文件5. 获取指定类型的文件

.jsp界面

<form>
              <table>
          <tr>
              <td>输入文件夹路径：</td>
              <td><input type="text" name="filesPath" /></td>
          </tr>
          <tr>
              <td>输入文件的扩展名：</td>
              <td><input type="text" name="type" /></td>
          </tr>
          <tr>
              <td colspan="2">
                  <input type="button"  value="提交"/>
              </td>
          </tr>
          <tr>
              <table id="file">
              
              </table>
          </tr>
      </table>
      </form>

.js代码

$().ready(function(){
    $("input[type='button']").click(function(){
        var filesPath=$("input[name='filesPath'").val();
        var type=$("input[name='type']").val();
        var xmlhttp=getXmlhttp();
        var data={"filesPath":filesPath,"type":type};
        xmlhttp.onreadystatechange=function() {
            if(xmlhttp.readyState==4 && xmlhttp.status==200) {
                var files=eval("("+xmlhttp.responseText+")");
                var table=$("#file");
                table.empty();
                var content="<tr><td>文件名</td><td>文件长度</td><td>修改日期</td></tr>";
                for(i in files) {
                     content+="<tr><td>"+files[i][0]+"</td><td>"+files[i][1]+"</td><td>"+files[i][2]+"</td></tr>";
                }
                table.html(content);
            }
        };
        xmlhttp.open("POST","showFile","true");
        xmlhttp.setRequestHeader("Content-Type","application/json");
        xmlhttp.send(JSON.stringify(data));
    });
});
//获取xmlHttp
function getXmlhttp() {
    var xmlhttp;
    if(window.XMLHttpRequest) {
        xmlhttp=new XMLHttpRequest;
    } else {
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
    return xmlhttp;
}

servlet层ShowSomeType.java

protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");
        PrintWriter out=resp.getWriter();
        JSONObject data=getJsonObject(req);
        String filesPath=data.getString("filesPath");
        String type=data.getString("type");
        File[] files=null;
        if(filesPath!=null && type!=null) {
            CustomFilter fileFilter=new CustomFilter();
            fileFilter.setExtentName(type);
            File file=new File(filesPath);
            if(file.isDirectory()) {
                files=file.listFiles(fileFilter);
            }
        }
        if(files!=null) {
            List<Object[]> fileList=new ArrayList<Object[]>();
            for(File f:files) {
                Object[] file={f.getName(),f.length(),new Date(f.lastModified()).toLocaleString()};
                fileList.add(file);
            }
            JSONArray jsonFile=JSONArray.fromObject(fileList);
            out.write(jsonFile.toString());
        }
    }
    
    private JSONObject getJsonObject(HttpServletRequest req) {
        StringBuffer json=new StringBuffer();
        String lineString=null;
        BufferedReader reader;
        JSONObject data=null;
        try {
            reader = req.getReader();
            while((lineString=reader.readLine())!=null) {
                json.append(lineString);
            }
             data=JSONObject.fromObject(json.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
        return data;
    }