SSL：javax.net.ssl.SSLException: Received fatal alert: protocol

SSL：javax.net.ssl.SSLException: Received fatal alert: protocol_version

调用一个https的接口报错javax.net.ssl.SSLException: Received fatal alert: protocol_version

在Java 1.8上，默认TLS协议是v1.2。在Java 1.6和1.7上，默认是已废弃的TLS1.0，由于此项目使用的是jdk1.6，因此引发错误。

解决方法1：

在发起请求前面设置TLSv1.2协议

System.setProperty("https.protocols", "TLSv1.2");

解决方法2：

在发起请求前忽略ssl认证：

工具类：

import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.HostnameVerifier;
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;

public class SslUtils {

private static void trustAllHttpsCertificates() throws Exception {
TrustManager[] trustAllCerts = new TrustManager[1];
TrustManager tm = new miTM();
trustAllCerts[0] = tm;
SSLContext sc = SSLContext.getInstance("SSL");
sc.init(null, trustAllCerts, null);
HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
}

static class miTM implements TrustManager,X509TrustManager {
public X509Certificate[] getAcceptedIssuers() {
return null;
}

public boolean isServerTrusted(X509Certificate[] certs) {
return true;
}

public boolean isClientTrusted(X509Certificate[] certs) {
return true;
}

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

public void checkClientTrusted(X509Certificate[] certs, String authType)
throws CertificateException {
return;
}
}

/**
* 忽略HTTPS请求的SSL证书，必须在openConnection之前调用
* @throws Exception
*/
public static void ignoreSsl() throws Exception{
HostnameVerifier hv = new HostnameVerifier() {
public boolean verify(String urlHostName, SSLSession session) {
return true;
}
};
trustAllHttpsCertificates();
HttpsURLConnection.setDefaultHostnameVerifier(hv);
}
}

使用方法：

public String doHttpGetUTF8(String postUrl,String token) {
       OutputStreamWriter out = null;
BufferedReader in = null;
String result = "";
try {
   URL realUrl = new URL(postUrl);
   if("https".equalsIgnoreCase(realUrl.getProtocol())){
   SslUtils.ignoreSsl();
   }
   //打开 url之间的连接
   HttpURLConnection conn = (HttpURLConnection)realUrl.openConnection();
   //设置通用的请求属性
   conn.setRequestMethod("GET");
   conn.setUseCaches(false);
   conn.setRequestProperty("Accept-Charset", "utf-8");
   conn.setRequestProperty("contentType", "utf-8");
   conn.setRequestProperty("Content-Type", "application/x‑www‑form‑urlencoded");
   conn.setRequestProperty("Authorization", "Bearer "+token);
   conn.setConnectTimeout(5000);
   conn.setReadTimeout(5000);
   long start = System.currentTimeMillis();
   //获取 URLConnection对象输出对应的输出流

   // 定义BufferedReader输入流来读取URL的响应
   in = new BufferedReader(new InputStreamReader(conn.getInputStream(),"utf-8"));
   long end = System.currentTimeMillis();

   String line;
   while (null != (line = in.readLine())) {
       result += "\n" + line;
   }
   //建立
} catch (Exception e) {
System.out.println("发送GET请求出现异常！" + e);
e.printStackTrace();
}
// 使用finally块来关闭输出流、输入流
finally {
try {
if (out != null) {
out.close();
}
if (in != null) {
in.close();
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
return result;
}