poster
2019-12-10, 16:49
我正在使用MATLAB的urlread (http://www.mathworks.com/help/matlab/ref/urlread.html)命令访问内部数据库，直到该服务移至安全服务器（即使用HTTPS地址而不是HTTP地址）之前，一切工作正常。现在urlread不再成功检索结果。它给出了一个错误：
下载网址时出错。您的网络连接可能已断开，或者代理设置配置不正确。
我认为问题在于该服务正在使用无效的数字证书，因为如果我尝试直接在Web浏览器中访问资源，则会收到“不受信任的连接”警告，我可以通过将站点添加到“例外”列表中来通过该警告。 urlread没有解决此问题的明显方法。
urlread在urlread使用Java访问Web资源，并在此行引发错误：
inputStream = urlConnection.getInputStream; 其中urlConnection是Java对象： sun.net.www.protocol.https.HttpsURLConnectionImpl 。
有人建议解决此问题吗？
回答：
考虑下面的Java类。我将此页面用作参考：
在HTTPS连接中禁用证书验证 (http://www.java2s.com/Code/Java/Network-Protocol/DisablingCertificateValidationinanHTTPSConnection.htm)
C：\ MATLAB \ MyJavaClasses \ com \ stackoverflow \ Downloader.java
package com.stackoverflow; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.security.cert.X509Certificate; import javax.net.ssl.HttpsURLConnection; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLSession; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import javax.net.ssl.HostnameVerifier; public class Downloader { public static String getData(String address) throws Exception { // Create a trust manager that does not validate certificate chains TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() { public java.security.cert.X509Certificate[] getAcceptedIssuers() { return null; } public void checkClientTrusted(X509Certificate[] certs, String authType) { } public void checkServerTrusted(X509Certificate[] certs, String authType) { } } }; // Create a host name verifier that always passes HostnameVerifier allHostsValid = new HostnameVerifier() { public boolean verify(String hostname, SSLSession session) { return true; } }; // Install the all-trusting trust manager SSLContext sc = SSLContext.getInstance("SSL"); sc.init(null, trustAllCerts, new java.security.SecureRandom()); HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory()); // Install the all-trusting host verifier HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid); // open connection URL page = new URL(address); HttpURLConnection conn = (HttpURLConnection) page.openConnection(); BufferedReader buff = new BufferedReader(new InputStreamReader(conn.getInputStream())); // read text String line; StringBuffer text = new StringBuffer(); while ( (line = buff.readLine()) != null ) { //System.out.println(line); text.append(line + "\n"); } buff.close(); return text.toString(); } public static void main(String[] argv) throws Exception { String str = getData("https://expired.badssl.com/"); System.out.println(str); } } 的MATLAB
首先，我们编译Java类（必须使用与MATLAB兼容的JDK版本）：
>> version -java >> system('javac C:\MATLAB\MyJavaClasses\com\stackoverflow\Downloader.java'); 接下来，我们将其实例化并使用它作为MATLAB：
javaaddpath('C:\MATLAB\MyJavaClasses') dl = com.stackoverflow.Downloader; str = char(dl.getData('https://expired.badssl.com/')); web(['text://' str], '-new') 以下是一些带有错误SSL证书的URL以进行测试：
urls = { 'https://expired.badssl.com/' % expired 'https://wrong.host.badssl.com/' % wrong host 'https://self-signed.badssl.com/' % self-signed 'https://revoked.grc.com/' % revoked }; 更新：我应该提到，从R2014b开始，MATLAB有一个新功能webread (http://www.mathworks.com/help/matlab/ref/webread.html)取代了urlread (http://www.mathworks.com/help/matlab/ref/urlread.html) 。
更多&回答... (https://stackoverflow.com/questions/1638275)
下载网址时出错。您的网络连接可能已断开，或者代理设置配置不正确。
我认为问题在于该服务正在使用无效的数字证书，因为如果我尝试直接在Web浏览器中访问资源，则会收到“不受信任的连接”警告，我可以通过将站点添加到“例外”列表中来通过该警告。 urlread没有解决此问题的明显方法。
urlread在urlread使用Java访问Web资源，并在此行引发错误：
inputStream = urlConnection.getInputStream; 其中urlConnection是Java对象： sun.net.www.protocol.https.HttpsURLConnectionImpl 。
有人建议解决此问题吗？
回答：
考虑下面的Java类。我将此页面用作参考：
在HTTPS连接中禁用证书验证 (http://www.java2s.com/Code/Java/Network-Protocol/DisablingCertificateValidationinanHTTPSConnection.htm)
C：\ MATLAB \ MyJavaClasses \ com \ stackoverflow \ Downloader.java
package com.stackoverflow; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.security.cert.X509Certificate; import javax.net.ssl.HttpsURLConnection; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLSession; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import javax.net.ssl.HostnameVerifier; public class Downloader { public static String getData(String address) throws Exception { // Create a trust manager that does not validate certificate chains TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() { public java.security.cert.X509Certificate[] getAcceptedIssuers() { return null; } public void checkClientTrusted(X509Certificate[] certs, String authType) { } public void checkServerTrusted(X509Certificate[] certs, String authType) { } } }; // Create a host name verifier that always passes HostnameVerifier allHostsValid = new HostnameVerifier() { public boolean verify(String hostname, SSLSession session) { return true; } }; // Install the all-trusting trust manager SSLContext sc = SSLContext.getInstance("SSL"); sc.init(null, trustAllCerts, new java.security.SecureRandom()); HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory()); // Install the all-trusting host verifier HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid); // open connection URL page = new URL(address); HttpURLConnection conn = (HttpURLConnection) page.openConnection(); BufferedReader buff = new BufferedReader(new InputStreamReader(conn.getInputStream())); // read text String line; StringBuffer text = new StringBuffer(); while ( (line = buff.readLine()) != null ) { //System.out.println(line); text.append(line + "\n"); } buff.close(); return text.toString(); } public static void main(String[] argv) throws Exception { String str = getData("https://expired.badssl.com/"); System.out.println(str); } } 的MATLAB
首先，我们编译Java类（必须使用与MATLAB兼容的JDK版本）：
>> version -java >> system('javac C:\MATLAB\MyJavaClasses\com\stackoverflow\Downloader.java'); 接下来，我们将其实例化并使用它作为MATLAB：
javaaddpath('C:\MATLAB\MyJavaClasses') dl = com.stackoverflow.Downloader; str = char(dl.getData('https://expired.badssl.com/')); web(['text://' str], '-new') 以下是一些带有错误SSL证书的URL以进行测试：
urls = { 'https://expired.badssl.com/' % expired 'https://wrong.host.badssl.com/' % wrong host 'https://self-signed.badssl.com/' % self-signed 'https://revoked.grc.com/' % revoked }; 更新：我应该提到，从R2014b开始，MATLAB有一个新功能webread (http://www.mathworks.com/help/matlab/ref/webread.html)取代了urlread (http://www.mathworks.com/help/matlab/ref/urlread.html) 。
更多&回答... (https://stackoverflow.com/questions/1638275)