
相信各位后端开发工程师项目中util包中都会有HttpUtils这中字眼的工具类,它里面主要是用到:
import org.apache.http.HttpEntity;
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.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.config.ConnectionConfig;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.config.SocketConfig;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLContexts;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
然后我们在配置的时候是这样:
/**
* 发送http get请求
*
* @param url 请求的url
* @param headersMap 请求头
* @param params 请求的参数
* @return
*/
public static String getRequest(String url, Map<String, String> headersMap, Map<String, Object> params) {
String result = null;
CloseableHttpClient httpClient = buildHttpClient();
try {
String apiUrl = url;
if (null != params && params.size() > 0) {
StringBuffer param = new StringBuffer();
int i = 0;
for (String key : params.keySet()) {
if (i == 0)
param.append("?");
else
param.append("&");
param.append(key).append("=").append(params.get(key));
i++;
}
apiUrl += param;
}
HttpGet httpGet = new HttpGet(apiUrl);
if (null != headersMap && headersMap.size() > 0) {
for (Entry<String, String> entry : headersMap.entrySet()) {
String key = entry.getKey();
String value = entry.getValue();
httpGet.addHeader(new BasicHeader(key, value));
}
}
CloseableHttpResponse response = httpClient.execute(httpGet);
try {
HttpEntity entity = response.getEntity();
if (null != entity) {
result = EntityUtils.toString(entity, defaultEncoding);
}
} finally {
response.close();
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
httpClient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}
public static String connectHttpsByPost(String path, byte[] file,String fileName) throws Exception {
URL urlObj = new URL(path);
//连接
HttpURLConnection con = (HttpURLConnection) urlObj.openConnection();
String result = null;
con.setDoInput(true);
con.setDoOutput(true);
con.setUseCaches(false); // post方式不能使用缓存
// 设置请求头信息
con.setRequestProperty("Connection", "Keep-Alive");
con.setRequestProperty("Charset", "UTF-8");
// 设置边界
String BOUNDARY = "----------" + System.currentTimeMillis();
con.setRequestProperty("Content-Type",
"multipart/form-data; boundary="
+ BOUNDARY);
// 请求正文信息
// 第一部分:
StringBuilder sb = new StringBuilder();
sb.append("--"); // 必须多两道线
sb.append(BOUNDARY);
sb.append("\r\n");
sb.append("Content-Disposition: form-data;name=\"media\";filelength=\"" + file.length + "\";filename=\""
+ fileName + "\"\r\n");
sb.append("Content-Type:application/octet-stream\r\n\r\n");
byte[] head = sb.toString().getBytes("utf-8");
// 获得输出流
OutputStream out = new DataOutputStream(con.getOutputStream());
// 输出表头
out.write(head);
// 文件正文部分
// 把文件已流文件的方式 推入到url中
DataInputStream in = new DataInputStream(new ByteArrayInputStream(file));
int bytes = 0;
byte[] bufferOut = new byte[1024];
while ((bytes = in.read(bufferOut)) != -1) {
out.write(bufferOut, 0, bytes);
}
in.close();
// 结尾部分
byte[] foot = ("\r\n--" + BOUNDARY + "--\r\n").getBytes("utf-8");// 定义最后数据分隔线
out.write(foot);
out.flush();
out.close();
StringBuffer buffer = new StringBuffer();
BufferedReader reader = null;
try {
// 定义BufferedReader输入流来读取URL的响应
reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
if (result == null) {
result = buffer.toString();
}
} catch (IOException e) {
System.out.println("发送POST请求出现异常!" + e);
e.printStackTrace();
} finally {
if (reader != null) {
reader.close();
}
}
return result;
}
是不是很恶心,那么如何让我们http请求变得优雅些呢?
这里我就要隆重介绍Spring提供的一种机制:RestTemplate
RestTemplate是Spring提供的用于访问Rest服务的客户端,RestTemplate提供了多种便捷访问远程Http服务的方法,能够大大提高客户端的编写效率。
在spring项目中该如何配置进来呢?
这里我介绍两种配置方式
1.配置类
首先创建RestTemplateConfig.class
import com.alibaba.dubbo.common.logger.Logger;
import com.alibaba.dubbo.common.logger.LoggerFactory;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.impl.client.DefaultConnectionKeepAliveStrategy;
import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.Header;
import org.apache.http.message.BasicHeader;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.client.RestTemplate;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
/**
* RestTemplate 配置信息
*
* @author xc
* @date 2020/8/11
*/
@Configuration
public class RestTemplateConfig {
private static final Logger logger= LoggerFactory.getLogger(RestTemplateConfig.class);
@Bean
public RestTemplate restTemplate() {
// 添加内容转换器,使用默认的内容转换器
RestTemplate restTemplate = new RestTemplate(httpRequestFactory());
// 设置编码格式为UTF-8
List<HttpMessageConverter<?>> converterList = restTemplate.getMessageConverters();
HttpMessageConverter<?> converterTarget = null;
for (HttpMessageConverter<?> item : converterList) {
if (item.getClass() == StringHttpMessageConverter.class) {
converterTarget = item;
break;
}
}
if (converterTarget != null) {
converterList.remove(converterTarget);
}
HttpMessageConverter<?> converter = new StringHttpMessageConverter(StandardCharsets.UTF_8);
converterList.add(1,converter);
logger.info("-----restTemplate-----初始化完成");
return restTemplate;
}
@Bean
public ClientHttpRequestFactory httpRequestFactory() {
return new HttpComponentsClientHttpRequestFactory(httpClient());
}
@Bean
public HttpClient httpClient() {
// 长连接保持30秒
PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(30, TimeUnit.SECONDS);
//设置整个连接池最大连接数 根据自己的场景决定
connectionManager.setMaxTotal(500);
//同路由的并发数,路由是对maxTotal的细分
connectionManager.setDefaultMaxPerRoute(500);
//requestConfig
RequestConfig requestConfig = RequestConfig.custom()
//服务器返回数据(response)的时间,超过该时间抛出read timeout
.setSocketTimeout(10000)
//连接上服务器(握手成功)的时间,超出该时间抛出connect timeout
.setConnectTimeout(5000)
//从连接池中获取连接的超时时间,超过该时间未拿到可用连接,会抛出org.apache.http.conn.ConnectionPoolTimeoutException: Timeout waiting for connection from pool
.setConnectionRequestTimeout(500)
.build();
//headers
List<Header> headers = new ArrayList<>();
headers.add(new BasicHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.16 Safari/537.36"));
headers.add(new BasicHeader("Accept-Encoding", "gzip,deflate"));
headers.add(new BasicHeader("Accept-Language", "zh-CN"));
headers.add(new BasicHeader("Connection", "Keep-Alive"));
headers.add(new BasicHeader("Content-type", "application/json;charset=UTF-8"));
return HttpClientBuilder.create()
.setDefaultRequestConfig(requestConfig)
.setConnectionManager(connectionManager)
.setDefaultHeaders(headers)
// 保持长连接配置,需要在头添加Keep-Alive
.setKeepAliveStrategy(new DefaultConnectionKeepAliveStrategy())
//重试次数,默认是3次,没有开启
.setRetryHandler(new DefaultHttpRequestRetryHandler(2, true))
.build();
}
}
2.spring配置文件(推荐)
spring配置文件:
<!--使用httpclient的实现,带连接池-->
<bean id="pollingConnectionManager" class="org.apache.http.impl.conn.PoolingHttpClientConnectionManager">
<!--整个连接池的并发-->
<property name="maxTotal" value="1000" />
<!--每个主机的并发-->
<property name="defaultMaxPerRoute" value="1000" />
</bean>
<bean id="httpClientBuilder" class="org.apache.http.impl.client.HttpClientBuilder" factory-method="create">
<property name="connectionManager" ref="pollingConnectionManager" />
<!--开启重试-->
<property name="retryHandler">
<bean class="org.apache.http.impl.client.DefaultHttpRequestRetryHandler">
<constructor-arg value="2"/>
<constructor-arg value="true"/>
</bean>
</property>
<property name="defaultHeaders">
<list>
<bean class="org.apache.http.message.BasicHeader">
<constructor-arg value="User-Agent"/>
<constructor-arg value="Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.16 Safari/537.36"/>
</bean>
<bean class="org.apache.http.message.BasicHeader">
<constructor-arg value="Accept-Encoding"/>
<constructor-arg value="gzip,deflate"/>
</bean>
<bean class="org.apache.http.message.BasicHeader">
<constructor-arg value="Accept-Language"/>
<constructor-arg value="zh-CN"/>
</bean>
</list>
</property>
</bean>
<bean id="httpClient" factory-bean="httpClientBuilder" factory-method="build" />
<bean id="clientHttpRequestFactory" class="org.springframework.http.client.HttpComponentsClientHttpRequestFactory">
<constructor-arg ref="httpClient"/>
<!--连接超时时间,毫秒-->
<property name="connectTimeout" value="5000"/>
<!--读写超时时间,毫秒-->
<property name="readTimeout" value="10000"/>
</bean>
<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
<constructor-arg ref="clientHttpRequestFactory"/>
<property name="errorHandler">
<bean class="org.springframework.web.client.DefaultResponseErrorHandler"/>
</property>
<property name="messageConverters">
<list>
<bean class="org.springframework.http.converter.FormHttpMessageConverter"/>
<bean class="org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter"/>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/plain;charset=UTF-8</value>
</list>
</property>
</bean>
</list>
</property>
</bean>
这里给出一个我再调用微信公众号接口时的使用案例:
@Autowired
RestTemplateConfig restTemplateConfig;
private static final String file_url_ps = "https://api.weixin.qq.com/cgi-bin/media/uploadimg";
/**
* 微信公众号 群发图文信息
* 示例: https://api.weixin.qq.com/cgi-bin/media/uploadimg?access_token=ACCESS_TOKEN
*
* @param articles
* @return
*/
public String pulishNews(Articles articles) {
RestTemplate restTemplate = restTemplateConfig.restTemplate();
StringBuilder sb = new StringBuilder();
String refresh = refresh();
sb.append(file_url_ps).append(wenhao);
sb.append(access_token).append(dengyu).append(refresh);
String sendUrl = sb.toString();
String jsonNews = JSONObject.toJSONString(articles);
String jsonObject = restTemplate.postForObject(sendUrl, jsonNews, String.class);
return jsonObject;
}
这里我的一个post请求 在配置好RestTemplate之后总共就一行代码 【String jsonObject = restTemplate.postForObject(sendUrl, jsonNews, String.class);】就完成Post 这在以前都是不敢想象的。
其实我对resetTemplate很多高级用法尚未了解,这里只是简单应用,灵活应用可以减少我们的工作量,例如在post请求就有
