jsp上传图片，并加以显示

上传图片代码如下,首先是页面:

Jsp代码

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index1.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
这是一个图片上传程序,在上传的时候form必须加上 enctype="multipart/form-data"
否则则会有报错的情况发生,action类里新建一个demo对象,对应数据库里一条新的记录
大概方法就是这样,如果有需要的话还可以再扩展,图片上传代码完毕
<form id="form1" name="form1" action="text.do" method="post" enctype="multipart/form-data">
<input type="file" id="userImage" name="userImage">
<input type="text" id="mytext" name="mytext">
<input type="submit" value="确定">
</form>
</body>
</html>

传递至textAction这个类中

我用的是springside的框架,这个框架中的action默认执行的方法是list,其它不变

下边是action类

Java代码

package com.mytext.action;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import org.apache.commons.io.output.ByteArrayOutputStream;
import org.springframework.beans.factory.annotation.Autowired;
import org.springside.modules.web.struts2.CRUDActionSupport;
import com.mytext.entity.Demo;
import com.mytext.service.DemoServices;
import com.sun.xml.internal.ws.util.ByteArrayBuffer;
@SuppressWarnings("serial")
public class TextAction extends CRUDActionSupport<Demo>{
@Autowired
private DemoServices demoServices;
private Demo demo;
private String mytext;
private File userImage;
@Override
public String delete() throws Exception {
// TODO Auto-generated method stub
return null;
}
@Override
public String list() throws Exception {
if(userImage==null)
{
return "try";
}
prepareModel();
try {
BufferedImage tt = ImageIO.read(userImage);
demo.setImage(toByte(tt));
demo.setName(mytext);
<span style="background-color: #ffffff; color: #000000;">demoServices.save(demo);</span>
} catch (Exception e) {
System.out.println("保存失败");
return "try";
}
return "try";
//demoServices.getAllDemo();
}
//转化为流
private byte[] toByte(BufferedImage image) throws IOException
{
ByteArrayOutputStream cc = new ByteArrayOutputStream();
ImageIO.write(image, "jpg", cc);
return cc.toByteArray();
}
@Override
protected void prepareModel() throws Exception {
// TODO Auto-generated method stub
demo = new Demo();
}
@Override
public String save() throws Exception {
// TODO Auto-generated method stub
return null;
}
public Demo getModel() {
// TODO Auto-generated method stub
return demo;
}
public File getUserImg() {
return userImage;
}
public void setUserImg(File userImage) {
this.userImage = userImage;
}
public String getMytext() {
return mytext;
}
public void setMytext(String mytext) {
this.mytext = mytext;
}
public File getUserImage() {
return userImage;
}
public void setUserImage(File userImage) {
this.userImage = userImage;
}
}

保存方法,是springside独有的一个东西,不必深究,可跟据自己的框架来保存对象至数据库中

下边是我数据库的实体类

Java代码

package com.mytext.entity;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* Demo entity.
*
* @author MyEclipse Persistence Tools
*/
@Entity
@Table(name = "demo")
<span style="color: #000000;">public class Demo extends IdEntity implements java.io.Serializable</span>
{
private String name;
private byte[] image;
private String shouming;
public Demo() {
}
public Demo(String name, byte[] image) {
this.name = name;
this.image = image;
}
@Column(name = "name", length = 15)
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
@Column(name = "image")
public byte[] getImage() {
return this.image;
}
public void setImage(byte[] image) {
this.image = image;
}
@Column(name="shouming", length = 225)
public String getShouming() {
return shouming;
}
public void setShouming(String shouming) {
this.shouming = shouming;
}
}

继承了一个共用的类,用于id主键生成

Java代码

package com.mytext.entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;
//所有实体类的基类,实现id的自增长
@MappedSuperclass
public class IdEntity {
private Long id;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}

我用的是mysql数据库,测试己成功,action方法中继承的是springside框架中的action类,不用这个框架的不必深究,

以下是在jsp页面中读出图片的方法

先是jsp页面

Java代码

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<span style="color: #000000;"><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:set var="ctx" value="${pageContext.request.contextPath}"/>
<%@ taglib prefix="s" uri="/struts-tags" %></span>
<!-- 注意标签库的异入>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>jquery编辑器实例</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<link rel="stylesheet" href="${ctx }/edit/common.css" type="text/css" media="screen" />
<script type="text/javascript" src="${ctx }/edit/jquery/jquery-1.3.2.min.js"></script>
<script type="text/javascript" src="${ctx }/edit/xheditor.js"></script>
</head>
<body>
一般模式的edit
<form method="post" action="edit.do">
<h3>xhEditor demo1 : 默认模式</h3>
xheditor(默认完全):<br />
<textarea id="elm1" name="elm1" class="xheditor" rows="12" cols="80" style="width: 80%">
<p>请输入信息</p>
</textarea>
<br>
<input type="submit" value="试验中的jquery编辑器">
</form>
开始从数据库里边读出来一个图片<br>
<span style="color: #ff0000;"> <span style="color: #000000;"><img src="<s:url action="edit!getUserImgFromByte.do">
<s:param name="id" value="5"></s:param>
</s:url>" height="300px" width="300px"> </span>
</span>
</body>
</html>

可人为控制图看大小,上边的是一个类似于fck的jquery编辑器

action方法

Java代码

package com.mytext.action;
import java.io.IOException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springside.modules.web.struts2.CRUDActionSupport;
import org.springside.modules.web.struts2.Struts2Utils;
import com.mytext.entity.Demo;
import com.mytext.service.DemoServices;
public class EditAction extends CRUDActionSupport<Demo>{
/**
*
*/
@Autowired
private DemoServices demoSdrvices;
private Long id;
private String elm1;
private Demo demo;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
@Override
public String delete() throws Exception {
// TODO Auto-generated method stub
return null;
}
@Override
public String list() throws Exception {
id=1L;
getModel();
demo.setShouming(elm1);
demoSdrvices.save(demo);
return "showedit";
}
@Override
protected void prepareModel() throws Exception {
// TODO Auto-generated method stub
}
@Override
public String save() throws Exception {
// TODO Auto-generated method stub
return null;
}
public Demo getModel() {
if(id==null)
{
demo=new Demo();
}
else
{
demo = demoSdrvices.get(id);
}
return demo;
}
public String getElm1() {
return elm1;
}
public void setElm1(String elm1) {
this.elm1 = elm1;
}
public Demo getDemo() {
return demo;
}
public void setDemo(Demo demo) {
this.demo = demo;
}
<span style="color: #000000;">public String getUserImgFromByte() throws Exception {
getModel();
HttpServletResponse response = Struts2Utils.getResponse();
ServletOutputStream out = null;
try {
response.setContentType("image/jpeg");
out = response.getOutputStream();
out.write(demo.getImage());
out.flush();
} catch (Exception e) {
} finally {
try {
if (null != out)
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}</span>
}

转载自：

http://wineer200.iteye.com/blog/404303

来源：CSDN

作者：果冻酱

链接：https://blog.csdn.net/jiangguodong0215/article/details/44965593

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