java中http調用接口的工具類

maven中所需依賴

<!-- http -->
		<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpcore -->
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpcore</artifactId>
			<version>4.4.10</version>
		</dependency>

		<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
			<version>4.5.6</version>
		</dependency>
		<!-- alibaba json -->
		<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.13</version>
        </dependency>

工具類

package com.example.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Map;

import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;

import com.alibaba.fastjson.JSONObject;

public class HttpRequestUtil {
	private static CloseableHttpClient httpClient;
	private static final Map<String, Object> HRADERS = new HashMap<>();

	static {
		PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
		cm.setMaxTotal(100);
		cm.setDefaultMaxPerRoute(20);
		cm.setDefaultMaxPerRoute(50);
		httpClient = HttpClients.custom().setConnectionManager(cm).build();
		// headres全部接口都須要攜帶headers才能使用,若是不須要能夠不寫
		HRADERS.put("abc", "abc");
	}

	public static String get(String url) {
		CloseableHttpResponse response = null;
		BufferedReader in = null;
		String result = "";
		try {
			HttpGet httpGet = new HttpGet(url);
			RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30000)
					.setConnectionRequestTimeout(30000).setSocketTimeout(30000).build();
			httpGet.setConfig(requestConfig);
			httpGet.setConfig(requestConfig);
			httpGet.addHeader("Content-type", "application/json; charset=utf-8");
			httpGet.setHeader("Accept", "application/json");
			// 調用得接口都須要使用這些headers
			for (Map.Entry<String, Object> param : HRADERS.entrySet()) {
				httpGet.addHeader(param.getKey(), String.valueOf(param.getValue()));
			}

			response = httpClient.execute(httpGet);
			in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
			StringBuffer sb = new StringBuffer("");
			String line = "";
			String NL = System.getProperty("line.separator");
			while ((line = in.readLine()) != null) {
				sb.append(line + NL);
			}
			in.close();
			result = sb.toString();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (null != response) {
					response.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return result;
	}

	public static String post(String url, String jsonString) {
		CloseableHttpResponse response = null;
		BufferedReader in = null;
		String result = "";
		try {
			HttpPost httpPost = new HttpPost(url);
			RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30000)
					.setConnectionRequestTimeout(30000).setSocketTimeout(30000).build();
			httpPost.setConfig(requestConfig);
			httpPost.setConfig(requestConfig);
			httpPost.addHeader("Content-type", "application/json; charset=utf-8");
			httpPost.setHeader("Accept", "application/json");
			httpPost.setEntity(new StringEntity(jsonString, Charset.forName("UTF-8")));
			// 調用得接口都須要使用這些headers
			for (Map.Entry<String, Object> param : HRADERS.entrySet()) {
				httpPost.addHeader(param.getKey(), String.valueOf(param.getValue()));
			}

			response = httpClient.execute(httpPost);
			in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
			StringBuffer sb = new StringBuffer("");
			String line = "";
			String NL = System.getProperty("line.separator");
			while ((line = in.readLine()) != null) {
				sb.append(line + NL);
			}
			in.close();
			result = sb.toString();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (null != response) {
					response.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return result;
	}

	// 接口返回得String類型得json用來解析返回Map
	public Map<String, Object> jsonUtil(String json) {
		JSONObject obj = new JSONObject().parseObject(json);
		Map<String, Object> mapjson = new HashMap<>();

		for (String str : obj.keySet()) {
			mapjson.put(str, obj.get(str));
		}
		return mapjson;
	}

	public static void main(String[] args) {
		Map<String, Object> headers = new HashMap<>();
		String str = get("接口的url");
		HttpRequestUtil hru = new HttpRequestUtil();
		
		for(String key :(hru.jsonUtil(str).keySet())) {
			if("code".equals(key)) {
				System.out.println("value:"+hru.jsonUtil(str).get(key));
			}
		}

	}

}

get請求攜帶參數再url後面拼接

post請求把參數寫在post方法的jsonString參數中，必須是json格式的數據