1、文件上传
1. upload概念
uoload : 文件上传
客户端通过表单的文件域file, 把客户端的文件上传到服务器的硬盘上
2. 页面要求
(1)必须要有文件域 : <input type="file">
(2)表单提交的方式为 : method = "post"
(3)表单的enctype为 : multipart/form-data
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="/LianXi/FileUpLoadServlet" method="post" enctype="multipart/form-data">
<label>用户姓名 : </label>
<input type="text" name="uname"><br>
<label>用户密码 : </label>
<input type="password" name="upwd"><br>
<label>用户头像 : </label>
<input type="file" name="uphoto"><br>
<input type="submit" value="提交">
</form>
</body>
</html>
3. servlet
package com.java.filter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.UUID;
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 org.apache.commons.io.IOUtils;
import com.java.entity.User;
public class UploadServlet extends HttpServlet {
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//方式一 : 失败
//表单当中设置了enctype="multipart/form-data", 那么设置编码集和获取参数的方法失效
//resp.getWriter().print(req.getParameter("uname") + "," + req.getParameter("upwd") + "," + req.getParameter("uphoto"));
//方式二 : 当多部件表单提交时, 只能使用request的字节输入来接受数据
/*
* InputStream in = req.getInputStream(); byte[] buff = new byte[1024*1024]; int
* n = in.read(buff); String message = new String(buff,0,n,"utf-8");
* resp.getWriter().print(message);
*/
//方式三 :
DiskFileItemFactory factory = new DiskFileItemFactory();//创建工厂对象
ServletFileUpload upload = new ServletFileUpload(factory);//创建一个多部件表单解析器对象, 并关联工厂对象
User user = new User();
FileOutputStream fos = null;
try {
List<FileItem> list = upload.parseRequest(req);
for (FileItem fileItem : list) {
//获取文件域对象的文件类型, 普通组件为null
// System.out.println("getContentType-->" + fileItem.getContentType());
// System.out.println("getFieldName-->" + fileItem.getFieldName());//获取组件的name值
// System.out.println("getName-->" + fileItem.getName());//获取文件域的文件名
// System.out.println("getSize-->" + fileItem.getSize());//获取数据的字节格式
// System.out.println("getString-->" + fileItem.getString());//获取数据的字符串
// System.out.println("isFormField-->" + fileItem.isFormField());//判断是否为普通组件
// System.out.println("getInputStream-->" + fileItem.getInputStream());//获取数据的字节输入流
// System.out.println("========================================================");
if(fileItem.isFormField()) {//是普通组件
String fieldName = fileItem.getFieldName();
String fieldValue = fileItem.getString();
//解决文字乱码方法一 : 先对乱码进行iso-8859-1编码, 再用正确的编码解码
//fieldValue = new String(fieldValue.getBytes("iso-8859-1"), "utf-8");
//方法二 : 取值时就调用可设置编码集的方法
fieldValue = fileItem.getString("utf-8");
//判断是哪个值
if("uname".equals(fieldName)) {
user.setUname(fieldValue);
}else if("upwd".equals(fieldName)){
user.setUpwd(fieldValue);
}
}else {//是文件域
//组件名称和文件输入流
String fieldName = fileItem.getFieldName();
String fileName = fileItem.getName();
InputStream in = fileItem.getInputStream();
//把文件保存在硬盘中
//File descFile = new File("C:\\Users\\DreamBack\\Desktop\\Java\\imgs\\" + UUID.randomUUID() + fileName);
//fos = new FileOutputStream(descFile);
//
//把文件存入服务器
String path = req.getServletContext().getRealPath("/imgs/" + UUID.randomUUID() + fileName);
File descFile = new File(path);
fos = new FileOutputStream(descFile);
byte[] buff = new byte[1024];
// int n;
// while((n=in.read(buff))!=-1) {
// fos.write(buff, 0, n);
// }
//调用方法进行传输
IOUtils.copy(in, fos);
System.out.println(descFile.getName());
user.setUphoto(descFile.getName());//设置文件路径给user
//C:\Users\DreamBack\Desktop\Java\JavaEclipse\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\Day1014Upload\imgs
}
}
} catch (FileUploadException e) {
throw new RuntimeException(e);
}finally {
if(fos != null) {
fos.close();
}
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
2、文件下载
1 download概念
download:文件下载：
客户端点击页面的超链接 把服务器端的文件下载并保存到客户端的硬盘上
2 jsp
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>文件下载</title>
</head>
<body>
<h1>文件下载</h1>
<a href="<c:url value='/FileDownLoadServlet?fileName=1.jpg'/>">图片1</a><br/>
<a href="<c:url value='/FileDownLoadServlet?fileName=2.jpg'/>">图片2</a><br/>
<a href="<c:url value='/FileDownLoadServlet?fileName=3.jpg'/>">图片3</a><br/>
<a href="<c:url value='/FileDownLoadServlet?fileName=4.jpg'/>">图片4</a><br/>
<a href="<c:url value='/FileDownLoadServlet?fileName=5.jpg'/>">图片5</a><br/>
<a href="<c:url value='/FileDownLoadServlet?fileName=6.jpg'/>">图片6</a><br/>
</body>
</html>
3 servlet
package servlet;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URLEncoder;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class FileDownLoadServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 设置编码集UTF-8
request.setCharacterEncoding("UTF-8");
// 获取文件名字
String fileName = request.getParameter("fileName");
// 获取imgs的路径：
String path = request.getServletContext().getRealPath("/imgs");
// 绑定原文件路径和名称
File yuanFile = new File(path, fileName);
// 创建输入流 读取源文件的信息
FileInputStream fin = new FileInputStream(yuanFile);
// 根据文件名字 获取文件的大类型
String type = request.getServletContext().getMimeType(fileName);
// 设置两个响应头
// 响应头ContentType指定响应内容的类型
response.setHeader("Content-Type", type);
// 响应头Content-Disposition形式 指定以附件形式保存响应的信息
response.setHeader("Content-Disposition", "attachment;filename=" + (URLEncoder.encode(fileName, "utf-8")));
// 一边通过输入流读取信息 一边通过response的输出流写出去
OutputStream out = response.getOutputStream();
byte[] arr = new byte[1024];
int n;
while ((n = fin.read(arr)) != -1) {
out.write(arr, 0, n);
}
fin.close();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
3、验证码
1.java实现画验证码
package util;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.imageio.ImageIO;
public class YanZhengMa {
public static void main(String[] args) {
System.out.println(getYanZhengMa());
}
public static String getYanZhengMa() {
String path;
String message = "3456789abcdefghjkmnpqstuvwxy";
// 1.在内存中开辟空间 用于画画
BufferedImage bi = new BufferedImage(200, 50, BufferedImage.TYPE_INT_BGR);
// 2.获取画笔
Graphics2D g = (Graphics2D) bi.getGraphics();
// 3.涂染料 画背景
g.setColor(Color.WHITE);
// 4.画背景:长方形
g.fillRect(2, 2, 195, 45);
// 5.画主题 随机四五个字符
String yzm = "";
for (int i = 0; i < 4; i++) {
yzm += message.charAt((int) (Math.random() * (message.length())));
}
// 6.给字符设置文字样式
Font font = new Font(null, Font.BOLD, 34);
g.setFont(font);
// 7.把字符串中的所有字符画到画布上
for (int i = 0; i < yzm.length(); i++) {
// 8.笔蘸墨
g.setColor(new Color((int) (Math.random() * 100 + 120), (int) (Math.random() * 100 + 120),
(int) (Math.random() * 100 + 120)));
// 9.写字
g.drawString(yzm.charAt(i) + "", i * 45 + 10, 40);
}
// 10.画干扰线
for (int i = 0; i < (int) (Math.random() * 5 + 5); i++) {
g.setColor(new Color((int) (Math.random() * 50 + 120), (int) (Math.random() * 50 + 120),
(int) (Math.random() * 50 + 120)));
g.drawLine(2, (int) (Math.random() * 43 + 2), 195, (int) (Math.random() * 43 + 2));
}
try {
// 11.创建流与目的文件关联
path = "F:\\" + (int) (Math.random() * 100 + 120) + ".jpg";
File muDiFile = new File(path);
FileOutputStream fout = new FileOutputStream(muDiFile);
// 12.把内存中BufferedImage中的信息通过输出流写道目的文件中
ImageIO.write(bi, "JPEG", fout);
fout.close();
} catch (IOException e) {
throw new RuntimeException(e);
}
return path;
}
}
2. web实现验证码
- 页面的img的src请求servlet 生成验证码图片
- servlet需要把验证码保存到session中 用于登录判断输入的验证码是否正确
- 登录的servlet中通过判断请求参数的验证码和session中·的验证码是否一致 一致才登录成功
jsp:login.jsp
<%@page import="util.YanZhengMa"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>用户登录</title>
</head>
<body>
<h1>用户登录表单</h1>
<c:if test="${not empty requestScope.message}">
<h3>${requestScope.message}</h3>
</c:if>
<form method="get" action="<c:url value='/YZ_servlet' />">
<table>
<tr>
<th>用户名称：</th>
<td><input type="text" name="uname"/></td>
</tr>
<tr>
<th>用户密码：</th>
<td><input type="password" name="upwd"/></td>
</tr>
<tr>
<th><img src="<c:url value='/YZM_servlet'/>" id="img_yzm"/></th>
<td><input type="text" name="uyzm"/></td>
</tr>
<tr>
<th colspan="2"><INPUT type="reset" value="重置"/>
<INPUT type="submit" value="登录"/></th>
</tr>
</table>
</form>
<!-- 添加js事件 点击图片 图片更新 -->
<script type="text/javascript">
//文档加载完毕 给img_yzm注册点击事件
window.onload=function(){
//获取img_yzm
var oimg=document.getElementById("img_yzm");
oimg.onclick=function(){
//请求时 为了不使用缓存 添加一个无用的参数 参数值每次不同即可
this.src="<c:url value='/YZM_servlet?n='/>"+Math.random();
}
}
</script>
</body>
</html>
servlet:生成验证码
package servlet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class YZM_servlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String message = "3456789abcdefghjkmnpqstuvwxy";
// 1 在内存中开辟空间 用于画画
BufferedImage bin = new BufferedImage(148, 33, BufferedImage.TYPE_INT_RGB);
// 2 获取画笔
Graphics2D g = (Graphics2D) bin.getGraphics();
// 3 涂染料 画背景
g.setColor(Color.WHITE);
// 4 画背景:长方形
g.fillRect(2, 2, 150, 35);
// 5 画主题 随机四五个字符
String str = "";
for (int i = 0; i < 4; i++) {
str += message.charAt((int) (Math.random() * message.length()));
}
// 6 给字符设置文字样式
Font font = new Font(null, Font.BOLD, 20);
g.setFont(font);
// 7 把字符串中的所有字符画到画布上
for (int i = 0; i < str.length(); i++) {
// 8 笔蘸墨
g.setColor(new Color((int) (Math.random() * 100 + 120), (int) (Math.random() * 100 + 120),
(int) (Math.random() * 100 + 120)));
// 9 写字
g.drawString(str.charAt(i) + "", i * 40 + 5, 22);
}
// 10 画干扰线
for (int i = 0; i < (int) (Math.random() * 5 + 5); i++) {
g.setColor(new Color((int) (Math.random() * 50 + 120), (int) (Math.random() * 50 + 120),
(int) (Math.random() * 50 + 120)));
g.drawLine(2, (int) (Math.random() * 43 + 2), 195, (int) (Math.random() * 43 + 2));
}
// 11 把验证码的信息装入session
request.getSession().setAttribute("yzm", str);
// 12 把内存中图片的信息通过respionse的输出流 响应给客户端
ImageIO.write(bin, "JPEG", response.getOutputStream());
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
servlet:判断验证码登录
package servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import util.YanZhengMa;
public class YZ_servlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
// 获取请求参数
String uname = request.getParameter("uname");
String upwd = request.getParameter("upwd");
String uyzm = request.getParameter("uyzm");
String message = "";
// 判断参数的正确
if (!uname.equals("张三")) {
message = "用户名错误！";
} else if (!upwd.equals("123")) {
message = "用户密码错误！";
} else {
String yzm = request.getSession().getAttribute("yzm") + "";
if (!uyzm.equals(yzm)) {
message = "验证码错误！";
}
}
// 如果message有值 登录失败 回到登录页面
if (!message.isEmpty()) {
request.setAttribute("message", message);
request.getRequestDispatcher("/login.jsp").forward(request, response);
return;
}
response.getWriter().print("<font color='red'>" + uname + "登录成功！</font>");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
