1. httpclient介绍
HttpClient是Apache Jajarta Common下的子项目，用来提供高效的、最新的、功能丰富的支持HTTP协议的客户端编程工具包，并且它支持HTTP协议最新的版本和建议。
HttpClient和浏览器有点像，但不是浏览器，它是一个HTTP通信库，因此它只提供一个通用浏览器应用程序所期望的功能子集，最根本的区别是HttpClient中没有用户界面。
2. 快速使用httpclient
a) 引入jar包（Maven在pom.xml中引入HttpClient依赖）
|
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.test</groupId> <artifactId>com-test</artifactId> <version>0.0.1-SNAPSHOT</version> <dependencies> <!-- httpclient --> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.3.5</version> </dependency> <!-- Jackson Json处理工具包 --> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.4.2</version> </dependency> </dependencies> </project> |
b) get无参
|
/** * 无参get */ public static void testGet() { //1.通过HttpClientBuilder类的create方法创建HttpClientBuilder对象，再用HttpClientBuilder对象的builder方法创建closeableHttpClient对象； 相当于浏览器 CloseableHttpClient closeableHttpClient=HttpClientBuilder.create().build(); //2.创建httpGet对象 相当于在地址栏输入网址 HttpGet httpGet=new HttpGet("http://127.0.0.1:7001/rest/user/list"); CloseableHttpResponse httpResponse =null; try { //3.通过closeableHttpClient对象的execute方法创建httpResponse对象 相当于按回车键（访问网址） httpResponse = closeableHttpClient.execute(httpGet);
System.out.println(EntityUtils.toString(httpResponse.getEntity())); } catch (IOException e) { e.printStackTrace(); }finally { try { if(httpResponse!=null) { httpResponse.close(); } if(closeableHttpClient!=null) { closeableHttpClient.close(); } } catch (IOException e) { e.printStackTrace(); } } } |
c) get有参
|
/** * 有参get */ public static void testGetParams() { //1.通过HttpClientBuilder类的create方法创建HttpClientBuilder对象，再用HttpClientBuilder对象的builder方法创建closeableHttpClient对象； 相当于浏览器 CloseableHttpClient closeableHttpClient=HttpClientBuilder.create().build(); //2.创建httpGet对象 相当于在地址栏输入网址 // HttpGet httpGet=new HttpGet("http://127.0.0.1:7001/rest/user/list?rows=1");//第一种方式.在地址上加？后跟参数 CloseableHttpResponse httpResponse =null; try { /* * 第二种方式.通过URIBuilder类的add方法添加参数，在通过build方法得到uri对象 */ URI uri=new URIBuilder("http://127.0.0.1:7001/rest/user/list").addParameter("rows", "1").build(); HttpGet httpGet=new HttpGet(uri);
//3.通过closeableHttpClient对象的execute方法创建httpResponse对象 相当于按回车键（访问网址） httpResponse = closeableHttpClient.execute(httpGet);
System.out.println(EntityUtils.toString(httpResponse.getEntity())); } catch (IOException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); }finally { try { if(httpResponse!=null) { httpResponse.close(); } if(closeableHttpClient!=null) { closeableHttpClient.close(); } } catch (IOException e) { e.printStackTrace(); } } } |
d) post无参
|
/** * 无参post */ public static void testPost() { //1.通过HttpClientBuilder类的create方法创建HttpClientBuilder对象，再用HttpClientBuilder对象的builder方法创建closeableHttpClient对象； 相当于浏览器 CloseableHttpClient closeableHttpClient=HttpClientBuilder.create().build(); //2.创建httpPost对象 相当于在地址栏输入网址 HttpPost httpPost=new HttpPost("http://127.0.0.1:7001/rest/user/list"); CloseableHttpResponse httpResponse =null; try { //3.通过closeableHttpClient对象的execute方法创建httpResponse对象 相当于按回车键（访问网址） httpResponse = closeableHttpClient.execute(httpPost);
System.out.println(EntityUtils.toString(httpResponse.getEntity())); } catch (IOException e) { e.printStackTrace(); }finally { try { if(httpResponse!=null) { httpResponse.close(); } if(closeableHttpClient!=null) { closeableHttpClient.close(); } } catch (IOException e) { e.printStackTrace(); } } } |
e) post简单（基本类型，string，数组）参
|
/** * 简单参post */ public static void testPostParams() { //1.通过HttpClientBuilder类的create方法创建HttpClientBuilder对象，再用HttpClientBuilder对象的builder方法创建closeableHttpClient对象； 相当于浏览器 CloseableHttpClient closeableHttpClient=HttpClientBuilder.create().build(); //2.创建httpGet对象 相当于在地址栏输入网址 // HttpPost httpPost=new HttpPost("http://127.0.0.1:7001/rest/user/list?rows=1");//第一种方式.在地址上加？后跟参数 CloseableHttpResponse httpResponse =null; try { /* * 第二种方式.通过URIBuilder类的add方法添加参数，在通过build方法得到uri对象 */ URI uri=new URIBuilder("http://127.0.0.1:7001/rest/user/list").addParameter("ids", "1,2").build();//addParameter("ids", "1,2")传出去的是个数组 HttpPost httpPost=new HttpPost(uri);
//3.通过closeableHttpClient对象的execute方法创建httpResponse对象 相当于按回车键（访问网址） httpResponse = closeableHttpClient.execute(httpPost);
System.out.println(EntityUtils.toString(httpResponse.getEntity())); } catch (IOException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); }finally { try { if(httpResponse!=null) { httpResponse.close(); } if(closeableHttpClient!=null) { closeableHttpClient.close(); } } catch (IOException e) { e.printStackTrace(); } } } |
f) post简单参+对象：控制层接收的对象前一定要加注解@RequestBody，否则报错415
|
/** * 对象+简单参post */ public static void testPostParam() { ObjectMapper objectMapper=new ObjectMapper();//json字符串和java对象互转 //1.通过HttpClientBuilder类的create方法创建HttpClientBuilder对象，再用HttpClientBuilder对象的builder方法创建closeableHttpClient对象； 相当于浏览器 CloseableHttpClient closeableHttpClient=HttpClientBuilder.create().build(); //2.创建httpGet对象 相当于在地址栏输入网址 CloseableHttpResponse httpResponse =null; try { /* * 第一种方式.通过URIBuilder类的add方法添加参数，在通过build方法得到uri对象 */ URI uri=new URIBuilder("http://127.0.0.1:7001/rest/user/list").addParameter("ids", "1,2").build();//addParameter("ids", "1,2")传出去的是个数组 HttpPost httpPost=new HttpPost(uri); //创建user对象 User user=new User(null, "测试", null, null, null, null, null, null, null); //把user对象转成json字符串放到创建的StringEntity对象里，然后再用httpPost对象添加对象 httpPost.setEntity(new StringEntity(objectMapper.writeValueAsString(user),"utf-8"));
//一定要设置http头部信息 httpPost.setHeader("Content-Type", "application/json;charset=utf8");
//3.通过closeableHttpClient对象的execute方法创建httpResponse对象 相当于按回车键（访问网址） httpResponse = closeableHttpClient.execute(httpPost);
System.out.println(EntityUtils.toString(httpResponse.getEntity())); } catch (IOException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); }finally { try { if(httpResponse!=null) { httpResponse.close(); } if(closeableHttpClient!=null) { closeableHttpClient.close(); } } catch (IOException e) { e.printStackTrace(); } } } |
g) 连接管理器PoolHttpClientConnectionManager和请求配置器RequestConfig
|
/** * 1.连接管理器PoolingHttpClientConnectionManager，2.请求配置RequestConfig */ public static void testPoolAndConfig() { //1.创建连接管理器PoolingHttpClientConnectionManager PoolingHttpClientConnectionManager cm=new PoolingHttpClientConnectionManager(); cm.setMaxTotal(10);//设置最大连接数 cm.setDefaultMaxPerRoute(5);//设置最大路由数 doGet(cm); doGet(cm);
} public static void doGet(PoolingHttpClientConnectionManager cm) { //通过HttpClients的custom方法获得HttpClientBuilder对象，在用setConnectionManager方法设置连接管理器，再用build创建closeableHttpClient对象 CloseableHttpClient closeableHttpClient = HttpClients.custom().setConnectionManager(cm).build(); HttpGet httpGet=new HttpGet("http://127.0.0.1:7001/rest/user/list?rows=1");
//2.配置requestConfig RequestConfig requestConfig=RequestConfig.custom().setConnectTimeout(5000)//设置连接最大时间 .setConnectionRequestTimeout(3000)//设置连接请求最大时间 .setSocketTimeout(2000).build();//设置传输最大时间 httpGet.setConfig(requestConfig);//把requestConfig设置到httpGet对象里
CloseableHttpResponse httpResponse =null; try { httpResponse=closeableHttpClient.execute(httpGet); System.out.println(EntityUtils.toString(httpResponse.getEntity())); } catch (IOException e) { e.printStackTrace(); }finally { try { if(httpResponse!=null) { httpResponse.close(); } // if(closeableHttpClient!=null) { // closeableHttpClient.close();//一定不能close，否则报错：Exception in thread "main" java.lang.IllegalStateException: Connection pool shut down // } } catch (IOException e) { e.printStackTrace(); } } } |
Spring和HttpClient整合（spring和httpclient的配置文件，httpclient的公共ApiService）
1.spring和httpclient配置文件：applicationContent-httpclient.xml
|
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd">
<!-- 配置连接管理器 --> <bean id="cm" class="org.apache.http.impl.conn.PoolingHttpClientConnectionManager"> <property name="maxTotal" value="200"/> <property name="defaultMaxPerRoute" value="50"/> </bean>
<!-- 配置HttpClientBuilder用来创建CloseableHttpClient对象 --> <bean id="httpClientBuilder" class="org.apache.http.impl.client.HttpClientBuilder"> <property name="connectionManager" ref="cm"/> </bean> <!-- 创建CloseableHttpClient对象 --> <bean id="closeableHttpClient" class="org.apache.http.impl.client.CloseableHttpClient" factory-bean="httpClientBuilder" factory-method="build" scope="prototype"> </bean>
<!-- 配置Builder对象来获得RequestConfig对象 --> <bean id="builder" class="org.apache.http.client.config.RequestConfig.Builder"> <property name="connectTimeout" value="5000"/> <property name="connectionRequestTimeout" value="3000"/> <property name="socketTimeout" value="2000"/> </bean> <bean id="requestConfig" class="org.apache.http.client.config.RequestConfig" factory-bean="builder" factory-method="build"> </bean> </beans> |
2.公共的ApiService接口和实现类
|
ApiService接口： package com.zhiyou100.kfs.service; import java.util.Map; import com.zhiyou100.kfs.bean.HttpResult; public interface ApiService {
/** * 无参get * @param url */ String doGet(String url);
/** * 有参get * @param url * @param map * @return */ String doGet(String url,Map<String, Object> map);
/** * 无参post * @param url * @return */ String doPost(String url);
/** * 有参post * @param url * @param map * @return */ HttpResult doPost(String url,Map<String, Object> map); } 接口实现类ApiServiceImp： package com.zhiyou100.kfs.service; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import java.util.ArrayList; import java.util.List; import java.util.Map; import org.apache.http.NameValuePair; 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.client.utils.URIBuilder; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.message.BasicNameValuePair; import org.apache.http.util.EntityUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.zhiyou100.kfs.bean.HttpResult; /** * 把httpclient抽取出来 * @author KFS * */ @Service public class ApiServiceImp implements ApiService{ @Autowired private CloseableHttpClient closeableHttpClient; @Autowired private RequestConfig requestConfig;
/** * 无参get * @param url */ public String doGet(String url) { HttpGet httpGet=new HttpGet(url); httpGet.setConfig(requestConfig);
CloseableHttpResponse httpResponse =null; try { httpResponse = closeableHttpClient.execute(httpGet); if(httpResponse!=null&&httpResponse.getStatusLine().getStatusCode()==200) { return EntityUtils.toString(httpResponse.getEntity(),"utf-8"); } } catch (IOException e) { e.printStackTrace(); } return null; }
/** * 有参get * @param url * @param map * @return */ public String doGet(String url,Map<String, Object> map) { List<NameValuePair> nvps=new ArrayList<>(); if(!map.isEmpty()) { for(String key:map.keySet()) { NameValuePair nvp=new BasicNameValuePair(key, map.get(key).toString()); nvps.add(nvp); } }
CloseableHttpResponse httpResponse =null; try { URI uri=new URIBuilder(url).addParameters(nvps).build(); HttpGet httpGet=new HttpGet(uri); httpGet.setConfig(requestConfig);
httpResponse = closeableHttpClient.execute(httpGet); if(httpResponse!=null&&httpResponse.getStatusLine().getStatusCode()==200) { return EntityUtils.toString(httpResponse.getEntity(),"utf-8"); } } catch (IOException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); } return null; }
/** * 无参post * @param url * @return */ public String doPost(String url) { HttpPost httpPost=new HttpPost(url); httpPost.setConfig(requestConfig);
CloseableHttpResponse httpResponse =null; try { httpResponse = closeableHttpClient.execute(httpPost); if(httpResponse!=null&&httpResponse.getStatusLine().getStatusCode()==200) { return EntityUtils.toString(httpResponse.getEntity(),"utf-8"); } } catch (IOException e) { e.printStackTrace(); } return null; }
/** * 有参post * @param url * @param map * @return */ public HttpResult doPost(String url,Map<String, Object> map) { List<NameValuePair> nvps=new ArrayList<>(); if(!map.isEmpty()) { for(String key:map.keySet()) { NameValuePair nvp=new BasicNameValuePair(key, map.get(key).toString()); nvps.add(nvp); } }
CloseableHttpResponse httpResponse =null; try { URI uri=new URIBuilder(url).addParameters(nvps).build(); HttpPost httpPost=new HttpPost(uri); httpPost.setConfig(requestConfig);
httpResponse = closeableHttpClient.execute(httpPost); if(httpResponse!=null&&httpResponse.getStatusLine().getStatusCode()==200) { return new HttpResult(httpResponse.getStatusLine().getStatusCode(),EntityUtils.toString(httpResponse.getEntity(),"utf-8")); } } catch (IOException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); } return null; } } |