JSP上传图片并生成缩略图.docx
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JSP上传图片并生成缩略图
先看看三
本例子使用了jspsmart组件进行上传,这里可以免费下载该组件
下载解压后,将jar包复制到 \WEB-INF\lib 目录后重启服务器,jspsmart即可正常使用了
1、uploadimage.jsp
<%@pagecontentType="text/html;charset=gb2312"language="java"import="java.io.*,java.awt.Image,java.awt.image.*,com.sun.image.codec.jpeg.*,
java.sql.*,com.jspsmart.upload.*,java.util.*,cn.oof.database.*,cn.oof.house.*"%>
<%
SmartUploadmySmartUpload=newSmartUpload();
longfile_size_max=4000000;
StringfileName2="",ext="",testvar="";
Stringurl="uploadfile/images/"; //应保证在根目录中有此目录的存在
//初始化
mySmartUpload.initialize(pageContext);
//只允许上载此类文件
try{
mySmartUpload.setAllowedFilesList("jpg,gif");
//上载文件
mySmartUpload.upload();
}catch(Exceptione){
%>
alert("只允许上传.jpg和.gif类型图片文件");
window.location=''''upfile.jsp'''';
<%
}
try{
com.jspsmart.upload.FilemyFile=mySmartUpload.getFiles().getFile(0);
if(myFile.isMissing()){%>
alert("请先选择要上传的文件");
window.location=''''upfile.jsp'''';
<%}
else{
//StringmyFileName=myFile.getFileName();//取得上载的文件的文件名
ext=myFile.getFileExt(); //取得后缀名
intfile_size=myFile.getSize(); //取得文件的大小
Stringsaveurl="";
if(file_size //更改文件名,取得当前上传时间的毫秒数值
Calendarcalendar=Calendar.getInstance();
Stringfilename=String.valueOf(calendar.getTimeInMillis());
saveurl=request.getRealPath("/")+url;
saveurl+=filename+"."+ext; //保存路径
myFile.saveAs(saveurl,mySmartUpload.SAVE_PHYSICAL);
//out.print(filename);
//-----------------------上传完成,开始生成缩略图-------------------------
java.io.Filefile=newjava.io.File(saveurl); //读入刚才上传的文件
Stringnewurl=request.getRealPath("/")+url+filename+"_min."+ext; //新的缩略图保存地址
Imagesrc=javax.imageio.ImageIO.read(file); //构造Image对象
floattagsize=200;
intold_w=src.getWidth(null); //得到源图宽
intold_h=src.getHeight(null);
intnew_w=0;
intnew_h=0; //得到源图长
inttempsize;
floattempdouble;
if(old_w>old_h){
tempdouble=old_w/tagsize;
}else{
tempdouble=old_h/tagsize;
}
new_w=Math.round(old_w/tempdouble);
new_h=Math.round(old_h/tempdouble);//计算新图长宽
BufferedImagetag=newBufferedImage(new_w,new_h,BufferedImage.TYPE_INT_RGB);
tag.getGraphics().drawImage(src,0,0,new_w,new_h,null); //绘制缩小后的图
FileOutputStreamnewimage=newFileOutputStream(newurl); //输出到文件流
JPEGImageEncoderencoder=JPEGCodec.createJPEGEncoder(newimage);
encoder.encode(tag); //近JPEG编码
newimage.close();
}
else{
out.print("");
out.print("alert(''''上传文件大小不能超过"+(file_size_max/1000)+"K'''');");
out.print("window.location=''''upfile.jsp;''''");
out.print("");
}
}
}catch(Exceptione){
e.toString();
}
%>
2upload.htm
请选择上传的图片
请选择上传的图片
|
二
也谈一下文件上传
在这里看到很多讨论文件上传的文章,觉得各有利敝,有些只限于上传文件,而不能同时取得文本字段值,尤其是上传多个文件比较少,现本人做这个上传文件的类最多可支持上传255个文件,同时可取得文本字段值,请各位高手指正.
文件上传类:
MoqUploadBean.java
package net.jspcn.tool;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
*
* Title:
文件上传类
* Description:
既能对文件进行上传,又能取得输入框的值,最多可同时上传255个文件
* Copyright:
Copyright (c) 2002
* Company:
Tekson
* @author 莫琼
* @version 1.0
*/
public class UploadBean {
private String[] sourceFile = new String[255]; //源文件名
private String[] suffix = new String[255]; //文件后缀名
private String canSuffix = ".gif.jpg.jpeg.png"; //可上传的文件后缀名
private String objectPath = "c:
/"; //目标文件目录
private String[] objectFileName = new String[255]; //目标文件名
private ServletInputStream sis = null; //输入流
private String[] description = new String[255]; //描述状态
private long size = 100 * 1024; //限制大小
private int count = 0; //已传输文件数目
private byte[] b = new byte[4096]; //字节流存放数组
private boolean successful = true;
private Hashtable fields = new Hashtable();
public UploadBean() {
}
//设置上传文件的后缀名
public void setSuffix(String canSuffix) {
this.canSuffix = canSuffix;
}
//设置文件保存路径
public void setObjectPath(String objectPath) {
this.objectPath = objectPath;
}
//设置文件保存路径
public void setSize(long maxSize) {
this.size = maxSize;
}
//文件上传处理程序
public void setSourceFile(HttpServletRequest request) throws IOException {
sis = request.getInputStream();
int a = 0;
int k = 0;
String s = "";
while ( (a = sis.readLine(b, 0, b.length)) !
= -1) {
s = new String(b, 0, a);
if ( (k = s.indexOf("filename="")) !
= -1) {
// 取得文件数据
s = s.substring(k + 10);
k = s.indexOf(""");
s = s.substring(0, k);
sourceFile[count] = s;
k = s.lastIndexOf(".");
suffix[count] = s.substring(k + 1);
if (canTransfer(count)) {
transferFile(count);
}
++count;
} else if ( (k = s.indexOf("name="")) !
= -1) {
// 普通表单输入元素,获取输入元素名字
String fieldName = s.substring(k+6, s.length()-3);
sis.readLine(b, 0, b.length);
StringBuffer fieldValue = new StringBuffer(b.length);
while ( (a = sis.readLine(b, 0, b.length)) !
= -1) {
s = new String(b, 0, a-2);
if ( (b[0] == 45) && (b[1] == 45) && (b[2] == 45) && (b[3] == 45) && (b[4] == 45)) {
break;
} else {
fieldValue.append(s);
}
}
fields.put(fieldName, fieldValue.toString());
}
if (!
successful)
break;
}
}
//取得表单元素值
public String getFieldValue(String fieldName) {
if (fields == null || fieldName == null) {
return null;
}
return (String) fields.get(fieldName);
}
//取得上传文件数
public int getCount() {
return count;
}
//取得目标路径
public String getObjectPath() {
return objectPath;
}
//取得源文件名
public String[] getSourceFile() {
return sourceFile;
}
//取得目标文件名
public String[] getObjectFileName() {
return objectFileName;
}
//取得上传状态描述
public String[] getDescription() {
return description;
}
//判断上传文件的类型
private boolean canTransfer(int i) {
suffix[i] = suffix[i].toLowerCase();
//这个是用来传图片的,各位可以把后缀名改掉或者不要这个条件
if (sourceFile[i].equals("") || (!
(canSuffix.indexOf("."+suffix[i])>=0))) {
description[i] = "ERR:
File suffix is wrong.";
return false;
}
else {
return true;
}
}
//上传文件转换
private void transferFile(int i) {
String x = Long.toString(new java.util.Date().getTime());
try {
objectFileName[i] = x + "." + suffix[i];
FileOutputStream out = new FileOutputStream(objectPath + objectFileName[i]);
int a = 0;
int k = 0;
long hastransfered = 0; //标示已经传输的字节数
String s = "";
while ( (a = sis.readLine(b, 0, b.length)) !
= -1) {
s = new String(b, 0, a);
if ( (k = s.indexOf("Content-Type:
")) !
= -1) {
break;
}
}
sis.readLine(b, 0, b.length);
while ( (a = sis.readLine(b, 0, b.length)) !
= -1) {
s = new String(b, 0, a);
if ( (b[0] == 45) && (b[1] == 45) && (b[2] == 45) && (b[3] == 45) && (b[4] == 45)) {
break;
}
out.write(b, 0, a);
hastransfered += a;
if (hastransfered >= size) {
description[count] = "ERR:
The file " + sourceFile[count] +
" is too large to transfer. The whole process is interrupted.";
successful = false;
break;
}
}
if (successful) {
description[count] = "Right:
The file " + sourceFile[count] +
" has been transfered successfully.";
}
out.close();
if (!
successful) {
sis.close();
File tmp = new File(objectPath + objectFileName[count]);
tmp.delete();
}
}
catch (IOException ioe) {
description[i] = ioe.toString();
}
}
public static void main(String[] args) {
System.out.println("Test OK");
}
}
文件上传调用:
MoqUpload.jsp
〈%@ page contentType="text/html; charset=GB2312" %>
〈html>
〈head>
〈title>文件上载〈/title>
〈/head>
〈body>
〈form action="MoqUploadSubmit.jsp" enctype="MULTIPART/FORM-DATA" method="post">
作者姓名:
〈input type="text" name="Author" />
〈br />
公司名称:
〈input type="text" name="Company" />
〈br />
文件描述:
〈input type="text" name="Comment" />
〈br />
选择文件1:
〈input type="file" name="filename1" />
〈br />
选择文件2:
〈input type="file" name="filename2" />
〈br />
选择文件3:
〈input type="file" name="filename3" />
〈br />
选择文件4:
〈input type="file" name="filename4" />
〈br />
〈input type="submit" value="上载" />
〈/form>
〈/body>
〈/html>
文件上传提交:
MoqUploadSubmit.jsp
〈%@ page contentType="text/html;charset=gb2312"%>
〈jsp:
useBean id="fileBean"