android - JSON解析器适用于模拟器但不适用于手机

Question

我有一个要求，我的代码使用 json 解析器从 url 中提取信息。它在具有 android 2.2 部署的模拟器上运行良好。但是当我将它们部署在手机上时（galaxy y duos(2.3) 或 S2(4.0)），它不会给出空指针异常。您能否说明为什么会出现这种行为以及要在移动设备上进行哪些更改。

Answer 1

我遇到同样的问题，试试下面的代码

您应该从 org.apache.http.conn.ssl.SSLSocketFactory 创建一个自定义类

MySSLSocketFactory.java

public class MySSLSocketFactory extends SSLSocketFactory {
    SSLContext sslContext = SSLContext.getInstance("TLS");

    public MySSLSocketFactory(KeyStore truststore) throws NoSuchAlgorithmException, KeyManagementException, KeyStoreException, UnrecoverableKeyException {
        super(truststore);

        TrustManager tm = new X509TrustManager() {
            public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
            }

            public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
            }

            public X509Certificate[] getAcceptedIssuers() {
                return null;
            }
        };

        sslContext.init(null, new TrustManager[] { tm }, null);
    }

    @Override
    public Socket createSocket(Socket socket, String host, int port, boolean autoClose) throws IOException, UnknownHostException {
        return sslContext.getSocketFactory().createSocket(socket, host, port, autoClose);
    }

    @Override
    public Socket createSocket() throws IOException {
        return sslContext.getSocketFactory().createSocket();
    }
}

调用 HttpClient

HttpClient httpclient = getNewHttpClient();

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        StrictMode.setThreadPolicy(policy);


public HttpClient getNewHttpClient() {
        try {
            KeyStore trustStore = KeyStore.getInstance(KeyStore
                    .getDefaultType());
            trustStore.load(null, null);

            SSLSocketFactory sf = new MySSLSocketFactory(trustStore);
            sf.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);

            HttpParams params = new BasicHttpParams();
            HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
            HttpProtocolParams.setContentCharset(params, HTTP.UTF_8);

            SchemeRegistry registry = new SchemeRegistry();
            registry.register(new Scheme("http", PlainSocketFactory
                    .getSocketFactory(), 80));
            registry.register(new Scheme("https", sf, 443));



            ClientConnectionManager ccm = new ThreadSafeClientConnManager(
                    params, registry);

            return new DefaultHttpClient(ccm, params);
        } catch (Exception e) {
            return new DefaultHttpClient();
        }
    }