使用Struts2实现图片上传和拦截器

时间：2021-08-18 17:31:52

今天来分享一个图片上传

　　现在很多小项目里面基本上都有要显示图片的功能，所以呢图片上传是基本要掌握的啦

　　一般的图片上传原理就是从本地选择一张图片然后通过io流发布到服务器上去

　　上传方案基本有三种：

　　1、上传到tomcat服务器
　　2、上传到指定文件目录，添加服务器与真实目录的映射关系，从而解耦上传文件与tomcat的关系
　　文件服务器
　　3、在数据库表中建立二进制字段，将图片存储到数据库

　　一：创建数据库表并且连接数据库

　　struts_class表使用Struts2实现图片上传和拦截器

　　config.properties配置文件

　　使用Struts2实现图片上传和拦截器

　　二：dao层

　　ClassDao类

package com.crud.dao;

import java.sql.SQLException;

import java.util.List;

import com.crud.entity.Class;

import com.crud.util.BaseDao;

import com.crud.util.EntityBaseDao;

import com.crud.util.PageBean;

import com.crud.util.StringUtils;

/**

 * 班级dao方法类

 * @author Administrator

 */

public class ClassDao extends EntityBaseDao<Class>{

/**

 * 查询分页方法，查询数据公用方法

 * @param c

 * @param paBean

 * @return

 * @throws InstantiationException

 * @throws IllegalAccessException

 * @throws SQLException

 */

    public List<Class> list(Class c,PageBean paBean) throws InstantiationException, IllegalAccessException, SQLException{

        String sql="select * from struts_class where true ";

        String classname=c.getClassname();

        int cid=c.getCid();

        if (cid!=0) {

            sql +=" and cid = "+cid;

        }

        if (StringUtils.isNotBlank(classname)) {

            sql+=" and classname like '%"+classname+"%'";

        }

        return super.executeQuery(sql,paBean,Class.class);

    }

    /**

     * 新增方法

     * @param c

     * @return

     * @throws NoSuchFieldException

     * @throws SecurityException

     * @throws IllegalArgumentException

     * @throws IllegalAccessException

     * @throws SQLException

     */

    public int add(Class c) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException {

        String sql="insert into struts_class values(?,?,?)";

        return super.executeUpdate(sql, new String[] {"classname","cname","upload"},c);

    }

    /**

     * 删除方法

     * @param c

     * @return

     * @throws NoSuchFieldException

     * @throws SecurityException

     * @throws IllegalArgumentException

     * @throws IllegalAccessException

     * @throws SQLException

     */

    public int del(Class c) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException {

        String sql="delete from struts_class where cid=?";

        return super.executeUpdate(sql, new String[] {"cid"},c);

    }

    /**

     * 修改方法

     * @param c

     * @return

     * @throws NoSuchFieldException

     * @throws SecurityException

     * @throws IllegalArgumentException

     * @throws IllegalAccessException

     * @throws SQLException

     */

    public int edit(Class c) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException {

        String sql="update struts_class set classname=?,cname=?,upload=? where cid=?";

        return super.executeUpdate(sql, new String[] {"cid","classname","cname","upload"},c);

    }

}

　　三：web层　

　BaseAction类

package com.crud.web;

import javax.servlet.ServletContext;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import org.apache.struts2.interceptor.ServletRequestAware;

import org.apache.struts2.interceptor.ServletResponseAware;

/**

 * 每一个开发的子控制器要用的属性都定义在通用的action中。

 * @author Administrator

 *

 */

public class BaseAction implements ServletRequestAware, ServletResponseAware{

    /**

     * 为了传值使用

     */

    protected HttpServletResponse response;

    protected HttpServletRequest request;

    protected HttpSession session;

    protected ServletContext application;

    /**

     * 为了配置跳转页面所用

     */

    protected final static String SUCCESS = "success";

    protected final static String FAIL = "fail";

    protected final static String LIST = "list";

    protected final static String ADD = "add";

    protected final static String EDIT = "edit";

    protected final static String DETAIL = "detail";

    /**

     * 具体传值字段    后端向jsp页面传值所用字段

     */

    protected Object result;

    protected Object msg;

    protected int code;

    public Object getResult() {

        return result;

    }

    public Object getMsg() {

        return msg;

    }

    public int getCode() {

        return code;

    }

    @Override

    public void setServletResponse(HttpServletResponse arg0) {

        this.response = arg0;

    }

    @Override

    public void setServletRequest(HttpServletRequest arg0) {

        this.request = arg0;

        this.session = arg0.getSession();

        this.application = arg0.getServletContext();

    }

}

　　ClassAction类

package com.crud.web;

import java.io.File;

import java.io.IOException;

import java.sql.SQLException;

import java.util.List;

import org.apache.commons.io.FileUtils;

import com.crud.dao.ClassDao;

import com.crud.entity.Class;

import com.crud.util.PageBean;

import com.opensymphony.xwork2.ActionSupport;

import com.opensymphony.xwork2.ModelDriven;

/**

 * 班级web层

 * @author Administrator

 */

public class ClassAction extends BaseAction implements ModelDriven<Class>{

    private ClassDao cldao=new ClassDao();

    private Class cls=new Class();

    //

    private File file;

    private String fileContentType;

    private String fileFileName;   //文件名称

    public String list() {

        PageBean pageBean=new PageBean();

        pageBean.setRequest(request);

        try {

            List<Class> list = this.cldao.list(cls, pageBean);

            request.setAttribute("mylist", list);

            request.setAttribute("pageBean", pageBean);

        } catch (InstantiationException | IllegalAccessException | SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return "list";

    }

    /**

     * 直接上传图片

     * @return

     * @throws SQLException

     * @throws IllegalAccessException

     * @throws IllegalArgumentException

     * @throws SecurityException

     * @throws NoSuchFieldException

     */

    public String upload() throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException {

        try {

            //注意：在linux下是没有E盘的，linux下只有一个盘服，那么意味着当打包linux服务器的时候需要改动代码；

//        这个时候通常是这么解决的将targetPath对应目录串，配置到资源文件中，通过properties类进行读取

//        那么需要将项目发布到linux服务器的时候，只需要改变xxx.properties文件中targetPath=E:/黄婷 T221/Y2/struts2/04、拦截器与文件上传

//            实际图片的储存位置

            String targetPath="E:/黄婷 T221/Y2/struts2/04、拦截器与文件上传";

//            存到数据库中的地址

            String serverPath ="/uploads";

            FileUtils.copyFile(file, new File(targetPath+"/"+fileFileName));

//            注意：数据库存放是网络请求地址，而不是本地图片存放地址

            cls.setUpload(serverPath+"/"+fileFileName);

            this.cldao.edit(cls);

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return "toList";

    }

    /**

     * 跳转文件上传页面

     * @return

     * @throws SQLException

     * @throws IllegalAccessException

     * @throws InstantiationException

     */

    public String preupload() throws InstantiationException, IllegalAccessException, SQLException {

        Class cl = this.cldao.list(cls, null).get(0);

        request.setAttribute("cls",cl);

        return "toUpload";

    }

    /**

     * 跳转新增修改页面的公用方法

     * @return

     * @throws SQLException

     * @throws IllegalAccessException

     * @throws InstantiationException

     */

    public String preSave() throws InstantiationException, IllegalAccessException, SQLException {

        if (cls.getCid()!=0) {

            Class cl = this.cldao.list(cls, null).get(0);

            request.setAttribute("cls",cl);

        }

        return "preSave";

    }

    /**

     * 新增

     * @return

     */

    public String add() {

        try {

            result = this.cldao.add(cls);

        } catch (Exception e) {

            // TODO: handle exception

            e.printStackTrace();

        }

        return "toList";

    }

    /**

     * 删除

     * @return

     */

    public String del() {

        try {

            this.cldao.del(cls);

        } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException

                | SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return "toList";

    }

    /**

     * 修改

     * @return

     */

    public String edit() {

        try {

            this.cldao.edit(cls);

        } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException

                | SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return "toList";

    }

    @Override

    public Class getModel() {

        // TODO Auto-generated method stub

        return null;

    }

    //上传图片属性的getset方法

    public File getFile() {

        return file;

    }

    public void setFile(File file) {

        this.file = file;

    }

    public String getFileContentType() {

        return fileContentType;

    }

    public void setFileContentType(String fileContentType) {

        this.fileContentType = fileContentType;

    }

    public String getFileFileName() {

        return fileFileName;

    }

    public void setFileFileName(String fileFileName) {

        this.fileFileName = fileFileName;

    }

}

　　前端界面

　　clsList.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

    <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

    <%@taglib prefix="z" uri="/zking" %>

<!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>Insert title here</title>

</head>

<body>

<h2>班级</h2><br>

    <form action="${pageContext.request.contextPath }/sy/cls_list.action" method="post">

        班级名：<input type="text" name="classname">

              <input type="submit" value="确定">

    </form>

    <a href="${pageContext.request.contextPath }/sy/cls_preSave.action">新增</a>

    <table border="1" width="100%">

        <tr>

            <td>编号</td>

            <td>班级名</td>

            <td>学生名</td>

            <td>图片</td>

            <td>操作</td>

        </tr>

        <c:forEach items="${mylist }" var="c">

        <tr>

            <td>${c.cid }</td>

            <td>${c.classname }</td>

            <td>${c.cname}</td>

            <td>

            <img style="width: 60px;height:60px;" src="${pageContext.request.contextPath }/${c.cid }">

            </td>

            <td>

                <a href="${pageContext.request.contextPath }/sy/cls_preSave.action?cid=${c.cid}">修改</a>&nbsp;&nbsp;

                <a href="${pageContext.request.contextPath }/sy/cls_del.action?cid=${c.cid}">删除</a>&nbsp;&nbsp;

                 <a href="${pageContext.request.contextPath }/sy/cls_upload.action?cid=${c.cid}">图片上传</a>&nbsp;&nbsp;

            </td>

        </tr>

        </c:forEach>

    </table>

    <z:page pageBean="${pageBean}"></z:page>

</body>

</html>

效果图：

使用Struts2实现图片上传和拦截器

上传图片的前端页面：

　　upload.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<!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>Insert title here</title>

</head>

<body>

<form action="${pageContext.request.contextPath}/sy/cls_upload.action" method="post" enctype="multipart/form-data">

    <input type="hidden" name="cid" value="${cls.cid}"><br>

    <input type="hidden" name="classname" value="${cls.classname }"><br>

    <input type="hidden" name="cname" value="${cls.cname }"><br>

    <!-- name对应的值决定了action属性的命名 -->

    <input type="file" name="file" ><br>

    <input type="submit">

</form>

</body>

</html>

效果图：

使用Struts2实现图片上传和拦截器

修改server.xml配置文件

使用Struts2实现图片上传和拦截器

<Context path="/T224_struts/upload" docBase="E:/黄婷 T221/Y2/struts2/04、拦截器与文件上传/"/>

　　四：拦截器Interceptor

　　拦截器有两种方式

　　1.implements Interceptor

　　2.extends AbstractInterceptor

OneInterceptor 类
package com.crud.web;

import com.opensymphony.xwork2.ActionInvocation;

import com.opensymphony.xwork2.interceptor.Interceptor;

public class OneInterceptor implements Interceptor{

    @Override

    public void destroy() {

        // TODO Auto-generated method stub

    }

    @Override

    public void init() {

        // TODO Auto-generated method stub

    }

    @Override

    public String intercept(ActionInvocation arg0) throws Exception {

        // TODO Auto-generated method stub

        System.out.println("========OneInterceptor=====1");

        String invoke = arg0.invoke();

        System.out.println("============OneInterceptor============2");

        return invoke;

    }

}

TwoInterceptor类

package com.crud.web;

import com.opensymphony.xwork2.ActionInvocation;

import com.opensymphony.xwork2.interceptor.Interceptor;

public class TwoInterceptor implements Interceptor{

    @Override

    public void destroy() {

        // TODO Auto-generated method stub

    }

    @Override

    public void init() {

        // TODO Auto-generated method stub

    }

    @Override

    public String intercept(ActionInvocation arg0) throws Exception {

        // TODO Auto-generated method stub

        System.out.println("========TwoInterceptor=====1");

        String invoke = arg0.invoke();

        System.out.println("============TwoInterceptor============2");

        return invoke;

    }

}

效果图：

　　使用Struts2实现图片上传和拦截器

图解运行原理：

使用Struts2实现图片上传和拦截器

今天的分享到此结束！

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