java中如何实现文件拷贝? 用RandomAccessFile类或FileInputStream/FileOutputStream,打开文件,读,写,关闭。 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 /********************* CopyFile.java ***********************/import java.io.*;public class CopyFile { public static void main(String args[]) throws Exception { BufferedReader br = new BufferedReader( new FileReader("line.txt")); BufferedWriter bw = new BufferedWriter( new FileWriter("linenum.txt")); String s, space=" "; int num=0; while (br.ready()) { s=br.readLine(); num++; bw.write(String.valueOf(num)); bw.write(space); bw.write(s); bw.newLine(); } bw.close(); } }不知道这样是不是你需要的 ControlFile.java 拷贝莫路径下的所有文件import java.io.*;import java.text.*;import java.util.*;/** * @author ljt * * To change this generated comment edit the template variable "typecomment": * Window>Preferences>Java>Templates. * To enable and disable the creation of type comments go to * Window>Preferences>Java>Code Generation. */public class ControlFile { //已有文件的路径,需要备份到那个路径的名字 String filePath, aimFilePath; //保存已有文件路径下的所有的文件的名字 存放String Vector vec; public ControlFile() { filePath = ""; aimFilePath = ""; vec = new Vector(); } public ControlFile(String filePath, String aimFilePath) { this.filePath = filePath; this.aimFilePath = aimFilePath; vec = new Vector(); } //得到目录下所有文件的名字 private void getFileName() { File f = new File(filePath); String str[] = f.list(); for (int i = 0; i < str.length; i++) { vec.addElement(str[i]); } } // 文件的拷贝:::测试成功 private boolean bakFile(String fileName) { try { //读文件 FileReader raf = new FileReader(filePath + fileName); String detail = ""; BufferedReader buff = new BufferedReader(raf); String temp = buff.readLine(); while (temp != null) { detail += temp + "\n"; temp = buff.readLine(); } raf.close(); System.out.println(detail); //写文件 File file = new File(aimFilePath + fileName); PrintWriter out = new PrintWriter(new FileWriter(file)); out.print(detail); out.close(); } catch (FileNotFoundException e) { System.out.println("文件没有找到"); } catch (IOException e) { System.out.println("copyFile 出错"); } return true; } public static void main(String[] args) { ControlFile confile = new ControlFile("D:\\readFile\\", "D:\\work\\bakFile\\"); confile.getFileName(); Vector ve = new Vector(); ve = confile.vec; if (ve != null) for (int i = 0; i < ve.size(); i++) { System.out.println((String) ve.elementAt(i)); confile.bakFile((String) ve.elementAt(i)); } }} 呜呜~~我刚学用java不久,用jbuilder7.糊里糊涂。觉得不是很清楚你就帮帮我吧 关于mysql update语句的用法 列名 菜鸟提问:请问J2EE和J2ME有联系吗?不学J2EE是不是可以直接学习J2ME 请教大虾简单问题,关于图片载入。 那位朋友可以给我发一份SCJP的最新考试真题?100分 初学者 请教高手: request.getProperty(key) 返回值为UTF8编码,如何有效转换至可识别汉字? DIY自己的jvm 在jbuilder3中,单击按钮 出现文件对话框,让你选文件,怎么实现,请指教 【求助】DWR如何使用spring注解管理的bean 如何用java取得服务器时间 谁能帮我,就有分拿!
import java.io.*;
public class CopyFile
{
public static void main(String args[]) throws Exception
{
BufferedReader br = new BufferedReader(
new FileReader("line.txt"));
BufferedWriter bw = new BufferedWriter(
new FileWriter("linenum.txt"));
String s, space=" ";
int num=0;
while (br.ready())
{
s=br.readLine();
num++;
bw.write(String.valueOf(num));
bw.write(space);
bw.write(s);
bw.newLine();
}
bw.close();
}
}
不知道这样是不是你需要的
import java.text.*;
import java.util.*;/**
* @author ljt
*
* To change this generated comment edit the template variable "typecomment":
* Window>Preferences>Java>Templates.
* To enable and disable the creation of type comments go to
* Window>Preferences>Java>Code Generation.
*/
public class ControlFile {
//已有文件的路径,需要备份到那个路径的名字
String filePath, aimFilePath;
//保存已有文件路径下的所有的文件的名字 存放String
Vector vec;
public ControlFile() {
filePath = "";
aimFilePath = "";
vec = new Vector();
}
public ControlFile(String filePath, String aimFilePath) {
this.filePath = filePath;
this.aimFilePath = aimFilePath;
vec = new Vector();
}
//得到目录下所有文件的名字
private void getFileName() {
File f = new File(filePath);
String str[] = f.list();
for (int i = 0; i < str.length; i++) {
vec.addElement(str[i]);
}
} // 文件的拷贝:::测试成功
private boolean bakFile(String fileName) {
try {
//读文件
FileReader raf = new FileReader(filePath + fileName);
String detail = "";
BufferedReader buff = new BufferedReader(raf);
String temp = buff.readLine();
while (temp != null) {
detail += temp + "\n";
temp = buff.readLine();
}
raf.close();
System.out.println(detail);
//写文件
File file = new File(aimFilePath + fileName);
PrintWriter out = new PrintWriter(new FileWriter(file));
out.print(detail);
out.close(); } catch (FileNotFoundException e) {
System.out.println("文件没有找到");
} catch (IOException e) {
System.out.println("copyFile 出错");
}
return true;
}
public static void main(String[] args) {
ControlFile confile =
new ControlFile("D:\\readFile\\", "D:\\work\\bakFile\\");
confile.getFileName();
Vector ve = new Vector();
ve = confile.vec;
if (ve != null)
for (int i = 0; i < ve.size(); i++) {
System.out.println((String) ve.elementAt(i));
confile.bakFile((String) ve.elementAt(i));
}
}
}