Struts2.0 图片的上传与下载的实现

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图片上传的JSP页面，即register.jsp。此处要注意：要上传图片，必须要在form中加入此代码，enctype="multipart/form-data"，否则，上传无效的。

<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%><%@taglib uri="/struts-tags" prefix="s"%><!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>User Register</title></head><body><s:form action="Register.action" method="post" theme="simple"enctype="multipart/form-data"><table align="left" width="50%" border="0" cellpadding="0"cellspacing="0"><tr><td align="right"><s:text name="user.username"></s:text>:</td><td align="left" height="30" valign="middle"><s:textfieldname="username" key="user.username"></s:textfield></td></tr><tr><td align="right"><s:text name="user.password"></s:text>:</td><td align="left" height="30" valign="middle"><s:textfieldname="password" key="user.password"></s:textfield></td></tr><tr><td align="right" height="30" valign="middle"><s:textname="user.register.sex"></s:text>:</td><td align="left"><s:radio name="sex"list="%{#{'1':'男','0':'女'}}" value="1" theme="simple"></s:radio></td></tr><tr><td align="right" height="30" valign="middle"><s:textname="user.register.upload"></s:text>:</td><td align="left"><s:file label="上传" theme="simple"name="upload" /></td></tr><tr><td align="right"><s:submit class="btn" value="完成"></s:submit></td><td align="center"><s:reset class="btn" value="重置"></s:reset></td></tr></table></s:form></body></html>

RegisterAction.java中，通过get、set方法来获取表单传来的值即可。此处注意upload类型为File即可。

package com.struts.action;import java.io.File;import java.util.List;import com.opensymphony.xwork2.ActionSupport;import com.struts.bean.UserBean;import com.struts.dao.UserInfoDAO;public class RegisterAction extends ActionSupport {private String username="";private String password="user";private int sex;         private File upload;                public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public int getSex() {return sex;}public void setSex(int sex) {this.sex = sex;}public File getUpload() {return upload;}public void setUpload(File upload) {this.upload = upload;}public String execute() throws Exception {if(username.equalsIgnoreCase("")){return "input";}UserInfoDAO userDAO=new UserInfoDAO();int result=userDAO.registerUser(username,password,sex,upload);if (result != 0){return "success";}else{return "error";}}}

UserInfoDAO.java中的registerUser（）代码实现。数据库中upload的字段类型为：mediumblob。所以，此处用setBlob。

public int registerUser(String username, String password, int sex,File upload) throws SQLException, IOException {//FileInputStream in = null;conn = ConnectDB.getConn();//System.out.println(upload);//in = new FileInputStream(upload);String strSql = "insert into userlist(username,sex,upload,password)values(?,?,?,?)";pstmt = conn.prepareStatement(strSql);pstmt.setString(1, username);pstmt.setInt(2, sex);//pstmt.setBinaryStream(3, in, in.available());pstmt.setBlob(3, new FileInputStream(upload));pstmt.setString(4, password);result = pstmt.executeUpdate();return result;}

以上为图片的上传。很简单吧。

下面即为图片的下载了。

首先，我们要实现一个人员在查看详细信息时，要求显示这个人的头像。即：userdetails.jsp页面。

<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%><%@taglib uri="/struts-tags" prefix="s"%><%@page import="com.struts.bean.UserBean"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><%UserBean userBean = (UserBean) request.getAttribute("userBean");String username = userBean.getUsername();int sex = userBean.getSex();%><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>User Details</title></head><body><s:form action="UserInfo.action" method="post" theme="simple"><table align="left" width="30%" border="1" cellpadding="0"cellspacing="0"><tr><td align="right"><s:text name="user.username"></s:text>:</td><td align="left" height="30" valign="middle"><%=username%></td></tr><tr><td align="right"><s:text name="user.register.sex"></s:text>:</td><td align="left" height="30" valign="middle"><%if (sex == 0) {%><s:text name="女"></s:text> <% } else { %> <s:text name="男"></s:text> <% } %></td></tr><tr><td align="right"><s:text name="user.register.upload"></s:text>:</td><td><img name="upload"src="GetPhoto.action?username=<%=username%>" width="128"height="128" /></td></tr><tr><td align="right"><s:submit class="btn" value="返回"></s:submit></td></tr></table></s:form></body></html>

以上的userBean,即把，人员的详细信息封装在UserBean中。通过在后台中的UserDetailsAction.java中，以set、get方法来传到前台来。如下：

package com.struts.action;import com.struts.bean.UserBean;import com.struts.dao.UserInfoDAO;public class UserDetailsAction {private String username;private UserBean userBean;private int sex;public int getSex() {return sex;}public void setSex(int sex) {this.sex = sex;}public UserBean getUserBean() {return userBean;}public void setUserBean(UserBean userBean) {this.userBean = userBean;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String execute() throws Exception {UserInfoDAO userDetails = new UserInfoDAO();UserBean userBean = userDetails.queryUserDetails(username);this.userBean = userBean;return "userdetails";}}

具体后台的queryUserDetails（）方法的实现就不贴出来了，很简单的了。

现在来看userdetails.jsp页面中的<img name="upload"
src="GetPhoto.action?username=<%=username%>" width="128"
height="128" />

以下即是GetPhotoAction.java的实现。

package com.struts.action;import java.io.InputStream;import com.opensymphony.xwork2.ActionSupport;import com.struts.dao.UserInfoDAO;public class GetPhotoAction extends ActionSupport{private String username;public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String execute() throws Exception {return "success";}  public InputStream getPhoto() throws Exception{  UserInfoDAO userDetails = new UserInfoDAO();  return userDetails.getPhoto(username);  }}

上段代码中getPhoto()方法的实现。此段方法放在UserInfoDAO.java中。

public InputStream getPhoto(String username) throws SQLException,IOException {conn = ConnectDB.getConn();String sql = "select upload from userlist where username=?";pstmt = conn.prepareStatement(sql);pstmt.setString(1, username);rs = pstmt.executeQuery();if (rs.next()) {Blob bo = rs.getBlob("upload");BufferedInputStream ins = new BufferedInputStream(bo.getBinaryStream());int count = (int) bo.length();byte[] bt = new byte[count];ins.read(bt, 0, count);return new ByteArrayInputStream(bt);}return null;}

struts.xml中的代码，如下：

<action name="GetPhoto" class="com.struts.action.GetPhotoAction"><result name="success" type="stream"><param name="contentType">image/jpeg</param><param name="inputName">photo</param><param name="bufferSize">1024</param></result></action>

struts.xml中的<param name="inputName">photo</param> 此处的photo要与GetPhotoAction.java中getPhoto()方法中相对应。

以上即为简单的实现，还有很多不足的地方。

例如只能上传jpg格式的图片，下载的时候图片的名称也不能为中文（此处需要用到过滤器来实现即可）。

之所以写这些博客，主要是供自己以后学习的哈。

不过，也能帮助到其他人的吧。我在实现之前，一直有找资料。

发现网上有好多都是一样的，同样一段实现代码被copy来copy去的。

汗，也许是自己笨吧，别人的代码不太适合自己现在的这个框架，所以，自己多花了点时间，实现了一个哈。

如有不足之处，还望大家多多指教。共同进步哈。O(∩_∩)O~