Struts2上传图片到Mysql数据库中,以及显示到页面

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来源：http://blog.csdn.net/yjflinchong/article/details/5941138

数据库的创建：

数据库名叫：csdn

表名：savepicture

DROP TABLE IF EXISTS `savepicture`;
CREATE TABLE `savepicture` (
`id` int(10) NOT NULL auto_increment,
`picture` blob NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

好动手创建工程啦：

其实非常简单，一看就明白。把需要的包该导的都导了就行了。

接着我们创建上传页面：

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>File Upload</title>
<link href="<%=request.getContextPath()%>/css/fileupload.css"
   rel="stylesheet" type="text/css">
</head>
<body bgcolor="#cccccc">
<div style="padding-top: 30px; padding-left: 30px">
   <fieldset
    style="width: 600px; border-color: #000000; padding-left: 10px">
    <legend>
     <font size="-1" color="#000000"><b>上传图片</b> </font>
    </legend>
    <div class="ErrorDiv">
       <s:fielderror/>
     <s:actionerror/>
    </div>
    <s:form action="fileUpload.action" method="post" theme="simple"
     enctype="multipart/form-data">
     <table border="1" width="500px">
      <tr>
       <td class="tableTDCenter">
        图片路径：
       </td>
       <td class="tableTDCenter">
        <s:file name="file" cssClass="fileInput"/>
       </td>
      </tr>
      <tr>
       <td class="tableTDCenter" colspan="2">
        <s:submit value="提交" cssClass="button"></s:submit>
       </td>
      </tr>
     </table>
    </s:form>
   </fieldset>
</div>
</body>
</html>

很简单，就是个上传框和按钮，别的没有了。至于一些css就是稍微的装饰装饰，一会也在下面写上！

上传成功的画面：

下面我们看看struts2的配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.custom.i18n.resources"
value="messageResource" />
<constant name="struts.i18n.encoding" value="UTF-8" />
<package name="default" extends="struts-default">
     
<action name="fileUpload"
   class="org.csdn.action.FileUploadAction">
   <interceptor-ref name ="defaultStack" />
   <interceptor-ref name ="fileUpload">
                <param name ="allowedTypes">
                    image/bmp,image/png,image/gif,image/jpg
                </param>
                <param name="maximumSize">404800</param>
            </interceptor-ref>
   <result name="success">/uploadSuccess.jsp</result>
   <result name="input">/fileUpload.jsp</result>
</action>
   
<action name="outPicture"
   class="org.csdn.action.OutPictureAction">
   <result name="input">/uploadSuccess.jsp</result>
</action>
</package>
</struts>

至于里面的东西是什么，大家肯定根据名字一看就知道了。

上面我引用了messageResource资源文件，为了显示错误消息。比如上传类型不正确，超过大小，以及上传失败。

下面就是资源文件中的内容。

struts.messages.error.content.type.not.allowed=The file you uploaded is not a image
struts.messages.error.file.too.large=this picutre is too large
fileupload.fail=file upload is fail

如果没有重新定义上面两个key的话，显示的会是struts2默认的错误消息，很是难看，也乱起八糟的。所以我重新定义了。

接着我们就开始写上传和输出图片的action，以及相关的类信息

上传的action：

import java.io.File;
import java.util.List;
import org.csdn.service.FileUploadService;
import org.csdn.vo.Picture;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
/**
* @author closewubq
*/
public class FileUploadAction extends ActionSupport {
private static final long serialVersionUID = 1L;
private File file;
public File getFile() {
return file;
}
public void setFile(File file) {
this.file = file;
}
/**
* 上传文件
*/
@Override
public String execute() {
FileUploadService fuservice=new FileUploadService();
if(fuservice.fileUpload(file)){
   List<Picture> list=fuservice.findAll();
   ActionContext cxt=ActionContext.getContext();
   cxt.put("list",list);
   return SUCCESS;
}else{
   super.addActionError(this.getText("fileupload.fail"));
   return INPUT;
}
}
}

非常简单，因为我只单纯的用了struts2，没有用spring。所以FileUploadService就硬编码写在里面了。、

图片上传的主要业务类

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import org.csdn.connection.GetConnection;
import org.csdn.vo.Picture;
/**
* @author closewubq
*/
public class FileUploadService {

/**
* 上传图片到数据库
* @param flie
* @return boolean
*         上传是否成功
*/
public boolean fileUpload(File flie) {
FileInputStream in = null;
Connection conn = null;
PreparedStatement ps = null;
try {
   in = new FileInputStream(flie);
   String sql = "insert into savepicture(picture) value(?)";
   conn = GetConnection.getConn();
   if (conn == null) {
    System.out.println("连接为null");
    return false;
   }
   ps = conn.prepareStatement(sql);
   ps.setBinaryStream(1, in, in.available());
   if (ps.executeUpdate() > 0) {
    GetConnection.close(conn, ps, null);
    return true;
   } else {
    GetConnection.close(conn, ps, null);
    return false;
   }
} catch (Exception e) {
   System.out.println(e.getMessage());
   GetConnection.close(conn, ps, null);
   return false;
}
}

/**
* 检索所有图片
* @return list
*        返回所有图片记录
*/
public List<Picture> findAll() {
List<Picture> list = new ArrayList<Picture>();
Picture pic = null;
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
   String sql = "select id from savepicture";
   conn = GetConnection.getConn();
   if (conn == null) {
    System.out.println("连接为null");
    return null;
   }
   ps = conn.prepareStatement(sql);
   rs = ps.executeQuery();
   while (rs.next()) {
    pic = new Picture();
    pic.setId(rs.getInt("id"));
    list.add(pic);
   }
   GetConnection.close(conn, ps, rs);
   return list;
} catch (Exception e) {
   e.printStackTrace();
   GetConnection.close(conn, ps, rs);
   return null;
}

}

/**
* 根据图片ID获取流对象
* @param id
* @return InputStream
*/
public InputStream getPicById(int id) {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
InputStream is = null;
try {
   String sql = "select picture from savepicture where id=?";
   conn = GetConnection.getConn();
   ps = conn.prepareStatement(sql);
   ps.setInt(1, id);
   rs = ps.executeQuery();
   if(rs.next()){
    is = rs.getBinaryStream("picture");
    GetConnection.close(conn, ps, rs);
    return is;
   }
   GetConnection.close(conn, ps, rs);
   return null;
} catch (Exception ex) {
   ex.printStackTrace();
   GetConnection.close(conn, ps, rs);
   return null;
}
}

}

简单的写了个jdbc链接的获取类。

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
/**
* 获取数据库链接
* @author closewubq
*/
public class GetConnection {

/**
* 获取数据库连接
* @return Connection
*         返回数据库连接
*/
public static Connection getConn() {
try {
   Class.forName("com.mysql.jdbc.Driver").newInstance();
   String url = "jdbc:mysql://localhost/csdn?user=root&password=";
   Connection connection = DriverManager.getConnection(url);
   return connection;
} catch (Exception e) {
   e.printStackTrace();
   return null;
}
}

/**
* 关闭连接释放资源
* @param conn
* @param rs
* @param st
*/
public static void close(Connection conn,PreparedStatement ps,ResultSet rs){
if(rs!=null)
   try {
    rs.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
if(ps!=null)
   try {
    ps.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
if(conn!=null)
   try {
    conn.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }

}

}

还有保存图片信息的VO

public class Picture {
private int id;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}

输出图片信息的Action

import java.io.InputStream;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
import org.csdn.service.FileUploadService;
import com.opensymphony.xwork2.ActionSupport;
/**
* 图片输出
* @author closewubq
*
*/
public class OutPictureAction extends ActionSupport {
private static final long serialVersionUID = 1L;
@Override
public String execute() throws Exception {
    HttpServletRequest request = ServletActionContext.getRequest();
    int id=Integer.parseInt(request.getParameter("id"));
    FileUploadService service=new FileUploadService();
    InputStream in=service.getPicById(id);
    HttpServletResponse response=ServletActionContext.getResponse();
    response.setContentType("image/gif");
    int size=in.available();
    byte[] image=new byte[size];
    in.read(image);
    ServletOutputStream out=response.getOutputStream();
    out.write(image);
    return null;
}
}