apache.http.impl.client.HttpClients

try (CloseableHttpClient httpClient = HttpClients.custom().disableAutomaticRetries().build()) {
	HttpPost httpPost = new HttpPost("http://www.baidu.com");
	
	try (CloseableHttpResponse response = httpClient.execute(httpPost)) {
		int statusCode = response.getStatusLine().getStatusCode();
	}
}

package com.example.demo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class Main {

	public static void main(String[] args) throws IOException {
		try (CloseableHttpClient httpClient = HttpClients.custom().disableAutomaticRetries().build()) {
			HttpPost httpPost = new HttpPost("http://www.baidu.com");
			// HttpGet httGet = new HttpGet("http://www.baidu.com");
			// httpPost.setEntity("");
			// httpPost.setHeader("Accept", "application/json");
			// httpPost.setHeader("Content-Type", "application/json");

			try (CloseableHttpResponse response = httpClient.execute(httpPost)) {
				int statusCode = response.getStatusLine().getStatusCode();
				InputStream inputStream = response.getEntity().getContent();
				readByChars(inputStream);

				InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
				readWithBufferedReader(inputStreamReader);
				if (statusCode != 200) {
					final HttpEntity entity = response.getEntity();
					final String result = EntityUtils.toString(entity);

					System.out.println(result);
				}
			}
		}

	}

	/**
	 * 以字符为单位读取文件，常用于读文本，数字等类型的文件
	 */
	public static void readByChars(InputStream inputStream) {

		InputStreamReader reader = null;
		// try {
		// 	System.out.println("以字符为单位读取文件内容，一次读一个字节：");
		// 	//1. 一次读一个字符
		// 	reader = new InputStreamReader(inputStream);//可以是任意的InputStream类，不一定必须是FileInputStream
		// 	int tempchar;
		// 	while ((tempchar = reader.read()) != -1) {
		// 		if (((char)tempchar) != '\r') {
		// 			System.out.print((char)tempchar);
		// 		}
		// 	}
		// 	reader.close();
		// } catch (Exception e) {
		// 	e.printStackTrace();
		// }

		try {
			System.out.println("以字符为单位读取文件内容，一次读多个字节：");
			//2. 一次读多个字符
			char[] tempchars = new char[30];
			int charread = 0;
			reader = new InputStreamReader(inputStream);
			while ((charread = reader.read(tempchars)) != -1) {
				for (int i = 0; i < charread; i++) {
					if (tempchars[i] != '\r') {
						System.out.print(tempchars[i]);
					}
				}
			}

		} catch (Exception e1) {
			e1.printStackTrace();
		} finally {
			if (reader != null) {
				try {
					reader.close();
				} catch (IOException e1) {
				}
			}
		}
	}

	public static void readWithBufferedReader(InputStreamReader inputStreamReader) {
		BufferedReader reader = null;
		try {
			reader = new BufferedReader(inputStreamReader);
			String tempString = null;
			int line = 1;
			// 一次读入一行，直到读入null为文件结束
			while ((tempString = reader.readLine()) != null) {
				System.out.println("line " + line + ": " + tempString);
				line++;
			}
			reader.close();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (reader != null) {
				try {
					reader.close();
				} catch (IOException e1) {
				}
			}
		}
	}

}

参考文章