关于JAVA发送Https请求(HttpsURLConnection和HttpURLConnection)
https协议对于开发者而言其实只是多了一步证书验证的过程。这个证书正常情况下被jdk/jre/security/cacerts所管理。里面证书包含两种情况:
1、机构所颁发的被认证的证书,这种证书的网站在浏览器访问时https头显示为绿色如百度
2、个人所设定的证书,这种证书的网站在浏览器里https头显示为红色×,且需要点击信任该网站才能继续访问。而点击信任这一步的操作就是我们在java代码访问https网站时区别于http请求需要做的事情。
所以JAVA发送Https请求有两种情况,三种解决办法:
第一种情况:Https网站的证书为机构所颁发的被认证的证书,这种情况下和http请求一模一样,无需做任何改变,用HttpsURLConnection或者HttpURLConnection都可以
-
- public static void main(String[] args) throws Exception{
- URL serverUrl = new URL("https://xxxx");
- HttpURLConnection conn = (HttpURLConnection) serverUrl.openConnection();
- conn.setRequestMethod("GET");
- conn.setRequestProperty("Content-type", "application/json");
- //必须设置false,否则会自动redirect到重定向后的地址
- conn.setInstanceFollowRedirects(false);
- conn.connect();
- String result = getReturn(conn);
- }
- /*请求url获取返回的内容*/
- public static String getReturn(HttpURLConnection connection) throws IOException{
- StringBuffer buffer = new StringBuffer();
- //将返回的输入流转换成字符串
- try(InputStream inputStream = connection.getInputStream();
- InputStreamReader inputStreamReader = new InputStreamReader(inputStream, ConstantInfo.CHARSET);
- BufferedReader bufferedReader = new BufferedReader(inputStreamReader);){
- String str = null;
- while ((str = bufferedReader.readLine()) != null) {
- buffer.append(str);
- }
- String result = buffer.toString();
- return result;
- }
- }
第二种情况:个人所设定的证书,这种证书默认不被信任,需要我们自己选择信任,信任的办法有两种:
A、将证书导入java的运行环境中
- 从该网站下载或者从网站开发者出获取证书cacert.crt
- 运行命令将证书导入java运行环境:keytool -import -keystore %JAVA_HOME%\jre\lib\security\cacerts -file cacert.crt -alias xxx
- 完成。java代码中发送https的请求和http一样,同第一种情况。
B、忽略证书验证过程,忽略之后任何Https协议网站皆能正常访问,同第一种情况
-
- import java.security.cert.CertificateException;
- import java.security.cert.X509Certificate;
- import javax.net.ssl.X509TrustManager;
- public class MyX509TrustManager implements X509TrustManager {
- @Override
- public void checkClientTrusted(X509Certificate certificates[],String authType) throws CertificateException {
- }
- @Override
- public void checkServerTrusted(X509Certificate[] ax509certificate,String s) throws CertificateException {
- }
- @Override
- public X509Certificate[] getAcceptedIssuers() {
- // TODO Auto-generated method stub
- return null;
- }
- }
-
- public static void main(String[] args) throws Exception{
- SSLContext sslcontext = SSLContext.getInstance("SSL","SunJSSE");
- sslcontext.init(null, new TrustManager[]{new MyX509TrustManager()}, new java.security.SecureRandom());
- URL url = new URL("https://xxxx");
- HostnameVerifier ignoreHostnameVerifier = new HostnameVerifier() {
- public boolean verify(String s, SSLSession sslsession) {
- System.out.println("WARNING: Hostname is not matched for cert.");
- return true;
- }
- };
- HttpsURLConnection.setDefaultHostnameVerifier(ignoreHostnameVerifier);
- HttpsURLConnection.setDefaultSSLSocketFactory(sslcontext.getSocketFactory());
- //之后任何Https协议网站皆能正常访问,同第一种情况
- }
C、java代码中加载证书,必须使用HttpsURLConnection方式
- 从网站开发者出获取生成证书的密钥库cacert.keystore
-
- import java.io.FileInputStream;
- import java.security.KeyStore;
- import java.security.cert.CertificateException;
- import java.security.cert.X509Certificate;
- import javax.net.ssl.TrustManager;
- import javax.net.ssl.TrustManagerFactory;
- import javax.net.ssl.X509TrustManager;
- public class MyX509TrustManager implements X509TrustManager {
- /*
- * The default X509TrustManager returned by SunX509. We'll delegate
- * decisions to it, and fall back to the logic in this class if the
- * default X509TrustManager doesn't trust it.
- */
- X509TrustManager sunJSSEX509TrustManager;
- MyX509TrustManager() throws Exception {
- // create a "default" JSSE X509TrustManager.
- KeyStore ks = KeyStore.getInstance("JKS");
- ks.load(new FileInputStream("cancert.keystore"),
- "changeit".toCharArray());
- TrustManagerFactory tmf =
- TrustManagerFactory.getInstance("SunX509", "SunJSSE");
- tmf.init(ks);
- TrustManager tms [] = tmf.getTrustManagers();
- /*
- * Iterate over the returned trustmanagers, look
- * for an instance of X509TrustManager. If found,
- * use that as our "default" trust manager.
- */
- for (int i = 0; i < tms.length; i++) {
- if (tms[i] instanceof X509TrustManager) {
- sunJSSEX509TrustManager = (X509TrustManager) tms[i];
- return;
- }
- }
- /*
- * Find some other way to initialize, or else we have to fail the
- * constructor.
- */
- throw new Exception("Couldn't initialize");
- }
- /*
- * Delegate to the default trust manager.
- */
- public void checkClientTrusted(X509Certificate[] chain, String authType)
- throws CertificateException {
- try {
- sunJSSEX509TrustManager.checkClientTrusted(chain, authType);
- } catch (CertificateException excep) {
- // do any special handling here, or rethrow exception.
- }
- }
- /*
- * Delegate to the default trust manager.
- */
- public void checkServerTrusted(X509Certificate[] chain, String authType)
- throws CertificateException {
- try {
- sunJSSEX509TrustManager.checkServerTrusted(chain, authType);
- } catch (CertificateException excep) {
- /*
- * Possibly pop up a dialog box asking whether to trust the
- * cert chain.
- */
- }
- }
- /*
- * Merely pass this through.
- */
- public X509Certificate[] getAcceptedIssuers() {
- return sunJSSEX509TrustManager.getAcceptedIssuers();
- }
- }
-
- public static void main(String[] args) throws Exception{
- SSLContext sslcontext = SSLContext.getInstance("SSL","SunJSSE");
- sslcontext.init(null, new TrustManager[]{new MyX509TrustManager()}, new java.security.SecureRandom());
- URL serverUrl = new URL("https://xxxx");
- HttpsURLConnection conn = (HttpsURLConnection) serverUrl.openConnection();
- conn.setSSLSocketFactory(sslcontext.getSocketFactory());
- conn.setRequestMethod("GET");
- conn.setRequestProperty("Content-type", "application/json");
- //必须设置false,否则会自动redirect到重定向后的地址
- conn.setInstanceFollowRedirects(false);
- conn.connect();
- String result = getReturn(conn);
- }
- /*请求url获取返回的内容*/
- public static String getReturn(HttpsURLConnection connection) throws IOException{
- StringBuffer buffer = new StringBuffer();
- //将返回的输入流转换成字符串
- try(InputStream inputStream = connection.getInputStream();
- InputStreamReader inputStreamReader = new InputStreamReader(inputStream, ConstantInfo.CHARSET);
- BufferedReader bufferedReader = new BufferedReader(inputStreamReader);){
- String str = null;
- while ((str = bufferedReader.readLine()) != null) {
- buffer.append(str);
- }
- String result = buffer.toString();
- return result;
- }
- }