java 把a.txt文件中的内容复制到当前项目目录下的b.txt文件中，2种方式比较复制效率 毫秒比较

package xxx;import java.io.*;
public class JavaApplication1 {public static void main(String[] args) throws IOException {long start = System.currentTimeMillis();method1("E:/eclipse-workspace/java2/data/a.txt", "E:/eclipse-workspace/java2/data/b.txt");method2("E:/eclipse-workspace/java2/data/a.txt", "E:/eclipse-workspace/java2/data/b.txt");long end = System.currentTimeMillis();System.out.println("共耗时：" + (end - start) + "毫秒");}// 基本字节流一次读写一个字节public static void method1(String srcString, String destString) throws IOException {FileInputStream fis = new FileInputStream(srcString);FileOutputStream fos = new FileOutputStream(destString);int by = 0;while ((by = fis.read()) != -1) {fos.write(by);}fos.close();fis.close();}// 基本字节流一次读写一个字节数组public static void method2(String srcString, String destString) throws IOException {FileInputStream fis = new FileInputStream(srcString);FileOutputStream fos = new FileOutputStream(destString);byte[] bys = new byte[1024];int len = 0;while ((len = fis.read(bys)) != -1) {fos.write(bys, 0, len);}fos.close();fis.close();}
}

输出结果：
（1）基本字节流一次读写一个字节

（2）基本字节流一次读写一个字节数组

第一种方法读写速度优于第二种方法