用java写图片

登录注册的时候都会有图片验证，这是为了防止暴力破解和恶意注册。写一个思路来实现验证图片的实现，只是一个思路，随机生成文字并没有写。

import java.awt.Color;

import java.awt.Graphics2D;

import java.awt.image.BufferedImage;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import javax.imageio.ImageIO;

public class Image {

public static void main(String[] args) throws FileNotFoundException, IOException{

    //得到图片缓冲区

    BufferedImage bi=new BufferedImage(150,70, BufferedImage.TYPE_INT_RGB);

    //得到画笔

    Graphics2D g2=(Graphics2D) bi.getGraphics();

    //填充背景

    g2.setColor(Color.WHITE);

    g2.fillRect(0, 0, 150, 70);

    //设置边框

    g2.setColor(Color.RED);

    g2.drawRect(0, 0, 149, 69);

    //向图片上写字符串
　　g2.setFont(new Font("宋体", Font.BOLD, 10));
   g2.setColor(Color.BLACK);

    g2.drawString("grup", 19, 20);

    ImageIO.write(bi, "JPEG", new FileOutputStream("f:/g.jpg"));

}

}

可以做的文章有，第一是随机生成字符，第二随机生成颜色，第三随机生成干扰线，第四随机生成字体，第五随机生成字号等等

网页登录的时候需要图片验证，今天刚好用到，把之前没有做的东西补充上来。

import java.awt.BasicStroke;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics2D;

import java.awt.image.BufferedImage;

import java.io.IOException;

import java.io.OutputStream;

import java.util.Random;

import javax.imageio.ImageIO;

public class VerifyCode {

  //设置宽

  private  int w=;

 //设置高

  private  int h=;

  private Random r=new Random();

  //字体

  private String[]  fontNames={"宋体","华文楷体","黑体","微软雅黑","楷体_GB2312"};

  //字符

  private String codes="23456789abcdefghigklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

 //背景颜色

  private Color bgColor=new Color(, , );

  //图片文字

  private String text;

  //生成随机数

   private Color randomColor(){

       int red=r.nextInt();

       int green=r.nextInt();

       int blue=r.nextInt();

       return new Color(red,green,blue);

   }

   //生成随机字体

   private Font randomFont(){

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

       String fontName=fontNames[index];

       int style=r.nextInt();

       int size=r.nextInt()+;

       return new Font(fontName, style, size);

   }

   //生成随机字符

   private char randomChar(){

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

       return codes.charAt(index);

   }

   //生成空白图片

   private BufferedImage createImage(){

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

       Graphics2D g2=(Graphics2D)image.getGraphics();

       g2.setColor(this.bgColor);

       g2.fillRect(, , w, h);

       return image;

   }

   //生成随机乱线

   private void drawLine(BufferedImage image){

       int num=;

       Graphics2D g2=(Graphics2D)image.getGraphics();

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

           int x1=r.nextInt(w);

           int y1=r.nextInt(h);

           int x2=r.nextInt(w);

           int y2=r.nextInt(h);

           g2.setStroke(new BasicStroke(1.5F));

           g2.setColor(Color.BLUE);

           g2.drawLine(x1,y1,x2,y2);

       }

   }

   //将图片输出到某个输出流中

   public static void output(BufferedImage image,OutputStream out) throws IOException{

       ImageIO.write(image, "JPEG",out);

   }

   //得到图片上的文字

   public String getText(){

       return text;

   }

   //得到图片

   public BufferedImage getImage(){

       BufferedImage image=createImage();

       Graphics2D g2=(Graphics2D)image.getGraphics();

       StringBuilder sb=new StringBuilder();

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

           String s=randomChar()+"";

           sb.append(s);

           float x=i*1.0F*w/;

           g2.setFont(randomFont());

           g2.setColor(randomColor());

           g2.drawString(s, x, h-);

       }

       this.text=sb.toString();

       drawLine(image);

       return image;

   }

}

巴特西

用java写图片

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