1 package webserver; 2  3 import java.io.*; 4 import java.net.*; 5  6 public class WebServer { 7  8     /** 9      * web服务器：实现200和404操作10      * 原理：11      * 服务器监听一个端口，并读取浏览器的请求信息，从该信息提取出访问的资源（这里为文件名）。并在工作目录下查找是否有该资源，有则输出资源内容，否则返回40412      * 测试方法：13      * 1、用String path=System.getProperty("user.dir");获取当前的工作目录，并在该目录下放要测试的文件14      * 2、访问127.0.0.1:8080/test.html15      */16     public static void main(String[] args) {17         // TODO Auto-generated method stub18         ServerSocket server = null;19         Socket s=null;20         try21         {22             server=new ServerSocket(8080,3,InetAddress.getByName("127.0.0.1"));23         }catch(Exception e)24         {25             e.printStackTrace();26         }27         while(true)28         {29             try{30                 s=server.accept();31                 OutputStream output=s.getOutputStream();32                 InputStream input=s.getInputStream();33                 34                 //接收请求信息35                 Request request=new Request(input);36                 String filename=request.getUri();37                 //System.out.println(filename);38                 39                 //处理并响应请求信息40                 Response response=new Response(output,filename);41                 response.response();42 43             }catch(Exception e)44             {45                 e.printStackTrace();46             }47         }48     }49 50 }

 1 package webserver; 2 import java.io.*; 3 public class Request { 4     /* 5      * 接收请求的信息，并返回资源（文件名） 6      * */ 7     InputStream input; 8     public Request(InputStream input) 9     {10         this.input=input;11     }12     public String getUri() throws IOException13     {14         String content=null,str=null;15         StringBuffer request = new StringBuffer();  16         byte[] buffer = new byte[2048];  17         int i = 0;  18           19         try {  20             i = input.read(buffer);  //读取内容并存入buffer数组中，并返回读取的的字节数。21         } catch (IOException e) {  22             e.printStackTrace();  23             i = -1;  24         }  25         //将buffer数组转换为字符串26         for(int k = 0; k < i; k++) {  27             request.append((char)buffer[k]);  28         }  29         content=request.toString();30     /*    31      *以下方法错误！用该返回会使浏览器不断处于请求连接状态32      * BufferedReader br=new BufferedReader(new InputStreamReader(input));33         while((str=br.readLine())!=null)34         {35             content=content+str+"\r\n";36         }37     */    38         if(content!=null)39             return getFilename(content);40         else return null;41     }42     /*提取文件名*/43     public String getFilename(String content)44     {45         int a,b;46         a=content.indexOf(‘ ‘);47         if(a!=-1)48         {49             b=content.indexOf(‘?‘,a+1);50             if(b==-1)b=content.indexOf(‘ ‘,a+1);51             return content.substring(a+2,b);52         }53         return null;54     }55 }

 1 package webserver; 2  3 import java.io.*; 4 import java.io.File; 5 import java.io.IOException; 6 import java.io.OutputStream; 7  8 public class Response { 9     /**10      * 响应并处理请求信息11      */12     public OutputStream output;13     public String filename;14      private static final int BUFFER_SIZE = 1024; 15     public  Response(OutputStream output,String filename)16     {17         this.output=output;18         this.filename=filename;19     }20     public void response() throws IOException21     {22         String path=System.getProperty("user.dir");//获取当前的工作目录23         byte[] buffer = new byte[BUFFER_SIZE];  24         int ch;  25         FileInputStream fis = null;  26         //System.out.println(path+File.separator+filename);27         if(path!=null&&filename!=null)28         {29             File file=new File(path,filename);30             String str="";31             /*必须添加响应头，否则无法以html格式显示内容*/32             if(file.exists())33             {34                 fis = new FileInputStream(file);  35                 str = "HTTP/1.1 200 OK \r\n" +  36                  "Content-Type: text/html\r\n" +  37                  "\r\n" ;38                 output.write(str.getBytes());39                 ch = fis.read(buffer);                40                 while(ch != -1) {  41                     output.write(buffer, 0, ch);  42                     ch = fis.read(buffer, 0, BUFFER_SIZE);  43                 }  44             }45             else46             {47                  str = "HTTP/1.1 404 File Not Found \r\n" +  48                  "Content-Type: text/html\r\n" +  49                  "Content-Length: 100\r\n" +  50                  "\r\n" +  51                  "<h1>404 File Not Found!</h1>"; 52                 output.write(str.getBytes());53             }54         }55         output.close();56     }57 }