_119_Java_列印流與資料流
阿新 • • 發佈:2018-12-11
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列印流:
import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.PrintStream; import org.junit.Test; public class _001_PrintStream { //位元組流:PrintStream;字元流:PrintWriter;(輸出流) @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); //建立列印輸出流,設定為自動重新整理(寫入換行符或者位元組'\n'時都會重新整理輸出緩衝區) 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(); } }
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資料流
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 { /*資料流:用來處理基本資料型別、String、位元組陣列的資料,包括DtatInputStream、DataOutputStream*/ @Test public void testDataStream() { DataOutputStream dos=null; try { FileOutputStream fos = new FileOutputStream("data.txt"); dos=new DataOutputStream(fos); dos.writeUTF("打好防範和施法速度飛快"); 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(); } } } } }