HTTP（POST、GET、PUT和DELETE）请求方法示例

提前引入http相关依赖

<!-- http请求相关 -->
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpcore</artifactId>
			<version>4.4.6</version>
		</dependency>
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
			<version>4.5.2</version>
		</dependency>
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpmime</artifactId>
			<version>4.5.2</version>
		</dependency>

HTTP请求示例代码如下：

package com.itigation.tools;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpDelete;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.entity.StringEntity;
import org.apache.http.entity.mime.FormBodyPart;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import net.sf.json.JSONObject;

/**
 * Http请求工具类
 *
 * @author DaiHaijiao
 *
 */
@SuppressWarnings("deprecation")
public class HttpUtil {

	/**
	 * HTTP GET请求
	 * 
	 * @see此get请求若无参数,则params传null
	 * 
	 * @param url
	 * @param params
	 * @param headerMap
	 * 
	 * @return
	 * @throws ParseException
	 * @throws UnsupportedEncodingException
	 * @throws IOException
	 */
	public static String get(String url, Map<String, Object> params, Map<String, String> headerMap) throws ParseException, UnsupportedEncodingException, IOException {
		String jsonStr = null;
		HttpGet httpGet = new HttpGet(getOrPutNewUrl(url, params));
		if (null != headerMap && !headerMap.isEmpty()) {
			for (String key : headerMap.keySet()) {
				httpGet.setHeader(key, headerMap.get(key));
			}
		}
		// RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(10000).setConnectionRequestTimeout(8000).build();
		// CloseableHttpClient httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();
		CloseableHttpClient httpClient = HttpClientBuilder.create().build();
		CloseableHttpResponse response = httpClient.execute(httpGet);
		HttpEntity entity = response.getEntity();
		if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
		} else {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			throw new IllegalArgumentException(jsonStr);
		}
		return jsonStr;
	}

	/**
	 * HTTP PUT请求
	 * 
	 * @see此put请求若无参数,则params传null
	 * 
	 * @param url
	 * @param params
	 * @return
	 * @throws ClientProtocolException
	 * @throws IOException
	 */
	public static String put(String url, Map<String, Object> params) throws ClientProtocolException, IOException {
		String jsonStr = null;
		HttpPut httpPut = new HttpPut(getOrPutNewUrl(url, params));
		// RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(10000).setConnectionRequestTimeout(8000).build();
		// CloseableHttpClient httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();
		CloseableHttpClient httpClient = HttpClientBuilder.create().build();
		CloseableHttpResponse response = httpClient.execute(httpPut);
		HttpEntity entity = response.getEntity();
		if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
		} else {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
			throw new IllegalArgumentException(jsonStr);
		}
		return jsonStr;
	}

	/**
	 * 封装get请求参数
	 * 
	 * @param url
	 * @param params
	 * @return
	 * @throws ParseException
	 * @throws UnsupportedEncodingException
	 * @throws IOException
	 */
	private static String getOrPutNewUrl(String url, Map<String, Object> params) throws ParseException, UnsupportedEncodingException, IOException {
		if (null != params && !params.isEmpty()) {
			List<NameValuePair> pairs = new ArrayList<NameValuePair>(params.size());
			for (String key : params.keySet()) {
				pairs.add(new BasicNameValuePair(key, params.get(key).toString()));
			}
			url += "?" + EntityUtils.toString(new UrlEncodedFormEntity(pairs, "UTF-8"));
		}
		return url;
	}

	/**
	 * HTTP POST请求
	 * 
	 * @see此post请求若无参数,则params传null
	 * 
	 * @param url
	 * @param params
	 * @param headerMap
	 * @return
	 * @throws ClientProtocolException
	 * @throws IOException
	 */
	public static String httpPost(String url, Map<String, Object> params, Map<String, String> headerMap) throws ClientProtocolException, IOException {
		String jsonStr = null;
		// RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(10000).setConnectionRequestTimeout(8000).build();
		// CloseableHttpClient httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();
		CloseableHttpClient httpClient = HttpClientBuilder.create().build();
		HttpPost httpPost = new HttpPost(url);
		if (null != headerMap && !headerMap.isEmpty()) {
			for (String key : headerMap.keySet()) {
				httpPost.setHeader(key, headerMap.get(key));
			}
		}
		if (null != params && !params.isEmpty()) {
			httpPost.setEntity(new StringEntity(JSONObject.fromObject(params).toString(), "UTF-8"));
		}

		CloseableHttpResponse response = httpClient.execute(httpPost);
		HttpEntity entity = response.getEntity();
		if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
		} else {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
			throw new IllegalArgumentException(jsonStr);
		}
		return jsonStr;
	}

	/**
	 * HTTP POST请求
	 * 
	 * @see此post请求若无参数,则params传null;若无文件,则file和fileKey都传null
	 * 
	 * @param url
	 *            请求url
	 * @param params
	 *            请求参数
	 * @param file
	 *            请求文件
	 * @param fileKey
	 *            文件对应key,接口通过此key接收文件
	 * @param headerMap
	 *            http请求的header
	 * @return
	 * @throws ClientProtocolException
	 * @throws IOException
	 */
	public static String post(String url, Map<String, Object> params, File file, String fileKey, Map<String, String> headerMap) throws ClientProtocolException, IOException {
		String jsonStr = null;
		// RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(10000).setConnectionRequestTimeout(8000).build();
		// CloseableHttpClient httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();
		CloseableHttpClient httpClient = HttpClientBuilder.create().build();
		HttpPost httpPost = new HttpPost(url);
		if (null != headerMap && !headerMap.isEmpty()) {
			for (String key : headerMap.keySet()) {
				httpPost.setHeader(key, headerMap.get(key));
			}
		}
		httpPost.setEntity(postParamsEntry(params, file, fileKey));

		CloseableHttpResponse response = httpClient.execute(httpPost);
		HttpEntity entity = response.getEntity();
		if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
		} else {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
			throw new IllegalArgumentException(jsonStr);
		}
		return jsonStr;
	}

	/**
	 * 封装post请求参数
	 * 
	 * @param params
	 * @param file
	 * @param fileKey
	 * @return
	 * @throws UnsupportedEncodingException
	 */
	private static MultipartEntity postParamsEntry(Map<String, Object> params, File file, String fileKey) throws UnsupportedEncodingException {
		MultipartEntity entity = new MultipartEntity();
		if (null != file && file.isFile() && null != fileKey && !"".equals(fileKey.trim())) {
			FileBody fileBody = new FileBody(file);
			FormBodyPart filePart = new FormBodyPart(fileKey, fileBody);
			entity.addPart(filePart);
		}
		if (null != params && !params.isEmpty()) {
			Iterator<String> iterator = params.keySet().iterator();
			while (iterator.hasNext()) {
				String key = iterator.next();
				FormBodyPart field = new FormBodyPart(key, new StringBody(params.get(key) + "", Charset.forName("UTF-8")));
				entity.addPart(field);
			}
		}
		return entity;
	}

	/**
	 * HTTP DELETE请求
	 * 
	 * @see此delete请求仅限于宇视接口调用
	 * 
	 * @param url
	 * @param someParam 
	 * @return String
	 * @throws ClientProtocolException
	 * @throws IOException
	 */
	public static String delete(String url, String someParam, Map<String, String> headerMap) throws ClientProtocolException, IOException {
		String jsonStr = null;
		HttpDelete httpDelete = new HttpDelete(url + "/" + someParam);
		if (null != headerMap && !headerMap.isEmpty()) {
			for (String key : headerMap.keySet()) {
				httpDelete.setHeader(key, headerMap.get(key));
			}
		}
		// RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(10000).setConnectionRequestTimeout(8000).build();
		// CloseableHttpClient httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();
		CloseableHttpClient httpClient = HttpClientBuilder.create().build();
		CloseableHttpResponse response = httpClient.execute(httpDelete);
		HttpEntity entity = response.getEntity();
		if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
		} else {
			jsonStr = EntityUtils.toString(entity, "UTF-8");
			response.close();
			httpClient.close();
			throw new IllegalArgumentException(jsonStr);
		}
		return jsonStr;
	}

	/**
	 * 返回响应正文(无乱码)
	 * 
	 * @param response
	 * @return String
	 */
	public static String getResponseString(HttpResponse response) {
		HttpEntity entity = response.getEntity();// 响应实体类
		StringBuilder result = new StringBuilder();// 响应正文
		if (entity != null) {
			byte[] bytes = new byte[4096];
			int size;
			InputStream instream = null;
			try {
				instream = entity.getContent();
				while ((size = instream.read(bytes)) > 0) {
					String str = new String(bytes, 0, size, "utf-8");
					result.append(str);
				}
			} catch (IOException e) {
				e.printStackTrace();
			} finally {
				try {
					if (null != instream) {
						instream.close();
					}
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return result.toString();
	}

	public static void main(String[] args) throws URISyntaxException, IOException {
		// 测试get请求---无参
		// String jsonStr = HttpUtil.get("http://localhost:8080/Test/testGet", null);
		// System.out.println(jsonStr);
		// 测试get请求---有参<无文件>
		// Map<String, Object> map = new HashMap<String, Object>();
		// map.put("a", "aaa");
		// map.put("b", 666);
		// String jsonStr = HttpUtil.get("http://localhost:8080/Test/testGetAndParam", map);
		// System.out.println(jsonStr);
		// 测试put请求---无参
		// String jsonStr = HttpUtil.put("http://localhost:8080/Test/testPut", null);
		// System.out.println(jsonStr);
		// 测试put请求---有参<无文件>
		// Map<String, Object> map = new HashMap<String, Object>();
		// map.put("a", "aaa");
		// map.put("b", 666);
		// String jsonStr = HttpUtil.put("http://localhost:8080/Test/testPutAndParam", map);
		// System.out.println(jsonStr);
		// 测试post请求---无参
		// String jsonStr = HttpUtil.postUrl("http://localhost:8080/Test/testPost", null);
		// System.out.println(jsonStr);
		// 测试post请求---有参<无文件>
		// Map<String, Object> map = new HashMap<String, Object>();
		// map.put("a", "aaa");
		// map.put("b", 666);
		// String jsonStr = HttpUtil.post("http://localhost:8080/Test/testPostAndParam", map, null, null);
		// System.out.println(jsonStr);
		// 测试post请求---有参<有文件>
		// Map<String, Object> map = new HashMap<String, Object>();
		// map.put("a", "aaa");
		// map.put("b", 666);
		// String jsonStr = HttpUtil.post("http://localhost:8080/Test/testPostAndParamAndFile", map, new File("C:/Users/DaiHaijiao/Pictures/ll.jpg"), "imgFile");
		// System.out.println(jsonStr);
	}

}