CertPathValidatorException: Trust anchor for certification path not found解决方法

错误log:

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:413)
    at org.apache.harmony.xnet.provider.jsse.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:257)
    at libcore.net.http.HttpConnection.setupSecureSocket(HttpConnection.java:210)
    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:477)
    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:432)
    at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:282)
    at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:232)
    at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:80)
    at libcore.net.http.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:164)
    at com.etnet.global.ConnectionTool.post(ConnectionTool.java:462)
    at com.etnet.android.Welcome$3.run(Welcome.java:177)
 Caused by: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Trust anchor for   

certification path not found.
    at org.apache.harmony.xnet.provider.jsse.TrustManagerImpl.checkTrusted(TrustManagerImpl.java:184)
    at org.apache.harmony.xnet.provider.jsse.TrustManagerImpl.checkServerTrusted(TrustManagerImpl.java:163)
    at org.apache.harmony.xnet.provider.jsse.OpenSSLSocketImpl.verifyCertificateChain(OpenSSLSocketImpl.java:593)
    at org.apache.harmony.xnet.provider.jsse.NativeCrypto.SSL_do_handshake(Native Method)
    at org.apache.harmony.xnet.provider.jsse.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:410)
    ... 10 more

解决方法：忽略证书验证：

public static StringBuffer post(String urlString, String param) {
		StringBuffer sb = new StringBuffer();
		URL url = null;
		HttpURLConnection connection = null;
		DataOutputStream out = null;
		BufferedReader in = null;
		try {
			url = new URL(urlString);
			
			//关键代码
			//ignore https certificate validation |忽略 https 证书验证
			if (url.getProtocol().toUpperCase().equals("HTTPS")) {
				trustAllHosts();
				HttpsURLConnection https = (HttpsURLConnection) url
						.openConnection();
				https.setHostnameVerifier(HttpIgnoreSSL.DO_NOT_VERIFY);
				connection = https;
			} else {
				connection = (HttpURLConnection) url.openConnection();
			}
			
			connection.setReadTimeout(10000);
			connection.setDoInput(true);
			connection.setDoOutput(true);
			connection.setRequestMethod("POST");
			connection.setUseCaches(false);
			connection.setInstanceFollowRedirects(true);
			connection.setRequestProperty("Content-Type",
					"application/x-www-form-urlencoded");
			connection.connect();
			out = new DataOutputStream(
					connection.getOutputStream());
			out.writeBytes(param);
			out.flush();

			in = new BufferedReader(new InputStreamReader(
					connection.getInputStream()), 512);
			String line;
			while ((line = in.readLine()) != null) {
				sb.append(line.trim());
			}
		} catch (IOException e) {
			e.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			if (out != null) {
				try {
					out.close();
				} catch (IOException e) {
				}
			}
			if (in != null) {
				try {
					in.close();
				} catch (IOException e) {
				}
			}
			if (connection != null) {
				connection.disconnect();
			}
		}
		return sb;
	}

public static void trustAllHosts() {
		// Create a trust manager that does not validate certificate chains
		// Android use X509 cert
		TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() {
			public java.security.cert.X509Certificate[] getAcceptedIssuers() {
				return new java.security.cert.X509Certificate[] {};
			}

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

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

		// Install the all-trusting trust manager
		try {
			SSLContext sc = SSLContext.getInstance("TLS");
			sc.init(null, trustAllCerts, new java.security.SecureRandom());
			HttpsURLConnection
					.setDefaultSSLSocketFactory(sc.getSocketFactory());
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

public final static HostnameVerifier DO_NOT_VERIFY = new HostnameVerifier() {
		public boolean verify(String hostname, SSLSession session) {
			return true;
		}
	};