1. 程式人生 > >Servlet從本機讀取一個圖片,並顯示在html頁面

Servlet從本機讀取一個圖片,並顯示在html頁面

1、工具類

    //工具類
	package com.JavaBean;  
      
    import java.awt.image.BufferedImage;  
    import java.io.FileInputStream;  
    import java.io.IOException;  
      
    import javax.imageio.ImageIO;  
    import javax.servlet.ServletOutputStream;  
    import javax.servlet.http.HttpServletResponse;  
      
    public class ImgUtil {  
      
        public static final String JPG = "jpg";  
        public static final String PNG = "png";  
        public static final String BMP = "bmp";  
        public static final String GIF = "gif";  
      
        /**  
         * 在servlet中呼叫該方法, jsp頁面中img標籤的src指向該servlet, 則會顯示圖片  
         *   
         * @param response  
         * @param path  
         * @param isResponseClose  
         */  
        public static void showImage(HttpServletResponse response, String path, boolean isResponseClose) {  
            try {  
                ServletOutputStream outStream = response.getOutputStream();// 得到向客戶端輸出二進位制資料的物件  
                FileInputStream fis = new FileInputStream(path); // 以byte流的方式開啟檔案  
                // 讀資料  
                byte data[] = new byte[1000];  
                while (fis.read(data) > 0) {  
                    outStream.write(data);  
                }  
                fis.close();  
                response.setContentType("image/*"); // 設定返回的檔案型別  
                outStream.write(data); // 輸出資料  
                if (isResponseClose) {  
                    outStream.close();  
                }  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
      
        /**  
         * 在servlet中呼叫該方法, jsp頁面中img標籤的src指向該servlet, 則會顯示圖片  
         *   
         * @param response  
         * @param data  
         * @param isResponseClose  
         */  
        public static void showImage(HttpServletResponse response, byte[] data, boolean isResponseClose) {  
            try {  
                ServletOutputStream outStream = response.getOutputStream();// 得到向客戶端輸出二進位制資料的物件  
                // 讀資料  
                outStream.write(data);  
                response.setContentType("image/*"); // 設定返回的檔案型別  
                outStream.write(data); // 輸出資料  
                if (isResponseClose) {  
                    outStream.close();  
                }  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
      
        /**  
         * 在servlet中呼叫該方法, jsp頁面中img標籤的src指向該servlet, 則會顯示圖片  
         *   
         * @param response  
         * @param image  
         * @param imgType  
         * @param isResponseClose  
         */  
        public static void showImage(HttpServletResponse response, BufferedImage image, String imgType, boolean isResponseClose) {  
            try {  
                ImageIO.write(image, imgType, response.getOutputStream());  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
      
    }  

2、Servlet
package com.JavBean;  
  
import java.io.IOException;  
import com.JavaBean.ImgUtil; //匯入前面的工具類
import javax.servlet.ServletException;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
  
public class ImgServlet extends HttpServlet {  
  
    private static final long serialVersionUID = 3728441236122484282L;  
  
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {  
        doPost(request, response);  
    }  
  
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {  
        String imgPath = request.getParameter("imgPath");// 輸出圖片的型別的標誌  
        if(null != imgPath && !"".equals(imgPath.trim())) {  
            ImgUtil.showImage(response, imgPath, true);    
        }  
  
    }  
}

3、html頁面
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">  
<html xmlns="http://www.w3.org/1999/xhtml">  
    <head>  
        <title>顯示圖片</title>  
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">  
        <meta http-equiv="description" content="this is my page">  
        <meta http-equiv="content-type" content="text/html; charset=UTF-8">  
    </head>  
  
    <body style="overflow-x: hidden;overflow-y: hidden;margin: 0;padding: 0;">  
    </body>  
</html>     
<script>   
function request(paras){   
	var url = location.href;    
	var paraString = url.substring(url.indexOf("?")+1,url.length).split("&");    
	var paraObj = {}    
	for (i=0; j=paraString[i]; i++){    
		paraObj[j.substring(0,j.indexOf("=")).toLowerCase()] = j.substring(j.indexOf("=")+1,j.length);    
	}    
	var returnValue = paraObj[paras.toLowerCase()];    
	if(typeof(returnValue)=="undefined"){    
		return "";    
	}else{    
		return returnValue;    
	}    
}   
  
window.onload=function() {  
	var len=document.documentElement.clientWidth-40;  
	var hit=document.documentElement.clientHeight-10;  
	var addr=request('addr');   
	document.writeln("<img src='/ImgServlet?imgPath="+addr+"' border=0 width='"+len+"' height='"+hit+"'/>");  
}  
  
</script>