文章目录
图片上传
今天在上次增删查改的基础上把图片上传完善,要达到的效果:把图片上传到服务器并保存到本地,并且在jsp页面展示出来
三种上传方案
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
今天我们介绍的是第二种方式,并且了解它的原理
实现代码
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="${pageContext.request.contextPath}/sy/clz_Upload.action" method="post" enctype="multipart/form-data">
<input type="hidden" name="cid" value="${clz.cid }" /><br/>
<input type="hidden" name="cname" value="${clz.cname }" /><br/>
<input type="hidden" name="cteacher" value="${clz.cteacher }" /><br/>
<input type="file" name="file" />
<input type="submit" />
</form>
</body>
</html>
同样在我们的struts.xml中配置好
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
"http://struts.apache.org/dtds/struts-2.5.dtd">
<struts>
<package name="sy" extends="base" namespace="/sy">
<action name="/demo_*" class="com.xy.web.DemoAction" method="{1}" >
<result name="rs">/rs.jsp</result>
</action>
<action name="/stack_*" class="com.xy.test.DemoAction" method="{1}">
<result name="rs">/rs.jsp</result>
</action>
<action name="/clz_*" class="com.xy.crud.web.ClazzAction" method="{1}">
<result name="list">/clzList.jsp</result>
<result name="preSave">/clzEdit.jsp</result>
<result name="toList" type="redirectAction" >/clz_list</result>
<result name="toUpload">/upload.jsp</result>
</action>
</package>
</struts>
ClazzAction控制器,我们先是用struts的完成了图片上传,然后再增加增加写了一个缓冲流的文件上传
1、先定义好文件的属性,文件类型,文件名
2、接收文件和选择保存文件的路径
3、修改数据库中的图片路径字段,改成服务器能读到的路径
package com.xy.crud.web;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import org.apache.commons.io.FileUtils;
import com.opensymphony.xwork2.ModelDriven;
import com.xy.crud.dao.ClazzDao;
import com.xy.crud.entity.Clazz;
import com.xy.crud.util.BaseAction;
import com.xy.crud.util.PageBean;
public class ClazzAction extends BaseAction implements ModelDriven<Clazz> {
private ClazzDao clzDao = new ClazzDao();
private Clazz clz = new Clazz();
private File file;
private String fileContentType;
private String fileFileName;
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;
}
/**
* 上传图片
* @return
*/
public String Upload() {
try {
// 注意:在Linux下没有E盘的,Linux下只有哦一个盘符,那么意味着,当打包到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类进行动态读取
// 那么当需要将项目发布到Linux服务器的时候,只需要改变xxx.properties文件中的targetPath=/xxx/img/
// 实际图片存储的位置
String targetDir="F:/img";
// 存到数据中的地址
String serverPath="/uploads";
// FileUtils.copyFile(file, new File(targetDir+"/"+fileFileName));
copyBufFile(file, new File(targetDir+"/"+fileFileName));
// 注意:数据库存放的是网络请求地址,而不是本地储存地址
clz.setPic(serverPath+"/"+fileFileName);
this.clzDao.edit(clz);
} catch (Exception e) {
e.printStackTrace();
}
return "toList";
}
/**
* FileUtils.copyFile的底层,并且通过缓冲区进行了增强
* @param source
* @param target
* @throws FileNotFoundException
*/
public void copyBufFile(File source,File target) throws FileNotFoundException {
BufferedInputStream in=new BufferedInputStream(new FileInputStream(source));
BufferedOutputStream out=new BufferedOutputStream(new FileOutputStream(target));
byte[] bbuf=new byte[1024];
int len=0;
try {
while((len = in.read(bbuf))!=-1) {
out.write(bbuf,0,len);
}
in.close();
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 跳转文件上传页面
* @return
*/
public String preUpload() {
if(clz.getCid()!=0) {
Clazz z;
try {
z = this.clzDao.list(clz, null).get(0);
request.setAttribute("clz", z);
} catch (IllegalArgumentException | IllegalAccessException | InstantiationException | SQLException e) {
e.printStackTrace();
}
}
return "toUpload";
}
/**
* 查所有
*
* @return
* @throws SQLException
* @throws InstantiationException
* @throws IllegalAccessException
* @throws IllegalArgumentException
*/
public String list() throws IllegalArgumentException, IllegalAccessException, InstantiationException, SQLException {
PageBean pageBean = new PageBean();
pageBean.setRequest(request);
List<Clazz> list = this.clzDao.list(clz, pageBean);
request.setAttribute("clzList", list);
request.setAttribute("pageBean", pageBean);
return "list";
}
/**
* 跳转新增修改页面的公用方法
*
* @return
* @throws SQLException
* @throws InstantiationException
* @throws IllegalAccessException
* @throws IllegalArgumentException
*/
public String preSave() throws IllegalArgumentException, IllegalAccessException, InstantiationException, SQLException {
if(clz.getCid()!=0) {
Clazz z = this.clzDao.list(clz, null).get(0);
request.setAttribute("clz", z);
}
return "preSave";
}
public String edit() throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException {
this.clzDao.edit(clz);
return "toList";
}
/**
* 新增方法
* @return
*/
public String add() {
try {
result=this.clzDao.add(clz);
} catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException
| SQLException e) {
e.printStackTrace();
}
return "toList";
}
public String del() {
try {
this.clzDao.del(clz);
} catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException
| SQLException e) {
e.printStackTrace();
}
return "toList";
}
@Override
public Clazz getModel() {
return clz;
}
}
最后在你的本地servers的server.xml配置好全局上下文
path是网络地址,docBase是真实地址
<Context path="/T224_struts/upload" docBase="E:/temp/T224/"/>
拦截器Interceptor
两种实现拦截器的方法
implements Interceptor
extends AbstractInterceptor
与filter的区别:先过filter再过interceptor
定义拦截器,在你的struts.xml文件中加上interceptor,并且配置好服务
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
"http://struts.apache.org/dtds/struts-2.5.dtd">
<struts>
<package name="sy" extends="base" namespace="/sy">
<interceptors>
<interceptor name="one" class="com.xy.crud.interceptor.OneInterceptor"></interceptor>
<interceptor name="two" class="com.xy.crud.interceptor.TwoInterceptor"></interceptor>
</interceptors>
<action name="/demo_*" class="com.xy.web.DemoAction" method="{1}" >
<result name="rs">/rs.jsp</result>
</action>
<action name="/stack_*" class="com.xy.test.DemoAction" method="{1}">
<result name="rs">/rs.jsp</result>
</action>
<action name="/clz_*" class="com.xy.crud.web.ClazzAction" method="{1}">
<interceptor-ref name="one"></interceptor-ref>
<interceptor-ref name="two"></interceptor-ref>
<result name="list">/clzList.jsp</result>
<result name="preSave">/clzEdit.jsp</result>
<result name="toList" type="redirectAction" >/clz_list</result>
<result name="toUpload">/upload.jsp</result>
</action>
</package>
</struts>