Java 调用Restful API接口的几种方式(HTTPS)

摘要：最近有一个需求，为客户提供一些Restful API 接口，QA使用postman进行测试，但是postman的测试接口与java调用的相似但并不相同，于是想自己写一个程序去测试Restful API接口，由于使用的是HTTPS，所以还要考虑到对于HTTPS的处理。由于我也是首次使用Java调用restful接口，所以还要研究一番，自然也是查阅了一些资料。

分析：这个问题与模块之间的调用不同，比如我有两个模块front end 和back end，front end提供前台展示，back end提供数据支持。之前使用过Hession去把back end提供的服务注册成远程服务，在front end端可以通过这种远程服务直接调到back end的接口。但这对于一个公司自己的一个项目耦合性比较高的情况下使用，没有问题。但是如果给客户注册这种远程服务，似乎不太好，耦合性太高。所以就考虑用一下方式进行处理。

一、HttpClient

HttpClient大家也许比较熟悉但又比较陌生，熟悉是知道他可以远程调用比如请求一个URL，然后在response里获取到返回状态和返回信息，但是今天讲的稍微复杂一点，因为今天的主题是HTTPS，这个牵涉到证书或用户认证的问题。
确定使用HttpClient之后，查询相关资料，发现HttpClient的新版本与老版本不同，随然兼容老版本，但已经不提倡老版本是使用方式，很多都已经标记为过时的方法或类。今天就分别使用老版本4.2和最新版本4.5.3来写代码。

老版本4.2

需要认证

在准备证书阶段选择的是使用证书认证

package com.darren.test.https.v42; import java.io.File; import java.io.FileInputStream; import java.security.KeyStore; import org.apache.http.conn.ssl.SSLSocketFactory;  public class HTTPSCertifiedClient extends HTTPSClient {    public HTTPSCertifiedClient() {    }    @Override   public void prepareCertificate() throws Exception {     // 获得密匙库     KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());     FileInputStream instream = new FileInputStream(         new File("C:/Users/zhda6001/Downloads/software/xxx.keystore"));     // FileInputStream instream = new FileInputStream(new File("C:/Users/zhda6001/Downloads/xxx.keystore"));     // 密匙库的密码     trustStore.load(instream, "password".toCharArray());     // 注册密匙库     this.socketFactory = new SSLSocketFactory(trustStore);     // 不校验域名     socketFactory.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);   } } 

跳过认证

在准备证书阶段选择的是跳过认证

package com.darren.test.https.v42;  import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import javax.net.ssl.SSLContext; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager;  import org.apache.http.conn.ssl.SSLSocketFactory; public class HTTPSTrustClient extends HTTPSClient {   public HTTPSTrustClient() {    }    @Override   public void prepareCertificate() throws Exception {     // 跳过证书验证     SSLContext ctx = SSLContext.getInstance("TLS");     X509TrustManager tm = new X509TrustManager() {       @Override       public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {       }        @Override       public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {       }        @Override       public X509Certificate[] getAcceptedIssuers() {         return null;       }     };     // 设置成已信任的证书     ctx.init(null, new TrustManager[] { tm }, null);     // 穿件SSL socket 工厂，并且设置不检查host名称     this.socketFactory = new SSLSocketFactory(ctx, SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);   } } 

总结

现在发现这两个类都继承了同一个类HTTPSClient，并且HTTPSClient继承了DefaultHttpClient类，可以发现，这里使用了模板方法模式。

package com.darren.test.https.v42; 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.impl.client.DefaultHttpClient;  public abstract class HTTPSClient extends DefaultHttpClient {    protected SSLSocketFactory socketFactory;    /**    * 初始化HTTPSClient    *    * @return 返回当前实例    * @throws Exception    */   public HTTPSClient init() throws Exception {     this.prepareCertificate();     this.regist();      return this;   }    /**    * 准备证书验证    *    * @throws Exception    */   public abstract void prepareCertificate() throws Exception;    /**    * 注册协议和端口, 此方法也可以被子类重写    */   protected void regist() {     ClientConnectionManager ccm = this.getConnectionManager();     SchemeRegistry sr = ccm.getSchemeRegistry();     sr.register(new Scheme("https", 443, socketFactory));   } } 

下边是工具类

package com.darren.test.https.v42;  import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpRequestBase; import org.apache.http.message.BasicNameValuePair; import org.apache.http.util.EntityUtils;  public class HTTPSClientUtil {   private static final String DEFAULT_CHARSET = "UTF-8";    public static String doPost(HTTPSClient httpsClient, String url, Map<String, String> paramHeader,       Map<String, String> paramBody) throws Exception {     return doPost(httpsClient, url, paramHeader, paramBody, DEFAULT_CHARSET);   }    public static String doPost(HTTPSClient httpsClient, String url, Map<String, String> paramHeader,       Map<String, String> paramBody, String charset) throws Exception {      String result = null;     HttpPost httpPost = new HttpPost(url);     setHeader(httpPost, paramHeader);     setBody(httpPost, paramBody, charset);      HttpResponse response = httpsClient.execute(httpPost);     if (response != null) {       HttpEntity resEntity = response.getEntity();       if (resEntity != null) {         result = EntityUtils.toString(resEntity, charset);       }     }      return result;   }      public static String doGet(HTTPSClient httpsClient, String url, Map<String, String> paramHeader,       Map<String, String> paramBody) throws Exception {     return doGet(httpsClient, url, paramHeader, paramBody, DEFAULT_CHARSET);   }    public static String doGet(HTTPSClient httpsClient, String url, Map<String, String> paramHeader,       Map<String, String> paramBody, String charset) throws Exception {      String result = null;     HttpGet httpGet = new HttpGet(url);     setHeader(httpGet, paramHeader);      HttpResponse response = httpsClient.execute(httpGet);     if (response != null) {       HttpEntity resEntity = response.getEntity();       if (resEntity != null) {         result = EntityUtils.toString(resEntity, charset);       }     }      return result;   }    private static void setHeader(HttpRequestBase request, Map<String, String> paramHeader) {     // 设置Header     if (paramHeader != null) {       Set<String> keySet = paramHeader.keySet();       for (String key : keySet) {         request.addHeader(key, paramHeader.get(key));       }     }   }    private static void setBody(HttpPost httpPost, Map<String, String> paramBody, String charset) throws Exception {     // 设置参数     if (paramBody != null) {       List<NameValuePair> list = new ArrayList<NameValuePair>();       Set<String> keySet = paramBody.keySet();       for (String key : keySet) {         list.add(new BasicNameValuePair(key, paramBody.get(key)));       }        if (list.size() > 0) {         UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, charset);         httpPost.setEntity(entity);       }     }   } } 

然后是测试类：

package com.darren.test.https.v42; import java.util.HashMap; import java.util.Map;  public class HTTPSClientTest {    public static void main(String[] args) throws Exception {     HTTPSClient httpsClient = null;      httpsClient = new HTTPSTrustClient().init();     //httpsClient = new HTTPSCertifiedClient().init();      String url = "https://1.2.6.2:8011/xxx/api/getToken";     //String url = "https://1.2.6.2:8011/xxx/api/getHealth";      Map<String, String> paramHeader = new HashMap<>();     //paramHeader.put("Content-Type", "application/json");     paramHeader.put("Accept", "application/xml");     Map<String, String> paramBody = new HashMap<>();     paramBody.put("client_id", "[email protected]");     paramBody.put("client_secret", "P@ssword_1");     String result = HTTPSClientUtil.doPost(httpsClient, url, paramHeader, paramBody);          //String result = HTTPSClientUtil.doGet(httpsClient, url, null, null);          System.out.println(result);   }  } 

返回信息：

<?xml version="1.0" encoding="utf-8"?>
<token>jkf8RL0sw+Skkflj8RbKI5hP1bEQK8PrCuTZPpBINqMYKRMxY1kWCjmCfT191Zpp88VV1aGHW8oYNWjEYS0axpLuGAX89ejCoWNbikCc1UvfyesXHLktcJqyUFiVjevhrEQxJPHncLQYWP+Xse5oD9X8vKFKk7InNTMRzQK7YBTZ/e3U7gswM/5cvAHFl6o9rEq9cWPXavZNohyvnXsohSzDo+BXAtXxa1xpEDLy/8h/UaP4n4dlZDJJ3B8t1Xh+CRRIoMOPxf7c5wKhHtOkEOeXW+xoPQKKSx5CKWwJpPuGIIFWF/PaqWg+JUOsVT7QGdPv8PMWJ9DwEwjTdxguDg==</token>

新版本4.5.3

需要认证

package com.darren.test.https.v45;  import java.io.File; import java.io.FileInputStream; import java.security.KeyStore; import javax.net.ssl.SSLContext; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; import org.apache.http.conn.ssl.TrustSelfSignedStrategy; import org.apache.http.ssl.SSLContexts;  public class HTTPSCertifiedClient extends HTTPSClient {    public HTTPSCertifiedClient() {    }    @Override   public void prepareCertificate() throws Exception {     // 获得密匙库     KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());     FileInputStream instream = new FileInputStream(         new File("C:/Users/zhda6001/Downloads/software/xxx.keystore"));     // FileInputStream instream = new FileInputStream(new File("C:/Users/zhda6001/Downloads/xxx.keystore"));     try {       // 密匙库的密码       trustStore.load(instream, "password".toCharArray());     } finally {       instream.close();     }      SSLContext sslcontext = SSLContexts.custom().loadTrustMaterial(trustStore, TrustSelfSignedStrategy.INSTANCE)         .build();     this.connectionSocketFactory = new SSLConnectionSocketFactory(sslcontext);   }  } 

跳过认证

package com.darren.test.https.v45;  import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import javax.net.ssl.SSLContext; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; public class HTTPSTrustClient extends HTTPSClient {   public HTTPSTrustClient() {    }    @Override   public void prepareCertificate() throws Exception {     // 跳过证书验证     SSLContext ctx = SSLContext.getInstance("TLS");     X509TrustManager tm = new X509TrustManager() {       @Override       public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {       }        @Override       public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {       }        @Override       public X509Certificate[] getAcceptedIssuers() {         return null;       }     };     // 设置成已信任的证书     ctx.init(null, new TrustManager[] { tm }, null);     this.connectionSocketFactory = new SSLConnectionSocketFactory(ctx);   } } 

总结

package com.darren.test.https.v45;  import org.apache.http.config.Registry; import org.apache.http.config.RegistryBuilder; import org.apache.http.conn.socket.ConnectionSocketFactory; import org.apache.http.conn.socket.PlainConnectionSocketFactory; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.client.HttpClients; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;  public abstract class HTTPSClient extends HttpClientBuilder {   private CloseableHttpClient client;   protected ConnectionSocketFactory connectionSocketFactory;    /**    * 初始化HTTPSClient    *    * @return 返回当前实例    * @throws Exception    */   public CloseableHttpClient init() throws Exception {     this.prepareCertificate();     this.regist();      return this.client;   }    /**    * 准备证书验证    *    * @throws Exception    */   public abstract void prepareCertificate() throws Exception;    /**    * 注册协议和端口, 此方法也可以被子类重写    */   protected void regist() {     // 设置协议http和https对应的处理socket链接工厂的对象     Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()         .register("http", PlainConnectionSocketFactory.INSTANCE)         .register("https", this.connectionSocketFactory)         .build();     PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry);     HttpClients.custom().setConnectionManager(connManager);      // 创建自定义的httpclient对象     this.client = HttpClients.custom().setConnectionManager(connManager).build();     // CloseableHttpClient client = HttpClients.createDefault();   } } 

工具类：

package com.darren.test.https.v45;  import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Set;  import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpRequestBase; import org.apache.http.message.BasicNameValuePair; import org.apache.http.util.EntityUtils;  public class HTTPSClientUtil {   private static final String DEFAULT_CHARSET = "UTF-8";    public static String doPost(HttpClient httpClient, String url, Map<String, String> paramHeader,       Map<String, String> paramBody) throws Exception {     return doPost(httpClient, url, paramHeader, paramBody, DEFAULT_CHARSET);   }    public static String doPost(HttpClient httpClient, String url, Map<String, String> paramHeader,       Map<String, String> paramBody, String charset) throws Exception {      String result = null;     HttpPost httpPost = new HttpPost(url);     setHeader(httpPost, paramHeader);     setBody(httpPost, paramBody, charset);      HttpResponse response = httpClient.execute(httpPost);     if (response != null) {       HttpEntity resEntity = response.getEntity();       if (resEntity != null) {         result = EntityUtils.toString(resEntity, charset);       }     }      return result;   }      public static String doGet(HttpClient httpClient, String url, Map<String, String> paramHeader,       Map<String, String> paramBody) throws Exception {     return doGet(httpClient, url, paramHeader, paramBody, DEFAULT_CHARSET);   }    public static String doGet(HttpClient httpClient, String url, Map<String, String> paramHeader,       Map<String, String> paramBody, String charset) throws Exception {      String result = null;     HttpGet httpGet = new HttpGet(url);     setHeader(httpGet, paramHeader);      HttpResponse response = httpClient.execute(httpGet);     if (response != null) {       HttpEntity resEntity = response.getEntity();       if (resEntity != null) {         result = EntityUtils.toString(resEntity, charset);       }     }      return result;   }    private static void setHeader(HttpRequestBase request, Map<String, String> paramHeader) {     // 设置Header     if (paramHeader != null) {       Set<String> keySet = paramHeader.keySet();       for (String key : keySet) {         request.addHeader(key, paramHeader.get(key));       }     }   }    private static void setBody(HttpPost httpPost, Map<String, String> paramBody, String charset) throws Exception {     // 设置参数     if (paramBody != null) {       List<NameValuePair> list = new ArrayList<NameValuePair>();       Set<String> keySet = paramBody.keySet();       for (String key : keySet) {         list.add(new BasicNameValuePair(key, paramBody.get(key)));       }        if (list.size() > 0) {         UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, charset);         httpPost.setEntity(entity);       }     }   } } 

测试类：

package com.darren.test.https.v45;  import java.util.HashMap; import java.util.Map; import org.apache.http.client.HttpClient;  public class HTTPSClientTest {    public static void main(String[] args) throws Exception {     HttpClient httpClient = null;      //httpClient = new HTTPSTrustClient().init();     httpClient = new HTTPSCertifiedClient().init();      String url = "https://1.2.6.2:8011/xxx/api/getToken";     //String url = "https://1.2.6.2:8011/xxx/api/getHealth";      Map<String, String> paramHeader = new HashMap<>();     paramHeader.put("Accept", "application/xml");     Map<String, String> paramBody = new HashMap<>();     paramBody.put("client_id", "[email protected]");     paramBody.put("client_secret", "P@ssword_1");     String result = HTTPSClientUtil.doPost(httpClient, url, paramHeader, paramBody);          //String result = HTTPSClientUtil.doGet(httpsClient, url, null, null);          System.out.println(result);   }  } 

结果：

<?xml version="1.0" encoding="utf-8"?>
<token>RxitF9//7NxwXJS2cjIjYhLtvzUNvMZxxEQtGN0u07sC9ysJeIbPqte3hCjULSkoXPEUYGUVeyI9jv7/WikLrzxYKc3OSpaTSM0kCbCKphu0TB2Cn/nfzv9fMLueOWFBdyz+N0sEiI9K+0Gp7920DFEncn17wUJVmC0u2jwvM5FAjQKmilwodXZ6a0Dq+D7dQDJwVcwxBvJ2ilhyIb3pr805Vppmi9atXrVAKO0ODa006wEJFOfcgyG5p70wpJ5rrBL85vfy9WCvkd1R7j6NVjhXgH2gNimHkjEJorMjdXW2gKiUsiWsELi/XPswao7/CTWNwTnctGK8PX2ZUB0ZfA==</token>

二、HttpURLConnection

三、Spring的RestTemplate

其它方式以后补充

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持武林网。