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这是服务器部分
import java.net.*;
import java.io.*;
import java.util.*;
public class HTTPServer
{
String serverName;
String Version;
int serverPort;
// 构造一个server，并运行
public static void main(String args[])
{
HTTPServer server = new HTTPServer("HTTPServer", "1.0", 80);
server.run();
}
// 定义server的名字、版本号、端口
public HTTPServer(String name, String version, int port)
{
this.serverName = name;
this.Version = version;
this.serverPort = port;
}
public void run()
{
// 显示名字和版本号
System.out.println(serverName+" version ");
try
{
// 得到服务监听端口
ServerSocket server = getServerSocket();
do
{
// 等待连接请求
Socket client = server.accept();
// 为连接请求分配一个线程
(new HTTPServerThread(client)).start();
}while(true);
}
catch(Exception e)
{
e.printStackTrace();
System.exit(1);
}
}
//服务器的构造方法，
//我们可以对其构造方法进行扩展，
//参考JSSE技术一章中的SSL扩展
ServerSocket getServerSocket() throws Exception
{
return new ServerSocket(serverPort);
}
}
class HTTPServerThread extends Thread
{
Socket client;
public HTTPServerThread(Socket client)
{
this.client = client;
}
public void run()
{
try
{
describeConnectionInfo(client);
BufferedOutputStream outStream = new
BufferedOutputStream(client.getOutputStream());
//HTTPInputStream是自定义的过滤流
HTTPInputStream inStream = new HTTPInputStream(client.getInputStream());
//得到请求头
HTTPRequest request = inStream.getRequest();
//显示头信息
request.log();
//只处理GET请求
if(request.isGetRequest())
processGetRequest(request,outStream);
System.out.println("Request completed. Closing connection.");
//非持久性
client.close();
}
catch(IOException e)
{
System.out.println("IOException occurred .");
e.printStackTrace();
}
}
// Display info about the connection
void describeConnectionInfo(Socket client)
{
//服务端主机名
String destName = client.getInetAddress().getHostName();
//服务端IP地址
String destAddr = client.getInetAddress().getHostAddress();
//服务端端口
int destPort = client.getPort();
//打印信息
System.out.println("Accepted connection to "+destName+" ("+destAddr+")"+" on port "+destPort+".");
}
// 处理GET请求
void processGetRequest(HTTPRequest request,BufferedOutputStream outStream)
throws IOException
{
String fileName = request.getFileName();
File file = new File(fileName);
// Give them the requested file
if(file.exists()) sendFile(outStream,file);
else System.out.println("File "+file.getCanonicalPath()+" does not exist.");
}
// HTTP 1.0 回应
void sendFile(BufferedOutputStream out,File file)
{
try
{
DataInputStream in = new DataInputStream(new FileInputStream(file));
int len = (int) file.length();
byte buffer[] = new byte[len];
in.readFully(buffer);
in.close();
out.write("HTTP/1.0 200 OK\r\n".getBytes());
out.write(("Content-Length: " + buffer.length + "\r\n").getBytes());
out.write("Content-Type: text/HTML\r\n\r\n".getBytes());
out.write(buffer);
out.flush();
out.close();
System.out.println("File sent: "+file.getCanonicalPath());
System.out.println("Number of bytes: "+len);
}
catch(Exception e)
{
try
{
out.write(("HTTP/1.0 400 " + "No can do" + "\r\n").getBytes());
out.write("Content-Type: text/HTML\r\n\r\n".getBytes());
}
catch(IOException ioe)
{
}
System.out.println("Error retrieving "+file);
}
}
}
// 实现读客户端请求的帮助类
class HTTPInputStream extends FilterInputStream
{
public HTTPInputStream(InputStream in)
{
super(in);
}
// 读一行
public String readLine() throws IOException
{
StringBuffer result=new StringBuffer();
boolean finished = false;
//回车符
boolean cr = false;
do
{
int ch = -1;
ch = read();
if(ch==-1) return result.toString();
result.append((char) ch);
//去掉最后的'\n'
if(cr && ch==10)
{
result.setLength(result.length()-2);
return result.toString();
}
//读到回车符，设置标识
if(ch==13) cr = true;
else cr=false;
} while (!finished);
return result.toString();
}
// 得到所有的请求
public HTTPRequest getRequest() throws IOException
{
HTTPRequest request = new HTTPRequest();
String line;
do
{
line = readLine();
//将请求填入容器
if(line.length()>0) request.addLine(line);
else break;
}while(true);
return request;
}
}
// 客户端请求的封装类
class HTTPRequest
{
Vector lines = new Vector();
public HTTPRequest()
{
}
public void addLine(String line)
{
lines.addElement(line);
}
// 判断是否是Get请求
boolean isGetRequest()
{
if(lines.size() > 0)
{
String firstLine = (String) lines.elementAt(0);
if(firstLine.length() > 0)
if(firstLine.substring(0,3).equalsIgnoreCase("GET"))
return true;
}
return false;
}
// 从请求中解析到文件名
String getFileName()
{
if(lines.size()>0)
{
//得到vector中第一个元素
String firstLine = (String) lines.elementAt(0);
//得到文件名
//根据http消息格式
String fileName = firstLine.substring(firstLine.indexOf(" ")+1);
int n = fileName.indexOf(" ");
//URL在两个空格之间
if(n!=-1) fileName = fileName.substring(0,n);
//去掉第一个'/'
try
{
if(fileName.charAt(0) == '/') fileName = fileName.substring(1);
}
catch(StringIndexOutOfBoundsException ex) {}
//默认首页
//类似于'http://localhost:80'的情况
if(fileName.equals("")) fileName = "index.htm";
//类似于'http://localhost:80//'的情况
if(fileName.charAt(fileName.length()-1)=='/')
fileName+="index.htm";
return fileName;
}else return "";
}
// 显示请求信息
void log()
{
System.out.println("Received the following request:");
for(int i=0;i<lines.size();++i)
System.out.println((String) lines.elementAt(i));
}
}
运行：
C:\java>java HTTPServer
HTTPServer version
Accepted connection to 127.0.0.1 (127.0.0.1) on port 1057.
Received the following request:
GET /index.htm HTTP/1.1
User-Agent: Java/1.4.2_03
Host: 127.0.0.1
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alive
File sent: C:\java\index.htm
Number of bytes: 47
Request completed. Closing connection.
这是客户端部分
import java.io.*;
import java.net.*;
public class Browser
{
//网址URL
String urlString;
public static void main(String[] args) throws Exception
{
if(args.length != 1)
{
System.out.println("Usage: Java Browser url");
System.exit(1);
}
Browser browser = new Browser(args[0]);
browser.run();
}
public Browser(String urlString)
{
this.urlString = urlString;
}
public void run() throws Exception
{
//生成一个URL对象
URL url = new URL(urlString);
//得到输入流
HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
//打印头信息
System.out.println("THE HEADERS");
System.out.println("-----------");
for(int i=1;;++i)
{
String key;
String value;
if((key = urlc.getHeaderFieldKey(i)) == null) break;
if((value = urlc.getHeaderField(i)) == null) break;
System.out.print(key);
System.out.println(" is: " + value);
}
//得到输入流
BufferedReader reader = new BufferedReader(
new InputStreamReader(urlc.getInputStream()));
String line;
System.out.println("-----CONTENT------");
while((line = reader.readLine()) != null) System.out.println(line);
}
}
运行结果：
C:\java>java Browser http://127.0.0.1:80/index.htm
THE HEADERS
-----------
Content-Length is: 47
Content-Type is: text/HTML
-----CONTENT------
<html>
<body>
How do you do
</body>
</html> | 
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