package com.jiong.uploadify;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import com.jenmin.dao.UserDao;

public class UploadServlet extends HttpServlet
{

    /**
     * serialVersionUID
     */
    private static final long serialVersionUID = -919197936280771293L;

    UserDao ud = UserDao.getInstance();

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
    {
        this.doPost(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
    {
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        String userid = request.getParameter("userid");

        if (userid != null && !userid.equals(""))
        {
            String savePath = generateDir();
            processUpload(request, response, savePath, Integer.parseInt(userid));
        }

    }

    /*
     * 上传处理方法
     */
    @SuppressWarnings("unchecked")
    public void processUpload(HttpServletRequest request, HttpServletResponse response, String savePath, int userid)
    {

        DiskFileItemFactory factory = new DiskFileItemFactory();
        // 缓存大小512KB
        factory.setSizeThreshold(524288);
        // 设置一旦文件大小超过getSizeThreshold()的值时数据存放在硬盘的目录
        factory.setRepository(new File(savePath + "/temp"));
        // 初始化化上传控件
        ServletFileUpload upload = new ServletFileUpload(factory);
        // 指定单个上传文件的最大尺寸,单位:字节
        upload.setFileSizeMax(3145728);
        // 设置编码
        upload.setHeaderEncoding("UTF-8");

        List<FileItem> fileList = null;
        try
        {
            // 解析request请求
            fileList = upload.parseRequest(request);
        }
        catch(FileUploadException e)
        {
            e.printStackTrace();
        }

        Iterator<FileItem> it = fileList.iterator();
        String name = "";
        String filename = "";
        while (it.hasNext())
        {
            FileItem item = it.next();
            // 过滤掉表单中非文件域
            if (!item.isFormField())
            {
                // 获得上传文件的文件名
                name = item.getName();
                if (name != null && !name.trim().equals(""))
                {
                    // 生成文件名
                    filename = generateFileName(name);
                    File file = new File(savePath + "/" + filename);
                    try
                    {
                        item.write(file);
                        // 生成图片保存路径
                        String imgstr = this.getServletContext().getContextPath();
                        imgstr = imgstr + "/upload/" + filename;
                        // 更新数据库保存图片url
                        ud.updateImgBySql(imgstr, userid);

                        response.getWriter().write("http://localhost:8080" + imgstr);
                    }
                    catch(Exception e)
                    {
                        e.printStackTrace();
                    }
                }
            }
        }
    }

    /*
     * 初妾化文件存储路徿
     */
    private String generateDir()
    {
        String pathString = getServletConfig().getServletContext().getRealPath("/upload");
        String tempString = getServletConfig().getServletContext().getRealPath("/upload/temp");
        File dirPath = new File(pathString);
        File dirTemp = new File(tempString);
        if (!dirPath.exists())
        {
            dirPath.mkdirs();
        }
        if (!dirTemp.exists())
        {
            dirTemp.mkdirs();
        }
        return pathString;
    }

    /*
     * 生成文件名
     */
    private String generateFileName(String name)
    {
        long currentTime = System.currentTimeMillis();
        int i = (int) (Math.random() * 1000D + 1.0D);
        long result = currentTime + i;
        String filename = String.valueOf(result) + getFileExt(name);
        return filename;
    }

    /*
     * 获取文件格式
     */
    private String getFileExt(String name)
    {
        int pos = name.lastIndexOf(".");
        if (pos > 0)
        {
            return name.substring(pos);
        }
        else
        {
            return name;
        }
    }
}