ExceptionInInitializerError in Okhttp.Builder w/ sslSocketFactory

Question

我正在处理一个项目，该项目需要为单个调用使用“允许所有证书”，每当我尝试设置sslSocketFactory时，都会收到指示ExceptionInInitializerError的错误。

我搜索了一下，发现了这问题，但它并没有为我解决这个问题；这个Git问题也是如此。

我的示例代码如下：

    X509TrustManager trustManager = new X509TrustManager() {
        public void checkClientTrusted(X509Certificate[] xcs, String string)
                throws CertificateException {}
        public void checkServerTrusted(X509Certificate[] xcs, String string)
                throws CertificateException {}
        public X509Certificate[] getAcceptedIssuers() {
            return null;
        }
    };
    SSLContext sslContext;
    SSLSocketFactory sslSocketFactory = null;
    try {
        sslContext = SSLContext.getInstance("TLS");
        sslContext.init(null, new TrustManager[]{trustManager}, null);
        sslSocketFactory = sslContext.getSocketFactory();
    } catch (Exception e){
        e.printStackTrace();
    }
    OkHttpClient client = new OkHttpClient.Builder().sslSocketFactory(sslSocketFactory,
            trustManager).addInterceptor(interceptor).build();

当被发送的params都是有效的而不是null时，为什么我会收到一个错误？

Answer 1

事实证明，这个问题是由NullPointerException在okhttp3构建器方法中的深层调用引起的。确切的代码在这里：

Caused by: java.lang.NullPointerException: Attempt to get length of null array
        at okhttp3.internal.tls.BasicTrustRootIndex.<init>(BasicTrustRootIndex.java:32)
        at okhttp3.internal.platform.Platform.buildTrustRootIndex(Platform.java:288)
        at okhttp3.internal.platform.AndroidPlatform.buildTrustRootIndex(AndroidPlatform.java:280)
        at okhttp3.internal.platform.Platform.buildCertificateChainCleaner(Platform.java:172)
        at okhttp3.internal.platform.AndroidPlatform.buildCertificateChainCleaner(AndroidPlatform.java:230)
        at okhttp3.internal.tls.CertificateChainCleaner.get(CertificateChainCleaner.java:41)
        at okhttp3.OkHttpClient$Builder.sslSocketFactory(OkHttpClient.java:694)

造成此问题的原因是，我在Stackoverflow (IE 这里)上遵循了大量示例，这些示例告诉您如何使用该return null;行构建您的x509 TrustManager。

解决方法是简单地更改一行：

    X509TrustManager trustManager = new X509TrustManager() {
        public void checkClientTrusted(X509Certificate[] xcs, String string)
                throws CertificateException {}
        public void checkServerTrusted(X509Certificate[] xcs, String string)
                throws CertificateException {}
        public X509Certificate[] getAcceptedIssuers() {
            //Here
            return new X509Certificate[]{};
        }
    };
    .
    .
    .

这解决了这个问题。