httpclient.java

java实现ftp功能。其中含有一个监听端口并提供HTML文档的程序.内容

import java.net.*;
import java.io.*;
import java.awt.*;
import java.util.Properties;
import java.util.Enumeration;

public class HTTPClient{
	protected Socket client;
	protected BufferedOutputStream sender;
	protected BufferedInputStream receiver;
	protected ByteArrayInputStream byteStream;
	protected URL target;
	private int responseCode=-1;
	private String responseMessage="";
	private String serverVersion="";
	private Properties header = new Properties();
	public HTTPClient() { }
	public HTTPClient(String url) {
		GET(url) ;
	}
	
	/* GET????URL,????????????????????????? */
	public void GET(String url) {
		try {
			checkHTTP(url);
			openServer(target.getHost(),target.getPort() );
			String cmd = "GET "+ getURLFormat(target) 
				+" HTTP/1.0\r\n"+ getBaseHeads()+"\r\n";
			sendMessage(cmd);
			receiveMessage();
		}catch(ProtocolException p) {
			p.printStackTrace();
			return;
		}catch(UnknownHostException e) {
			e.printStackTrace();
			return;
		}catch(IOException i){
			i.printStackTrace();
			return;
		}
	}
	/*
	* HEAD?????URL????,???URL??????????????
	* ????,?????????????
	*/
	public void HEAD(String url) {
		try {
			checkHTTP(url);
			openServer(target.getHost(),target.getPort() );
			String cmd = "HEAD "+getURLFormat(target)
				+" HTTP/1.0\r\n"+getBaseHeads()+"\r\n";
			sendMessage(cmd);
			receiveMessage();
		}catch(ProtocolException p) {
			p.printStackTrace();
			return;
		}catch(UnknownHostException e) {
			e.printStackTrace();
			return;
		}catch(IOException i){
			i.printStackTrace();
			return;
		}
	}
	
	/*
	* POST???????????,?????????????????????
	* ?????
	*/
	public void POST(String url,String content) {
		try {
			checkHTTP(url);
			openServer(target.getHost(),target.getPort() );
			String cmd = "POST "+ getURLFormat(target) 
				+"HTTP/1.0\r\n"+getBaseHeads();
			cmd += "Content-type: application/x-www-form-urlencoded\r\n";
			cmd += "Content-length: " + content.length() + "\r\n\r\n";
			cmd += content+"\r\n";
			sendMessage(cmd);
			receiveMessage();
		}catch(ProtocolException p) {
			p.printStackTrace();
			return;
		}catch(UnknownHostException e) {
			e.printStackTrace();
			return;
		}catch(IOException i){
			i.printStackTrace();
			return;
		}
	}
	
	protected void checkHTTP(String url) throws ProtocolException {
		try {
			URL target = new URL(url);
			if(target==null || !target.getProtocol().toUpperCase().equals("HTTP") )
				throw new ProtocolException("???HTTP??");
			this.target = target;
		}catch(MalformedURLException m) {
			throw new ProtocolException("??????");
		}
	}
	
	/*
	* ?Web??????????Web???,InetAddress???UnknownHostException
	* ????Socket????,???IOException???
	*/
	protected void openServer(String host,int port) throws
		UnknownHostException,IOException {
		header.clear();
		responseMessage=""; 
		responseCode=-1;
		try {
			if(client!=null) closeServer();
			if(byteStream != null) {
				byteStream.close(); 
				byteStream=null;
			}
			InetAddress address = InetAddress.getByName(host);
			client = new Socket(address,port==-1?80:port);
			sender = new BufferedOutputStream(client.getOutputStream());
			receiver = new BufferedInputStream(client.getInputStream());
		}catch(UnknownHostException u) {
			throw u;
		}catch(IOException i) {
			throw i;
		}
	}
	/* ???Web?????? */
	protected void closeServer() throws IOException {
		if(client==null) return;
		try {
			client.close(); 
			sender.close(); 
			receiver.close();
		}catch(IOException i) {
			throw i;
		}
		client=null; 
		sender=null; 
		receiver=null;
	}
	
	protected String getURLFormat(URL target) {
		String spec = "http://"+target.getHost();
		if(target.getPort()!=-1)
			spec+=":"+target.getPort();
		return spec+=target.getFile();
	}
	
	/* ?Web??????? */
	protected void sendMessage(String data) throws IOException{
		sender.write(data.getBytes(),0,data.length());
		sender.flush();
	}
	
	/* ????Web?????? */
	protected void receiveMessage() throws IOException{
		byte data[] = new byte[1024];
		int count=0;
		int word=-1;
		// ?????
		while( (word=receiver.read())!=-1 ) {
			if(word=='\r'||word=='\n') {
				word=receiver.read();
				if(word=='\n') 
					word=receiver.read();
				break;
			}
			if(count == data.length) 
				data = addCapacity(data);
			data[count++]=(byte)word;
		}
		String message = new String(data,0,count);
		int mark = message.indexOf(32);
		serverVersion = message.substring(0,mark);
		while( mark<message.length() && message.charAt(mark+1)==32 ) 
			mark++;
		responseCode = Integer.parseInt(message.substring(mark+1,mark+=4));
		responseMessage = message.substring(mark,message.length()).trim();
		// ?????????????
		switch(responseCode) {
			case 400:
				throw new IOException("????");
			case 404:
				throw new FileNotFoundException( getURLFormat(target) );
			case 503:
				throw new IOException("??????" );
		}
		if(word==-1) 
			throw new ProtocolException("????????");
		int symbol=-1;
		count=0;
		// ?????
		while( word!='\r' && word!='\n' && word>-1) {
			if(word=='\t') 
				word=32;
			if(count==data.length) 
				data = addCapacity(data);
			data[count++] = (byte)word;
parseLine: {
			while( (symbol=receiver.read()) >-1 ) {
				switch(symbol) {
					case '\t':
						symbol=32; 
						break;
					case '\r':
					case '\n':
						word = receiver.read();
						if( symbol=='\r' && word=='\n') {
							word=receiver.read();
						if(word=='\r') 
							word=receiver.read();
						}
						if( word=='\r' || word=='\n' || word>32) 
							break parseLine;
						symbol=32; 
						break;
				}
				if(count==data.length) 
					data = addCapacity(data);
				data[count++] = (byte)symbol;
			}
			word=-1;
			}
			message = new String(data,0,count);
			mark = message.indexOf(':');
			String key = null;
			if(mark>0) 
				key = message.substring(0,mark);
			mark++;
			while( mark<message.length() && message.charAt(mark)<=32 ) 
				mark++;
			String value = message.substring(mark,message.length() );
			header.put(key,value);
			count=0;
		}
		// ??????
		while( (word=receiver.read())!=-1) {
			if(count == data.length) 
				data = addCapacity(data);
			data[count++] = (byte)word;
		}
		if(count>0) 
			byteStream = new ByteArrayInputStream(data,0,count);
		data=null;
		closeServer();
	}
	
	public String getResponseMessage() {
		return responseMessage;
	}
	
	public int getResponseCode() {
		return responseCode;
	}
	
	public String getServerVersion() {
		return serverVersion;
	}
	
	public InputStream getInputStream() {
		return byteStream;
	}
	
	public synchronized String getHeaderKey(int i) {
		if(i>=header.size()) 
			return null;
		Enumeration enum = header.propertyNames();
		String key = null;
		for(int j=0; j<=i; j++)
			key = (String)enum.nextElement();
		return key;
	}
	public synchronized String getHeaderValue(int i) {
		if(i>=header.size()) 
			return null;
		return header.getProperty(getHeaderKey(i));
	}
	
	public synchronized String getHeaderValue(String key) {
		return header.getProperty(key);
	}
	
	protected String getBaseHeads() {
		String inf = "User-Agent: myselfHttp/1.0\r\n"+
			"Accept: www/source; text/html; image/gif; */*\r\n";
		return inf;
	}
	
	private byte[] addCapacity(byte rece[]){
		byte temp[] = new byte[rece.length+1024];
		System.arraycopy(rece,0,temp,0,rece.length);
		return temp;
	}
	
	public static void main(String args[]){
		Frame f = new Frame("HTTPClient");
		Label l = new Label("http://");
		TextField tf = new TextField("127.0.0.1",20);
		TextArea ta = new TextArea();
		HTTPClient hc = new HTTPClient("http://127.0.0.1");
		f.add(l);
		f.add(tf);
		f.pack();
	}
}