Use new date/time API

acme4j-client/src/main/java/org/shredzone/acme4j/Authorization.java

@@ -17,11 +17,11 @@ import static org.shredzone.acme4j.util.AcmeUtils.parseTimestamp;
 
 import java.net.HttpURLConnection;
 import java.net.URI;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Date;
 import java.util.List;
 
 import org.shredzone.acme4j.challenge.Challenge;
@@ -43,7 +43,7 @@ public class Authorization extends AcmeResource {
 
     private String domain;
     private Status status;
-    private Date expires;
+    private Instant expires;
     private List<Challenge> challenges;
     private List<List<Challenge>> combinations;
     private boolean loaded = false;
@@ -86,7 +86,7 @@ public class Authorization extends AcmeResource {
     /**
      * Gets the expiry date of the authorization, if set by the server.
      */
-    public Date getExpires() {
+    public Instant getExpires() {
         load();
         return expires;
     }

acme4j-client/src/main/java/org/shredzone/acme4j/Registration.java

@@ -19,10 +19,10 @@ import java.net.HttpURLConnection;
 import java.net.URI;
 import java.security.KeyPair;
 import java.security.cert.X509Certificate;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.Date;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Objects;
@@ -234,7 +234,7 @@ public class Registration extends AcmeResource {
      *            for default. May be ignored by the server.
      * @return The {@link Certificate}
      */
-    public Certificate requestCertificate(byte[] csr, Date notBefore, Date notAfter)
+    public Certificate requestCertificate(byte[] csr, Instant notBefore, Instant notAfter)
                 throws AcmeException {
         Objects.requireNonNull(csr, "csr");
 

acme4j-client/src/main/java/org/shredzone/acme4j/Session.java

@@ -15,8 +15,9 @@ package org.shredzone.acme4j;
 
 import java.net.URI;
 import java.security.KeyPair;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.ArrayList;
-import java.util.Date;
 import java.util.EnumMap;
 import java.util.List;
 import java.util.Locale;
@@ -48,7 +49,7 @@ public class Session {
     private JSON directoryJson;
     private Metadata metadata;
     private Locale locale = Locale.getDefault();
-    protected Date directoryCacheExpiry;
+    protected Instant directoryCacheExpiry;
 
     /**
      * Creates a new {@link Session}.
@@ -210,10 +211,10 @@ public class Session {
      */
     private void readDirectory() throws AcmeException {
         synchronized (this) {
-            Date now = new Date();
+            Instant now = Instant.now();
-            if (directoryJson == null || !directoryCacheExpiry.after(now)) {
+            if (directoryJson == null || !directoryCacheExpiry.isAfter(now)) {
                 directoryJson = provider().directory(this, getServerUri());
-                directoryCacheExpiry = new Date(now.getTime() + 60 * 60 * 1000L);
+                directoryCacheExpiry = now.plus(Duration.ofHours(1));
 
                 JSON meta = directoryJson.get("meta").asObject();
                 if (meta != null) {

acme4j-client/src/main/java/org/shredzone/acme4j/challenge/Challenge.java

@@ -15,7 +15,7 @@ package org.shredzone.acme4j.challenge;
 
 import java.net.HttpURLConnection;
 import java.net.URI;
-import java.util.Date;
+import java.time.Instant;
 import java.util.Objects;
 
 import org.shredzone.acme4j.AcmeResource;
@@ -113,8 +113,8 @@ public class Challenge extends AcmeResource {
     /**
      * Returns the validation date, if returned by the server.
      */
-    public Date getValidated() {
+    public Instant getValidated() {
-        return data.get(KEY_VALIDATED).asDate();
+        return data.get(KEY_VALIDATED).asInstant();
     }
 
     /**

acme4j-client/src/main/java/org/shredzone/acme4j/connector/DefaultConnection.java

@@ -27,12 +27,13 @@ import java.security.KeyPair;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Date;
 import java.util.List;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.OptionalInt;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -253,9 +254,9 @@ public class DefaultConnection implements Connection {
 
         try {
             if (conn.getResponseCode() == HttpURLConnection.HTTP_ACCEPTED) {
-                Date retryAfter = getRetryAfterHeader();
+                Optional<Instant> retryAfter = getRetryAfterHeader();
-                if (retryAfter != null) {
+                if (retryAfter.isPresent()) {
-                    throw new AcmeRetryAfterException(message, retryAfter);
+                    throw new AcmeRetryAfterException(message, retryAfter.get());
                 }
             }
         } catch (IOException ex) {
@@ -338,29 +339,31 @@ public class DefaultConnection implements Connection {
     /**
      * Gets the instant sent with the Retry-After header.
      */
-    private Date getRetryAfterHeader() {
+    private Optional<Instant> getRetryAfterHeader() {
         // See RFC 2616 section 14.37
         String header = conn.getHeaderField(RETRY_AFTER_HEADER);
-        if (header == null) {
+        if (header != null) {
-            return null;
-        }
-
             try {
                 // delta-seconds
                 if (header.matches("^\\d+$")) {
                     int delta = Integer.parseInt(header);
                     long date = conn.getHeaderFieldDate(DATE_HEADER, System.currentTimeMillis());
-                return new Date(date + delta * 1000L);
+                    return Optional.of(Instant.ofEpochMilli(date).plusSeconds(delta));
                 }
 
                 // HTTP-date
                 long date = conn.getHeaderFieldDate(RETRY_AFTER_HEADER, 0L);
-            return date != 0 ? new Date(date) : null;
+                if (date != 0) {
+                    return Optional.of(Instant.ofEpochMilli(date));
+                }
             } catch (Exception ex) {
                 throw new AcmeProtocolException("Bad retry-after header value: " + header, ex);
             }
         }
 
+        return Optional.empty();
+    }
+
     /**
      * Handles a problem by throwing an exception. If a JSON problem was returned, an
      * {@link AcmeServerException} or subtype will be thrown. Otherwise a generic
@@ -386,9 +389,9 @@ public class DefaultConnection implements Connection {
         }
 
         if ("rateLimited".equals(error)) {
-            Date retryAfter = getRetryAfterHeader();
+            Optional<Instant> retryAfter = getRetryAfterHeader();
             Collection<URI> rateLimits = getLinks("rate-limit");
-            return new AcmeRateLimitExceededException(type, detail, retryAfter, rateLimits);
+            return new AcmeRateLimitExceededException(type, detail, retryAfter.orElse(null), rateLimits);
         }
 
         return new AcmeServerException(type, detail);

acme4j-client/src/main/java/org/shredzone/acme4j/exception/AcmeRateLimitExceededException.java

@@ -14,9 +14,9 @@
 package org.shredzone.acme4j.exception;
 
 import java.net.URI;
+import java.time.Instant;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Date;
 
 /**
  * An exception that is thrown when a rate limit was exceeded.
@@ -24,7 +24,7 @@ import java.util.Date;
 public class AcmeRateLimitExceededException extends AcmeServerException {
     private static final long serialVersionUID = 4150484059796413069L;
 
-    private final Date retryAfter;
+    private final Instant retryAfter;
     private final Collection<URI> documents;
 
     /**
@@ -41,7 +41,7 @@ public class AcmeRateLimitExceededException extends AcmeServerException {
      * @param documents
      *            URIs pointing to documents about the rate limit that was hit
      */
-    public AcmeRateLimitExceededException(String type, String detail, Date retryAfter, Collection<URI> documents) {
+    public AcmeRateLimitExceededException(String type, String detail, Instant retryAfter, Collection<URI> documents) {
         super(type, detail);
         this.retryAfter = retryAfter;
         this.documents =
@@ -52,8 +52,8 @@ public class AcmeRateLimitExceededException extends AcmeServerException {
      * Returns the moment the request is expected to succeed again. {@code null} if this
      * moment is not known.
      */
-    public Date getRetryAfter() {
+    public Instant getRetryAfter() {
-        return retryAfter != null ? new Date(retryAfter.getTime()) : null;
+        return retryAfter;
     }
 
     /**

acme4j-client/src/main/java/org/shredzone/acme4j/exception/AcmeRetryAfterException.java

@@ -13,7 +13,7 @@
  */
 package org.shredzone.acme4j.exception;
 
-import java.util.Date;
+import java.time.Instant;
 import java.util.Objects;
 
 /**
@@ -23,7 +23,7 @@ import java.util.Objects;
 public class AcmeRetryAfterException extends AcmeException {
     private static final long serialVersionUID = 4461979121063649905L;
 
-    private final Date retryAfter;
+    private final Instant retryAfter;
 
     /**
      * Creates a new {@link AcmeRetryAfterException}.
@@ -33,7 +33,7 @@ public class AcmeRetryAfterException extends AcmeException {
      * @param retryAfter
      *            retry-after date returned by the server
      */
-    public AcmeRetryAfterException(String msg, Date retryAfter) {
+    public AcmeRetryAfterException(String msg, Instant retryAfter) {
         super(msg);
         this.retryAfter = Objects.requireNonNull(retryAfter);
     }
@@ -41,8 +41,8 @@ public class AcmeRetryAfterException extends AcmeException {
     /**
      * Returns the retry-after date returned by the server.
      */
-    public Date getRetryAfter() {
+    public Instant getRetryAfter() {
-        return new Date(retryAfter.getTime());
+        return retryAfter;
     }
 
 }

acme4j-client/src/main/java/org/shredzone/acme4j/util/AcmeUtils.java

@@ -17,10 +17,9 @@ import java.io.UnsupportedEncodingException;
 import java.net.IDN;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
-import java.util.Calendar;
+import java.time.Instant;
-import java.util.Date;
+import java.time.ZoneId;
-import java.util.GregorianCalendar;
+import java.time.ZonedDateTime;
-import java.util.TimeZone;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -164,12 +163,12 @@ public final class AcmeUtils {
      *
      * @param str
      *            Date string
-     * @return {@link Date} that was parsed
+     * @return {@link Instant} that was parsed
      * @throws IllegalArgumentException
      *             if the date string was not RFC 3339 formatted
      * @see <a href="https://www.ietf.org/rfc/rfc3339.txt">RFC 3339</a>
      */
-    public static Date parseTimestamp(String str) {
+    public static Instant parseTimestamp(String str) {
         Matcher m = DATE_PATTERN.matcher(str);
         if (!m.matches()) {
             throw new IllegalArgumentException("Illegal date: " + str);
@@ -198,11 +197,9 @@ public final class AcmeUtils {
             tz = TZ_PATTERN.matcher(tz).replaceAll("GMT$1$2:$3");
         }
 
-        Calendar cal = GregorianCalendar.getInstance(TimeZone.getTimeZone(tz));
+        return ZonedDateTime.of(
-        cal.clear();
+                year, month, dom, hour, minute, second, ms * 1_000_000,
-        cal.set(year, month - 1, dom, hour, minute, second);
+                ZoneId.of(tz)).toInstant();
-        cal.set(Calendar.MILLISECOND, ms);
-        return cal.getTime();
     }
 
     /**

acme4j-client/src/main/java/org/shredzone/acme4j/util/JSON.java

@@ -27,8 +27,8 @@ import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.time.Instant;
 import java.util.Collections;
-import java.util.Date;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
@@ -349,12 +349,11 @@ public final class JSON implements Serializable {
         }
 
         /**
-         * Returns the value as {@link Date}.
+         * Returns the value as {@link Instant}.
          *
-         * @return {@link Date}, or {@code null} if the value was not set. The returned
+         * @return {@link Instant}, or {@code null} if the value was not set.
-         *         {@link Date} object is not shared and can be modified safely.
          */
-        public Date asDate() {
+        public Instant asInstant() {
             if (val == null) {
                 return null;
             }

acme4j-client/src/main/java/org/shredzone/acme4j/util/JSONBuilder.java

@@ -17,12 +17,11 @@ import static org.shredzone.acme4j.util.AcmeUtils.base64UrlEncode;
 
 import java.security.Key;
 import java.security.PublicKey;
-import java.text.SimpleDateFormat;
+import java.time.Instant;
+import java.time.format.DateTimeFormatter;
 import java.util.Collections;
-import java.util.Date;
 import java.util.Map;
 import java.util.Objects;
-import java.util.TimeZone;
 import java.util.TreeMap;
 
 import org.jose4j.json.JsonUtil;
@@ -62,25 +61,22 @@ public class JSONBuilder {
     }
 
     /**
-     * Puts a {@link Date} to the JSON. If a property with the key exists, it will be
+     * Puts an {@link Instant} to the JSON. If a property with the key exists, it will be
      * replaced.
      *
      * @param key
      *            Property key
      * @param value
-     *            Property {@link Date} value
+     *            Property {@link Instant} value
      * @return {@code this}
      */
-    public JSONBuilder put(String key, Date value) {
+    public JSONBuilder put(String key, Instant value) {
         if (value == null) {
             put(key, (Object) null);
             return this;
         }
 
-        SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
+        put(key, DateTimeFormatter.ISO_INSTANT.format(value));
-        fmt.setTimeZone(TimeZone.getTimeZone("UTC"));
-        String date = fmt.format(value);
-        put(key, date);
         return this;
     }
 

acme4j-client/src/test/java/org/shredzone/acme4j/AuthorizationTest.java

@@ -21,8 +21,9 @@ import static org.shredzone.acme4j.util.TestUtils.*;
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.URI;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.Collection;
-import java.util.Date;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.junit.Test;
@@ -228,7 +229,7 @@ public class AuthorizationTest {
      */
     @Test
     public void testUpdateRetryAfter() throws Exception {
-        final long retryAfter = System.currentTimeMillis() + 30 * 1000L;
+        final Instant retryAfter = Instant.now().plus(Duration.ofSeconds(30));
 
         TestableConnectionProvider provider = new TestableConnectionProvider() {
             @Override
@@ -250,7 +251,7 @@ public class AuthorizationTest {
 
             @Override
             public void handleRetryAfter(String message) throws AcmeException {
-                throw new AcmeRetryAfterException(message, new Date(retryAfter));
+                throw new AcmeRetryAfterException(message, retryAfter);
             }
         };
 
@@ -267,7 +268,7 @@ public class AuthorizationTest {
             auth.update();
             fail("Expected AcmeRetryAfterException");
         } catch (AcmeRetryAfterException ex) {
-            assertThat(ex.getRetryAfter(), is(new Date(retryAfter)));
+            assertThat(ex.getRetryAfter(), is(retryAfter));
         }
 
         assertThat(auth.getDomain(), is("example.org"));

acme4j-client/src/test/java/org/shredzone/acme4j/CertificateTest.java

@@ -22,7 +22,8 @@ import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.URI;
 import java.security.cert.X509Certificate;
-import java.util.Date;
+import java.time.Duration;
+import java.time.Instant;
 
 import org.junit.Test;
 import org.shredzone.acme4j.connector.Resource;
@@ -107,7 +108,7 @@ public class CertificateTest {
      */
     @Test
     public void testRetryAfter() throws AcmeException, IOException {
-        final long retryAfter = System.currentTimeMillis() + 30 * 1000L;
+        final Instant retryAfter = Instant.now().plus(Duration.ofSeconds(30));
 
         TestableConnectionProvider provider = new TestableConnectionProvider() {
             @Override
@@ -125,7 +126,7 @@ public class CertificateTest {
 
             @Override
             public void handleRetryAfter(String message) throws AcmeException {
-                throw new AcmeRetryAfterException(message, new Date(retryAfter));
+                throw new AcmeRetryAfterException(message, retryAfter);
             }
         };
 
@@ -135,7 +136,7 @@ public class CertificateTest {
             cert.download();
             fail("Expected AcmeRetryAfterException");
         } catch (AcmeRetryAfterException ex) {
-            assertThat(ex.getRetryAfter(), is(new Date(retryAfter)));
+            assertThat(ex.getRetryAfter(), is(retryAfter));
         }
 
         provider.close();

acme4j-client/src/test/java/org/shredzone/acme4j/RegistrationTest.java

@@ -23,9 +23,10 @@ import java.net.HttpURLConnection;
 import java.net.URI;
 import java.security.KeyPair;
 import java.security.cert.X509Certificate;
-import java.util.Calendar;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.ZoneId;
 import java.util.Iterator;
-import java.util.TimeZone;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.jose4j.jws.JsonWebSignature;
@@ -335,15 +336,12 @@ public class RegistrationTest {
         provider.putTestResource(Resource.NEW_CERT, resourceUri);
 
         byte[] csr = TestUtils.getResourceAsByteArray("/csr.der");
-        Calendar notBefore = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+        ZoneId utc = ZoneId.of("UTC");
-        notBefore.clear();
+        Instant notBefore = LocalDate.of(2016, 1, 1).atStartOfDay(utc).toInstant();
-        notBefore.set(2016, Calendar.JANUARY, 1);
+        Instant notAfter = LocalDate.of(2016, 1, 8).atStartOfDay(utc).toInstant();
-        Calendar notAfter = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
-        notAfter.clear();
-        notAfter.set(2016, Calendar.JANUARY, 8);
 
         Registration registration = new Registration(provider.createSession(), locationUri);
-        Certificate cert = registration.requestCertificate(csr, notBefore.getTime(), notAfter.getTime());
+        Certificate cert = registration.requestCertificate(csr, notBefore, notAfter);
 
         assertThat(cert.download(), is(originalCert));
         assertThat(cert.getLocation(), is(locationUri));

acme4j-client/src/test/java/org/shredzone/acme4j/SessionTest.java

@@ -21,7 +21,7 @@ import static org.shredzone.acme4j.util.TestUtils.getJsonAsObject;
 import java.io.IOException;
 import java.net.URI;
 import java.security.KeyPair;
-import java.util.Date;
+import java.time.Instant;
 
 import org.junit.Test;
 import org.mockito.ArgumentMatchers;
@@ -173,7 +173,7 @@ public class SessionTest {
                         ArgumentMatchers.any(URI.class));
 
         // Simulate a cache expiry
-        session.directoryCacheExpiry = new Date();
+        session.directoryCacheExpiry = Instant.now();
 
         // Make sure directory is read once again
         assertSession(session);

acme4j-client/src/test/java/org/shredzone/acme4j/challenge/ChallengeTest.java

@@ -25,7 +25,8 @@ import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
-import java.util.Date;
+import java.time.Duration;
+import java.time.Instant;
 
 import org.jose4j.lang.JoseException;
 import org.junit.Before;
@@ -229,7 +230,7 @@ public class ChallengeTest {
      */
     @Test
     public void testUpdateRetryAfter() throws Exception {
-        final long retryAfter = System.currentTimeMillis() + 30 * 1000L;
+        final Instant retryAfter = Instant.now().plus(Duration.ofSeconds(30));
 
         TestableConnectionProvider provider = new TestableConnectionProvider() {
             @Override
@@ -252,7 +253,7 @@ public class ChallengeTest {
 
             @Override
             public void handleRetryAfter(String message) throws AcmeException {
-                throw new AcmeRetryAfterException(message, new Date(retryAfter));
+                throw new AcmeRetryAfterException(message, retryAfter);
             }
         };
 
@@ -265,7 +266,7 @@ public class ChallengeTest {
             challenge.update();
             fail("Expected AcmeRetryAfterException");
         } catch (AcmeRetryAfterException ex) {
-            assertThat(ex.getRetryAfter(), is(new Date(retryAfter)));
+            assertThat(ex.getRetryAfter(), is(retryAfter));
         }
 
         assertThat(challenge.getStatus(), is(Status.VALID));

acme4j-client/src/test/java/org/shredzone/acme4j/connector/DefaultConnectionTest.java

@@ -25,9 +25,10 @@ import java.net.HttpURLConnection;
 import java.net.URI;
 import java.net.URL;
 import java.security.cert.X509Certificate;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
@@ -254,12 +255,12 @@ public class DefaultConnectionTest {
      */
     @Test
     public void testHandleRetryAfterHeaderDate() throws AcmeException, IOException {
-        Date retryDate = new Date(System.currentTimeMillis() + 10 * 60 * 60 * 1000L);
+        Instant retryDate = Instant.now().plus(Duration.ofHours(10));
         String retryMsg = "absolute date";
 
         when(mockUrlConnection.getResponseCode()).thenReturn(HttpURLConnection.HTTP_ACCEPTED);
         when(mockUrlConnection.getHeaderField("Retry-After")).thenReturn(retryDate.toString());
-        when(mockUrlConnection.getHeaderFieldDate("Retry-After", 0L)).thenReturn(retryDate.getTime());
+        when(mockUrlConnection.getHeaderFieldDate("Retry-After", 0L)).thenReturn(retryDate.toEpochMilli());
 
         try (DefaultConnection conn = new DefaultConnection(mockHttpConnection)) {
             conn.conn = mockUrlConnection;
@@ -297,7 +298,7 @@ public class DefaultConnectionTest {
             conn.handleRetryAfter(retryMsg);
             fail("no AcmeRetryAfterException was thrown");
         } catch (AcmeRetryAfterException ex) {
-            assertThat(ex.getRetryAfter(), is(new Date(now + delta * 1000L)));
+            assertThat(ex.getRetryAfter(), is(Instant.ofEpochMilli(now).plusSeconds(delta)));
             assertThat(ex.getMessage(), is(retryMsg));
         }
 

acme4j-client/src/test/java/org/shredzone/acme4j/exception/AcmeRateLimitExceededExceptionTest.java

@@ -17,9 +17,10 @@ import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.assertThat;
 
 import java.net.URI;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Date;
 
 import org.junit.Test;
 
@@ -35,7 +36,7 @@ public class AcmeRateLimitExceededExceptionTest {
     public void testAcmeRateLimitExceededException() {
         String type = "urn:ietf:params:acme:error:rateLimited";
         String detail = "Too many requests per minute";
-        Date retryAfter = new Date(System.currentTimeMillis() + 60 * 1000L);
+        Instant retryAfter = Instant.now().plus(Duration.ofMinutes(1));
         Collection<URI> documents = Arrays.asList(
                         URI.create("http://example.com/doc1.html"),
                         URI.create("http://example.com/doc2.html"));

acme4j-client/src/test/java/org/shredzone/acme4j/exception/AcmeRetryAfterExceptionTest.java

@@ -16,7 +16,8 @@ package org.shredzone.acme4j.exception;
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.assertThat;
 
-import java.util.Date;
+import java.time.Duration;
+import java.time.Instant;
 
 import org.junit.Test;
 
@@ -31,16 +32,12 @@ public class AcmeRetryAfterExceptionTest {
     @Test
     public void testAcmeRetryAfterException() {
         String detail = "Too early";
-        Date retryAfter = new Date(System.currentTimeMillis() + 60 * 1000L);
+        Instant retryAfter = Instant.now().plus(Duration.ofMinutes(1));
 
-        AcmeRetryAfterException ex
+        AcmeRetryAfterException ex = new AcmeRetryAfterException(detail, retryAfter);
-                = new AcmeRetryAfterException(detail, retryAfter);
 
         assertThat(ex.getMessage(), is(detail));
         assertThat(ex.getRetryAfter(), is(retryAfter));
-
-        // make sure we get a copy of the Date object
-        assertThat(ex.getRetryAfter(), not(sameInstance(retryAfter)));
     }
 
     /**
@@ -48,16 +45,12 @@ public class AcmeRetryAfterExceptionTest {
      */
     @Test
     public void testNullAcmeRetryAfterException() {
-        Date retryAfter = new Date(System.currentTimeMillis() + 60 * 1000L);
+        Instant retryAfter = Instant.now().plus(Duration.ofMinutes(1));
 
-        AcmeRetryAfterException ex
+        AcmeRetryAfterException ex = new AcmeRetryAfterException(null, retryAfter);
-                = new AcmeRetryAfterException(null, retryAfter);
 
         assertThat(ex.getMessage(), nullValue());
         assertThat(ex.getRetryAfter(), is(retryAfter));
-
-        // make sure we get a copy of the Date object
-        assertThat(ex.getRetryAfter(), not(sameInstance(retryAfter)));
     }
 
     /**

acme4j-client/src/test/java/org/shredzone/acme4j/util/AcmeUtilsTest.java

@@ -21,11 +21,10 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Modifier;
 import java.security.KeyPair;
 import java.security.Security;
-import java.text.SimpleDateFormat;
+import java.time.Instant;
-import java.util.Calendar;
+import java.time.ZoneId;
-import java.util.Date;
+import java.time.ZonedDateTime;
-import java.util.Locale;
+import java.time.format.DateTimeFormatter;
-import java.util.TimeZone;
 
 import javax.xml.bind.DatatypeConverter;
 
@@ -247,57 +246,55 @@ public class AcmeUtilsTest {
     /**
      * Matches the given time.
      */
-    private DateMatcher isDate(int year, int month, int dom, int hour, int minute, int second) {
+    private InstantMatcher isDate(int year, int month, int dom, int hour, int minute, int second) {
         return isDate(year, month, dom, hour, minute, second, 0);
     }
 
     /**
      * Matches the given time and milliseconds.
      */
-    private DateMatcher isDate(int year, int month, int dom, int hour, int minute, int second, int ms) {
+    private InstantMatcher isDate(int year, int month, int dom, int hour, int minute, int second, int ms) {
-        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+        Instant cmp = ZonedDateTime.of(
-        cal.clear();
+                    year, month, dom, hour, minute, second, ms * 1_000_000,
-        cal.set(year, month - 1, dom, hour, minute, second);
+                    ZoneId.of("UTC")).toInstant();
-        cal.set(Calendar.MILLISECOND, ms);
+        return new InstantMatcher(cmp);
-        return new DateMatcher(cal);
     }
 
     /**
      * Date matcher that gives a readable output on mismatch.
      */
-    private static class DateMatcher extends BaseMatcher<Date> {
+    private static class InstantMatcher extends BaseMatcher<Instant> {
-        private final Calendar cal;
+        private final Instant cmp;
-        private final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.ENGLISH);
+        private final DateTimeFormatter dtf = DateTimeFormatter.ISO_INSTANT;
 
-        public DateMatcher(Calendar cal) {
+        public InstantMatcher(Instant cmp) {
-            this.cal = cal;
+            this.cmp = cmp;
-            sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
         }
 
         @Override
         public boolean matches(Object item) {
-            if (!(item instanceof Date)) {
+            if (!(item instanceof Instant)) {
                 return false;
             }
 
-            Date date = (Date) item;
+            Instant date = (Instant) item;
-            return date.equals(cal.getTime());
+            return date.equals(cmp);
         }
 
         @Override
         public void describeTo(Description description) {
-            description.appendValue(sdf.format(cal.getTime()));
+            description.appendValue(dtf.format(cmp));
         }
 
         @Override
         public void describeMismatch(Object item, Description description) {
-            if (!(item instanceof Date)) {
+            if (!(item instanceof Instant)) {
-                description.appendText("is not a Date");
+                description.appendText("is not an Instant");
                 return;
             }
 
-            Date date = (Date) item;
+            Instant date = (Instant) item;
-            description.appendText("was ").appendValue(sdf.format(date));
+            description.appendText("was ").appendValue(dtf.format(date));
         }
     }
 

acme4j-client/src/test/java/org/shredzone/acme4j/util/JSONBuilderTest.java

@@ -19,10 +19,10 @@ import static org.junit.Assert.assertThat;
 import java.io.IOException;
 import java.security.KeyPair;
 import java.security.NoSuchAlgorithmException;
-import java.util.Calendar;
+import java.time.Instant;
-import java.util.Date;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
 import java.util.Map;
-import java.util.TimeZone;
 
 import org.jose4j.json.JsonUtil;
 import org.jose4j.lang.JoseException;
@@ -81,13 +81,11 @@ public class JSONBuilderTest {
      */
     @Test
     public void testDate() {
-        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT+2"));
+        Instant date = ZonedDateTime.of(2016, 6, 1, 5, 13, 46, 0, ZoneId.of("GMT+2")).toInstant();
-        cal.clear();
-        cal.set(2016, Calendar.JUNE, 1, 5, 13, 46);
 
         JSONBuilder cb = new JSONBuilder();
-        cb.put("fooDate", cal.getTime());
+        cb.put("fooDate", date);
-        cb.put("fooNull", (Date) null);
+        cb.put("fooNull", (Instant) null);
 
         assertThat(cb.toString(), is("{\"fooDate\":\"2016-06-01T03:13:46Z\",\"fooNull\":null}"));
     }

acme4j-client/src/test/java/org/shredzone/acme4j/util/JSONTest.java

@@ -26,10 +26,11 @@ import java.io.ObjectOutputStream;
 import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URL;
-import java.util.Calendar;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.ZoneId;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
-import java.util.TimeZone;
 
 import org.junit.Test;
 import org.shredzone.acme4j.exception.AcmeProtocolException;
@@ -145,9 +146,7 @@ public class JSONTest {
      */
     @Test
     public void testGetter() throws MalformedURLException {
-        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+        Instant date = LocalDate.of(2016, 1, 8).atStartOfDay(ZoneId.of("UTC")).toInstant();
-        cal.clear();
-        cal.set(2016, 0, 8);
 
         JSON json = TestUtils.getJsonAsObject("json");
 
@@ -155,7 +154,7 @@ public class JSONTest {
         assertThat(json.get("number").asInt(), is(123));
         assertThat(json.get("uri").asURI(), is(URI.create("mailto:foo@example.com")));
         assertThat(json.get("url").asURL(), is(new URL("http://example.com")));
-        assertThat(json.get("date").asDate(), is(cal.getTime()));
+        assertThat(json.get("date").asInstant(), is(date));
 
         JSON.Array array = json.get("array").asArray();
         assertThat(array.get(0).asString(), is("foo"));
@@ -181,7 +180,7 @@ public class JSONTest {
         assertThat(json.get("none").asString(), is(nullValue()));
         assertThat(json.get("none").asURI(), is(nullValue()));
         assertThat(json.get("none").asURL(), is(nullValue()));
-        assertThat(json.get("none").asDate(), is(nullValue()));
+        assertThat(json.get("none").asInstant(), is(nullValue()));
         assertThat(json.get("none").asArray(), is(nullValue()));
         assertThat(json.get("none").asObject(), is(nullValue()));
 
@@ -246,7 +245,7 @@ public class JSONTest {
         }
 
         try {
-            json.get("text").asDate();
+            json.get("text").asInstant();
             fail("no exception was thrown");
         } catch (AcmeProtocolException ex) {
             // expected

acme4j-utils/src/main/java/org/shredzone/acme4j/util/CertificateUtils.java

@@ -25,6 +25,8 @@ import java.security.KeyPair;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.Date;
 
 import org.bouncycastle.asn1.x500.X500Name;
@@ -212,17 +214,17 @@ public final class CertificateUtils {
      */
     private static X509Certificate createCertificate(KeyPair keypair, String... subject) throws IOException {
         final long now = System.currentTimeMillis();
-        final long validSpanMs = 7 * 24 * 60 * 60 * 1000L;
         final String signatureAlg = "SHA256withRSA";
 
         try {
             X500Name issuer = new X500Name("CN=acme.invalid");
             BigInteger serial = BigInteger.valueOf(now);
-            Date notBefore = new Date(now);
+            Instant notBefore = Instant.ofEpochMilli(now);
-            Date notAfter = new Date(now + validSpanMs);
+            Instant notAfter = notBefore.plus(Duration.ofDays(7));
 
             JcaX509v3CertificateBuilder certBuilder = new JcaX509v3CertificateBuilder(
-                        issuer, serial, notBefore, notAfter, issuer, keypair.getPublic());
+                        issuer, serial, Date.from(notBefore), Date.from(notAfter),
+                        issuer, keypair.getPublic());
 
             GeneralName[] gns = new GeneralName[subject.length];
             for (int ix = 0; ix < subject.length; ix++) {

acme4j-utils/src/test/java/org/shredzone/acme4j/util/CertificateUtilsTest.java

@@ -28,6 +28,8 @@ import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.CertificateParsingException;
 import java.security.cert.X509Certificate;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.Date;
 import java.util.HashSet;
 import java.util.List;
@@ -132,13 +134,13 @@ public class CertificateUtilsTest {
 
         X509Certificate cert = CertificateUtils.createTlsSniCertificate(keypair, subject);
 
-        Date now = new Date();
+        Instant now = Instant.now();
-        Date end = new Date(now.getTime() + (8 * 24 * 60 * 60 * 1000L));
+        Instant end = now.plus(Duration.ofDays(8));
 
         assertThat(cert, not(nullValue()));
-        assertThat(cert.getNotAfter(), is(greaterThan(now)));
+        assertThat(cert.getNotAfter(), is(greaterThan(Date.from(now))));
-        assertThat(cert.getNotAfter(), is(lessThan(end)));
+        assertThat(cert.getNotAfter(), is(lessThan(Date.from(end))));
-        assertThat(cert.getNotBefore(), is(lessThanOrEqualTo(now)));
+        assertThat(cert.getNotBefore(), is(lessThanOrEqualTo(Date.from(now))));
         assertThat(cert.getSubjectX500Principal().getName(), is("CN=acme.invalid"));
         assertThat(getSANs(cert), containsInAnyOrder(subject));
     }
@@ -156,13 +158,13 @@ public class CertificateUtilsTest {
 
         X509Certificate cert = CertificateUtils.createTlsSni02Certificate(keypair, sanA, sanB);
 
-        Date now = new Date();
+        Instant now = Instant.now();
-        Date end = new Date(now.getTime() + (8 * 24 * 60 * 60 * 1000L));
+        Instant end = now.plus(Duration.ofDays(8));
 
         assertThat(cert, not(nullValue()));
-        assertThat(cert.getNotAfter(), is(greaterThan(now)));
+        assertThat(cert.getNotAfter(), is(greaterThan(Date.from(now))));
-        assertThat(cert.getNotAfter(), is(lessThan(end)));
+        assertThat(cert.getNotAfter(), is(lessThan(Date.from(end))));
-        assertThat(cert.getNotBefore(), is(lessThanOrEqualTo(now)));
+        assertThat(cert.getNotBefore(), is(lessThanOrEqualTo(Date.from(now))));
         assertThat(cert.getSubjectX500Principal().getName(), is("CN=acme.invalid"));
         assertThat(getSANs(cert), containsInAnyOrder(sanA, sanB));
     }