<满血复活之Tomcat原理实现> 创建一个基本的Server

今天看了How Tomcat work的第一章。

关键有三个类.

　　..HttpServer
　　..Request

　　..Response

HttpServer  主要是有个方法能处理http发起请求的url 

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;

public class HttpServer {
public static final String WEB_ROOT=System.getProperty("user.dir")+File.separator+"webroot";

private static final String SHUTDOWN_COMMAND="/shutdown";

boolean shutdown = false;

public void await() throws IOException{
ServerSocket serverSocket = null;
int port = 8080;

try {
serverSocket = new ServerSocket(port,1,InetAddress.getByName("127.0.0.1"));
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
System.exit(1);
}

while(!shutdown){
Socket socket = null;
InputStream input = null;
OutputStream output = null;


socket = serverSocket.accept();
input = socket.getInputStream();
output = socket.getOutputStream();

Request request = new Request(input);
request.parse();


Response response = new Response(output);
response.setRequest(request);
response.sendStaticResourse();

socket.close();

shutdown = request.getUri().equals(SHUTDOWN_COMMAND);
}

}


public static void main(String[] args) throws IOException {
HttpServer hs = new HttpServer();
hs.await();
System.out.println(WEB_ROOT);
}

}

Request类 处理socket流里面信息

import java.io.IOException;
import java.io.InputStream;

public class Request {
InputStream input = null;
String uri = null;
public Request(InputStream input) {
this.input = input;
}

public void parse(){
StringBuffer request = new StringBuffer(2048);

int i ;

byte[] buffer = new byte[2048];

try{
i = input.read(buffer);

}catch(IOException e){
e.printStackTrace();
i = -1;
}

for (int j=0; j < i; j++){
request.append(buffer[j]);
}

System.out.println(request.toString());
uri = parseUri(request.toString());
}


public String parseUri(String url){
int index1,index2;
index1 = url.indexOf(" ");
if(index1 != -1){
index2 = url.indexOf(" ", index1 + 1);
if(index2 > index1){
return url.substring(index1+1,index2);
}
}

return "";
}

public String getUri(){
return uri;
}
}

Response

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;

public class Response {
OutputStream output = null;
Request request = null;

public Response(OutputStream output) {
this.output = output;
}

public void setRequest(Request request){
this.request = request;
}

public void sendStaticResourse() throws IOException{
byte[] b = new byte[2048];

FileInputStream fis = null;
try {
File file = new File(HttpServer.WEB_ROOT,request.getUri());


if(file.exists()){

fis = new FileInputStream(file);
int ch = fis.read(b,0,2048);

while(ch != -1 ){
output.write(b, 0,2048);
}


}else{
String errorMessage = "HTTP/1.1 200 File Not Found " +
"Content-Type: text/html;charset=ISO-8859-1 " +
"Content-Length: 23 " +
" " +
"<h1>$)$)404 File not Found</h1>";
System.out.println(errorMessage);
output.write(errorMessage.getBytes());
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(fis != null){
fis.close();
}
}

}
}