本文共 2761 字,大约阅读时间需要 9 分钟。
应付面试吧:
package colin;import java.io.File;import java.io.IOException;public class IOTest { public static void main(String[] args) { //创建一个文件路径 File file = new File("/log/testData.txt"); if (file.exists()) {//得到文件路径 System.out.println(file.getAbsolutePath());//得到文件大小 System.out.println("文件大小:" + file.length()); } else { try { file.createNewFile(); } catch (IOException e) { e.printStackTrace(); } }//创建文件和创建文件夹 File file1 = new File("/log/iotest.txt"); if (!file1.exists()) { try { file1.createNewFile(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } else { System.out.println("文件已存在"); }//创建文件夹 File file2 = new File("/log/testIO"); if (file2.isDirectory()) { System.out.println("文件夹存在"); } else { file2.mkdir(); }//列出一个文件夹下的所有文件 File f = new File("/log/testIO"); if (f.isDirectory()) { File lists[] = f.listFiles(); for (int i = 0; i < lists.length; i++) { System.out.println(lists[i].getName()); } } }}
对文本类的处理:
package colin;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.FileReader;import java.io.FileWriter;public class WriteText { public static void main(String[] args) { writeText(); } private static void writeText() { try { FileReader fr=new FileReader("/log/1.txt"); FileWriter fw = new FileWriter("/log/2.txt"); BufferedReader br=new BufferedReader(fr); BufferedWriter bw=new BufferedWriter(fw); String len; while ((len=br.readLine())!=null){ bw.write(len); } bw.close(); br.close();// fw.write("我很好,你呢?");// fw.flush();// fw.write("如果有一天你要走,请告诉我"); fw.close(); }catch (Exception e){ e.printStackTrace(); } }}
对于图片的处理:
package colin;import java.io.FileInputStream;import java.io.FileOutputStream;public class CopyPic { public static void main(String[] args) { copyPic(); } public static void copyPic(){ try { FileInputStream fis=new FileInputStream("/log/p1/p1.png"); FileOutputStream fos=new FileOutputStream("/log/p2/p2.png"); byte[] bytes=new byte[1024]; int len=0; while((len=fis.read(bytes))!=-1){ fos.write(bytes,0,len); } } catch (Exception e) { e.printStackTrace(); } }}
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