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j2se--用java流如何将一个文件拷贝到别的地方-->清高手指教

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j2se--用java流如何将一个文件拷贝到别的地方-->清高手指教

发表于：2007-03-16 21:48:56 楼主

请教高手如何用java流将一个文件拷贝到别的地方

我在jdk中没有看到关于copy的方法．．．

发表于：2007-03-16 22:19:511楼得分:0

拷贝，自己实现吧
就是读出再写入

发表于：2007-03-16 22:53:132楼得分:0

就是读出再写入

就是把一个文件的内容读出来在写到另个文件里吗

这不叫拷贝吧..

发表于：2007-03-17 00:08:463楼得分:0

是叫copy啊,从输入流读入在输出到指定的文件就是copy啊

发表于：2007-03-17 00:14:114楼得分:0

哦,是的,拷贝的可以是目录,这里有个很好的程序,供参考,有次看到的,

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));
}
}
}

发表于：2007-03-17 00:14:235楼得分:0

public static void main（string[] args) {
file oldfile = new file（ "c:/oldfile.txt ");
file newfile = new file（ "c:/newfile.txt ");
try {
fileinputstream inputstream = new fileinputstream（oldfile);
fileoutputstream outputstream = new fileoutputstream（newfile);
byte[] bytearr = new byte[512];
while （inputstream.read（bytearr) > 0) {
outputstream.write（bytearr);
outputstream.flush（);
}
outputstream.close（);
inputstream.close（);
} catch （exception ex) {
ex.printstacktrace（);
}
}

发表于：2007-03-17 12:55:116楼得分:0

用通道不就得了？好多人问....
package test;

import java.io.file;
import java.io.fileinputstream;
import java.io.filenotfoundexception;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.nio.channels.filechannel;
import java.nio.channels.writablebytechannel;

public class copyfile {
public static void main （string args[])
{
file f= new file （ "d://emule-0.47c-verycd1215-setup.exe ");
try {
fileinputstream fin = new fileinputstream （f);
filechannel fc = fin.getchannel（);
fileoutputstream fout = new fileoutputstream（ "d://1.exe ");
writablebytechannel to = fout.getchannel（);
fc.transferto（0, fc.size（),to );
} catch （filenotfoundexception e) {
system.err.println（ "file not found! ");
} catch （ioexception e) {
system.err.println（ "there are errors on processing ");
}

}
}

发表于：2007-03-17 17:12:207楼得分:0

刚刚写了个程序:

/**
* @param args
* @throws ioexception
* @throws ioexception
* function: 实现文件的copy功能,把read.txt的内容拷贝到text.txt文件
*/
public static void main（string[] args) throws ioexception {
// todo auto-generated method stub

file read = new file（ "d://read.txt ");
system.out.println（read.length（));
fileinputstream readstream = new fileinputstream（read);

byte[] b = new byte[（int)read.length（)];
readstream.read（b);

file s = new file（ "d://text.txt ");

fileoutputstream writestream = new fileoutputstream（s);

writestream.write（b);
readstream.close（);
writestream.close（);
writestream.flush（);

}

发表于：2007-03-17 17:13:488楼得分:0

给完整的代码吧!
import java.io.file;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.io.fileinputstream;

public class fileoutputtest {

/**
* @param args
* @throws ioexception
* @throws ioexception
* function: 实现文件的copy功能,把read.txt的内容拷贝到text.txt文件
*/
public static void main（string[] args) throws ioexception {
// todo auto-generated method stub

file read = new file（ "d://read.txt ");
system.out.println（read.length（));
fileinputstream readstream = new fileinputstream（read);

byte[] b = new byte[（int)read.length（)];
readstream.read（b);

file s = new file（ "d://text.txt ");

fileoutputstream writestream = new fileoutputstream（s);

writestream.write（b);
readstream.close（);
writestream.close（);
writestream.flush（);

}

发表于：2007-03-22 18:04:159楼得分:0

mark

发表于：2007-03-22 18:23:1710楼得分:0

大部分人平时用io都喜欢用fileoutputstream和fileinputstream吗

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