<%@ page import="java.io.*"%>
<html>
<head>
<title>文g的徏立、检查与删除</title>
</head>
<body>
<%
String path=request.getRealPath("");
//out.println(path);
File f=new File(path,"File.txt");
//out.println(f);
//out.println(f.exists());
if(f.exists()){//(g)查File.txt是否存在
f.delete();//删除File.txt文g
out.println(path + "\\File.txt 存在Q已删除?);
}else{
f.createNewFile();//在当前目录下建立一个名为File.txt的文?br />out.println(path + "\\File.txt 不存在，已徏立?);//输出目前所在的目录路径
}
%>
目录的徏?(g)查与删除
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>目录的徏?(g)查与删除</title>
</head>
<body>
<%
String path=request.getRealPath("");//此步获得当前路径。如果要获得其他的\径。如:
(tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) // String path=request.getRealPath("../qqq/www/");
(tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) //则\径名"../qqq/www/"必须真实存在Q否则以?br /> (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) (tng) //代码不会(x)创徏指定的\径，管不报?br />path=path + "\\Sub";//要建立的目录\?br />File d=new File(path);//建立代表Sub目录的File对象Qƈ得到它的一个引?br />if(d.exists()){//(g)查Sub目录是否存在
d.delete();
out.println("Sub目录存在Q已删除");
}else{
d.mkdir();//建立Sub目录
out.println("Sub目录不存在，已徏?);
}
%>
</body>
</html>
如何在JSP中处理虚拟目?br /><%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>JSP中如何处理虚拟目?lt;/title>
</head>
<body>
取得虚拟目录对应的磁盘\?lt;br>
Web站点ȝ录的位置?lt;font color=#ff0000><%=request.getRealPath("/")%></font><br>
JSP|页所在的目录位置<font color=#ff0000><%=request.getRealPath("./")%></font><br>
JSP|页所在目录上一层目录的位置<font color=#ff0000><%=request.getRealPath("../")%></font><br>
</body>
</html>
文g属性的取得
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.util.Date,java.io.*"%>
<html>
<head>
<title>文g属性的取得</title>
</head>
<body>
<%
String path=request.getRealPath("/");
File f=new File(path,"ReadData.txt");
if(f.exists()){
%>
<%=f.getName()%>的属性如下：(x)<br><br>
文g长度为：(x)<%=f.length()%>
<%=f.isFile()?"是文?:"不是文g"%><br>
<%=f.isDirectory()?"是目?:"不是目录"%><br>
<%=f.canRead()?"可读?:"不可d"%><br>
<%=f.canWrite()?"可写?:"不可写入"%><br>
<%=f.isHidden()?"是隐藏文?:"不是隐藏文g"%><br>
文g的最后修Ҏ(gu)期ؓ(f)Q?lt;%=new Date(f.lastModified())%><br>
<%
}else{
f.createNewFile();//在当前目录下建立一个名为ReaData.txt的文?br />%>
<%=f.getName()%>的属性如下：(x)<br><br>
文g长度为：(x)<%=f.length()%>
<%=f.isFile()?"是文?:"不是文g"%><br>
<%=f.isDirectory()?"是目?:"不是目录"%><br>
<%=f.canRead()?"可读?:"不可d"%><br>
<%=f.canWrite()?"可写?:"不可写入"%><br>
<%=f.isHidden()?"是隐藏文?:"不是隐藏文g"%><br>
文g的最后修Ҏ(gu)期ؓ(f)Q?lt;%=new Date(f.lastModified())%><br>
<%
}
%>
</body>
</html>
取出目录中文件的Ҏ(gu)
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>取出目录中文件的Ҏ(gu)--列出目录中的文g</title>
</head>
<body>
<%
String path=request.getRealPath("/");
File d=new File(path);//建立当前目录中文件的File对象
File list[]=d.listFiles();//取得代表目录中所有文件的File对象数组
out.println("<font color=#ff0000>" + path + "目录下的文gQ?lt;/font><br>");
for(int i=0;i<list.length;i++){
if(list<I>.isFile()){
out.println(list<I>.getName() + "<br>");
}
}
out.println("<br><font color=#ff0000>" + path + "目录下的目录Q?lt;/font><br>");
for(int i=0;i<list.length;i++){
if(list<I>.isDirectory()){
out.println(list<I>.getName() + "<br>");
}
}
%>
</body>
</html>
判断是否为空白文?br /><%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>判断是否为空白文?lt;/title>
</head>
<body>
<%
String path=request.getRealPath("/");
out.println(path);
FileReader fr=new FileReader(path + "\\AtEnd.txt");//建立FileReader对象Qƈ实例化ؓ(f)fr
//对FileReadercȝ成的对象使用read()Ҏ(gu)Q可以从字符中d下一个字W?br />if(fr.read()==-1)//判断是否已读到文件的l尾
{
out.print("AtEnd.txt文g中没有数?lt;br>");
}else{
out.println("AtEnd.txt文g中有数据");
}
fr.close();
%>
</body>
</html>
d所有的文g数据
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*,java.lang.*"%>
<html>
<head>
<title>d所有的文g数据</title>
</head>
<body>
<%
String path=request.getRealPath(".");
FileReader fr=new FileReader(path + "\\ReadData.txt");
//关键在于dq程中，要判断所d的字W是否已l到?jin)文件的末尾Qƈ且这个字W是不是文g中的断行W，卛_断该字符值是否ؓ(f)13?br />int c=fr.read();//从文件中d一个字W?br />//判断是否已读到文件结?br />while(c!=-1){
out.print((char)c);//输出d的数?br />c=fr.read();//从文件中l箋(hu)d数据
if(c==13){//判断是否为断行字W?br />out.print("<br>");//输出分行标签
fr.skip(1);//略过一个字W?br />//c=fr.read();//d一个字W?br />}
}
fr.close();
%>
</body>
</html>
一行一行读取数?br /><%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>文gd</title>
</head>
<body>
<%
String path=request.getRealPath("");//取得当前目录的\?br />FileReader fr=new FileReader(path + "\\file\\inc\\t.txt");//建立FileReader对象Qƈ实例化ؓ(f)fr
BufferedReader br=new BufferedReader(fr);//建立BufferedReader对象Qƈ实例化ؓ(f)br
String Line=br.readLine();//从文件读取一行字W串
//判断d到的字符串是否不为空
while(Line!=null){
out.println(Line + "<br>");//输出从文件中d的数?br />Line=br.readLine();//从文件中l箋(hu)d一行数?br />}
br.close();//关闭BufferedReader对象
fr.close();//关闭文g
%>
</body>
</html>
略过文g中的字符不读?br /><%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>略过字节不读?lt;/title>
</head>
<body>
<%
String path=request.getRealPath(".");
FileReader fr=new FileReader(path + "\\ReadData.txt");
fr.skip(2);//跌2个字?br />int c=fr.read();//d一个字?br />while(c!=-1){
out.print((char)c);
c=fr.read();
}
fr.close();
%>
</body>
</html>
数据写入文?br /><%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>数据写入文?lt;/title>
</head>
<body>
<%
String path=request.getRealPath(".");
FileWriter fw=new FileWriter(path + "\\WriteData.txt");//建立FileWriter对象Qƈ实例化fw
//字W串写入文g
fw.write("大家好！");
fw.write("本书是《JSP~程技巧?);
fw.write("请多多指教！");
fw.write("email:stride@sina.com");
fw.close();
FileReader fr=new FileReader(path + "\\WriteData.txt");
BufferedReader br=new BufferedReader(fr);//建立BufferedReader对象Qƈ实例化ؓ(f)br
String Line=br.readLine();
//d一行数?br />out.println(Line + "<br>");
br.close();//关闭BufferedReader对象
fr.close();
%>
</body>
</html>
写入文件的数据分行
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>写入文件的数据分行</title>
</head>
<body>
<%
String path=request.getRealPath(".");
FileWriter fw=new FileWriter(path + "\\WriteData.txt");
BufferedWriter bw=new BufferedWriter(fw);
bw.write("大家好！");
bw.write("本书是《JSP~程技巧》?);
bw.newLine();//断行
bw.write("请多多指教！");
bw.newLine();//断行
bw.write("email: [email]stride@sina.com[/email]");
bw.flush();//数据更新至文g
fw.close();//关闭文g?br />out.println("写入文g内容为：(x)<br>");
FileReader fr=new FileReader(path + "\\WriteData.txt");
BufferedReader br=new BufferedReader(fr);
String Line=br.readLine();//d一行数?br />while(Line!=null){
out.println(Line + "<br>");
Line=br.readLine();
}
fr.close();
%>
</body>
</html>
如何数据追加写入到文g
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.io.*"%>
<html>
<head>
<title>如何数据追加写入到文g</title>
</head>
<body>
<%
String path=request.getRealPath(".");
RandomAccessFile rf=new RandomAccessFile(path + "\\WriteData.txt","rw");//定义一个类RandomAccessFile的对象，q实例化
rf.seek(rf.length());//指针移动到文g末尾
rf.writeBytes("\nAppend a line to the file!");
rf.close();//关闭文g?br />out.println("写入文g内容为：(x)<br>");
FileReader fr=new FileReader(path + "\\WriteData.txt");
BufferedReader br=new BufferedReader(fr);//d文g的BufferedRead对象
String Line=br.readLine();
while(Line!=null){
out.println(Line + "<br>");
Line=br.readLine();
}
fr.close();//关闭文g
%>
</body>
</html>
]]>
]]>
java.awt.image.*,java.util.*,javax.imageio.*" (tng)%> (tng)
<% (tng)
// (tng)在内存(sh)创徏图象 (tng)
int (tng)width=60, (tng)height=20; (tng)
BufferedImage (tng)image (tng)= (tng)new (tng)BufferedImage(width, (tng)height, (tng)
BufferedImage.TYPE_INT_RGB); (tng)
// (tng)获取囑Ş上下文?br />Graphics (tng)g (tng)= (tng)image.getGraphics(); (tng)
// (tng)讑֮背景色?br />g.setColor(new (tng)Color(0xDCDCDC)); (tng)
g.fillRect(0, (tng)0, (tng)width, (tng)height); (tng)
//画边框?br />g.setColor(Color.black); (tng)
g.drawRect(0,0,width-1,height-1); (tng)
// (tng)取随Z生的认证?4位数? (tng)
String (tng)rand (tng)= (tng)request.getParameter("rand"); (tng)
rand (tng)= (tng)rand.substring(0,rand.indexOf(".")); (tng)
switch(rand.length()) (tng)
{ (tng)
case (tng)1: (tng)rand (tng)= (tng)"000"+rand; (tng)break; (tng)
case (tng)2: (tng)rand (tng)= (tng)"00"+rand; (tng)break; (tng)
case (tng)3: (tng)rand (tng)= (tng)"0"+rand; (tng)break; (tng)
default: (tng)rand (tng)= (tng)rand.substring(0,4); (tng)break; (tng)
} (tng)
// (tng)认证码存入SESSION (tng)
session.setAttribute("rand",rand); (tng)
// (tng)认证码昄到图象中 (tng)
g.setColor(Color.black); (tng)
Integer (tng)tempNumber (tng)= (tng)new (tng)I(yng)nteger(rand); (tng)
String (tng)numberStr (tng)= (tng)tempNumber.toString(); (tng)
g.setFont(new (tng)Font("Atlantic (tng)I(yng)nline",Font.PLAIN,18)); (tng)
String (tng)Str (tng)= (tng)numberStr.substring(0,1); (tng)
g.drawString(Str,8,17); (tng)
Str (tng)= (tng)numberStr.substring(1,2); (tng)
g.drawString(Str,20,15); (tng)
Str (tng)= (tng)numberStr.substring(2,3); (tng)
g.drawString(Str,35,18); (tng)
Str (tng)= (tng)numberStr.substring(3,4); (tng)
g.drawString(Str,45,15); (tng)
// (tng)随机产生88个干扰点Q图象中的认证码不易被其它E序探测刊W?br />Random (tng)random (tng)= (tng)new (tng)Random(); (tng)
for (tng)(int (tng)i=0;i<20;i++) (tng)
{ (tng)
int (tng)x (tng)= (tng)random.nextInt(width); (tng)
int (tng)y (tng)= (tng)random.nextInt(height); (tng)
g.drawOval(x,y,0,0); (tng)
} (tng)
// (tng)图象生效 (tng)
g.dispose(); (tng)
// (tng)输出图象到页面?br />ImageIO.write(image, (tng)"JPEG", (tng)response.getOutputStream()); (tng)
%>
code source http://jspcn.net/htmlnews/13004003160.html
]]>