用Java实现一个简单的HTTP服务器

原创 ╰+攻爆jí腚メ 2024-10-18 21:30 58阅读 0赞

在Java中，我们可以使用内置的`ServerSocket`和`Socket`类来实现一个简单的HTTP服务器。以下是一个基本的例子：

```java
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

public class SimpleHttpServer {
    private static final int PORT = 8000; // Change this to your desired port

public static void main(String[] args) {
        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
            System.out.println("HTTP Server is listening on port " + PORT);

while (true) {
                Socket clientSocket = serverSocket.accept();
                System.out.println("New connection from " + clientSocket.getRemoteSocketAddress()));

String requestLine = readRequest(clientSocket);
                if ("EXIT".equalsIgnoreCase(requestLine)) {
                    break;
                }

OutputStream responseOutputStream = clientSocket.getOutputStream();
                writeResponse(responseOutputStream, requestLine);
            }
        } catch (IOException e) {
            System.err.println("Error occurred while running the HTTP server: " + e.getMessage());
            e.printStackTrace();
        }
    }

private static String readRequest(Socket socket) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())));

StringBuilder requestLine = new StringBuilder();
        String line;

while ((line = in.readLine()) != null) {
            if (requestLine.length() > 0) {
                // We already have a non-empty request line
                break;
            }

// The first line is the request line
            if (!line.startsWith("GET")) && !line.startsWith("POST")) {
                System.err.println("Invalid request format! Expected 'GET' or 'POST'.");
                return null;
            }
            requestLine.append(line.trim() + "\n"));
        }

in.close();

// Remove the newline from the end of the request line
        requestLine.setLength(requestLine.length() - 1));

return requestLine.toString();
    }

private static void writeResponse(OutputStream outputStream, String requestLine) throws IOException {
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream)));

StringBuilder responseStatusLine = new StringBuilder("HTTP/1.1 ");
        responseStatusLine.append(200); // This is a dummy status code for demonstration purposes

writer.write(responseStatusLine.toString() + "\n\n"));

if ("GET".equals(requestLine.split(" ")[0])) || "POST".equals(requestLine.split(" ")[0]))) {
            writer.write(requestLine + "\n\n");
        }

writer.flush();
    }
}
```

这个简单的HTTP服务器会在`8000`端口监听请求，处理基本的`GET`和`POST`请求，并返回一个简单的响应。