myserver.js

/** 
 * 请求localhost:8081
 * 响应列表
 * <ul>
 *      <li>
 *          <a href = "/file?fileId=">文件名称</a>
 *      </li>
 *      <li>
 *          <a href = "/file?fileId">文件名称</a>
 *      </li>
 * </ul>
 * 
 * 点击超链接时，将超连接诶对应的文件内容，响应到页面是
 * 显示
*/

const http = require("http");
const url = require("url");
const path = require("path");
const fs = require("fs");

http.createServer(httpManager).listen(8081);
function httpManager(req,res) {
    var reqObj = url.parse(req.url, true);
    var pathName = reqObj.pathname;
    switch(pathName) {
        case "/":
            showIndex(res);
            break;
        case "/file":
            showFile(reqObj,res);
            break;
        default:
            res.end("error");
            break;
    }
}


var fileList = ["t1.txt", "t2.txt"];
function showIndex(res) {
    var str = "<ul>";
    for (var i = 0; i< fileList.length; i++) {
        var liNode = "<li><a href='/file?fileId=" +i +"'>" +fileList[i] + "</a></li? "
        str +=liNode;
    }
    str = str + "</ul>";
    res.writeHead(200, {"Content-Type":"text/html"});
    res.write(str);
    res.end();
}

function showFile(reqObj,res) {
    var fileId = reqObj.query.fileId;
    var fileName = fileList[fileId];
    var filePath = path.join(__dirname,"/" + fileName);
    var fileContent = fs.readFileSync(filePath);
    res.end(fileContent);
}