JAVA实现HTTPserver端

用java socket实现了一个简单的httpserver， 能够处理GET, POST,以及带一个附件的multipart类型的POST。尽管中途遇到了非常多问题， 只是通过在论坛和几个高手交流了一下，问题都攻克了。假设你认为程序有些地方看不明确,能够參看这个帖子:http://topic.csdn.net/u/20090625/22/59a5bfc8-a6b6-445d-9829-ea6d462a4fe6.html .

尽管解析http头不是非常规范，本来应该用原始的字节流， 我採用了一个折衷的方案，用DataInputStream.

本代码的有用性==0，可是能够帮助非常好地了解http协议，然后其它的应用层协议大都如此。

假设你从来都没有了解过http协议，建议先搜索阅读一下，或者你还能够用以下的代码来简单的看一看究竟浏览器和server之间都相互发送了什么数据。

MyHttpClient.java: 模拟浏览器的行为， 向server发送get/post请求，然后打印出server返回的消息。这样就能够查看当一个请求到来之后， server究竟都给浏览器发送了哪些消息。

package socket; import java.io.*; import java.net.*; public class MyHttpClient { public static void main(String[] args) throws Exception{ InetAddress inet = InetAddress.getByName("www.baidu.com"); System.out.println(inet.getHostAddress()); Socket socket = new Socket(inet.getHostAddress(),80); InputStream in = socket.getInputStream(); OutputStream out = socket.getOutputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(in)); PrintWriter writer = new PrintWriter(out); writer.println("GET /home.html HTTP/1.1");//home.html是关于百度的页面 writer.println("Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/msword, application/vnd.ms-excel, application/vnd.ms-powerpoint, */*"); writer.println("Accept-Language: en-us,zh-cn;q=0.5"); writer.println("Accept-Encoding: gzip, deflate"); writer.println("Host: www.baidu.com"); writer.println("User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)"); writer.println("Connection: Keep-Alive"); writer.println(); writer.flush(); String line = reader.readLine(); while(line!=null){ System.out.println(line); line = reader.readLine(); } reader.close(); writer.close(); } }

MyServer.java: 模拟server端接收浏览器的请求，然后把整个请求的报文打印出来。程序执行之后直接用浏览器測试。

package socket; import java.io.*; import java.net.*; public class MyServer { public static void main(String[] args) throws IOException{ ServerSocket svrSocket = new ServerSocket(8080); while(true){ Socket socket = svrSocket.accept(); //足够大的一个缓冲区 byte[] buf = new byte[1024*1024]; InputStream in = socket.getInputStream(); int byteRead = in.read(buf, 0, 1024*1024); String dataString = new String(buf, 0, byteRead); System.out.println(dataString); in.close(); socket.close(); } } }

主程序MyHttpServer.

package socket; import java.io.*; import java.net.*; /** * MyHttpServer 实现一个简单的HTTPserver端，能够获取用户提交的内容 * 并给用户一个response * 由于时间的关系，对http头的处理显得不规范 * 对于上传附件，临时仅仅能解析仅仅上传一个附件并且附件位置在第一个的情况 * 转载请注明来自http://blog.csdn.net/sunxing007 * **/ public class MyHttpServer { //server根文件夹，post.html, upload.html都放在该位置 public static String WEB_ROOT = "c:/root"; //port private int port; //用户请求的文件的url private String requestPath; //mltipart/form-data方式提交post的分隔符, private String boundary = null; //post提交请求的正文的长度 private int contentLength = 0; public MyHttpServer(String root, int port) { WEB_ROOT = root; this.port = port; requestPath = null; } //处理GET请求 private void doGet(DataInputStream reader, OutputStream out) throws Exception { if (new File(WEB_ROOT + this.requestPath).exists()) { //从server根文件夹下找到用户请求的文件并发送回浏览器 InputStream fileIn = new FileInputStream(WEB_ROOT + this.requestPath); byte[] buf = new byte[fileIn.available()]; fileIn.read(buf); out.write(buf); out.close(); fileIn.close(); reader.close(); System.out.println("request complete."); } } //处理post请求 private void doPost(DataInputStream reader, OutputStream out) throws Exception { String line = reader.readLine(); while (line != null) { System.out.println(line); line = reader.readLine(); if ("".equals(line)) { break; } else if (line.indexOf("Content-Length") != -1) { this.contentLength = Integer.parseInt(line.substring(line.indexOf("Content-Length") + 16)); } //表明要上传附件， 跳转到doMultiPart方法。 else if(line.indexOf("multipart/form-data")!= -1){ //得multiltipart的分隔符 this.boundary = line.substring(line.indexOf("boundary") + 9); this.doMultiPart(reader, out); return; } } //继续读取普通post（没有附件）提交的数据 System.out.println("begin reading posted data......"); String dataLine = null; //用户发送的post数据正文 byte[] buf = {}; int size = 0; if (this.contentLength != 0) { buf = new byte[this.contentLength]; while(size<this.contentLength){ int c = reader.read(); buf[size++] = (byte)c; } System.out.println("The data user posted: " + new String(buf, 0, size)); } //发送回浏览器的内容 String response = ""; response += "HTTP/1.1 200 OK/n"; response += "Server: Sunpache 1.0/n"; response += "Content-Type: text/html/n"; response += "Last-Modified: Mon, 11 Jan 1998 13:23:42 GMT/n"; response += "Accept-ranges: bytes"; response += "/n"; String body = "<html><head><title>test server</title></head><body><p>post ok:</p>" + new String(buf, 0, size) + "</body></html>"; System.out.println(body); out.write(response.getBytes()); out.write(body.getBytes()); out.flush(); reader.close(); out.close(); System.out.println("request complete."); } //处理附件 private void doMultiPart(DataInputStream reader, OutputStream out) throws Exception { System.out.println("doMultiPart ......"); String line = reader.readLine(); while (line != null) { System.out.println(line); line = reader.readLine(); if ("".equals(line)) { break; } else if (line.indexOf("Content-Length") != -1) { this.contentLength = Integer.parseInt(line.substring(line.indexOf("Content-Length") + 16)); System.out.println("contentLength: " + this.contentLength); } else if (line.indexOf("boundary") != -1) { //获取multipart分隔符 this.boundary = line.substring(line.indexOf("boundary") + 9); } } System.out.println("begin get data......"); /*以下的凝视是一个浏览器发送带附件的请求的全文，全部中文都是说明性的文字***** <HTTP头部内容略> ............ Cache-Control: no-cache <这里有一个空行，表明接下来的内容都是要提交的正文> -----------------------------7d925134501f6<这是multipart分隔符> Content-Disposition: form-data; name="myfile"; filename="mywork.doc" Content-Type: text/plain <附件正文>........................................ ................................................. -----------------------------7d925134501f6<这是multipart分隔符> Content-Disposition: form-data; name="myname"<其它字段或附件> <这里有一个空行> <其它字段或附件的内容> -----------------------------7d925134501f6--<这是multipart分隔符，最后一个分隔符多两个-> ****************************************************************/ /** * 上面的凝视是一个带附件的multipart类型的POST的全文模型， * 要把附件去出来，就是要找到附件正文的起始位置和结束位置 * **/ if (this.contentLength != 0) { //把全部的提交的正文，包含附件和其它字段都先读到buf. byte[] buf = new byte[this.contentLength]; int totalRead = 0; int size = 0; while (totalRead < this.contentLength) { size = reader.read(buf, totalRead, this.contentLength - totalRead); totalRead += size; } //用buf构造一个字符串，能够用字符串方便的计算出附件所在的位置 String dataString = new String(buf, 0, totalRead); System.out.println("the data user posted:/n" + dataString); int pos = dataString.indexOf(boundary); //下面略过4行就是第一个附件的位置 pos = dataString.indexOf("/n", pos) + 1; pos = dataString.indexOf("/n", pos) + 1; pos = dataString.indexOf("/n", pos) + 1; pos = dataString.indexOf("/n", pos) + 1; //附件開始位置 int start = dataString.substring(0, pos).getBytes().length; pos = dataString.indexOf(boundary, pos) - 4; //附件结束位置 int end = dataString.substring(0, pos).getBytes().length; //下面找出filename int fileNameBegin = dataString.indexOf("filename") + 10; int fileNameEnd = dataString.indexOf("/n", fileNameBegin); String fileName = dataString.substring(fileNameBegin, fileNameEnd); /** * 有时候上传的文件显示完整的文件名称路径,比方c:/my file/somedir/project.doc * 但有时候仅仅显示文件的名字，比方myphoto.jpg. * 所以须要做一个推断。 */ if(fileName.lastIndexOf("//")!=-1){ fileName = fileName.substring(fileName.lastIndexOf("//") + 1); } fileName = fileName.substring(0, fileName.length()-2); OutputStream fileOut = new FileOutputStream("c://" + fileName); fileOut.write(buf, start, end-start); fileOut.close(); fileOut.close(); } String response = ""; response += "HTTP/1.1 200 OK/n"; response += "Server: Sunpache 1.0/n"; response += "Content-Type: text/html/n"; response += "Last-Modified: Mon, 11 Jan 1998 13:23:42 GMT/n"; response += "Accept-ranges: bytes"; response += "/n"; out.write("<html><head><title>test server</title></head><body><p>Post is ok</p></body></html>".getBytes()); out.flush(); reader.close(); System.out.println("request complete."); } public void service() throws Exception { ServerSocket serverSocket = new ServerSocket(this.port); System.out.println("server is ok."); //开启serverSocket等待用户请求到来，然后依据请求的类别作处理 //在这里我仅仅针对GET和POST作了处理 //当中POST具有解析单个附件的能力 while (true) { Socket socket = serverSocket.accept(); System.out.println("new request coming."); DataInputStream reader = new DataInputStream((socket.getInputStream())); String line = reader.readLine(); String method = line.substring(0, 4).trim(); OutputStream out = socket.getOutputStream(); this.requestPath = line.split(" ")[1]; System.out.println(method); if ("GET".equalsIgnoreCase(method)) { System.out.println("do get......"); this.doGet(reader, out); } else if ("POST".equalsIgnoreCase(method)) { System.out.println("do post......"); this.doPost(reader, out); } socket.close(); System.out.println("socket closed."); } } public static void main(String args[]) throws Exception { MyHttpServer server = new MyHttpServer("c:/root", 8080); server.service(); } }

測试文件post.html, upload.html都放在上面程序定义的WEB_ROOT以下。

post.html:处理普通的post请求

<html> <head> <title>test my server</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body> <p>upload</p> 来自http://blog.csdn.net/sunxing007<br> <form name="UploadForm" method="post" action="http://localhost:8080/"> <input type="text" name="myname" /><br> <select name="myage"> <option value="18">18</option> <option value="20">20</option> <option value="22">22</option> </select><br> <input type="submit"value="Sutmit"> </form> </body> </html>

upload.html:測试带附件的post请求

<head> <title>my page</title> <style> table{ border-collapse: collapse; } </style> </head> <body> 来自http://blog.csdn.net/sunxing007<br> <form action='http://localhost:8080/' method='post' enctype='multipart/form-data'> file: <input type='file' name='myfile' /><br> <input type='submit' /> </form> </body> </html>

一切准备妥当,而且MyHttpServer执行之后, 在浏览器输入http://localhost:8080/post.html和http://localhost:8080/upload.html就可以进行測试.

转载请注明来自http://blog.csdn.net/sunxing007