简单实现Java验证码功能

简单实现Java验证码功能

今晚看到网上有关验证码的实现的代码，很早就想写一个了，感觉验证码挺有意思的，于是就写了一个，然而后来一直加载不出图片。尝试了很多方法，后来终于解决了，原来是我项目里面的 web.xml中没有部署servlet的映射，web.xml如下图：

运行效果如下：

代码如下：

package model;

import javax.imageio.ImageIO;

import java.awt.*;

import java.awt.image.BufferedImage;

import java.io.IOException;

import java.io.OutputStream;

import java.util.Random;

/**

* Created by Petty on 2017/5/4.

*/

public class VCode {

private int w; //图片宽

private int h;//图片高

private Color bgColor = new Color(240,240,240);//背景色

private Random random = new Random();//随机对象

//设置字体范围

private String[] fontNames = {"宋体","华文楷体","黑体","华文新魏","华文隶书","微软雅黑","楷体"};

//设置字体样式范围

private int[] fontstyle = {0,1,2,3};

//设置字号范围

private int[] fontSizes = {24,25qsICwwQdwZ,26,27,28};

//设置所有字符串范围

private String codes="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

//无参数构造函数

public VCode(){

}

//带宽和高的构造函数

public VCode(int w,int h){

this.w = w;

this.h = h;

}

//返回一张背景图片

private BufferedImage createImage(){

/**

* 1.创建图片 2.设置背景色

*/

//创建图片

BufferedImage img = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);

//设置背景色

Graphics g = img.getGraphics();

g.setColor(bgColor);

g.fillRect(0,0,w,h);

return img;

}

// 随机返回字体颜色

private Color randomColor() {

int r = random.nextInt(256);

int g = random.nextInt(256);

int b = random.nextInt(256);

return new Color(r, g, b);

}

//随机返回字体样式

private Font randomFont(){

//随机生成字体下标，随机从给定的范围内获取一个字体

int index = random.nextInt(fontNames.length);

String name = fontNames[index];

//随机生成字体样式下标，随即从给定的范围内获取一个字体样式

index = random.nextInt(fontstyle.length);

int style = fontstyle[index];

//随机生成字体大小下标，随机从给定的范围内获取一个字体大小

index = random.nextInt(fontSizes.length);

int size = fontSizes[index];

return new Font(name,style,size);

}

//随机返回字体内容

private String randomChar(){

int index = random.nextInt(codes.length());

return codes.charAt(index)+"";

}

//随机返回几条干扰线

private void getLine(BufferedImage img){

//设置干扰线的宽度为1.5倍宽，随机画五条

Graphics2D g =(Graphics2D) img.getGraphics();

g.setColor(Color.BLACK);

g.setStroke(new BasicStroke(1.5f));

for(int i=0;i<5;i++){

int x1 = random.nextInt(w);

int y1 = random.nextInt(h);

int x2 = random.nextInt(w);

int y2 = random.nextInt(h);

g.drawLine(x1,y1,x2,y2);

}

}

//用户调用该方法获取图片

public BufferedImage getImage(){

/**

* 随机生成字符0-9A-Za-z,设置字体，字号，是否粗体，字符颜色，都是随机的

*/

BufferedImage img = createImage();

this.getLine(img);

//获取画笔

Graphics g = img.getGraphics();

//画内容

for(int i=0;i<4;i++){

g.setColor(this.randomColor());//获取随机颜色

g.setFont(this.randomFont());//获取随机字体

g.drawString(this.randomChar(),w/4*i,h-5);//获取字符串随机内容

}

return img;

}

//用户调用该方法保存图片到本地

public void saveImage(BufferedImage img, OutputStream ous){

try {

ImageIO.write(img,"JPEG",ous);

} catch (IOException e) {

e.printStackTrace();

}

}

}

package model;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import jahttp://vax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.awt.image.BufferedImage;

import java.io.IOException;

/**

* Created by Petty on 2017/5/4.

*/

@WebServlet(name = "BServlet")

public class BServlet extends HttpServlet {

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

VCode v = new VCode(70,35);

BufferedImage img = v.getImage();

v.saveImage(img,response.getOutputStream());

}

public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

VCode v = new VCode(70,35 );

BufferedImage img = v.getImage();

v.saveImage(img,response.getOutputStream());

}

}

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