Http服务器版本2.

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class HttpServerV2 {
    //1、修改代码格式
    //2、解析url中的包含的参数
    //3、演示cookie工作流程
    private ServerSocket serverSocket = null;
    public HttpServerV2(int port) throws IOException {
        serverSocket = new ServerSocket(port);
    }
    public void start() throws IOException {
        System.out.println("服务器启动");

        ExecutorService executorService = Executors.newCachedThreadPool();
        while (true) {
            Socket clienSocket = serverSocket.accept();
            executorService.execute(new Runnable() {
                @Override
                public void run() {
                    try {
                        process(clienSocket);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    }

    private void process(Socket clienSocket) throws IOException {

        try {
            //1、读取请求并解析
            HttpRequest request = HttpRequest.build(clienSocket.getInputStream());
            System.out.println("request: "+request);
            HttpResponse response = HttpResponse.build(clienSocket.getOutputStream());
            //2、根据请求计算响应
            response.setHeader("content-type","text/html");
            if (request.getUrl().startsWith("/hello")) {
                response.setStatus(200);
                response.setMessage("OK");
                response.writeBody("
hello
");
            } else if (request.getUrl().startsWith("/calc")) {
                String aStr =  request.getParameters("a");
                String bStr = request.getParameters("b");
                int a = Integer.parseInt(aStr);
                int b = Integer.parseInt(bStr);
                int result = a + b;
                response.setStatus(200);
                response.setMessage("OK");
                response.writeBody("
result = "+result+"
");
            } else if (request.getUrl().startsWith("/cookie")){
                response.setStatus(200);
                response.setMessage("OK");
                response.setHeader("set-cookie","user=yfy time="+ System.currentTimeMillis()/1000);
                response.writeBody("
set-cookie
");
            } else{
                response.setStatus(200);
                response.setMessage("OK");
                response.writeBody("
default
");
            }

            //3、把响应写回到客户端
            response.flush();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            clienSocket.close();
        }
    }

    public static void main(String[] args) throws IOException {
        HttpServerV2 serverV2 = new HttpServerV2(9090);
        serverV2.start();
    }
}

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.HashMap;
import java.util.Map;

public class HttpResponse {
    //表示一个HTTP响应
    private String version = "HTTP/1.1";
    private int status; //状态码
    private String message; //状态码的描述信息
    private Map headers = new HashMap<>();
    private StringBuilder body = new StringBuilder();//方便拼接
    //需要把响应写回到客户端时，写到outputStream中去
    private OutputStream outputStream = null;

    public static HttpResponse build(OutputStream outputStream) {
        HttpResponse response = new HttpResponse();
        response.outputStream = outputStream;
        return response;
    }

    public void setVersion(String version) {
        this.version = version;
    }

    public void setStatus(int status) {
        this.status = status;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public void setHeader(String key, String value) {
        headers.put(key,value);
    }

    public void writeBody(String content) {
        body.append(content);
    }

    public void flush() throws IOException {
        BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream));
        bufferedWriter.write(version +" "+ status +" "+ message + "\n");
        headers.put("content-Length: " ,body.toString().getBytes().length+"");
        for (Map.Entry entry : headers.entrySet()) {
            System.out.println(entry.getKey()+":"+entry.getValue()+"\n");
        }
        bufferedWriter.write("\n");
        bufferedWriter.write(body.toString());
        bufferedWriter.flush();
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;

public class HttpRequest {
    private String method;
    private String url;
    private String version;
    private Map headers = new HashMap<>();
    private Map parameters = new HashMap<>();

    //请求的构造逻辑，也使用工厂模式
    //此处的参数是从socket中获取到的InputStream对象
    public static HttpRequest build(InputStream inputStream) throws IOException {
        HttpRequest request = new HttpRequest();
        //此处的逻辑中，不能把bufferedread写到try中，写进去意味着bufferedreader会被关闭
        //影响clientSocket的状态
        //等到整个请求处理完了再关闭
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        //build的过程就是解析请求的过程
        //1、解析首行
        String firstLine = bufferedReader.readLine();
        String[] firstLineTokens = firstLine.split(" ");
        request.method = firstLineTokens[0];
        request.url = firstLineTokens[1];
        request.version = firstLineTokens[2];
        //2、解析url中的参数 /index.html?a=10&b=20
        int post = request.url.indexOf("?");
        if (post != -1) {
            //看看url中是否有？，如果没有说明不带参数，也就不用解析
            String parameters = request.url.substring(post+1);//a=10&b=20
            parseKV(parameters, request.parameters);
        }
        //3、解析header
        String line = "";
        while ((line = bufferedReader.readLine()) != null && line.getBytes().length != 0){
            String[] headerTokens = line.split(": ");
            request.headers.put(headerTokens[0],headerTokens[1]);
        }
        //4、解析body
        return request;
    }

    private static void parseKV(String input, Map output) {
        //按照&切分成若干组键值对
        String[] KVTokens = input.split("&");
        //按照切分结果再进行=切分
        for(String KV : KVTokens) {
            String[] result = KV.split("=");
            output.put(result[0],result[1]);
        }
    }

    //给这个类构造一些getter方法
    //请求的对象是从网络上解析来的，所以不需要setter

    public String getMethod() {
        return method;
    }

    public String getUrl() {
        return url;
    }

    public String getVersion() {
        return version;
    }

    public String getHeader (String key) {
        return headers.get(key);
    }

    public String getParameters (String key) {
        return parameters.get(key);
    }

    @Override
    public String toString() {
        return "HttpRequest{" +
                "method='" + method + '\'' +
                ", url='" + url + '\'' +
                ", version='" + version + '\'' +
                ", headers=" + headers +
                ", parameters=" + parameters +
                '}';
    }
}