Controller return picture in SPRINGMVC (go)

This article transferred from: http://blog.csdn.net/u011637069/article/details/51112187

SPRINGMVC the controller by returning Modelandview and then finding the corresponding view through Viewresolver. Can return JSP can return map and so on.

What to do when I do a captcha picture, let me perplexed, use struts2 to return a byte stream in action, and then configure the type of result in the Struts.xml file as stream. But how to deal with it in the SPRINGMVC?

Below I will explain how to generate the captcha image in Springmvc in code:

First, the CAPTCHA image generation tool class:

Imageutil.java

 PackageOrg.qxl.onlinexam.util;ImportJava.awt.Color;ImportJava.awt.Font;ImportJava.awt.Graphics;ImportJava.awt.image.BufferedImage;ImportJava.io.FileOutputStream;Importjava.io.IOException;ImportJava.io.OutputStream;ImportJava.util.Random;ImportJavax.imageio.ImageIO; Public Final classImageutil {//Verification Code Character Set    Private Static Final Char[] chars = {         ' 0 ', ' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ', ' 6 ', ' 7 ', ' 8 ', ' 9 ',         ' A ', ' B ', ' C ', ' d ', ' e ', ' f ', ' g ', ' h ', ' I ', ' j ', ' K ', ' l ', ' m ', ' n ',        ' O ', ' P ', ' Q ', ' R ', ' s ', ' t ', ' u ', ' V ', ' w ', ' x ', ' y ', ' z ',        ' A ', ' B ', ' C ', ' D ', ' E ', ' F ', ' G ', ' H ', ' I ', ' J ', ' K ', ' L ', ' M ', ' N ',         ' O ', ' P ', ' Q ', ' R ', ' S ', ' T ', ' U ', ' V ', ' W ', ' X ', ' Y ', ' Z '}; //Number of characters    Private Static Final intSIZE = 4; //number of interference lines    Private Static Final intLINES = 5; //width    Private Static Final intWIDTH = 80; //Height    Private Static Final intHEIGHT = 40; //Font Size    Private Static Final intFont_size = 30; /*** Generate random verification code and image * Object[0]: captcha string; * object[1]: Captcha picture. */     Public Staticobject[] CreateImage () {StringBuffer sb=NewStringBuffer (); //1. Create a blank imageBufferedImage image =Newbufferedimage (WIDTH, HEIGHT, Bufferedimage.type_int_rgb); //2. Get the picture brushGraphics graphic =Image.getgraphics (); //3. Set the brush colorGraphic.setcolor (Color.light_gray); //4. Draw a rectangular backgroundGraphic.fillrect (0, 0, WIDTH, HEIGHT); //5. Draw random charactersRandom ran =NewRandom ();  for(inti = 0; I <SIZE; i++) {            //take random character index            intn =Ran.nextint (chars.length); //Set Random ColorsGraphic.setcolor (Getrandomcolor ()); //Set Font sizeGraphic.setfont (NewFont (NULL, Font.Bold +Font.Italic, font_size)); //stooped charactersgraphic.drawstring (Chars[n]+ "", I * width/size, HEIGHT*2/3); //Record characterssb.append (Chars[n]); }        //6. Draw the interference line         for(inti = 0; i < LINES; i++) {            //Set Random ColorsGraphic.setcolor (Getrandomcolor ()); //Random Draw LineGraphic.drawline (Ran.nextint (width), ran.nextint (HEIGHT), ran.nextint (width), ran.next        Int (HEIGHT)); }        //7. Return verification code and pictures        return Newobject[]{sb.tostring (), image}; }    /*** Random Color extraction*/     Public StaticColor Getrandomcolor () {Random ran=NewRandom (); Color Color=NewColor (Ran.nextint (256), Ran.nextint (), Ran.nextint (256)); returncolor; }         Public Static voidMain (string[] args)throwsIOException {object[] objs=createimage (); BufferedImage Image= (bufferedimage) objs[1]; OutputStream OS=NewFileOutputStream ("D:/1.png"); Imageio.write (Image,"PNG", OS);    Os.close (); }}

Then, write the controller

    //generate a Captcha picture@RequestMapping ("/valicode.do")//corresponding/user/valicode.do request     Public voidValicode (HttpServletResponse response,httpsession session)throwsexception{//Create a picture with the picture tool//The first parameter is the generated verification code, the second parameter is the resulting pictureobject[] Objs =Imageutil.createimage (); //Save verification Code to sessionSession.setattribute ("Imagecode", objs[0]); //output a picture to a browserBufferedImage image = (bufferedimage) objs[1]; Response.setcontenttype ("Image/png"); OutputStream OS=Response.getoutputstream (); Imageio.write (Image,"PNG", OS); }

Results:

Since then, it's all over. Isn't it easy?

Controller return picture in SPRINGMVC (go)