package com.shengke.servlet;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;

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

/**
 * Servlet implementation class UploadServlet
 */
public class UploadServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doPost(request,response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		//从request当中获取流信息
		InputStream fileSource = request.getInputStream();
		String tempFileName = "/home/shengke/图片/tempFile";
		//tempFile指向临时文件
		File tempFile = new File(tempFileName);
		//outputStram文件输出流指向这个临时文件
		FileOutputStream outputStream = new FileOutputStream(tempFile);
		//循环读取输入流信息到输出流
		byte b[] = new byte[1024];
		int n;
		while(( n = fileSource.read(b)) != -1){
			outputStream.write(b, 0, n);
		}
		//关闭输出流、输入流
		outputStream.close();
		fileSource.close();
		
		//获取上传文件的名称，可能需要根据实际情况修改
		RandomAccessFile randomFile = new RandomAccessFile(tempFile,"r");
		System.out.println(randomFile.readLine());
		String str = randomFile.readLine();
		int beginIndex = str.lastIndexOf("filename=\"") + 10;
		int endIndex = str.lastIndexOf("\"");
		String filename = str.substring(beginIndex, endIndex);
		System.out.println("fileName:" + filename);
		
		//重新定位文件指针到文件头
		randomFile.seek(0);
		long startPosition = 0;
		int i = 1;
		//获取文件内容 开始位置，如果不等与-1且小于4
		while(( n = randomFile.readByte()) != -1 && i <=4){
			//如果读取到换行符，从新得到文件指针，这样就循环读取4行换行符
			if(n == '\n'){
				startPosition = randomFile.getFilePointer();
				i ++;
			}
		}
		startPosition = randomFile.getFilePointer() -1;
		
		//获取文件内容 结束位置
		randomFile.seek(randomFile.length());
		long endPosition = randomFile.getFilePointer();
		int j = 1;
		//从后往前读
		while(endPosition >=0 && j<=2){
			endPosition--;
			randomFile.seek(endPosition);
			if(randomFile.readByte() == '\n'){
				j++;
			}
		}
		endPosition = endPosition -1;
		
		//设置保存上传文件的路径
//		String realPath = getServletContext().getRealPath("/") + "images";
		String realPath = "/home/shengke/workspace/fileSCXZ/WebContent/images";
		System.out.println("realPath:"+realPath);
		File fileupload = new File(realPath);
		//如果路径不存在，就创建路径
		if(!fileupload.exists()){
			fileupload.mkdir();
		}
		File saveFile = new File(realPath,filename);
		RandomAccessFile randomAccessFile = new RandomAccessFile(saveFile,"rw");
		//从临时文件当中读取文件内容（根据起止位置获取）
		randomFile.seek(startPosition);
		while(startPosition < endPosition){
			randomAccessFile.write(randomFile.readByte());
			startPosition = randomFile.getFilePointer();
		}
		//关闭输入输出流、删除临时文件
		randomAccessFile.close();
		randomFile.close();
		//如果想看看你上传的临时文件，可以把下面这行注释了，就可以在tempFileName路径下看到临时文件了
		tempFile.delete();
		
		request.setAttribute("result", "上传成功！");
		RequestDispatcher dispatcher = request.getRequestDispatcher("jsp/index.jsp");
		dispatcher.forward(request, response);
	}

}