jsp怎么上传图片？求代码！
4个回答
展开全部
Apache commons-fileupload是一个很好的文件上传工具，最近使用commons-fileupload实现了图片的上传及显示，可将图片保存在指定的文件夹中，也可以将图片存放在数据库，并支持四种常用的图片格式:jpg,png,gif,bmp。
首先，跟上传一般文件一样，需要写一个servlet来处理上传的文件，你可以修改保存路径或选择将图片保存在数据库中，只需要做简单的修改就行了，servlet代码如下：
FileUploadServlet.java
java 代码 package com.ek.servlet; import java.awt.image.BufferedImage; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.util.Iterator; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import com.ek.image.ImageUtil; public class FileUploadServlet extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; private static String filePath = ""; /** * Destruction of the servlet.
*/ public void destroy() { super.destroy(); // Just puts "destroy" string in log // Put your code here } /** * The doPost method of the servlet.
* * This method is called when a form has its tag value method equals to * post. * * @param request * the request send by the client to the server * @param response * the response send by the server to the client * @throws ServletException * if an error occurred * @throws IOException * if an error occurred */ public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { res.setContentType("text/html; charset=UTF-8"); DiskFileItemFactory factory = new DiskFileItemFactory(); // maximum size that will be stored in memory factory.setSizeThreshold(4096); // the location for saving data that is larger than getSizeThreshold() factory.setRepository(new File(filePath)); ServletFileUpload upload = new ServletFileUpload(factory); // maximum size before a FileUploadException will be thrown upload.setSizeMax(1000000); try { List fileItems = upload.parseRequest(req); Iterator iter = fileItems.iterator(); // Get the file name String regExp = ".+\\\\(.+\\.?())$"; Pattern fileNamePattern = Pattern.compile(regExp); while (iter.hasNext()) { FileItem item = (FileItem) iter.next(); if (!item.isFormField()) { String name = item.getName(); long size = item.getSize(); if ((name == null || name.equals("")) && size == 0) continue; Matcher m = fileNamePattern.matcher(name); boolean result = m.find(); if (result) { try { // String type = // m.group(1).substring(m.group(1).lastIndexOf('.')+1); InputStream stream = item.getInputStream(); ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] b = new byte[1000]; while (stream.read(b) > 0) { baos.write(b); } byte[] imageByte = baos.toByteArray(); String type = ImageUtil.getImageType(imageByte); if (type.equals(ImageUtil.TYPE_NOT_AVAILABLE)) throw new Exception("file is not a image"); BufferedImage myImage = ImageUtil .readImage(imageByte); // display the image ImageUtil.printImage(myImage, type, res .getOutputStream()); // save the image // if you want to save the file into database, do it here // when you want to display the image, use the method printImage in ImageUtil item.write(new File(filePath + "\\" + m.group(1))); stream.close(); baos.close(); } catch (Exception e) { e.printStackTrace(); } } else { throw new IOException("fail to upload"); } } } } catch (IOException e) { e.printStackTrace(); } catch (FileUploadException e) { e.printStackTrace(); } } /** * Initialization of the servlet.
* * @throws ServletException * if an error occure */ public void init() throws ServletException { // Change the file path here filePath = getServletContext().getRealPath("/"); } 请打勾满意，原创谢谢
首先，跟上传一般文件一样，需要写一个servlet来处理上传的文件，你可以修改保存路径或选择将图片保存在数据库中，只需要做简单的修改就行了，servlet代码如下：
FileUploadServlet.java
java 代码 package com.ek.servlet; import java.awt.image.BufferedImage; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.util.Iterator; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import com.ek.image.ImageUtil; public class FileUploadServlet extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; private static String filePath = ""; /** * Destruction of the servlet.
*/ public void destroy() { super.destroy(); // Just puts "destroy" string in log // Put your code here } /** * The doPost method of the servlet.
* * This method is called when a form has its tag value method equals to * post. * * @param request * the request send by the client to the server * @param response * the response send by the server to the client * @throws ServletException * if an error occurred * @throws IOException * if an error occurred */ public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { res.setContentType("text/html; charset=UTF-8"); DiskFileItemFactory factory = new DiskFileItemFactory(); // maximum size that will be stored in memory factory.setSizeThreshold(4096); // the location for saving data that is larger than getSizeThreshold() factory.setRepository(new File(filePath)); ServletFileUpload upload = new ServletFileUpload(factory); // maximum size before a FileUploadException will be thrown upload.setSizeMax(1000000); try { List fileItems = upload.parseRequest(req); Iterator iter = fileItems.iterator(); // Get the file name String regExp = ".+\\\\(.+\\.?())$"; Pattern fileNamePattern = Pattern.compile(regExp); while (iter.hasNext()) { FileItem item = (FileItem) iter.next(); if (!item.isFormField()) { String name = item.getName(); long size = item.getSize(); if ((name == null || name.equals("")) && size == 0) continue; Matcher m = fileNamePattern.matcher(name); boolean result = m.find(); if (result) { try { // String type = // m.group(1).substring(m.group(1).lastIndexOf('.')+1); InputStream stream = item.getInputStream(); ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] b = new byte[1000]; while (stream.read(b) > 0) { baos.write(b); } byte[] imageByte = baos.toByteArray(); String type = ImageUtil.getImageType(imageByte); if (type.equals(ImageUtil.TYPE_NOT_AVAILABLE)) throw new Exception("file is not a image"); BufferedImage myImage = ImageUtil .readImage(imageByte); // display the image ImageUtil.printImage(myImage, type, res .getOutputStream()); // save the image // if you want to save the file into database, do it here // when you want to display the image, use the method printImage in ImageUtil item.write(new File(filePath + "\\" + m.group(1))); stream.close(); baos.close(); } catch (Exception e) { e.printStackTrace(); } } else { throw new IOException("fail to upload"); } } } } catch (IOException e) { e.printStackTrace(); } catch (FileUploadException e) { e.printStackTrace(); } } /** * Initialization of the servlet.
* * @throws ServletException * if an error occure */ public void init() throws ServletException { // Change the file path here filePath = getServletContext().getRealPath("/"); } 请打勾满意，原创谢谢
本回答由网友推荐
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
