從一個文本文件中讀取數(shù)據(jù)
public class FileInputStreamDemo1 { /** * 使用InputStream抽象類的子類FileInputStream類 * 從一個文件中讀取流數(shù)據(jù) */ public static void test1() { try { FileInputStream myStream = new FileInputStream("src/a.txt"); int a = 0; while((a=myStream.read())!=-1){ //從a.txt讀取內(nèi)容一直到文件的末尾 System.out.PRint((char)a); } myStream.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] args) { test1(); }}簡單的輸出流 輸入一個字符到文本中
public class Demo1 { /** * 輸入一個字符到文件中 */ public static void test1() { try { OutputStream os = new FileOutputStream("src/b.txt"); os.write(97); os.flush(); os.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } }運(yùn)行結(jié)果為a，因為ascii碼97對應(yīng)的字符為‘a(chǎn)’；輸出一個數(shù)組/** * 輸出一個數(shù)組 */ public static void test2() { byte myArray[] = new byte[5]; myArray[0]=97; myArray[1]=98; myArray[2]=99; myArray[3]=100; myArray[4]=101; try { OutputStream os = new FileOutputStream("src/b.txt"); os.write(myArray); os.flush(); os.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } }輸出結(jié)果為abcde 輸出字符串
public static void test3() { String myContent = "I am a good man!"; try { OutputStream os = new FileOutputStream("src/b.txt"); os.write(myContent.getBytes()); os.flush(); os.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } }運(yùn)行結(jié)果為：I am a good man! 。
將一個文件的內(nèi)容輸出到另一個文件中
public static void copy(){ try { FileInputStream myStream = new FileInputStream("src/1.png"); OutputStream os = new FileOutputStream("2.jpg"); int a = 0; while((a = myStream.read())!=-1){ //一直讀到文件的末尾 os.write((char)a); } os.flush(); os.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } }新聞熱點
疑難解答
