java libraries relatively common http request

Common java library http request has httpclient, RestTemplate, OKhttp, a higher level package feign, retrofit

1、HttpClient

HttpClient: code complexity, you have to worry about resource recycling. Code is very complex, multi-redundant code, not recommended for direct use.

2, Rest Template

RestTemplate: Spring is provided by the client for accessing Rest services, RestTemplate offers a variety of convenient methods to access the remote Http services, can greatly improve the efficiency of the preparation of the client.

Introducing jar package:

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

Adding initial configuration (can also be unworthy, have default) - Note RestTemplate only initial configuration, there is no connection pool

package com.itunion.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

@Configuration
public class ApiConfig {
    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory factory) {
        return new RestTemplate(factory);
    }

    @Bean
    public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();//默认的是JDK提供http连接，需要的话可以//通过setRequestFactory方法替换为例如Apache HttpComponents、Netty或//OkHttp等其它HTTP library。
        factory.setReadTimeout(5000);//单位为ms
        factory.setConnectTimeout(5000);//单位为ms
        return factory;
    }
}

(1) get request (i.e., without reference to the parameters canceled)

// 1-getForObject()
User user1 = this.restTemplate.getForObject(uri, User.class);

// 2-getForEntity()
ResponseEntity<User> responseEntity1 = this.restTemplate.getForEntity(uri, User.class);
HttpStatus statusCode = responseEntity1.getStatusCode();
HttpHeaders header = responseEntity1.getHeaders();
User user2 = responseEntity1.getBody();
  
// 3-exchange()
RequestEntity requestEntity = RequestEntity.get(new URI(uri)).build();
ResponseEntity<User> responseEntity2 = this.restTemplate.exchange(requestEntity, User.class);
User user3 = responseEntity2.getBody();

　　　　method one:

Notice notice = restTemplate.getForObject("http://fantj.top/notice/list/{1}/{2}"
                , Notice.class,1,5);

　　　　Second way:

Map<String,String> map = new HashMap();
        map.put("start","1");
        map.put("page","5");
        Notice notice = restTemplate.getForObject("http://fantj.top/notice/list/"
                , Notice.class,map);

(2) post request:

// 1-postForObject()
User user1 = this.restTemplate.postForObject(uri, user, User.class);

// 2-postForEntity()
ResponseEntity<User> responseEntity1 = this.restTemplate.postForEntity(uri, user, User.class);

// 3-exchange()
RequestEntity<User> requestEntity = RequestEntity.post(new URI(uri)).body(user);
ResponseEntity<User> responseEntity2 = this.restTemplate.exchange(requestEntity, User.class);

　　method one:

String url = "http://demo/api/book/";
        HttpHeaders headers = new HttpHeaders();
        MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
        headers.setContentType(type);
        String requestJson = "{...}";
        HttpEntity<String> entity = new HttpEntity<String>(requestJson,headers);
        String result = restTemplate.postForObject(url, entity, String.class);
        System.out.println(result);

　　Second way:

@Test
public void rtPostObject(){
    RestTemplate restTemplate = new RestTemplate();
    String url = "http://47.xxx.xxx.96/register/checkEmail";
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
    MultiValueMap<String, String> map= new LinkedMultiValueMap<>();
    map.add("email", "[email protected]");
 
    HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(map, headers);
    ResponseEntity<String> response = restTemplate.postForEntity( url, request , String.class );
    System.out.println(response.getBody());
}

Other: also supports upload and download;

3、okhttp

okhttp: OkHttp is an efficient HTTP client, a request to allow a host address with all share the same socket connection; reduction request latency connection pool; GZIP compression reduces the size of the transparent response data; cache the response content, completely avoid repetition the request

When network problems when OkHttp still adhere to their responsibilities, it will automatically resume normal connectivity problems, if your service has multiple IP addresses, when the first IP request fails, try another OkHttp will alternate your IP configuration , OkHttp TLS using modern technology (SNI, ALPN) initialize a new connection when the handshake fails will fall back to TLS 1.0.

(1): its request / response mode is configured using API builders to design, blocking it supports synchronous and asynchronous requests back tone.

Introducing jar package:

<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <version>3.10.0</version>
</dependency>

(2) configuration file:

import okhttp3.ConnectionPool;
import okhttp3.OkHttpClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.concurrent.TimeUnit;

@Configuration
public class OkHttpConfiguration {

    @Bean
    public OkHttpClient okHttpClient() {
        return new OkHttpClient.Builder()
                //.sslSocketFactory(sslSocketFactory(), x509TrustManager())
                .retryOnConnectionFailure(false)
                .connectionPool(pool())
                .connectTimeout(30, TimeUnit.SECONDS)
                .readTimeout(30, TimeUnit.SECONDS)
                .writeTimeout(30,TimeUnit.SECONDS)
                .build();
    }

    @Bean
    public X509TrustManager x509TrustManager() {
        return new X509TrustManager() {
            @Override
            public void checkClientTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
            }
            @Override
            public void checkServerTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
            }
            @Override
            public X509Certificate[] getAcceptedIssuers() {
                return new X509Certificate[0];
            }
        };
    }

    @Bean
    public SSLSocketFactory sslSocketFactory() {
        try {
            //信任任何链接
            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(null, new TrustManager[]{x509TrustManager()}, new SecureRandom());
            return sslContext.getSocketFactory();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (KeyManagementException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * Create a new connection pool with tuning parameters appropriate for a single-user application.
     * The tuning parameters in this pool are subject to change in future OkHttp releases. Currently
     */
    @Bean
    public ConnectionPool pool() {
        return new ConnectionPool(200, 5, TimeUnit.MINUTES);
    }
}

(3) util Tools:

import okhttp3.*;
import org.apache.commons.lang3.exception.ExceptionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.util.Iterator;
import java.util.Map;

public class OkHttpUtil{
    private static final Logger logger = LoggerFactory.getLogger(OkHttpUtil.class);
    
    private static OkHttpClient  okHttpClient;

    @Autowired
    public OkHttpUtil(OkHttpClient  okHttpClient) {
        OkHttpUtil.okHttpClient= okHttpClient;
    } 
    
    /**
     * get
     * @param url     请求的url
     * @param queries 请求的参数，在浏览器？后面的数据，没有可以传null
     * @return
     */
    public static  String get(String url, Map<String, String> queries) {
        String responseBody = "";
        StringBuffer sb = new StringBuffer(url);
        if (queries != null && queries.keySet().size() > 0) {
            boolean firstFlag = true;
            Iterator iterator = queries.entrySet().iterator();
            while (iterator.hasNext()) {
                Map.Entry entry = (Map.Entry<String, String>) iterator.next();
                if (firstFlag) {
                    sb.append("?" + entry.getKey() + "=" + entry.getValue());
                    firstFlag = false;
                } else {
                    sb.append("&" + entry.getKey() + "=" + entry.getValue());
                }
            }
        }
        Request request = new Request.Builder()
                .url(sb.toString())
                .build();
        Response response = null;
        try { 
            response = okHttpClient.newCall(request).execute();
            int status = response.code();
            if (response.isSuccessful()) {
                return response.body().string();
            }
        } catch (Exception e) {
            logger.error("okhttp3 put error >> ex = {}", ExceptionUtils.getStackTrace(e));
        } finally {
            if (response != null) {
                response.close();
            }
        }
        return responseBody;
    }

    /**
     * post
     *
     * @param url    请求的url
     * @param params post form 提交的参数
     * @return
     */
    public static String post(String url, Map<String, String> params) {
        String responseBody = "";
        FormBody.Builder builder = new FormBody.Builder();
        //添加参数
        if (params != null && params.keySet().size() > 0) {
            for (String key : params.keySet()) {
                builder.add(key, params.get(key));
            }
        }
        Request request = new Request.Builder()
                .url(url)
                .post(builder.build())
                .build();
        Response response = null;
        try { 
            response = okHttpClient.newCall(request).execute();
            int status = response.code();
            if (response.isSuccessful()) {
                return response.body().string();
            }
        } catch (Exception e) {
            logger.error("okhttp3 post error >> ex = {}", ExceptionUtils.getStackTrace(e));
        } finally {
            if (response != null) {
                response.close();
            }
        }
        return responseBody;
    }

    /**
     * get
     * @param url     请求的url
     * @param queries 请求的参数，在浏览器？后面的数据，没有可以传null
     * @return
     */
    public static String getForHeader(String url, Map<String, String> queries) {
        String responseBody = "";
        StringBuffer sb = new StringBuffer(url);
        if (queries != null && queries.keySet().size() > 0) {
            boolean firstFlag = true;
            Iterator iterator = queries.entrySet().iterator();
            while (iterator.hasNext()) {
                Map.Entry entry = (Map.Entry<String, String>) iterator.next();
                if (firstFlag) {
                    sb.append("?" + entry.getKey() + "=" + entry.getValue());
                    firstFlag = false;
                } else {
                    sb.append("&" + entry.getKey() + "=" + entry.getValue());
                }
            }
        }
        Request request = new Request.Builder()
                .addHeader("key", "value")
                .url(sb.toString())
                .build();
        Response response = null;
        try { 
            response = okHttpClient.newCall(request).execute();
            int status = response.code();
            if (response.isSuccessful()) {
                return response.body().string();
            }
        } catch (Exception e) {
            logger.error("okhttp3 put error >> ex = {}", ExceptionUtils.getStackTrace(e));
        } finally {
            if (response != null) {
                response.close();
            }
        }
        return responseBody;
    }

    /**
     * Post请求发送JSON数据....{"name":"zhangsan","pwd":"123456"}
     * 参数一：请求Url
     * 参数二：请求的JSON
     * 参数三：请求回调
     */
    public static String postJsonParams(String url, String jsonParams) {
        String responseBody = "";
        RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonParams);
        Request request = new Request.Builder()
                .url(url)
                .post(requestBody)
                .build();
        Response response = null;
        try { 
            response = okHttpClient.newCall(request).execute();
            int status = response.code();
            if (response.isSuccessful()) {
                return response.body().string();
            }
        } catch (Exception e) {
            logger.error("okhttp3 post error >> ex = {}", ExceptionUtils.getStackTrace(e));
        } finally {
            if (response != null) {
                response.close();
            }
        }
        return responseBody;
    }

    /**
     * Post请求发送xml数据....
     * 参数一：请求Url
     * 参数二：请求的xmlString
     * 参数三：请求回调
     */
    public static String postXmlParams(String url, String xml) {
        String responseBody = "";
        RequestBody requestBody = RequestBody.create(MediaType.parse("application/xml; charset=utf-8"), xml);
        Request request = new Request.Builder()
                .url(url)
                .post(requestBody)
                .build();
        Response response = null;
        try { 
            response = okHttpClient.newCall(request).execute();
            int status = response.code();
            if (response.isSuccessful()) {
                return response.body().string();
            }
        } catch (Exception e) {
            logger.error("okhttp3 post error >> ex = {}", ExceptionUtils.getStackTrace(e));
        } finally {
            if (response != null) {
                response.close();
            }
        }
        return responseBody;
    }
}