In my case, the root & intermediate certificates was successfully installed but I still got "Trust anchor for certification path not found." exception!. After digging the android document, found out that by default, secure connections (using protocols like TLS and HTTPS) from all apps trust the pre-installed system CAs, and apps targeting Android 6.0 (API level 23) and lower also trust the user-added CA store by default. If your app running on a OS with api level higher than 23 you should explicitly allow the app to trust user-added CA by adding its address to network_security_config like bellow:

<domain-config>
        <domain includeSubdomains="true">PUT_YOUR_SERVER_ADDERESS</domain>
        <trust-anchors>
            <certificates src="user" />
        </trust-anchors>
</domain-config>

有时，当管理员错误地设置证书时，会发生这种情况 点击此处查看URL https://www.sslshopper.com/ssl-checker.html

在我的例子中，出现了一个错误

证书在所有浏览器中都不受信任。您可能需要安装中间证书/链证书以将其链接到受信任的根证书。了解关于此错误的更多信息。您可以按照GlobalSign针对您的服务器平台的证书安装说明来解决这个问题。注意中级证书部分。

我使用这些方法，其中一个是上述解决方案对我有效: 第一:

   public  okhttp3.OkHttpClient getUnsafeOkHttpClient() {
    try {
        // Create a trust manager that does not validate 
   certificate chains
        final TrustManager[] trustAllCerts = new TrustManager[] {
                new X509TrustManager() {
                    @Override
                    public void 
   checkClientTrusted(java.security.cert.X509Certificate[] chain, 
   String authType) throws CertificateException {
                    }

                    @Override
                    public void 
  checkServerTrusted(java.security.cert.X509Certificate[] chain, 
  String authType) throws CertificateException {
                    }

                    @Override
                    public java.security.cert.X509Certificate[] 
   getAcceptedIssuers() {
                        return new 
  java.security.cert.X509Certificate[]{};
                    }
                }
        };

        // Install the all-trusting trust manager
        final SSLContext sslContext = 
  SSLContext.getInstance("SSL");
        sslContext.init(null, trustAllCerts, new 
  java.security.SecureRandom());

        // Create an ssl socket factory with our all-trusting 
       manager
        final SSLSocketFactory sslSocketFactory = 
       sslContext.getSocketFactory();

        okhttp3.OkHttpClient.Builder builder = new 
      okhttp3.OkHttpClient.Builder();
        builder.sslSocketFactory(sslSocketFactory, 
      (X509TrustManager)trustAllCerts[0]);
        builder.hostnameVerifier(new HostnameVerifier() {
            @Override
            public boolean verify(String hostname, SSLSession 
       session) {
                return true;
            }
        });

        okhttp3.OkHttpClient okHttpClient = builder.build();
        return okHttpClient;
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}

第二:

    @SuppressLint("TrulyRandom")
    public static void handleSSLHandshake() {
    try {
        TrustManager[] trustAllCerts = new TrustManager[]{new 
       X509TrustManager() {
            public X509Certificate[] getAcceptedIssuers() {
                return new X509Certificate[0];
            }

            @Override
            public void checkClientTrusted(X509Certificate[] 
        certs, String authType) {
            }

            @Override
            public void checkServerTrusted(X509Certificate[] 
       certs, String authType) {
            }
        }};

        SSLContext sc = SSLContext.getInstance("SSL");
        sc.init(null, trustAllCerts, new SecureRandom());
        



  HttpsURLConnection
 .setDefaultSSLSocketFactory(sc.getSocketFactory());
        HttpsURLConnection.setDefaultHostnameVerifier(new 
    HostnameVerifier() {
            @Override
            public boolean verify(String arg0, SSLSession arg1) {
                return true;
            }
        });
    } catch (Exception ignored) {
    }
}

和: 把这些库放到你的类路径中:

 implementation 'com.squareup.okhttp:okhttp:2.3.0'
implementation 'com.squareup.okhttp:okhttp-urlconnection:2.3.0'
    androidTestImplementation 'androidx.test.espresso:espresso- 
    core:3.3.0'

一定要在课堂上给他们打电话

根据最新的Android文档(2017年3月)更新:

当你得到这种类型的错误:

javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
        at org.apache.harmony.xnet.provider.jsse.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:374)
        at libcore.net.http.HttpConnection.setupSecureSocket(HttpConnection.java:209)
        at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:478)
        at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:433)
        at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
        at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
        at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:282)
        at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:177)
        at libcore.net.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:271)

问题可能是以下情况之一:

颁发服务器证书的CA未知 服务器证书不是由CA签署的，而是自签署的 服务器配置缺少一个中间CA

解决方案是教会HttpsURLConnection信任一组特定的ca。怎么做?请查看https://developer.android.com/training/articles/security-ssl.html#CommonProblems

其他使用com.loopj的AsyncHTTPClient的人。android:android-async-http库，请检查设置AsyncHttpClient使用HTTPS。

您可以在运行时信任特定的证书。 只需从服务器下载，放入资产，然后使用ssl-utils-android像这样加载:

OkHttpClient client = new OkHttpClient();
SSLContext sslContext = SslUtils.getSslContextForCertificateFile(context, "BPClass2RootCA-sha2.cer");
client.setSslSocketFactory(sslContext.getSocketFactory());

在上面的例子中，我使用了OkHttpClient，但是SSLContext可以用于Java中的任何客户端。

如果你有任何问题，请提出来。我是这个小图书馆的作者。

@Chrispix的解决方案是危险的!相信所有的证书允许任何人做一个人在中间攻击!只要向客户端发送任何证书，它就会接受它!

将您的证书添加到自定义信任管理器，如本文所述:通过HTTPS使用HttpClient信任所有证书

虽然使用自定义证书建立安全连接有点复杂，但它将为您带来所需的ssl加密安全，而没有中间人攻击的危险!