HttpClient方式调用接口的实例

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使用HttpClient的方式调用接口的实例。

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	/**
	 * 测试调用第三方接口
	 */
	@RequestMapping(value = "/test", method = RequestMethod.POST, produces = "application/json;charset=UTF-8")
	@ResponseBody
	public Response test(@RequestBody QueryMonthRentOrder query) {
		Response response = new Response<>(ResponseCodeType.SUCCESS);
		// 把对象转换成json字符串
		Gson gson = new Gson();
		String json = gson.toJson(query);
		// 请求接口地址
		String url = "https://blog.csdn.net/qq_36725282";

		HttpClient httpclient = null;
		PostMethod post = null;
		GetMethod get = null;
		try {
			// 创建连接
			httpclient = new HttpClient();
			post = new PostMethod(url);
			// 设置编码方式
			post.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, "UTF-8");
			// 添加参数
			post.setRequestBody(json);
			// 设置表头
			post.setRequestHeader("XXXXXX", "XXXXXX");
			post.setRequestHeader("Content-Type", "application/json");
			// 执行请求
			httpclient.executeMethod(post);
			// 接口返回信息
			String info = new String(post.getResponseBody(), "UTF-8");
			System.out.println("***************" + info);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			// 关闭连接，释放资源
			post.releaseConnection();
			((SimpleHttpConnectionManager) httpclient.getHttpConnectionManager()).shutdown();
		}

		response.setData("");
		return response;
	}

还有一种工具类的

package com.stars.park.util;

import java.io.IOException;
import java.io.InputStream;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;

/**
 * 测试httpclient 4.0 1. 重新设计了HttpClient 4.0 API架构，彻底从内部解决了所有 HttpClient 3.x 已知的架构缺陷代码。 2. HttpClient 4.0 提供了更简洁，更灵活，更明确的API。 3. HttpClient 4.0 引入了很多模块化的结构。 4.
 * HttpClient 4.0性能方面得到了不小的提升，包括更少的内存使用，通过使用HttpCore模块更高效完成HTTP传输。 5. 通过使用 协议拦截器(protocol interceptors), HttpClient 4.0实现了 交叉HTTP（cross-cutting HTTP protocol）
 * 协议 6. HttpClient 4.0增强了对连接的管理，更好的处理持久化连接，同时HttpClient 4.0还支持连接状态 7. HttpClient 4.0增加了插件式（可插拔的）的 重定向（redirect） 和 验证（authentication）处理。 8. HttpClient
 * 4.0支持通过代理发送请求，或者通过一组代理发送请求。 9. 更灵活的SSL context 自定义功能在HttpClient 4.0中得以实现。 10. HttpClient 4.0减少了在省城HTTP请求 和 解析HTTP响应 过程中的垃圾信息。 11. HttpClient团队鼓励所有的项目升级成
 * HttpClient 4.0
 *
 * 
 */
public class HttpClientUtils {

	// private HttpClient client;
	private CloseableHttpClient client;
	private RequestConfig requestConfig;
	private StringBuffer url = new StringBuffer();
	private String encoding = "UTF-8";
	private List params = new ArrayList();

	public HttpClientUtils(String url) {
		this.url.append(url);
		this.url.setLength(0);
		this.url.append(url);
		client = HttpClients.createDefault();
		this.requestConfig = RequestConfig.custom().setConnectTimeout(5* 1000).setSocketTimeout(8 * 1000).build();
		/*
		 * client = new DefaultHttpClient(); HttpParams params = client.getParams(); params.setParameter(CoreProtocolPNames.HTTP_CONTENT_CHARSET, encoding);
		 * params.setParameter(CoreProtocolPNames.HTTP_ELEMENT_CHARSET, encoding); params.setParameter(CoreProtocolPNames.PROTOCOL_VERSION,
		 * HttpVersion.HTTP_1_1); HttpConnectionParams.setConnectionTimeout(params, 30 * 1000);// 链接时间 HttpConnectionParams.setSoTimeout(params, 2 * 60 *
		 * 1000);// 请求时间
		 */
	}

	public String doPostWithNoParamsName(String content) {
		String result = null;
		try {
			HttpResponse response = null;
			HttpPost postMethod = new HttpPost(this.url.toString());
			StringEntity se = new StringEntity(content, "utf-8");
			se.setContentEncoding("utf-8");
			se.setContentType("application/json");
			postMethod.setEntity(se);
			postMethod.setConfig(requestConfig);
			// HttpClient client = new DefaultHttpClient();
			response = client.execute(postMethod);
			result = EntityUtils.toString(response.getEntity(), "utf-8");

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			close();
			// client.getConnectionManager().shutdown();
		}
		return result;
	}

	@SuppressWarnings("deprecation")
	public String doPost() {
		String result = null;
		try {
			HttpPost post = new HttpPost(this.url.toString());
			// 由抛异常改为catch，防止控制台输出连接失败信息
			post.setConfig(requestConfig);
			post.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
			result = getRespone(post);
		
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			close();
			// client.getConnectionManager().shutdown();
		}
		return result;
	}
	
	@SuppressWarnings("deprecation")
	public InputStream doPostForStream() {
		InputStream result = null;
		try {
			HttpPost post = new HttpPost(this.url.toString());
			// 由抛异常改为catch，防止控制台输出连接失败信息
			post.setConfig(requestConfig);
			post.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
			result = getResponeForStream(post);
		
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			close();
			// client.getConnectionManager().shutdown();
		}
		return result;
	}
	
	@SuppressWarnings("deprecation")
	public String doPostWithSetHeader(LinkedHashMap headers) {
		//HashMap无序 TreeMap根据键排序，默认升序 LinkedHashMap遍历结果跟插入顺序一致
		String result = null;
		try {
			HttpPost post = new HttpPost(this.url.toString());
			for (String key : headers.keySet()) {
				post.setHeader(key, headers.get(key));
			}
			post.setConfig(requestConfig);
			post.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
			result = getRespone(post);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			close();
			// client.getConnectionManager().shutdown();
		}
		return result;
	}
	public String doPostWithNoParamsNameSetHeader(LinkedHashMap headers,String content) {
		//HashMap无序 TreeMap根据键排序，默认升序 LinkedHashMap遍历结果跟插入顺序一致
		String result = null;
		try {
			HttpPost post = new HttpPost(this.url.toString());
			for (String key : headers.keySet()) {
				post.setHeader(key, headers.get(key));
			}
			StringEntity se = new StringEntity(content, "utf-8");
			se.setContentEncoding("utf-8");
			se.setContentType("application/json");
			post.setEntity(se);
			post.setConfig(requestConfig);
			result = getRespone(post);
			
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			close();
			// client.getConnectionManager().shutdown();
		}
		return result;
	}
	

	public void setParams(String key, Object value) {
		if (value != null) {
			params.add(new BasicNameValuePair(key, value.toString()));
		}
	}

	public void setInitUrl(String newUrl) {
		//this.url.delete(0, url.length());//清空StringBuffer方法一
		this.url.setLength(0);//清空StringBuffer方法二
		url.append(newUrl);
	}

	@SuppressWarnings("deprecation")
	public String doGet(){
		String result = null;
		try {
			int count = 0;
			for (NameValuePair nv : params) {
				if (count == 0) {
					url.append("?");
				} else {
					url.append("&");
				}
				String key = nv.getName();
				String value = nv.getValue();
				url.append(key);
				url.append("=");
				url.append(value);

				count++;
			}
			//System.out.println(this.url.toString());
			HttpGet get = new HttpGet(this.url.toString());
			get.setConfig(requestConfig);
			result = getRespone(get);
		}catch (Exception e) {
			e.printStackTrace();
		}finally {
			close();//当同一个客户的client需要依次访问多个url时则不允许close() --即注释掉close()
			//client.getConnectionManager().shutdown();
		}
		return result;
	}

	public String getUrl() throws Exception {
		int count = 0;
		for (NameValuePair nv : params) {
			if (count == 0) {
				url.append("?");
			} else {
				url.append("&");
			}
			String key = nv.getName();
			String value = nv.getValue();
			url.append(key);
			url.append("=");
			url.append(value);

			count++;
		}
		return this.url.toString();
	}

	private String getRespone(HttpUriRequest req) throws Exception {
		String result = "";
		// 查看默认request头部信息
		// System.out.println("Accept-Charset:" +
		// req.getFirstHeader("Accept-Charset"));
		// 以下这条如果不加会发现无论你设置Accept-Charset为gbk还是utf-8，他都会默认返回gb2312（本例针对google.cn来说）
		req.setHeader("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.1.2)");
		// 用逗号分隔显示可以同时接受多种编码
		req.setHeader("Accept-Language", "zh-cn,zh;q=0.5");
		req.setHeader("Accept-Charset", "GB2312,utf-8;q=0.7,*;q=0.7");
		req.setHeader("Cache-Control","max-age=100000");
	
		// 验证头部信息设置生效
		// System.out.println("Accept-Charset:" +
		// req.getFirstHeader("Accept-Charset").getValue());
		HttpResponse response;
		try {
			response = client.execute(req);
			HttpEntity entity = response.getEntity();
			
			if (entity != null) {
				result = EntityUtils.toString(entity, encoding);
				// EntityUtils.consume(entity);
			}
		} catch (SocketTimeoutException ex) {
			throw ex;
		} catch (RuntimeException ex) {
			throw ex;
		} catch (Exception ex) {
			throw ex;
		}
		return result;
	}
	
	@SuppressWarnings("unused")
	private InputStream getResponeForStream(HttpUriRequest req) throws Exception {
		InputStream result = null;
		// 查看默认request头部信息
		// System.out.println("Accept-Charset:" +
		// req.getFirstHeader("Accept-Charset"));
		// 以下这条如果不加会发现无论你设置Accept-Charset为gbk还是utf-8，他都会默认返回gb2312（本例针对google.cn来说）
		req.setHeader("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.1.2)");
		// 用逗号分隔显示可以同时接受多种编码
		req.setHeader("Accept-Language", "zh-cn,zh;q=0.5");
		req.setHeader("Accept-Charset", "GB2312,utf-8;q=0.7,*;q=0.7");
		req.setHeader("Cache-Control","max-age=100000");
	
		// 验证头部信息设置生效
		// System.out.println("Accept-Charset:" +
		// req.getFirstHeader("Accept-Charset").getValue());
		HttpResponse response;
		try {
			response = client.execute(req);
			HttpEntity entity = response.getEntity();
			result=entity.getContent();
		} catch (SocketTimeoutException ex) {
			throw ex;
		} catch (RuntimeException ex) {
			throw ex;
		} catch (Exception ex) {
			throw ex;
		}
		return result;
	}
	
	public void setEncoding(String encoding) {
		this.encoding = encoding;
	}

	/**
	 * 关闭httpClient 请求
	 */
	public void close() {
		try {
			client.close();
		} catch (IOException e) {
			e.printStackTrace();
		}

	}
}

测试工具类

    public static void main(String[] args) {
    	HttpClientUtils http = new HttpClientUtils("http://restapi.amap.com/v3/geocode/geo");
    	Map params = new HashMap<>();
    	params.put("key", "389880a06e3f893ea46036f030c94700");
    	params.put("s", "rsv3");
    	params.put("city", "35");
    	params.put("address", "范县希望中学");
    	/*http.setParams("key", "389880a06e3f893ea46036f030c94700");
    	http.setParams("s", "rsv3");
    	http.setParams("city", "35");
    	http.setParams("address", "范县希望中学");*/
    	for (String qqq : params.keySet()) {
    		http.setParams(qqq, params.get(qqq));
		}
    	String doGet = http.doGet();
		System.out.println(doGet);
	}