Java 調用Restful API接口的幾種方式(HTTPS)

摘要：最近有一個需求，為客戶提供一些Restful API 接口，QA使用postman進行測試，但是postman的測試接口與java調用的相似但並不相同，於是想自己寫一個程序去測試Restful API接口，由於使用的是HTTPS，所以還要考慮到對於HTTPS的處理。由於我也是首次使用Java調用restful接口，所以還要研究一番，自然也是查閱了一些資料。

分析：這個問題與模塊之間的調用不同，比如我有兩個模塊front end 和back end，front end提供前台展示，back end提供數據支持。之前使用過Hession去把back end提供的服務註冊成遠程服務，在front end端可以通過這種遠程服務直接調到back end的接口。但這對於一個公司自己的一個項目耦合性比較高的情況下使用，沒有問題。但是如果給客戶註冊這種遠程服務，似乎不太好，耦合性太高。所以就考慮用一下方式進行處理。

一、HttpClient

HttpClient大家也許比較熟悉但又比較陌生，熟悉是知道他可以遠程調用比如請求一個URL，然後在response裡獲取到返回狀態和返回信息，但是今天講的稍微複雜一點，因為今天的主題是HTTPS，這個牽涉到證書或用戶認證的問題。
確定使用HttpClient之後，查詢相關資料，發現HttpClient的新版本與老版本不同，隨然兼容老版本，但已經不提倡老版本是使用方式，很多都已經標記為過時的方法或類。今天就分別使用老版本4.2和最新版本4.5.3來寫代碼。

老版本4.2

需要認證

在準備證書階段選擇的是使用證書認證

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 { // 獲得密匙庫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")); // 密匙庫的密碼trustStore.load(instream, "password".toCharArray()); // 註冊密匙庫this.socketFactory = new SSLSocketFactory(trustStore); // 不校驗域名socketFactory.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER); } }

跳過認證

在準備證書階段選擇的是跳過認證

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 { // 跳過證書驗證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; } }; // 設置成已信任的證書ctx.init(null, new TrustManager[] { tm }, null); // 穿件SSL socket 工廠，並且設置不檢查host名稱this.socketFactory = new SSLSocketFactory(ctx, SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER); } }

總結

現在發現這兩個類都繼承了同一個類HTTPSClient，並且HTTPSClient繼承了DefaultHttpClient類，可以發現，這裡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 返回當前實例* @throws Exception */ public HTTPSClient init() throws Exception { this.prepareCertificate(); this.regist(); return this; } /** * 準備證書驗證* * @throws Exception */ public abstract void prepareCertificate() throws Exception; /** * 註冊協議和端口, 此方法也可以被子類重寫*/ protected void regist() { ClientConnectionManager ccm = this.getConnectionManager(); SchemeRegistry sr = ccm.getSchemeRegistry(); sr.register(new Scheme("https", 443, socketFactory)); } }

下邊是工具類

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) { // 設置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 { // 設置參數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); } } } }

然後是測試類：

 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

需要認證

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 { // 獲得密匙庫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 { // 密匙庫的密碼trustStore.load(instream, "password".toCharArray()); } finally { instream.close(); } SSLContext sslcontext = SSLContexts.custom().loadTrustMaterial(trustStore, TrustSelfSignedStrategy.INSTANCE) .build(); this.connectionSocketFactory = new SSLConnectionSocketFactory(sslcontext); } }

跳過認證

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 { // 跳過證書驗證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; } }; // 設置成已信任的證書ctx.init(null, new TrustManager[] { tm }, null); this.connectionSocketFactory = new SSLConnectionSocketFactory(ctx); } }

總結

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 返回當前實例* @throws Exception */ public CloseableHttpClient init() throws Exception { this.prepareCertificate(); this.regist(); return this.client; } /** * 準備證書驗證* * @throws Exception */ public abstract void prepareCertificate() throws Exception; /** * 註冊協議和端口, 此方法也可以被子類重寫*/ protected void regist() { // 設置協議http和https對應的處理socket鏈接工廠的對象Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create() .register("http", PlainConnectionSocketFactory.INSTANCE) .register("https", this.connectionSocketFactory) .build(); PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry); HttpClients.custom().setConnectionManager(connManager); // 創建自定義的httpclient對象this.client = HttpClients.custom().setConnectionManager(connManager).build(); // CloseableHttpClient client = HttpClients.createDefault(); } }

工具類：

 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) { // 設置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 { // 設置參數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); } } } }

測試類：

 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); } }

結果：

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

二、HttpURLConnection

三、Spring的RestTemplate

其它方式以後補充

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。