HttpClient—与SpringBoot整合
一、HttpClient
两个系统间如何互相访问？两个tomcat上的项目如何互相访问
采用HttpClient实现跨系统的接口调用。
1.2、 什么是HttpClient
官网：http://hc.apache.org/index.html
特点：
-
HttpClient别名：HttpComponents
-
HttpClient可以发送get、post、put、delete、…等请求
-
1.3、 HttpClient入门案例
org.apache.httpcomponents httpclient 4.4
1.3.1、 发起Get请求
1创建一个客户端 CloseableHttpClient
2创建一个get方法请求实例 HttpGet
3发送请求 execute
4获取响应的头信息
5获取响应的主题内容
6关闭响应对象
使用HttpClient发起Get请求的案例代码：
public class DoGET {
public static void main(String[] args) throws Exception {
// 创建Httpclient对象,相当于打开了浏览器
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建HttpGet请求，相当于在浏览器输入地址
HttpGet httpGet = new HttpGet("http://www.baidu.com/");
CloseableHttpResponse response = null;
try {
// 执行请求，相当于敲完地址后按下回车。获取响应
response = httpclient.execute(httpGet);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 解析响应，获取数据
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
// 关闭资源
response.close();
}
// 关闭浏览器
httpclient.close();
}
}
}
1.3.2、 带参数的Get请求
1创建一个客户端 CloseableHttpClient
2 通过URIBuilder传递参数
3创建一个get方法请求实例 HttpGet
4发送请求 execute
5获取响应的头信息
6获取响应的主题内容
7关闭响应对象
访问网站的爬虫协议：
public class DoGETParam {
public static void main(String[] args) throws Exception {
// 创建Httpclient对象
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建URI对象，并且设置请求参数
URI uri = new URIBuilder("http://www.baidu.com/s").setParameter("wd", "java").build();
// 创建http GET请求
HttpGet httpGet = new HttpGet(uri);
// HttpGet get = new HttpGet("http://www.baidu.com/s?wd=java");
CloseableHttpResponse response = null;
try {
// 执行请求
response = httpclient.execute(httpGet);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 解析响应数据
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
response.close();
}
httpclient.close();
}
}
}
1.3.4、 带参数POST请求
/*
* 演示：使用HttpClient发起带有参数的POST请求
*/
public class DoPOSTParam {
public static void main(String[] args) throws Exception {
// 创建Httpclient对象
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建http POST请求，访问开源中国
HttpPost httpPost = new HttpPost("http://www.oschina.net/search");
// 根据开源中国的请求需要，设置post请求参数
List parameters = new ArrayList(0);
parameters.add(new BasicNameValuePair("scope", "project"));
parameters.add(new BasicNameValuePair("q", "java"));
parameters.add(new BasicNameValuePair("fromerr", "8bDnUWwC"));
// 构造一个form表单式的实体
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);
// 将请求实体设置到httpPost对象中
httpPost.setEntity(formEntity);
CloseableHttpResponse response = null;
try {
// 执行请求
response = httpclient.execute(httpPost);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 解析响应体
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
response.close();
}
// 关闭浏览器
httpclient.close();
}
}
}
SpringBoot官方并没有对HttpClient的启动器。所以我们需要自己完成配置
不过，SpringBoot虽然没有提供启动器，但是却提供了一个对Restful服务进行调用的模板类：RestTemplate，底层可以使用HttpClient来实现。有了这个我们就无需自己定义APIService了。
1、导入maven坐标
org.apache.httpcomponents
httpclient
2、在application.properties添加如下配置:
#The config for HttpClient
http.maxTotal=300
http.defaultMaxPerRoute=50
http.connectTimeout=1000
http.connectionRequestTimeout=500
http.socketTimeout=5000
http.staleConnectionCheckEnabled=true
创建HttpClientConfig类–类似util(配置,无需搞懂,拿来即用)
/**
* HttpClient的配置类
*
*/
@Configuration
@ConfigurationProperties(prefix = "http", ignoreUnknownFields = true)
public class HttpClientConfig {
private Integer maxTotal;// 最大连接
private Integer defaultMaxPerRoute;// 每个host的最大连接
private Integer connectTimeout;// 连接超时时间
private Integer connectionRequestTimeout;// 请求超时时间
private Integer socketTimeout;// 响应超时时间
/**
* HttpClient连接池
* @return
*/
@Bean
public HttpClientConnectionManager httpClientConnectionManager() {
PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
connectionManager.setMaxTotal(maxTotal);
connectionManager.setDefaultMaxPerRoute(defaultMaxPerRoute);
return connectionManager;
}
/**
* 注册RequestConfig
* @return
*/
@Bean
public RequestConfig requestConfig() {
return RequestConfig.custom().setConnectTimeout(connectTimeout)
.setConnectionRequestTimeout(connectionRequestTimeout).setSocketTimeout(socketTimeout)
.build();
}
/**
* 注册HttpClient
* @param manager
* @param config
* @return
*/
@Bean
public HttpClient httpClient(HttpClientConnectionManager manager, RequestConfig config) {
return HttpClientBuilder.create().setConnectionManager(manager).setDefaultRequestConfig(config)
.build();
}
/**
* 使用连接池管理连接
* @param httpClient
* @return
*/
@Bean
public ClientHttpRequestFactory requestFactory(HttpClient httpClient) {
return new HttpComponentsClientHttpRequestFactory(httpClient);
}
/**
* 使用HttpClient来初始化一个RestTemplate
* @param requestFactory
* @return
*/
@Bean
public RestTemplate restTemplate(ClientHttpRequestFactory requestFactory) {
RestTemplate template = new RestTemplate(requestFactory);
List> list = template.getMessageConverters();
for (HttpMessageConverter mc : list) {
if (mc instanceof StringHttpMessageConverter) {
((StringHttpMessageConverter) mc).setDefaultCharset(Charset.forName("UTF-8"));
}
}
return template;
}
public Integer getMaxTotal() {
return maxTotal;
}
public void setMaxTotal(Integer maxTotal) {
this.maxTotal = maxTotal;
}
public Integer getDefaultMaxPerRoute() {
return defaultMaxPerRoute;
}
public void setDefaultMaxPerRoute(Integer defaultMaxPerRoute) {
this.defaultMaxPerRoute = defaultMaxPerRoute;
}
public Integer getConnectTimeout() {
return connectTimeout;
}
public void setConnectTimeout(Integer connectTimeout) {
this.connectTimeout = connectTimeout;
}
public Integer getConnectionRequestTimeout() {
return connectionRequestTimeout;
}
public void setConnectionRequestTimeout(Integer connectionRequestTimeout) {
this.connectionRequestTimeout = connectionRequestTimeout;
}
public Integer getSocketTimeout() {
return socketTimeout;
}
public void setSocketTimeout(Integer socketTimeout) {
this.socketTimeout = socketTimeout;
}
}
-
引入RestTemplate模板
在FixedAreaController中，引入RestTemplate模板，发送rest请求
@Autowired private RestTemplate restTemplate; -
编写FixedAreaController的方法
// 查询未关联定区列表 @GetMapping("/findNoAssociationCustomers") public ResponseEntityfindNoAssociationCustomers() { // 使用HttpClient调用 远程接口 String url = Constants.CRM_MANAGEMENT_HOST + "/customer/noAssociationCustomers"; ResponseEntity result = restTemplate.getForEntity(url, String.class); HttpStatus statusCode = result.getStatusCode(); String body = result.getBody(); return new ResponseEntity<>(body,statusCode); }
1
public class Constants {
public static final String BOS_MANAGEMENT_HOST = "http://localhost:8088";
public static final String CRM_MANAGEMENT_HOST = "http://localhost:8090";
private static final String BOS_MANAGEMENT_CONTEXT = "/bos_management";
private static final String CRM_MANAGEMENT_CONTEXT = "/crm_management";
}
1
// 查询已关联到定区的用户列表
@GetMapping(value = "/findHasAssociationFixedAreaCustomers")
public ResponseEntity findHasAssociationFixedAreaCustomers(@RequestParam("id")String fixedAreaId) {
// 使用HttpClient调用 接口
String url = Constants.CRM_MANAGEMENT_HOST + "/customer/associationFixedAreaCustomers?fixedAreaId="+fixedAreaId;
ResponseEntity result = restTemplate.getForEntity(url, String.class);
// return result;
HttpStatus statusCode = result.getStatusCode();
String body = result.getBody();
return new ResponseEntity<>(body,statusCode);
}