java 生成图片并在页面显示

imageBean:

package com.c.elmer.util.image;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;

public class ImageBean {


	int width = 100;
	int height = 100;

	int imagewidth = 100;
	int imageheight = 100;

	Color defaultBG = new Color(217,233,243);

	BufferedImage image = null;
	Graphics2D g = null;

	public BufferedImage getImage() {
		g.dispose();
		image.flush();
		return image;
	}

	public ImageBean(int width,int height){
		this.width = width ;
		this.height = height;
		image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		g = image.createGraphics();
		g.setBackground(defaultBG);
		g.setColor(new Color(140,201,253));
	}

	public ImageBean(int width,int height,int imgwidth,int imgheight){
		this.width = width ;
		this.height = height;
		this.imagewidth = imgwidth;
		this.imageheight = imgheight;

		this.height = imgheight*width/imgwidth;

		image = new BufferedImage(this.width, this.height, BufferedImage.TYPE_INT_RGB);
		g = image.createGraphics();
		g.clipRect(0, 0, this.width, this.height);
		g.setBackground(defaultBG);
		g.setColor(new Color(242,242,242));
		g.fillRect( 0,0,this.width,this.height);
		g.setColor(new Color(210,224,242));
		g.drawRect(1, 1, this.width - 2, this.height - 2);
//		System.out.println(g.getBackground().toString());
	}

	/**
	 * <p>取比</p>
	 * @param a
	 * @return
	 */
	public int percentXY(int x,int width,int imgwidth){
		return (imgwidth*x) / width;
	}


	public ImageBean setBgColor(Color c){
		g.setBackground(c);
		return this;
	}


	public ImageBean set3dRect(boolean is3d){
		if(is3d){
			g.draw3DRect(0, 0, width - 1, height - 1, true);
		}
		return this;
	}

	public ImageBean setText(String text,String style){
		g.setColor(Color.red);
		if(style.equals("top")){
			g.drawString(text,  0, 12);
		}
		if(style.equals("center")){
			g.drawString(text, this.width - this.width/2-30, this.height/2);
		}
		if(style.equals("bottom")){
			g.drawString(text, this.width - this.width/2-30, this.height-20);
		}
		return this;
	}

	public ImageBean addRect(int x,int y,int width,int height,Color c,String text){
		x = percentXY(x,this.imagewidth,this.width);
		y =  percentXY(y,this.imageheight,this.height);
		int w = percentXY(width,this.imagewidth,this.width);
		int h =  percentXY(height,this.imageheight,this.height);

		g.setColor(new Color(14,159,241));
		g.setBackground(defaultBG);
		g.drawRect( x , y , w, h);
		g.drawString(text, x + 2, y + 10);
		return this;
	}
	public ImageBean fillRect(int x,int y,int width,int height,Color c,String text){
		x = percentXY(x,this.imagewidth,this.width);
		y =  percentXY(y,this.imageheight,this.height);
		int w = percentXY(width,this.imagewidth,this.width);
		int h =  percentXY(height,this.imageheight,this.height);

		g.setColor(c);
		g.setBackground(defaultBG);
		g.fillRect( x , y , w, h);
		g.drawString(text, x + 2, y + 20);
		return this;
	}

	public int getImageheight() {
		return imageheight;
	}

	public void setImageheight(int imageheight) {
		this.imageheight = imageheight;
	}

	public int getImagewidth() {
		return imagewidth;
	}

	public void setImagewidth(int imagewidth) {
		this.imagewidth = imagewidth;
	}



}

java servlet:

package com.ibox.util;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.c.elmer.util.image.ImageBean;
import com.provideo.ibox.model.dao.ModelDAO;
import com.provideo.ibox.model.forms.ModelLocationsBean;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class CreateImage extends HttpServlet {

	public CreateImage() {
		super();
	}

	public void destroy() {
		super.destroy();
	}

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

	Color getRandColor(int fc, int bc) {// 给定范围获得随机颜色
		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

	public BufferedImage getImage(){
		int width = 100;
		int height = 100;
		BufferedImage bi = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		Graphics2D g = bi.createGraphics();
		g.setBackground(Color.BLUE);
		g.clearRect(0, 0, width, height);
		g.setColor(Color.RED);
		g.dispose();
		bi.flush();
		return bi;
	}

	private void createImage(OutputStream out) {
		int width = 100;
		int height = 100;
		int allwidth = 1024;
		int allheight = 888;
		BufferedImage bi = 
			new ImageBean(width,height,allwidth,allheight)
			.setBgColor(new Color(217,233,243))
			.set3dRect(true)
			.addRect(22, 222,288,234 , Color.red, "")
			.addRect(400, 200,300,500, Color.green, "")
			.addRect(2, 500,400,444 , Color.BLUE, "")
			.getImage();
		/*
		BufferedImage bi = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		Graphics2D g = bi.createGraphics();
		// set background:
		g.setBackground(new Color(217,233,243));
		g.setColor(new Color(140,201,253));
		g.clearRect(0, 0, width, height);
		g.drawRect(0, 0, 44, 33);
		g.drawArc(32, 45, 78, 54, 45, 222);

//		g.drawOval(12, 12, 45, 45);
//		g.drawRoundRect(21, 5, 48, 55, 55, 55);

		g.setColor(new Color(242,242,242));
		g.drawString("Power Ibox", 12, 93);

		g.draw3DRect(0, 0, width - 1, height - 1, true);
		// set fore color:
		g.setColor(Color.RED);
		// start draw:
		g.drawLine(0, 66, 100, 66);
		g.drawLine(66, 0, 66, 66);
		// end draw:
		g.dispose();
		bi.flush();
		// encode:
		*/

		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
		JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bi);
		param.setQuality(1.0f, false);
		encoder.setJPEGEncodeParam(param);
		try {
			encoder.encode(bi);
		} catch (IOException ioe) {
			ioe.printStackTrace();
		}
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		ModelDAO dao = new ModelDAO();
		int tid = 246 ;
		if(request.getParameter("tid") != null){
			tid = Integer.parseInt(request.getParameter("tid"));
		}
		int width = 100;
		if(request.getParameter("width") != null){
			width = Integer.parseInt(request.getParameter("width"));
		}
		String model = "default";
		if(request.getParameter("model") != null){
			model = request.getParameter("model");
		}
		String tname = "";
		List list = dao.getModelLocationById(tid);

		int height = 100;
		int allwidth = 1024;
		int allheight = 888;
		BufferedImage bi = null;
		ImageBean imgbean = null;
		for(int i=0;i<list.size();i++){
			ModelLocationsBean bean = (ModelLocationsBean) list.get(i);
			String wh = bean.getWh();
			int w = Integer.parseInt( wh.split("x")[0]);
			int h = Integer.parseInt( wh.split("x")[1]);
			imgbean = new ImageBean(width,height,w,h);
			tname = bean.getTname();
			break;
		}

		for(int i=0;i<list.size();i++){
			ModelLocationsBean bean = (ModelLocationsBean)list.get(i);
			String location = bean.getLocation();
			String[] ls = location.split("x");

			int w = Integer.parseInt(ls[0]);

			String l = ls[1];

			l = l.replace("-", "+-").replace("+", " ");
			String[] htl = l.split(" ");

			int h = Integer.parseInt( htl[0]);
			int top = Integer.parseInt( htl[1]);
			int left = Integer.parseInt( htl[2]);

			String type = bean.getType();
			String text = "";
			Color c = new Color(217,233,243);
			if(type.equals("1")){
				c = new Color(147,165,180);
				text = "video";
			}
			else if(type.equals("2")){
				c = new Color(248,165,180);
				text = "pic";
			}
			else if(type.equals("3")){
				c = new Color(176,165,122);
				text = "flash";
			}
			else if(type.equals("4")){
				c = new Color(219,222,223);
				text = "text";
			}
			else if(type.equals("5")){
				c = new Color(219,237,225);
				text = "url";
			}
			else if(type.equals("6")){
				c = new Color(147,165,180);
				text = "live";
			}
			else if(type.equals("7")){
				c = new Color(248,165,122);
				text = "ppt";
			}

			if(model.equals("default")){
				c = Color.red;
				imgbean.setText(tname, "top");
				imgbean.addRect(top, left, w, h, c, "");
			}
			if(model.equals("text")){
				c = Color.red;
				imgbean.addRect(top, left, w, h, c, text);
			}
			if(model.equals("name")){
				c = Color.red;
				imgbean.setText(tname, "top");
				imgbean.addRect(top, left, w, h, c, text);
			}
			if(model.equals("empty")){
				imgbean.addRect(top, left, w, h, c, "");				
			}
			if(model.equals("fill")){
				imgbean.setText(tname, "top");
				imgbean.fillRect(top, left, w, h, c, "");				
			}
		}
		bi = imgbean.getImage();

		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(response.getOutputStream());
		JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bi);
		param.setQuality(1.0f, false);
		encoder.setJPEGEncodeParam(param);
		try {
			encoder.encode(bi);
		} catch (IOException ioe) {
			ioe.printStackTrace();
		}


//		response.setContentType("image/jpeg");
//		createImage(response.getOutputStream());

		/*
		//阻止生成的页面内容被缓存，保证每次重新生成验证码  
		response.setContentType("image/jpeg");  

		BufferedImage image = getImage();

		ImageIO.write(image,"JPEG",response.getOutputStream()); */
	}

	public void init() throws ServletException {
		// Put your code here
	}

}

web.xml:

  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>CreateImage</servlet-name>
    <servlet-class>com.ibox.util.CreateImage</servlet-class>
  </servlet>

页面：

<img id="iboxitem<%=i %>" width="70" src="${pageContext.request.contextPath%20}/servlet/CreateImage?tid=<%=bean.getOid()%20%>&model=text" name="tempimgs" style="-moz-opacity:0.5; filter:alpha(opacity=50);cursor:hand;" onmouseover="imgMouseOver(this)" onmouseout="imgMoused(this);" onclick="tempImgClicked(<%=bean.getOid() %>,this,'<%=bean.getTname() %>')" />

最后效果：
这是从个人项目中剪下来的，（代码也是,不同需求可以更简单)
[img]http://dl.iteye.com/upload/attachment/133549/0dec6623-fe92-3617-ba5e-e3cf568e625e.jpg[/img]

原文链接：https://blog.csdn.net/wuzijingaip/article/details/83438821