java中调用第三方接口很常见，本文使用的是CloseableHttpClient方式。
CloseableHttpClient是在HttpClient的基础上修改更新而来的，这里还涉及到请求头token的设置（请求验证），利用fastjson转换请求或返回结果字符串为json格式。
- 导入jar包
<properties>
<httpclient.version>4.5.5</httpclient.version>
<slf4j.version>1.7.25</slf4j.version>
<fastjson.version>1.2.47</fastjson.version>
</properties>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>${httpclient.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>${fastjson.version}</version>
</dependency>
- httpclient公共类：
package com.howdy.callapi.common;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.sun.istack.internal.logging.Logger;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.config.ConnectionConfig;
import org.apache.http.config.SocketConfig;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.util.EntityUtils;
import org.springframework.stereotype.Service;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.nio.charset.Charset;
import java.util.Map;
@Service
public class HttpUtil {
private static Logger logger = Logger.getLogger(HttpUtil.class);
private static CloseableHttpClient httpClient = null;
private static final Charset CHAR_SET = Charset.forName("utf-8");
private static PoolingHttpClientConnectionManager cm;
public HttpUtil(){
init();
}
public void init() {
cm = new PoolingHttpClientConnectionManager();
//设置最大连接数
cm.setMaxTotal(300);
//设置每个主机地址的并发数
// cm.setDefaultMaxPerRoute(100);
cm.setDefaultConnectionConfig(ConnectionConfig.custom()
.setCharset(CHAR_SET).build());
SocketConfig socketConfig = SocketConfig.custom().setSoTimeout(30000)
.setSoReuseAddress(true).build();
cm.setDefaultSocketConfig(socketConfig);
httpClient = HttpClientBuilder.create().setConnectionManager(cm)
.build();
}
public CloseableHttpClient getHttpClient() {
int timeout=5;
RequestConfig config = RequestConfig.custom()
.setConnectTimeout(timeout * 1000) //设置连接超时时间，单位毫秒
//.setConnectionRequestTimeout(timeout * 1000) //设置从connect Manager获取Connection 超时时间，单位毫秒
.setSocketTimeout(timeout * 1000).build(); //请求获取数据的超时时间，单位毫秒
CloseableHttpClient _httpClient = HttpClients.custom()
.setConnectionManager(cm)
// .setDefaultRequestConfig(config) //使用此方法连接池会关闭
.setConnectionManagerShared(true)
.build();
if(cm!=null&&cm.getTotalStats()!=null) { //打印连接池的状态
logger.info("now client pool {}"+cm.getTotalStats().toString());
}
return _httpClient;
}
/**
* get请求
*
* @return
*/
public String doGet(String url) {
try {
HttpClient client = getHttpClient();
//发送get请求
HttpGet request = new HttpGet(url);
HttpResponse response = client.execute(request);
/**请求发送成功，并得到响应**/
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
/**读取服务器返回过来的json字符串数据**/
String strResult = EntityUtils.toString(response.getEntity());
request.releaseConnection();
return strResult;
}
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/**
* post请求 参数为map格式
*
* @param url
* @param params
* @return
*/
public String doPost(String url, Map params) {
BufferedReader in = null;
try {
// 定义HttpClient
CloseableHttpClient client =getHttpClient();
// 实例化HTTP方法
HttpPost request = new HttpPost();
request.setURI(new URI(url));
request.setHeader("Content-Type","application/json; charset=utf-8");
StringEntity s = new StringEntity(JSON.toJSONString(params));
request.setEntity(s);
HttpResponse response = client.execute(request);
int code = response.getStatusLine().getStatusCode();
if (code == 200) {
//返回json格式
String res = EntityUtils.toString(response.getEntity());
request.releaseConnection();
return res;
} else { //
System.out.println("状态码：" + code);
return null;
}
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 以post方式 请求参数为json格式
* @param url
* @param json
* @return
*/
public String doPost(String url, JSONObject json){
HttpPost post = new HttpPost(url);
try {
if (httpClient == null){
// httpClient = HttpClientBuilder.create().build();
httpClient= HttpClients.custom().setConnectionManager(cm).setConnectionManagerShared(true).build();
}
httpClient=getHttpClient();
//api_gateway_auth_token自定义header头，用于token验证使用
// post.addHeader("api_gateway_auth_token", tokenString);
post.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36");
post.setHeader("Content-type", "application/json;charset=utf-8");
post.setHeader("Connection", "Close");
StringEntity s = new StringEntity(json.toString());
s.setContentEncoding("UTF-8");
//发送json数据需要设置contentType
s.setContentType("application/x-www-form-urlencoded");
//设置请求参数
post.setEntity(s);
HttpResponse response = httpClient.execute(post);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
//返回json格式
String res = EntityUtils.toString(response.getEntity());
post.releaseConnection();
return res;
}
} catch (Exception e) {
logger.info("excep:"+e.getMessage());
e.printStackTrace();
}finally {
if (post != null)
post.releaseConnection();
if (httpClient != null){
try {
httpClient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
}
- controller调用：
package com.howdy.callapi.controller;
import com.alibaba.fastjson.JSONObject;
import com.howdy.callapi.common.HttpUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.HashMap;
import java.util.Map;
@RestController
@RequestMapping("/callapi")
public class CallController {
@Autowired
private HttpUtil httpUtil;
@GetMapping("/getdetail")
public String getdetail(){
String result= httpUtil.doGet("https://***/ById?id=3");
System.out.println(result);
return result;
}
@PostMapping("/getlist")
public String getlist(){
HttpUtil util=new HttpUtil();
JSONObject jsonObject=new JSONObject();
jsonObject.put("pageIndex",1);
jsonObject.put("pageCount",10);
jsonObject.put("start_time","");
jsonObject.put("end_time","");
String result= httpUtil.doPost("https://***/GetMen",jsonObject);
System.out.println("jsonobject:"+result);
return result;
}
@PostMapping("/getlist2")
public String getlist2(){
Map params=new HashMap<>();
params.put("pageIndex",1);
params.put("pageCount",10);
params.put("start_time","");
params.put("end_time","");
String result2= httpUtil.doPost(https://***/GetMen",params);
System.out.println("jsonobject2:"+result2);
return result2;
}
}
参考：https://www.cnblogs.com/wq-9/articles/14137121.html
https://www.cnblogs.com/Eillot/p/9042284.html