使用Struts2实现图片上传和拦截器

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

　　config.properties配置文件

　　

　　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：

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：

修改server.xml配置文件

<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：

　　

图解运行原理：

今天的分享到此结束！