java httpclient简单使用

httpClient 官网

https://hc.apache.org/index.html

https://hc.apache.org/httpcomponents-client-5.1.x/index.html#

这里以httpClient5.1为列

httpClient5.1基本使用

进入后，可以看到常用demo的一些源代码：

package org.apache.hc.client5.http.examples;

import java.io.IOException;

import org.apache.hc.client5.http.ClientProtocolException;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.ClassicHttpResponse;
import org.apache.hc.core5.http.HttpEntity;
import org.apache.hc.core5.http.HttpStatus;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.io.HttpClientResponseHandler;
import org.apache.hc.core5.http.io.entity.EntityUtils;

/**
 * This example demonstrates the use of the {@link HttpClientResponseHandler} to simplify
 * the process of processing the HTTP response and releasing associated resources.
 */
public class ClientWithResponseHandler {

    public static void main(final String[] args) throws Exception {
        try (final CloseableHttpClient httpclient = HttpClients.createDefault()) {
            final HttpGet httpget = new HttpGet("http://httpbin.org/get");

            System.out.println("Executing request " + httpget.getMethod() + " " + httpget.getUri());

            // Create a custom response handler
            final HttpClientResponseHandler<String> responseHandler = new HttpClientResponseHandler<String>() {

                @Override
                public String handleResponse(
                        final ClassicHttpResponse response) throws IOException {
                    final int status = response.getCode();
                    if (status >= HttpStatus.SC_SUCCESS && status < HttpStatus.SC_REDIRECTION) {
                        final HttpEntity entity = response.getEntity();
                        try {
                            return entity != null ? EntityUtils.toString(entity) : null;
                        } catch (final ParseException ex) {
                            throw new ClientProtocolException(ex);
                        }
                    } else {
                        throw new ClientProtocolException("Unexpected response status: " + status);
                    }
                }

            };
            final String responseBody = httpclient.execute(httpget, responseHandler);
            System.out.println("----------------------------------------");
            System.out.println(responseBody);
        }
    }

}

httpclient5.1 使用maven依赖

 

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