Access file inside WebContent from servlet

问题

I trying to access the html files inside the WebContent/alerts folder using its relative path from servlet. But i unable to access it using its relative path,

Access the file inside WebContent from Servlet using relative path:

protected Element getSummary(String value) throws IOException
{
    Element element=null;
    Summary summary = Summary.valueOf(value);
    switch(summary) {
    case rtp_summary:
        element=parseDIV(new File("../../WebContent/alerts/rtp_bcklg_mail.html"),"rtp_summary");
        break;
    case ffu_summary:
        element=parseDIV(new File("/../../WebContent/alerts/ffu_comp_bcklg_mail.html"),"ffu_summary");
        break;    
    default:
        System.out.println("Enter a valid choice");
        break;
    }
    return element;
}

Access the file inside WebContent from Java Thread using relative path:

 public class WriteJSONFile implements Runnable{

WriteJSONFile(){
}

@Override

public void run()
{
    try {
        createJSONFile();
    } catch (IOException e) {

        e.printStackTrace();
    }
}

@SuppressWarnings("unchecked")
private static void createJSONFile() throws IOException
{
    String path="C:/Users/Thiru/Documents/Website Design/Macaw/";
    JSONArray jsonArray=new JSONArray();
    JSONObject rtpStatus=new JSONObject();
    rtpStatus.put("name","RTP");
    rtpStatus.put("status",parseDIV(new File(path+"WebContent/alerts/rtp_bcklg_mail.html"),"rtp_health"));
    jsonArray.add(rtpStatus);

    JSONObject proposalattribStatus=new JSONObject();
    proposalattribStatus.put("name","PROPOSAL ATTRIBUTE");
    proposalattribStatus.put("status",parseDIV(new File(path+"WebContent/alerts/prpsl_txtsrch.html"),"prpsl_attrb_health"));
    jsonArray.add(proposalattribStatus);

    writetoFile(jsonArray);
}


private static void writetoFile(JSONArray jsonArray) {
    try {
        String path="C:/Users/Thiru/Documents/Website Design/Macaw/";
        FileWriter file = new FileWriter(path+"WebContent/properties/status.json");
        file.write(jsonArray.toJSONString());
        file.flush();
        file.close();

    } catch (IOException e) {
        e.printStackTrace();
    }   
}

protected static String parseDIV(File input, String divElement)
        throws IOException {
    Document doc = Jsoup.parse(input, "UTF-8");
    String content = doc.getElementById(divElement).val();
    System.out.println(divElement +" "+content);
    return content;
}

}

And i also want to access the files inside Webcontent from RESTful web service method using relative path. Thanks in advance.

回答1:

Use ServletContext.getRealPath() to locate the file on disk. Note that this only works if the webapp is "exploded" during deployment.

For example:

   File f = new File(getServletContext().getRealPath("alerts/rtp_bcklg_mail.html"));

回答2:

Current location of your files could be considered as a security issue. It is advisable to place such files in WEB-INF.

String filePath = getServletContext().getRealPath("/WEB-INF/alerts/rtp_bcklg_mail.html");

回答3:

Properties props=new Properties();
    props.load(this.getServletContext().getResourceAsStream("/alerts/"+your_fileName+".html"));

by Calling ServletContext object we can get WebContext root from now on wards we can pass our file file statically

回答4:

You can use servlet url pattern in your html page form action or html page a href tag.But your web.xml use servlet-mapping's url pattern like this (/projectname/servleturl)

来源：https://stackoverflow.com/questions/21415413/access-file-inside-webcontent-from-servlet