SpringBoot访问外部接口

原生的Http请求

@RequestMapping("/doPostGetJson")
public String doPostGetJson() throws ParseException {
   //此处将要发送的数据转换为json格式字符串
   String jsonText = "{id: 1}";
   JSONObject json = (JSONObject) JSONObject.parse(jsonText);
   JSONObject sr = this.doPost(json);
   System.out.println("返回参数: " + sr);
   return sr.toString();
}

public static JSONObject doPost(JSONObject date) {
   HttpClient client = HttpClients.createDefault();
   // 要调用的接口方法
   String url = "http://192.168.1.101:8080/getJson";
   HttpPost post = new HttpPost(url);
   JSONObject jsonObject = null;
   try {
      StringEntity s = new StringEntity(date.toString());
      s.setContentEncoding("UTF-8");
      s.setContentType("application/json");
      post.setEntity(s);
      post.addHeader("content-type", "text/xml");
      HttpResponse res = client.execute(post);
      String response1 = EntityUtils.toString(res.getEntity());
      System.out.println(response1);
      if (res.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
         String result = EntityUtils.toString(res.getEntity());// 返回json格式: 
         jsonObject = JSONObject.parseObject(result);
      }
   } catch (Exception e) {
      throw new RuntimeException(e);
   }
   return jsonObject;
}

HttpUtils

import org.apache.commons.lang.StringUtils;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpDelete;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.entity.ByteArrayEntity;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class HttpUtils {

    /**
     * get
     *
     * @param host
     * @param path
     * @param headers
     * @param querys
     * @return
     * @throws Exception
     */
    public static HttpResponse doGet(String host, String path,
                                     Map<String, String> headers,
                                     Map<String, String> querys)
            throws Exception {
        HttpClient httpClient = wrapClient(host);

        HttpGet request = new HttpGet(buildUrl(host, path, querys));
        for (Map.Entry<String, String> e : headers.entrySet()) {
            request.addHeader(e.getKey(), e.getValue());
        }

        return httpClient.execute(request);
    }

    /**
     * post form
     *
     * @param host
     * @param path
     * @param method
     * @param headers
     * @param querys
     * @param bodys
     * @return
     * @throws Exception
     */
    public static HttpResponse doPost(String host, String path, String method,
                                      Map<String, String> headers,
                                      Map<String, String> querys,
                                      Map<String, String> bodys)
            throws Exception {
        HttpClient httpClient = wrapClient(host);

        HttpPost request = new HttpPost(buildUrl(host, path, querys));
        for (Map.Entry<String, String> e : headers.entrySet()) {
            request.addHeader(e.getKey(), e.getValue());
        }

        if (bodys != null) {
            List<NameValuePair> nameValuePairList = new ArrayList<NameValuePair>();

            for (String key : bodys.keySet()) {
                nameValuePairList.add(new BasicNameValuePair(key, bodys.get(key)));
            }
            UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(nameValuePairList, "utf-8");
            formEntity.setContentType("application/x-www-form-urlencoded; charset=UTF-8");
            request.setEntity(formEntity);
        }

        return httpClient.execute(request);
    }

    /**
     * Post String
     *
     * @param host
     * @param path
     * @param method
     * @param headers
     * @param querys
     * @param body
     * @return
     * @throws Exception
     */
    public static HttpResponse doPost(String host, String path, String method,
                                      Map<String, String> headers,
                                      Map<String, String> querys,
                                      String body)
            throws Exception {
        HttpClient httpClient = wrapClient(host);
        RequestConfig requestConfig =
                RequestConfig.custom().setSocketTimeout(20000).setConnectTimeout(20000).build();
        HttpPost request = new HttpPost(buildUrl(host, path, querys));
        request.setConfig(requestConfig);
        for (Map.Entry<String, String> e : headers.entrySet()) {
            request.addHeader(e.getKey(), e.getValue());
        }

        if (org.apache.commons.lang.StringUtils.isNotBlank(body)) {
            request.setEntity(new StringEntity(body, "utf-8"));
        }

        return httpClient.execute(request);
    }

    /**
     * Post stream
     *
     * @param host
     * @param path
     * @param method
     * @param headers
     * @param querys
     * @param body
     * @return
     * @throws Exception
     */
    public static HttpResponse doPost(String host, String path, String method,
                                      Map<String, String> headers,
                                      Map<String, String> querys,
                                      byte[] body)
            throws Exception {
        HttpClient httpClient = wrapClient(host);

        HttpPost request = new HttpPost(buildUrl(host, path, querys));
        for (Map.Entry<String, String> e : headers.entrySet()) {
            request.addHeader(e.getKey(), e.getValue());
        }

        if (body != null) {
            request.setEntity(new ByteArrayEntity(body));
        }

        return httpClient.execute(request);
    }

    /**
     * Put String
     * @param host
     * @param path
     * @param method
     * @param headers
     * @param querys
     * @param body
     * @return
     * @throws Exception
     */
    public static HttpResponse doPut(String host, String path, String method,
                                     Map<String, String> headers,
                                     Map<String, String> querys,
                                     String body)
            throws Exception {
        HttpClient httpClient = wrapClient(host);

        HttpPut request = new HttpPut(buildUrl(host, path, querys));
        for (Map.Entry<String, String> e : headers.entrySet()) {
            request.addHeader(e.getKey(), e.getValue());
        }

        if (org.apache.commons.lang.StringUtils.isNotBlank(body)) {
            request.setEntity(new StringEntity(body, "utf-8"));
        }

        return httpClient.execute(request);
    }

    /**
     * Put stream
     * @param host
     * @param path
     * @param method
     * @param headers
     * @param querys
     * @param body
     * @return
     * @throws Exception
     */
    public static HttpResponse doPut(String host, String path, String method,
                                     Map<String, String> headers,
                                     Map<String, String> querys,
                                     byte[] body)
            throws Exception {
        HttpClient httpClient = wrapClient(host);

        HttpPut request = new HttpPut(buildUrl(host, path, querys));
        for (Map.Entry<String, String> e : headers.entrySet()) {
            request.addHeader(e.getKey(), e.getValue());
        }

        if (body != null) {
            request.setEntity(new ByteArrayEntity(body));
        }

        return httpClient.execute(request);
    }

    /**
     * Delete
     *
     * @param host
     * @param path
     * @param method
     * @param headers
     * @param querys
     * @return
     * @throws Exception
     */
    public static HttpResponse doDelete(String host, String path, String method,
                                        Map<String, String> headers,
                                        Map<String, String> querys)
            throws Exception {
        HttpClient httpClient = wrapClient(host);

        HttpDelete request = new HttpDelete(buildUrl(host, path, querys));
        for (Map.Entry<String, String> e : headers.entrySet()) {
            request.addHeader(e.getKey(), e.getValue());
        }

        return httpClient.execute(request);
    }

    private static String buildUrl(String host, String path, Map<String, String> querys) throws UnsupportedEncodingException {
        StringBuilder sbUrl = new StringBuilder();
        sbUrl.append(host);
        if (!org.apache.commons.lang.StringUtils.isBlank(path)) {
            sbUrl.append(path);
        }
        if (null != querys) {
            StringBuilder sbQuery = new StringBuilder();
            for (Map.Entry<String, String> query : querys.entrySet()) {
                if (0 < sbQuery.length()) {
                    sbQuery.append("&");
                }
                if (org.apache.commons.lang.StringUtils.isBlank(query.getKey()) && !org.apache.commons.lang.StringUtils.isBlank(query.getValue())) {
                    sbQuery.append(query.getValue());
                }
                if (!org.apache.commons.lang.StringUtils.isBlank(query.getKey())) {
                    sbQuery.append(query.getKey());
                    if (!StringUtils.isBlank(query.getValue())) {
                        sbQuery.append("=");
                        sbQuery.append(URLEncoder.encode(query.getValue(), "utf-8"));
                    }
                }
            }
            if (0 < sbQuery.length()) {
                sbUrl.append("?").append(sbQuery);
            }
        }

        return sbUrl.toString();
    }

    private static HttpClient wrapClient(String host) {
        HttpClient httpClient = new DefaultHttpClient();
        if (host.startsWith("https://")) {
            sslClient(httpClient);
        }

        return httpClient;
    }

    private static void sslClient(HttpClient httpClient) {
        try {
            SSLContext ctx = SSLContext.getInstance("TLS");
            X509TrustManager tm = new X509TrustManager() {
                public X509Certificate[] getAcceptedIssuers() {
                    return null;
                }
                public void checkClientTrusted(X509Certificate[] xcs, String str) {

                }
                public void checkServerTrusted(X509Certificate[] xcs, String str) {

                }
            };
            ctx.init(null, new TrustManager[] { tm }, null);
            SSLSocketFactory ssf = new SSLSocketFactory(ctx);
            ssf.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
            ClientConnectionManager ccm = httpClient.getConnectionManager();
            SchemeRegistry registry = ccm.getSchemeRegistry();
            registry.register(new Scheme("https", 443, ssf));
        } catch (KeyManagementException ex) {
            throw new RuntimeException(ex);
        } catch (NoSuchAlgorithmException ex) {
            throw new RuntimeException(ex);
        }
    }
}

Feign进行消费

1.在maven项目中添加依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-feign</artifactId>
    <version>1.2.2.RELEASE</version>
</dependency>

2.编写接口，放置在service层

这里的decisionEngine.url 是配置在properties中的是ip地址和端口号 decisionEngine.url=http://10.2.1.148:3333/decision/person 是接口名字

@FeignClient(url = "${decisionEngine.url}",name="engine")
public interface DecisionEngineService {
　　@RequestMapping(value="/decision/person",method= RequestMethod.POST)
　　public JSONObject getEngineMesasge(@RequestParam("uid") String uid,@RequestParam("productCode") String productCode);

}

3.在Java的启动类上加上@EnableFeignClients

@EnableFeignClients //参见此处
@EnableDiscoveryClient
@SpringBootApplication
@EnableResourceServer
public class Application   implements CommandLineRunner {
    private static final Logger LOGGER = LoggerFactory.getLogger(Application.class);
    @Autowired
    private AppMetricsExporter appMetricsExporter;

    @Autowired
    private AddMonitorUnitService addMonitorUnitService;

    public static void main(String[] args) {
        new SpringApplicationBuilder(Application.class).web(true).run(args);
    }    
}

4.在代码中调用接口即可

@Autowired
private DecisionEngineService decisionEngineService ;
// ...
decisionEngineService.getEngineMesasge("uid" ,  "productCode");

RestTemplate方法

在Spring-Boot开发中，RestTemplate同样提供了对外访问的接口API，这里主要介绍Get和Post方法的使用。Get请求提供了两种方式的接口getForObject 和 getForEntity，getForEntity提供如下三种方法的实现。

1.配置RestTemplate

import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.http.converter.ByteArrayHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.ResourceHttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter;
import org.springframework.http.converter.xml.SourceHttpMessageConverter;
import org.springframework.web.client.RestTemplate;

import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

@Configuration
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class RestTemplateConfig {

    // 配置 RestTemplate
    @Bean
    public RestTemplate restTemplate(MappingJackson2HttpMessageConverter jackson2HttpMessageConverter){
        RestTemplate restTemplate = new RestTemplate(simpleClientHttpRequestFactory());
        List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
        StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter(StandardCharsets.UTF_8);
        messageConverters.add(stringHttpMessageConverter);
        messageConverters.add(jackson2HttpMessageConverter);
        messageConverters.add(new ByteArrayHttpMessageConverter());
        messageConverters.add(new ResourceHttpMessageConverter());
        messageConverters.add(new SourceHttpMessageConverter<>());
        messageConverters.add(new AllEncompassingFormHttpMessageConverter());
        restTemplate.setMessageConverters(messageConverters);
        return restTemplate;
    }

    @Bean
    public HttpComponentsClientHttpRequestFactory simpleClientHttpRequestFactory(){
        // 禁用Cookie回话保持功能
        CloseableHttpClient build = HttpClientBuilder.create().disableCookieManagement().useSystemProperties().build();
        // 创建一个 httpCilent 简单工厂
        HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory(build);
        // 设置连接超时
        factory.setConnectTimeout(15000);
        // 设置读取超时
        factory.setReadTimeout(5000);

        return factory;
    }
}

2.注入RestTemplate

在使用RestTemplate方法的类中注入RestTemplate

    @Autowired
    private RestTemplate restTemplate;

3.Get请求

getForEntity(Stringurl,Class responseType,Object…urlVariables)

该方法提供了三个参数，其中url为请求的地址，responseType为请求响应body的包装类型，urlVariables为url中的参数绑定，该方法的参考调用如下:

// http://USER-SERVICE/user?name={name)
RestTemplate restTemplate=new RestTemplate();
Map<String,String> params=new HashMap<>();
params.put("name","dada");  //
ResponseEntity<String> responseEntity=restTemplate.getForEntity("http://USERSERVICE/user?name={name}",String.class,params);

getForEntity(URI url,Class responseType)

该方法使用URI对象来替代之前的url和urlVariables参数来指定访问地址和参数绑定。URI是JDK java.net包下的一个类，表示一个统一资源标识符(Uniform Resource Identifier)引用。参考如下:

RestTemplate restTemplate=new RestTemplate();
UriComponents uriComponents=UriComponentsBuilder.fromUriString("http://USER-SERVICE/user?name={name}")
    .build()
    .expand("dodo")
    .encode();
URI uri=uriComponents.toUri();
ResponseEntity<String> responseEntity=restTemplate.getForEntity(uri,String.class).getBody();

getForObject

getForObject方法可以理解为对getForEntity的进一步封装，它通过HttpMessageConverterExtractor对HTTP的请求响应体body内容进行对象转换，实现请求直接返回包装好的对象内容。getForObject方法有如下:

getForObject(String url,Class responseType,Object...urlVariables)
getForObject(String url,Class responseType,Map urlVariables)
getForObject(URI url,Class responseType)

4.Post请求

Post请求提供有三种方法，postForEntity、postForObject和postForLocation。其中每种方法都存在三种方法，postForEntity方法使用如下:

estTemplate restTemplate=new RestTemplate();
User user=newUser("didi",30);
ResponseEntity<String> responseEntity=restTemplate.postForEntity("http://USER-SERVICE/user",user,String.class); //提交的body内容为user对象，请求的返回的body类型为String
String body=responseEntity.getBody();

postForEntity存在如下三种方法的重载,postForEntity中的其它参数和getForEntity的参数大体相同

postForEntity(String url,Object request,Class responseType,Object... uriVariables)
postForEntity(String url,Object request,Class responseType,Map uriVariables)
postForEntity(URI url,Object request，Class responseType)

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