关于文件上传的坑，tomcat一重启图片就消失

首先在tomcat的conf的server.xml中配置一个配置.

记得要找到Host标签。在这个标签里面添加

<Context path ="/File" docBase ="D:/File" debug ="0" privileged ="true">
        </Context>

最终效果是这样的:

<Host name="localhost" appBase="webapps" unpackWARs="true" autoDeploy="true">

        <!-- SingleSignOn valve, share authentication between web applications Documentation at: /docs/config/valve.html -->
        <!-- <Valve className="org.apache.catalina.authenticator.SingleSignOn" /> -->
        <Context path ="/File" docBase ="D:/File" debug ="0" privileged ="true">
        </Context>
        <!-- Access log processes all example. Documentation at: /docs/config/valve.html Note: The pattern used is equivalent to using pattern="common" -->
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log" suffix=".txt" pattern="%h %l %u %t &quot;%r&quot; %s %b" />

      </Host>

 

在后台用的时候就能够这样写

String productName = req.getParameter("productName"); String productDesc = req.getParameter("productDesc"); String productPrice = req.getParameter("productPrice"); Part cover = req.getPart("productImage"); Long da = new Date().getTime()/1000; String filePath = "/"+da+"_"+cover.getSubmittedFileName(); File file = new File("/File"); //这里是重点
        String destPath = file.getAbsolutePath()+filePath; new File(destPath).getParentFile().mkdir(); cover.write(destPath); int categoryId = Integer.parseInt(req.getParameter("categoryId")); Product product = new Product(productName,productDesc,new BigDecimal(productPrice),filePath,categoryId); ProductService service = new ProductService(); service.insertProduct(product); resp.sendRedirect(req.getContextPath()+"/index");

上面我标记的地方就会去找D://File

idea里面在配置一个东西

 

在上面的HTTP port 右侧点上勾

就能够用在jsp使用了

 

<img id="image" src="/File${product.productImage}" style="width: 100px" >