httpclient5/src/test/java/org/apache/hc/client5/http/examples/ClientWithResponseHandler.java

/*
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 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
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 * <http://www.apache.org/>.
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 */

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);
        }
    }

}