Servlet
Package com.htpo.net;
Import Java.awt.Color;
Import Java.awt.Font;
Import Java.awt.Graphics2D;
Import Java.awt.image.BufferedImage;
Import java.io.IOException;
Import Java.io.PrintWriter;
Import Java.util.Random;
Import javax.servlet.ServletException;
Import Javax.servlet.ServletOutputStream;
Import Javax.servlet.http.HttpServlet;
Import Javax.servlet.http.HttpServletRequest;
Import Javax.servlet.http.HttpServletResponse;
Import Com.sun.image.codec.jpeg.JPEGCodec;
Import Com.sun.image.codec.jpeg.JPEGImageEncoder;
public class Testget extends HttpServlet {
/**
* Constructor of the object.
*/
Public Testget () {
Super ();
}
public static final char[] CHARS = {' 2 ', ' 3 ', ' 4 ', ' 5 ', ' 6 ', ' 7 ', ' 8 ',
' 9 ', ' 0 ', ' A ', ' Q ', ' w ', ' E ', ' R ', ' T ', ' g ', ' D ', ' S ', ' w ', ' G ',
' H '};//A dictionary of random characters
public static random random = new random ();//random number
public static String getrandomstring () {
Caching of characters
StringBuffer buf = new StringBuffer ();
for (int i = 0; i < 6; i++) {//Loop six times
Buf.append (Chars[random.nextint (chars.length));
}
return buf.tostring ();
}
public static Color Getrandomcolor () {
return new Color (Random.nextint (255), Random.nextint (255),
Random.nextint (255));
}
public static color Getreversecolor (color c) {
return new Color (255-c.getred (), 255-c.getgreen (),
255-c.getblue ());
}
/**
* Destruction of the servlet. <br>
*/
public void Destroy () {
Super.destroy (); Just puts "destroy" string in log
Put Your code here
}
/**
* The Doget method of the servlet. <br>
*
* This method was called when a form had its tag value method equals to get.
*
* @param request
* The request send by the client to the server
* @param response
* The response send by the server to the client
* @throws servletexception
* If an error occurred
* @throws IOException
* If an error occurred
*/
public void doget (HttpServletRequest request, httpservletresponse response)
Throws Servletexception, IOException {
/*
* Response.setcontenttype ("text/html"); String re =
* Request.getparameter ("username"); System.out.println (re); PrintWriter
* out = Response.getwriter ();
*
*//Response.sendredirect ("test.jsp"); String s =
* "[{id:1, pid:0, Name:" Pnode
* 1 ", open:true},{id:11, pid:1, Name:" Pnode
* One "},{id:111, Pid:11, Name:" Leaf node
* 111 "},{id:112, Pid:11, Name:" Leaf node
* "},{id:113, Pid:11, Name:" Leaf node
* 113 "},{id:114, Pid:11, Name:" Leaf node
* "},{id:12, Pid:1, Name:" Pnode "},{id:121, Pid:12, Name:" Leaf
* Node 121 "},{id:122, Pid:12, Name:" Leaf node
* 122 "},{id:123, Pid:12, Name:" Leaf node
* 123 "},{id:124, Pid:12, Name:" Leaf node
* 124 "},{id:13, Pid:1, Name:" Pnode 13-no
* Child ", isparent:true},{Id:2, pid:0, Name:" Pnode
* 2 "},{id:21, Pid:2, Name:" Pnode
* + ", open:true},{id:211, pid:21, Name:" Leaf node
* 211 "},{id:212, pid:21, Name:" Leaf node
* 212 "},{id:213, pid:21, Name:" Leaf node
* 213 "},{id:214, pid:21, Name:" Leaf node
* 214 "},{id:22, Pid:2, Name:" Pnode "},{id:221, pid:22, Name:" Leaf
* Node 221 "},{id:222, pid:22, Name:" Leaf node
* 222 "},{id:223, pid:22, Name:" Leaf node
* 223 "},{id:224, pid:22, Name:" Leaf node
* 224 "},{id:23, Pid:2, Name:" Pnode "},{id:231, pid:23, Name:" Leaf
* Node 231 "},{id:232, pid:23, Name:" Leaf node
* 232 "},{id:233, pid:23, Name:" Leaf node
* 233 "},{id:234, pid:23, Name:" Leaf node
* 234 "},{Id:3, pid:0, Name:" Pnode 3-no Child ", isparent:true}]";
* Out.write (s);
*
* OUT.PRINTLN (
* "<! DOCTYPE HTML public \ "-//W3C//DTD HTML 4.01 transitional//en\" > ");
* OUT.PRINTLN ("<HTML>");
* OUT.PRINTLN ("* OUT.PRINTLN ("<BODY>"); Out.print ("This is");
* Out.print (This.getclass ()); Out.println (", using the GET method");
* OUT.PRINTLN ("</BODY>"); Out.println ("</HTML>");
*
* Out.flush (); Out.close ();
*/
String s = request.getparameter ("username");
System.out.println (s);
Response.setcontenttype ("Image/jpeg");//Set the type of output
String randomstring = getrandomstring ();//Gets the character set returned
Request.getsession (True). SetAttribute ("RandomString", randomstring);
int with = 100;
int hight = 30;//the size of the resulting picture
Color color = Getrandomcolor ();//For background color
Color reverse = getreversecolor (color);//For foreground color
BufferedImage bi = new BufferedImage (with, hight,
BUFFEREDIMAGE.TYPE_INT_RGB);//Create a color picture
Graphics2D g = bi.creategraphics ();//Get to drawing object
G.setfont (New Font (FONT.SANS_SERIF, Font.Bold, 16));//Set Font
G.setcolor (color);//Set color
G.fillrect (0, 0, with, hight);//Draw background
G.setcolor (reverse);//Set color
g.DrawString (RandomString, 18, 20);//Draw random characters
for (int i = 0, n = random.nextint (+), I < n; i++) {//Draw up to 100 noise points
G.drawrect (Random.nextint (with), Random.nextint (hight), 1, 1);//random noise point
}
Servletoutputstream out = Response.getoutputstream ();
Convert picture format
JPEGImageEncoder encoder = Jpegcodec.createjpegencoder (out);
Encoder.encode (BI);//encode a picture
Out.flush ();//Output
}
/**
* The DoPost method of the servlet. <br>
*
* This method was called when a form have its tag value method equals to
* Post.
*
* @param request
* The request send by the client to the server
* @param response
* The response send by the server to the client
* @throws servletexception
* If an error occurred
* @throws IOException
* If an error occurred
*/
/**
* Initialization of the servlet. <br>
*
* @throws servletexception
* If an error occurs
*/
public void Init () throws Servletexception {
Put Your code here
}
}
---------------------------------------
Jsp
function Reloadimage () {
Document.getelementbyidx_x_x ("Btn"). Disabled=false;
Document.getelementbyidx_x_x ("Identity"). src= ' testget?ts= ' +new Date (). GetTime ();
}
function Yanzheng () {
}
</script>
<input type= "button" id= "btn" value= "Change Picture" onclick= "reloadimage ()"/>
Servlet Verification Code Generation
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