

public class _002_DataStream {
	
	/*数据流：用来处理基本数据类型、String、字节数组的数据，包括DtatInputStream、DataOutputStream*/
	@Test
	public void testDataStream() {
		DataOutputStream dos=null;
		
		try {
			FileOutputStream fos = new FileOutputStream("data.txt");
			dos=new DataOutputStream(fos);
			dos.writeUTF("打好防范和施法速度飞快");
			dos.writeBoolean(true);
			dos.writeLong(875878898488L);
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			if(dos!=null) {
				try {
					dos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
			
		
	}
	
	@Test
	public void testA() {
		DataInputStream dis=null;
		try {
			FileInputStream fis = new FileInputStream("data.txt");
			
			dis=new DataInputStream(fis);
			String str = dis.readUTF();
			boolean readBoolean = dis.readBoolean();
			long longValue = dis.readLong();
			
			System.out.println(str+"  "+readBoolean+" "+longValue);
			
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			if(dis!=null) {
				try {
					dis.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			
		}
	}

}