Apache HTTPCORE framework in the Java class library's application and principle analysis (Analysis of Application and Principles of Apache HTTPCORE FRAMEWORK in Java Class Libraares)
The application and principle analysis of the Apache HTTPCORE framework in the Java library
Overview:
Apache HTTPCORE is an open source JAVA library for building a high -performance server -side and client application based on the HTTP protocol.It provides a set of rich APIs to handle HTTP requests and responses, build HTTP services, and implement HTTP clients.This article will analyze the application and principles of the Apache HTTPCORE framework in the Java class library, and provide some Java code examples to help readers better understand and use the framework.
Application scenario:
1. Build a server -side application based on the HTTP protocol: Apache HTTPCORE framework provides a set of flexible and easy -to -use APIs for processing HTTP requests and responses.Developers can use these APIs to build custom HTTP services, such as the RESTFUL -based Web service or proxy server.
The following is a simple example. Demonstrate how to use the HTTPCORE framework to build a basic HTTP server:
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.HttpVersion;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.DefaultHttpResponseFactory;
import org.apache.http.params.CoreConnectionPNames;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.HttpRequestHandler;
import org.apache.http.protocol.HttpRequestHandlerRegistry;
import org.apache.http.protocol.HttpService;
import org.apache.http.protocol.ResponseConnControl;
import org.apache.http.protocol.ResponseContent;
import org.apache.http.protocol.ResponseDate;
import org.apache.http.protocol.ResponseServer;
import org.apache.http.protocol.UriHttpRequestHandlerMapper;
import org.apache.http.protocol.VersionInfo;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
public class SimpleHttpServer {
public static void main(String[] args) throws IOException {
int port = 8080;
// Create a server socket
ServerSocket serverSocket = new ServerSocket(port);
// Create an HTTP processor registration form
HttpRequestHandlerRegistry registry = new HttpRequestHandlerRegistry();
// Register processing procedure
registry.register("/hello", new HelloWorldHandler());
// Create HTTP service
HttpService httpService = new HttpService(
new CustomHttpProcessor(),
new DefaultConnectionReuseStrategy(),
new DefaultHttpResponseFactory(),
registry,
null
);
// Start the server
while (true) {
Socket socket = serverSocket.accept();
HttpContext context = new BasicHttpContext(null);
httpService.handleRequest(socket, context);
socket.close();
}
}
static class HelloWorldHandler implements HttpRequestHandler {
@Override
public void handle(org.apache.http.HttpRequest request, HttpResponse response, HttpContext context) throws org.apache.http.HttpException, IOException {
response.setStatusCode(HttpStatus.SC_OK);
response.setEntity(new StringEntity("Hello, World!"));
}
}
static class CustomHttpProcessor implements HttpProcessor {
@Override
public void process(org.apache.http.HttpRequest request, HttpContext context) throws org.apache.http.HttpException, IOException {
VersionInfo vi = VersionInfo.loadVersionInfo("org.apache.http", getClass().getClassLoader());
response.addHeader("Server", "CustomServer/1.0");
}
}
}
2. Client application based on the HTTP protocol: The Apache HTTPCORE framework also provides a set of powerful APIs to achieve the HTTP client.By using these APIs, developers can easily send HTTP requests, handle HTTP responses, and management words.Developers can also use the HTTPCORE interceptor mechanism to define and customize the HTTP client.
The following is a simple example. Demonstrate how to build a basic HTTP client with the HTTPCORE framework:
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.params.HttpParams;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class SimpleHttpClient {
public static void main(String[] args) throws IOException {
String url = "http://example.com";
// Create an HTTP client
HttpClient httpClient = createHttpClient();
// Create HTTP GET request
HttpGet httpGet = new HttpGet(url);
// Send a request and get a response
HttpResponse httpResponse = httpClient.execute(httpGet);
// Read the response content
BufferedReader reader = new BufferedReader(new InputStreamReader(httpResponse.getEntity().getContent()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
// Turn off the connection manager
httpClient.getConnectionManager().shutdown();
}
private static HttpClient createHttpClient() {
// Create an HTTP parameter and set the protocol version
HttpParams params = new BasicHttpParams();
params.setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);
// Create the default HTTP client
return new DefaultHttpClient(params);
}
}
Original analysis:
1. Core component:
-Httpprocessor: The interceptor chain for handling HTTP requests and response, including the request interceptor and response interceptor.
-Httprequesthandler: HTTP processor for processing a specific request URI.
-HttprequestHandlerRegistry: The registry for managing multiple httprequestHandler.
-HTTPSERVICE: The main components used to handle HTTP requests are responsible for finding the corresponding httprequestHandler according to the request URI, and handed the request and response to it for processing.
2. Process process:
-Colon the HTTPSERVER or HTTPClient instance and configure the necessary settings.
-But on HTTPSERVER or send HTTP request.
-Es when HTTPSERVER receives the HTTP request, it will find the corresponding httprequesthandler according to the request URI, and hand over the request and response to it for processing.
-Httprequesthandler generates response based on the request content, and then returns the response to HTTPSERVER.
-HTTPSERVER will return to the client or the next interceptor.
3. Interceptor mechanism:
-HTTPPROCESSOR uses the interceptor chain to process HTTP requests and responses.Developers can customize and customize the interceptor in the interceptor chain to achieve specific functions.
-The request interceptor: Do some processing before sending the request, such as setting the request header, processing cookies, etc.
-A response interceptor: Do some processing after receiving the response, such as parsing response content, processing cookies, etc.
4. Network communication:
-HTTPSERVER uses Serversocket to listen to the specified port and receive the HTTP request of the client.
-HTTPClient uses sockets to communicate with the server, send HTTP requests and receive response.
Summarize:
The Apache HTTPCORE framework is a powerful and easy -to -use Java class library to build a high -performance server -side and client application based on the HTTP protocol.By using the HTTPCORE framework, developers can easily handle HTTP requests and responses, build HTTP services, and implement HTTP clients.The interceptor mechanism and flexible API design enables developers to customize and customize HTTP applications according to their needs.Whether it is building a RESTFUL Web service or a customized HTTP client, the Apache HTTPCORE framework is an indispensable tool.
