File tree servlet

It is a Java servlet lets you obtain file tree info in JSON format. You can use this servlet in your client site (JavaScript) code for getting file info from your server.

    <servlet>
     <servlet-name>FileTree</servlet-name>
     <servlet-class>com.jsos.file.FileTreeServlet</servlet-class>
    </servlet>

    <servlet-mapping>
     <servlet-name>FileTree</servlet-name>
     <url-pattern>/servlet/filetree</url-pattern>
    </servlet-mapping>

you can pass a name for the directory (or file) you are interested in as a parameter dir. And parameter callback describes a name for your JavaScript function (JSONP). E.g. the following code lists data from the directory /WEB-INF/data:

<html>
<head>
<script>

function f(dir)
{
var cbscript = document.createElement("script");
cbscript.src = "http://myhost/servlet/filetree?dir="+dir+"&callback=c";
cbscript.type = 'text/javascript';
document.body.appendChild(cbscript);
}

function c(list)
{
var s="";
for (var i=0; i {
var o = list[i];

if (o.isDir=="true")
s+="<"+o.name+"><br/>"
else
s+=o.name+"<br/>";
}

document.getElementById("d").innerHTML=s;
}
</script>
</head>
<body>

<input type="button" onClick="f('WEB-INF/data')" value="Get dir"/>

<div id="d">

</div>
</body>
</html>

our JavaScript callback gets back an array with info about files. You can obtain the following information about each object:

isDir possible values are true or false - is it directory or file
name describes a name
size describes a size for file
lastModified describes a last modified time

Also you can describe an initital parameter for this servlet: root. This parameter describes some directory on your server and restricts access to the server-side file system to this directory and its sub-directories only. Parameter dir (if any) describes in this case a subdirectory. E.g.:

    <servlet>
     <servlet-name>FileTree</servlet-name>
     <servlet-class>com.jsos.file.FileTreeServlet</servlet-class>
    <init-param>
    <param-name>root</param-name>
    <param-value>/WEB-INF/data</param-value>
    </init-param>
    </servlet>

and /servlet/filetree?dir=pics will describe actually a directory /WEB-INF/data/pics

File tree servlet 1.1