本文来源是Apache官网例子：

httpcomponents-client/ClientAuthentication.java at 4.5.x · apache/httpcomponents-client · GitHub

之前找过很多博客上的例子发现都不对，后来还是去官网找。事实证明官网绝对比博客k

例子：

//https://github.com/apache/httpcomponents-client/blob/4.5.x/httpclient/src/examples/org/apache/http/examples/client/ClientAuthentication.java

/*
 * ====================================================================
 * 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
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */
package org.apache.http.examples.client;

import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

/**
 * A simple example that uses HttpClient to execute an HTTP request against
 * a target site that requires user authentication.
 */
public class ClientAuthentication {

    public static void main(String[] args) throws Exception {
        CredentialsProvider credsProvider = new BasicCredentialsProvider();
        credsProvider.setCredentials(
                new AuthScope("httpbin.org", 80),
                new UsernamePasswordCredentials("user", "passwd"));
        CloseableHttpClient httpclient = HttpClients.custom()
                .setDefaultCredentialsProvider(credsProvider)
                .build();
        try {
            HttpGet httpget = new HttpGet("http://httpbin.org/basic-auth/user/passwd");

            System.out.println("Executing request " + httpget.getRequestLine());
            CloseableHttpResponse response = httpclient.execute(httpget);
            try {
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());
                System.out.println(EntityUtils.toString(response.getEntity()));
            } finally {
                response.close();
            }
        } finally {
            httpclient.close();
        }
    }
}

//下面是正常http请求，直接发送json格式的作为参数传到服务器

HttpPost post = new HttpPost(url);
		//post.setHeader("Content-Type","application/json;charset=utf-8");
		StringEntity entity = new StringEntity(obj.toString(),"utf-8");
		entity.setContentEncoding("UTF-8");    
		entity.setContentType("application/json");  
		
		post.setEntity(entity);
		CloseableHttpClient createDefault = HttpClients.createDefault();
		CloseableHttpResponse result = createDefault.execute(post);
		String responseMsg = EntityUtils.toString(result.getEntity(),"UTF-8"));