https协议对于开发者而言其实只是多了一步证书验证的过程。这个证书正常情况下被jdk/jre/security/cacerts所管理。里面证书包含两种情况：
1、机构所颁发的被认证的证书，这种证书的网站在浏览器访问时https头显示为绿色如百度
2、个人所设定的证书，这种证书的网站在浏览器里https头显示为红色×，且需要点击信任该网站才能继续访问。而点击信任这一步的操作就是我们在java代码访问https网站时区别于http请求需要做的事情。
所以JAVA发送Https请求有两种情况，三种解决办法：
第一种情况：Https网站的证书为机构所颁发的被认证的证书，这种情况下和http请求一模一样，无需做任何改变，用HttpsURLConnection或者HttpURLConnection都可以
[java] view plain copy public static void main(String[] args) throws Exception{ URL serverUrl = new URL("https://xxxx"); HttpURLConnection conn = (HttpURLConnection) serverUrl.openConnection(); conn.setRequestMethod("GET"); conn.setRequestProperty("Content-type", "application/json"); //必须设置false，否则会自动redirect到重定向后的地址 conn.setInstanceFollowRedirects(false); conn.connect(); String result = getReturn(conn); } /*请求url获取返回的内容*/ public static String getReturn(HttpURLConnection connection) throws IOException{ StringBuffer buffer = new StringBuffer(); //将返回的输入流转换成字符串 try(InputStream inputStream = connection.getInputStream(); InputStreamReader inputStreamReader = new InputStreamReader(inputStream, ConstantInfo.CHARSET); BufferedReader bufferedReader = new BufferedReader(inputStreamReader);){ String str = null; while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } String result = buffer.toString(); return result; } }
第二种情况：个人所设定的证书，这种证书默认不被信任，需要我们自己选择信任，信任的办法有两种：
A、将证书导入java的运行环境中
从该网站下载或者从网站开发者出获取证书cacert.crt运行命令将证书导入java运行环境：keytool -import -keystore %JAVA_HOME%\jre\lib\security\cacerts -file cacert.crt -alias xxx完成。java代码中发送https的请求和http一样，同第一种情况。
B、忽略证书验证过程，忽略之后任何Https协议网站皆能正常访问，同第一种情况
[java] view plain copy import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import javax.net.ssl.X509TrustManager; public class MyX509TrustManager implements X509TrustManager { @Override public void checkClientTrusted(X509Certificate certificates[],String authType) throws CertificateException { } @Override public void checkServerTrusted(X509Certificate[] ax509certificate,String s) throws CertificateException { } @Override public X509Certificate[] getAcceptedIssuers() { // TODO Auto-generated method stub return null; } } [java] view plain copy public static void main(String[] args) throws Exception{ SSLContext sslcontext = SSLContext.getInstance("SSL","SunJSSE"); sslcontext.init(null, new TrustManager[]{new MyX509TrustManager()}, new java.security.SecureRandom()); URL url = new URL("https://xxxx"); HostnameVerifier ignoreHostnameVerifier = new HostnameVerifier() { public boolean verify(String s, SSLSession sslsession) { System.out.println("WARNING: Hostname is not matched for cert."); return true; } }; HttpsURLConnection.setDefaultHostnameVerifier(ignoreHostnameVerifier); HttpsURLConnection.setDefaultSSLSocketFactory(sslcontext.getSocketFactory()); //之后任何Https协议网站皆能正常访问，同第一种情况 }
C、java代码中加载证书，必须使用HttpsURLConnection方式
从网站开发者出获取生成证书的密钥库cacert.keystore [java] view plain copy import java.io.FileInputStream; import java.security.KeyStore; import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import javax.net.ssl.TrustManager; import javax.net.ssl.TrustManagerFactory; import javax.net.ssl.X509TrustManager; public class MyX509TrustManager implements X509TrustManager { /* * The default X509TrustManager returned by SunX509. We'll delegate * decisions to it, and fall back to the logic in this class if the * default X509TrustManager doesn't trust it. */ X509TrustManager sunJSSEX509TrustManager; MyX509TrustManager() throws Exception { // create a "default" JSSE X509TrustManager. KeyStore ks = KeyStore.getInstance("JKS"); ks.load(new FileInputStream("cancert.keystore"), "changeit".toCharArray()); TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509", "SunJSSE"); tmf.init(ks); TrustManager tms [] = tmf.getTrustManagers(); /* * Iterate over the returned trustmanagers, look * for an instance of X509TrustManager. If found, * use that as our "default" trust manager. */ for (int i = 0; i < tms.length; i++) { if (tms[i] instanceof X509TrustManager) { sunJSSEX509TrustManager = (X509TrustManager) tms[i]; return; } } /* * Find some other way to initialize, or else we have to fail the * constructor. */ throw new Exception("Couldn't initialize"); } /* * Delegate to the default trust manager. */ public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException { try { sunJSSEX509TrustManager.checkClientTrusted(chain, authType); } catch (CertificateException excep) { // do any special handling here, or rethrow exception. } } /* * Delegate to the default trust manager. */ public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException { try { sunJSSEX509TrustManager.checkServerTrusted(chain, authType); } catch (CertificateException excep) { /* * Possibly pop up a dialog box asking whether to trust the * cert chain. */ } } /* * Merely pass this through. */ public X509Certificate[] getAcceptedIssuers() { return sunJSSEX509TrustManager.getAcceptedIssuers(); } } [java] view plain copy [java] view plain copy public static void main(String[] args) throws Exception{ SSLContext sslcontext = SSLContext.getInstance("SSL","SunJSSE"); sslcontext.init(null, new TrustManager[]{new MyX509TrustManager()}, new java.security.SecureRandom()); URL serverUrl = new URL("https://xxxx"); HttpsURLConnection conn = (HttpsURLConnection) serverUrl.openConnection(); conn.setSSLSocketFactory(sslcontext.getSocketFactory()); conn.setRequestMethod("GET"); conn.setRequestProperty("Content-type", "application/json"); //必须设置false，否则会自动redirect到重定向后的地址 conn.setInstanceFollowRedirects(false); conn.connect(); String result = getReturn(conn); } /*请求url获取返回的内容*/ public static String getReturn(HttpsURLConnection connection) throws IOException{ StringBuffer buffer = new StringBuffer(); //将返回的输入流转换成字符串 try(InputStream inputStream = connection.getInputStream(); InputStreamReader inputStreamReader = new InputStreamReader(inputStream, ConstantInfo.CHARSET); BufferedReader bufferedReader = new BufferedReader(inputStreamReader);){ String str = null; while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } String result = buffer.toString(); return result; } }
转载于:https://www.cnblogs.com/mengen/p/9138214.html
