Question

我们正在开发一个文件共享站点，其中包含使用servlet 2.5，jsp和jdbc的用户和管理员的概念。我们已经通过servlet实现了文件上传/下载部分。用户应该在网站上看到他上传的文件和文件夹。但我们仍然坚持通过servlet实现文件夹级别视图。我们在pl / sql中维护了一个add_file db表，并检索了仅由特定用户上传的文件详细信息。但是，我们还必须显示文件夹，我们无法显示。我遇到了一个简单的改变apache tomcat 6.0的web.xml的解决方案，但是它会让每个用户都能看到每个文件夹和文件里面，它不依赖于数据库。但我们必须仅根据数据库显示这些内容。有没有办法实现这个目标？

UploadedFileView.jsp

-----------代码在这里

<c:forEach items="${files}" var="file">``
        <c:url value="/DownloadServlet" var="url">
            <c:param name="name" value="${file.name }" />
        </c:url>

        <a href="<c:out value="${url}"/>"><c:out value="${file.name}" />
        </a>


        <br>
    </c:forEach>

DownloadServlet.java

protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");
        HttpSession session = request.getSession();
        String filename = null;
        filename = request.getParameter("name");
        PrintWriter out = response.getWriter();
        String filepath = null;
        if (session.getAttribute("deletedfiles") != null)
        {
            filepath = DeleteLocationBO.DELETE_DIRECTORY;


        }
        else
        {
            filepath = UploadLocationBO.UPLOAD_DIRECTORY;
            }
        response.setContentType("APPLICATION/OCTET-STREAM");
        response.setHeader("Content-Disposition", "attachment; filename=\""
                + filename + "\"");

        FileInputStream fileInputStream = new FileInputStream(filepath
                + filename);

        int i;
        while ((i = fileInputStream.read()) != -1) {
            out.write(i);
        }
        fileInputStream.close();
        out.close();
    }

错误Stacktrace :(测试是foldername）

D：\ Users \ projectname \ uploads \ test（访问被拒绝：Http状态500）

    exception 
        SEVERE: Servlet.service() for servlet DownloadServlet threw exception
    java.io.FileNotFoundException:D:\Users\projectname\uploads\test (Access is denied)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(Unknown Source)
at java.io.FileInputStream.<init>(Unknown Source)
at com.servlets.DownloadServlet.doGet(DownloadServlet.java:57)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:606)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)

Answer 1

这是非常简单的算法，但这里有一个让你入门的例子：

public void displayFileTree(File rootDirectory) {
    displayFileTree(rootDirectory, "");
}

private void displayFileTree(File rootDirectory, String indent) {
    for (File file : rootDirectory.listFiles()) {
        System.out.println(indent + file.getName());
        if (file.isDirectory()) {
            displayFileTree(file, indent + "    ");
        } 
    }
}

从简单的控制台程序运行此代码，然后根据您的具体Web问题进行调整。

如果您想要一个可以在JSP中使用的Java bean，它将只具有与文件相同的结构：

public class Node
    private boolean directory;
    private String name;
    private List<Node> children;

    // getters omitted for brevity
}

查看本地文件系统的文件夹

1 个答案: