編寫MyCP.java 實現相似Linux下cp XXX1 XXX2的功能,要求MyCP支持兩個參數:java
String[] args 能夠看出來是一個數組。在命令行中好比運行 Test.class 文件
java MyCP MyCP -tx a.txt b.bin
至關於給數組傳入了一個 MyCP MyCP -tx a.txt b.bin 字符串。git
十進制轉二進制 public static String toBinaryString(int i)
數組
二進制轉十進制public static Integer valueOf(String s, int radix)
命令行
從文件讀取,輸出到文件->選擇緩衝流,能夠一次把數據讀取設計
import java.io.*; public class MyCP { public static void main(String[] args) { String transformMethod = args[0]; File source = new File(args[1]); File target = new File(args[2]); try { Reader in = new FileReader(source); BufferedReader bufferedReader = new BufferedReader(in); String srcNum = bufferedReader.readLine(); String tarNum = ""; if(transformMethod.equals("-tx")){ //十進制轉二進制 tarNum = Integer.toBinaryString(Integer.parseInt(srcNum)); } else{ tarNum = Integer.valueOf(srcNum,2).toString(); } Writer out = new FileWriter(target); BufferedWriter bufferedWriter = new BufferedWriter(out); bufferedWriter.write(tarNum); bufferedReader.close(); bufferedWriter.close(); } catch (Exception e) { System.out.println(e); } } }