【IO流】24 - 字節流 - 字節流的四種復制文件方式對比
阿新 • • 發佈:2018-02-04
字節數 tput 單個 exc pub exce long 四種 cast
package cn.itcast.copy; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; /* * 文件復制方式,字節流,一共4個方式 * 1. 字節流讀寫單個字節 125250 毫秒 * 2. 字節流讀寫字節數組 193 毫秒 OK * 3. 字節流緩沖區流讀寫單個字節 1210 毫秒 * 4. 字節流緩沖區流讀寫字節數組 73 毫秒 OK*/ public class Copy { public static void main(String[] args)throws IOException { long s = System.currentTimeMillis(); copy_4(new File("c:\\q.exe"), new File("d:\\q.exe")); long e = System.currentTimeMillis(); System.out.println(e-s); } /* * 方法,實現文件復制 * 4. 字節流緩沖區流讀寫字節數組*/ public static void copy_4(File src,File desc)throws IOException{ BufferedInputStream bis = new BufferedInputStream(new FileInputStream(src)); BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(desc)); int len = 0 ; byte[] bytes = new byte[1024];while((len = bis.read(bytes))!=-1){ bos.write(bytes,0,len); } bos.close(); bis.close(); } /* * 方法,實現文件復制 * 3. 字節流緩沖區流讀寫單個字節 */ public static void copy_3(File src,File desc)throws IOException{ BufferedInputStream bis = new BufferedInputStream(new FileInputStream(src)); BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(desc)); int len = 0 ; while((len = bis.read())!=-1){ bos.write(len); } bos.close(); bis.close(); } /* * 方法,實現文件復制 * 2. 字節流讀寫字節數組 */ public static void copy_2(File src,File desc)throws IOException{ FileInputStream fis = new FileInputStream(src); FileOutputStream fos = new FileOutputStream(desc); int len = 0 ; byte[] bytes = new byte[1024]; while((len = fis.read(bytes))!=-1){ fos.write(bytes,0,len); } fos.close(); fis.close(); } /* * 方法,實現文件復制 * 1. 字節流讀寫單個字節 */ public static void copy_1(File src,File desc)throws IOException{ FileInputStream fis = new FileInputStream(src); FileOutputStream fos = new FileOutputStream(desc); int len = 0 ; while((len = fis.read())!=-1){ fos.write(len); } fos.close(); fis.close(); } }
【IO流】24 - 字節流 - 字節流的四種復制文件方式對比