引用MarkDown编辑器

下载插件：
http://pandao.github.io/editor.md/

将下载的插件解压拷贝进项目中

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>











    

        

            ${topic.topic_markdown_content}
        
        提交
    

解密后保存工具类

package com.neuedu.util;

import java.io.FileOutputStream;
import java.io.OutputStream;

import sun.misc.BASE64Decoder;

public class picEncode {
    /**
     * @Description: 将base64编码字符串转换为图片
     * @Author:
     * @CreateTime:
     * @param imgStr
     *            base64编码字符串
     * @param path
     *            图片路径-具体到文件
     * @return
     */
    public static boolean generateImage(String imgStr, String path) {
        if (imgStr == null)
            return false;
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            // 解密
            byte[] b = decoder.decodeBuffer(imgStr);
            // 处理数据
            for (int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {
                    b[i] += 256;
                }
            }
            OutputStream out = new FileOutputStream(path);
            out.write(b);
            out.flush();
            out.close();
            return true;
        } catch (Exception e) {
            return false;
        }
    }
}

实体类，用来响应页面请求

package com.neuedu.util;

public class imgUploadBackData {
    private String path;
    private int code;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getPath() {
        return path;
    }

    public void setPath(String path) {
        this.path = path;
    }
}

Controller或Servlet

package com.neuedu.servlet;

import java.io.File;
import java.io.IOException;
import java.util.UUID;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.alibaba.fastjson.JSON;
import com.neuedu.util.imgUploadBackData;
import com.neuedu.util.picEncode;

@WebServlet("/topic/uploadimg")
public class UploadImgServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String strTemp = request.getParameter("base");
        System.out.println(strTemp);
        strTemp = strTemp.replace("data:image/png;base64,","");
//        String strPath = this.getClass().getClassLoader().getResource("/../../upload").getPath();
        String strPath = request.getServletContext().getRealPath(File.separator+"upload");
        String strUUid = UUID.randomUUID().toString();
        System.out.println(strPath);
        File file = new File(strPath);
        if(!file.exists())
        {
            file.mkdirs();
        }
        String strSavePath = strPath+File.separator+strUUid+".jpg";
        picEncode.generateImage(strTemp,strSavePath);
        imgUploadBackData iubd = new imgUploadBackData();
        iubd.setPath("upload"+File.separator+strUUid+".jpg");
        iubd.setCode(1);
        String strJson = JSON.toJSONString(iubd);
        response.getWriter().println(strJson);
    }
}

提交表单时可以观察请求体中的参数，会发现内容包含两部分，一部分是markdown语法部分，方便发布者修改文章，还有一部分是markdown渲染出的html部分，是作为展示的，所以，对应数据库中应该也有两个字段支持。