Posted on 2006-11-26 13:21
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J2EE技術專區
java中提供了io類庫，可以輕松的用java實現對文件的各種操作。下面就來說一下如何用java來實現這些操作。
?
新建目錄<%@?page?contentType="text/html;charset=gb2312"%>
<%
//String?URL?=?request.getRequestURI();
String?filePath="C:\\測試\\";
filePath=filePath.toString();//中文轉換
java.io.File?myFilePath=new?java.io.File(filePath);
if(!myFilePath.exists())
myFilePath.mkdir();
%>
?
新建文件
<%@?page?contentType="text/html;charset=gb2312"%>
<%@?page?import="java.io.*"?%>
<%
String?filePath="c:/測試/newFile.txt";
filePath=filePath.toString();
File?myFilePath=new?File(filePath);
if(!myFilePath.exists())
myFilePath.createNewFile();
FileWriter?resultFile=new?FileWriter(myFilePath);
PrintWriter?myFile=new?PrintWriter(resultFile);
String?content?="這是測試數據";
String?strContent?=?content.toString();
myFile.println(strContent);
resultFile.close();
%>
?
刪除文件<%@?page?contentType="text/html;charset=gb2312"%>
<%
String?filePath="c://測試//newFile.txt";
filePath=filePath.toString();
java.io.File?myDelFile=new?java.io.File(filePath);
if(myDelFile.exists())
{??
????myDelFile.delete();
????out.println(filePath+"刪除成功！！！");
}
else
{
????out.println(filePath+"該文件不存在");
}
%>
文件拷貝<%@?page?contentType="text/html;?charset=gb2312"?%>
<%@?page?import="java.io.*"?%>
<%
int?bytesum=0;
int?byteread=0;
//file:讀到流中
InputStream?inStream=new?FileInputStream("c://測試//newFile.txt");
FileOutputStream?fs=new?FileOutputStream(?"c://測試//copyFile.txt");
byte[]??buffer?=new??byte[1444];
int?length;
while?((byteread=inStream.read(buffer))!=-1)
?{
???out.println("<DT><B>"+byteread+"</B></DT>");
???bytesum+=byteread;
???out.println(bytesum);
???fs.write(buffer,0,byteread);
?}
inStream.close();
%>
?
整個文件夾拷貝
<%@?page?contentType="text/html;charset=gb2312"%>
<%@?page?import="java.io.*"?%>
<%String?url1="C:/aaa";
??String?url2="d:/java/";
??(new?File(url2)).mkdirs();
?File[]?file=(new?File(url1)).listFiles();
?for(int?i=0;i<file.length;i++){
??if(file[i].isFile()){
???file[i].toString();
???FileInputStream?input=new?FileInputStream(file[i]);
???FileOutputStream?output=new?FileOutputStream(url2+"/"+(file[i].getName()).toString());
???byte[]?b=new?byte[1024*5];
????int?len;
????while((len=input.read(b))!=-1){
????output.write(b,0,len);
????}
????output.flush();
????output.close();
????input.close();
??}
?}
%>
?
文件下載
<%@?page?contentType="text/html;?charset=gb2312"%>
<%@?page?import="java.io.*"?%>
<%
??String?fileName?=?"newFile.txt".toString();
??//讀到流中
??InputStream?inStream=new?FileInputStream("c://測試//newFile.txt");
??//設置輸出的格式
??response.reset();
??response.setContentType("text/plain");
??response.addHeader("Content-Disposition","attachment;?filename=\""?+?fileName?+?"\"");
??//循環取出流中的數據
??byte[]?b?=?new?byte[100];
??int?len;
??ServletOutputStream?outStream?=?response.getOutputStream();
?
??while((len=inStream.read(b))?>0)
??outStream.write(b,0,len);
??outStream.flush();
??outStream.close();
??inStream.close();
%>
?
數據庫字段中的文件下載
<%@?page?contentType="text/html;charset=gb2312"%>
<%@?page?import="java.util.*,java.sql.*,java.io.*"%>
<%
????String?id?=?request.getParameter("id");
????if(id==null)
????{???throw?new?Exception?("沒有找到圖片");
????}
????else
????{
???????try
???????{
com.gzrealmap.lib.jdbc.JDBCUtil??SqlBean=?com.gzrealmap.lib.jdbc.JDBCUtil.getInstance();
???????????????SqlBean.connect();
???????????????String?sql?=?"select?*?from?innernews?where?id?=?'"+79+"'";
???????????????ResultSet?rs?=?SqlBean.queryforUpdate(sql);
???????????????rs.next();
???????????????//String?fileNamedb?=?rs.getString("imageName");
???????????????String?file=?rs.getString("acc");
???????????????//String?fileName?=?new?String(fileNamedb.getBytes(),"iso-8859-1");
???????????????String?fileName?=?"a.jpg";
????????????????response.setHeader("Content-Disposition",??"inline;?filename=\""?+?fileName?+?"\"");????
???????????????String?filter?=?fileName.substring(fileName.lastIndexOf("."));
??????????????
???????????????if(filter.equals(".txt"))
???????????????{
???????????????????response.setContentType("text/plain");
???????????????}
???????????????else?if(filter.equals(".doc")||filter.equals(".dot"))
???????????????{
???????????????????response.setContentType("application/msword");
???????????????}
???????????????else
???????????????{
?????????????????response.setContentType("image/jpeg;charset=GB2312");
???????????????}
???????????????ServletOutputStream?o?=?response.getOutputStream();
???????????????//o.write(file);
???????????????out.println(file);
???????????????//o.flush();
???????????????//o.close();
???????????????SqlBean.disconnect();
???????}
????????catch(Exception?ex)
???????{
???????????out.println(ex.getMessage());
???????}
????}??
%>
?
把網頁保存成文件<%@?page?contentType="text/html;charset=gb2312"%>
<%@?page?import="java.text.*,java.util.*,java.net.*,java.io.*"%>
<%
?URL?stdURL?=?null;
?BufferedReader?stdIn?=?null;
?PrintWriter?stdOut?=?null;
?try?{
??stdURL?=?new?URL("http://www.163.com");
?}
?catch?(MalformedURLException?e)?{
???throw?e;
?}
?
try?{
????//將字節流轉變成為字符流
????stdIn?=?new?BufferedReader(new?InputStreamReader(stdURL.openStream()));
????String?theFileName?=?"c://測試//163.html";
????stdOut?=?new?PrintWriter(new?BufferedWriter(new?FileWriter(theFileName.toString())));
?}
?catch?(IOException?e)?{
?}
?
?/***把URL指定的頁面以流的形式讀出，寫成指定的文件***/
?try?{
????String?strHtml?=?"";
???while((strHtml?=?stdIn.readLine())!=null)?{
???stdOut.println(strHtml);
???}
?}
?catch?(IOException?e)?{
???throw?e;
?}
?finally?{??
???try?{
?????if(stdIn?!=?null)
???????stdIn.close();
?????if(stdOut?!=?null)
???????stdOut.close();
???????}
???catch?(Exception?e)?{
?????System.out.println(e);
???}
?}
%>
?
直接下載網上的文件
<%@?page?contentType="text/html;charset=gb2312"%>
<%@?page?import="java.io.*"%>
<%@?page?import="java.net.*"%>
<%
??int?bytesum=0;
??int?byteread=0;
??URL?url?=?new?URL("http://pimg.163.com/sms/micheal/logo.gif");
??URLConnection?conn?=?url.openConnection();
??InputStream?inStream?=?conn.getInputStream();
?
??/**
??String?theFileName?=?"c:/測試/logo.gif";
??theFileName?=?theFileName.toString();
??File?myFilePath=new?File(theFileName);
??if(!myFilePath.exists())
??myFilePath.createNewFile();
??**/
?
??FileOutputStream?fs=new?FileOutputStream("c:/測試/logo2.gif");
??byte[]??buffer?=new??byte[1444];
????while?((byteread=inStream.read(buffer))!=-1)
????{
???????out.println("<DT><B>"+byteread+"</B></DT>");
???????bytesum+=byteread;
???????//System.out.println(bytesum);
???????fs.write(buffer,0,byteread);
?????}
%>
?
按行讀文件?<%@?page?contentType="text/html;?charset=gb2312"?%>
<%@?page?import="java.io.*"?%>
<%
FileReader?myFileReader=new?FileReader("c:/哈哈.txt");
BufferedReader?myBufferedReader=new?BufferedReader(myFileReader);
String?myString=null;
String?resultString=new?String();
while((myString=myBufferedReader.readLine())!=null)?{
resultString=resultString+myString+"<br>";
}
out.println(resultString);
myFileReader.close();
%>
?
對word文檔的處理（上傳與下載）<%@?page?contentType="application/msword"?%>
<!--?以上這行設定本網頁為excel格式的網頁?-->
<%
???response.setHeader("Content-disposition","inline;?filename=test1.doc");?//線上瀏覽方式
??//?response.setHeader("Content-disposition","attachment;?filename=test1.doc");//下載方式
???//以上這行設定傳送到前端瀏覽器時的檔名為test1.doc
???//就是靠這一行，讓前端瀏覽器以為接收到一個word檔
%>
//然后輸出動態內容就可以得到一個word文檔了
?
1,打開：
1）文件頭上加：<%@?page??contentType="application/msword"%>?
xml文件里：
<mime-mapping>
????????<extension>doc</extension>
????????<mime-type>application/msword</mime-type>
</mime-mapping>
2）可以用js,以下代碼來自引用：
<%@?page?contentType="text/html;charset=gb2312"?import=?"java.io.*"%>
<HTML>
<script>
var?wrd=new?ActiveXObject("Word.Application")
wrd.visible=true
alert?("您的"+wrd.Application.Caption+"安裝路徑為：\n"+wrd.Application.Path+"\n版本號是："+?wrd.Application.version+"\n注冊使用者是："+wrd.Application.UserName)
wrd.Documents.Add()
//wrd.Documents.Open("c:\\exam.doc")
wrd.Selection.TypeText("This?is?some?text.")
wrd.Application.Activate()
wrd.ActiveDocument.SaveAs("c:\\exam111.doc")
wrd=null
</script>
</HTML>
?
2，下載：
<%@?page?contentType="text/html;charset=gb2312"?import=?"java.io.*"%>
<%//?得到文件名字和路徑
??String?filename?=?"jsp.doc";
??String?filepath?=?"C:\\";
?
??//?設置響應頭和下載保存的文件名
??response.setContentType("APPLICATION/OCTET-STREAM");
??response.setHeader("Content-Disposition","attachment;?filename=\""?+?filename?+?"\"");
?
??//?打開指定文件的流信息
??java.io.FileInputStream?fileInputStream?=?new?java.io.FileInputStream(filepath?+?filename);
??//FileOutputStream?out??=?new?FileOutputStream(filepath+"測試\\"?+?filename);
??//?寫出流信息
??int?i;
??while?((i=fileInputStream.read())?!=?-1)?{
???out.write(i);
??}
??fileInputStream.close();
??out.close();
?%>? |