DATAMONGO-2112 - Polishing.

Align Indexed(expireAfter) default to empty string according to the documentation. Slightly reword Javadoc.

Import DurationStyle to reuse duration parsing until Spring Framework provides a similar utility. Document ISO-8601 duration style. Prevent null index name evaluation to render "null" as String.

Convert assertions from Hamcrest to AssertJ.

Original pull request: #647.

Author: mp911de

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/DurationStyle.java

@@ -0,0 +1,216 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.index;
+
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
+import java.util.function.Function;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Duration format styles.
+ * <p/>
+ * Fork of {@code org.springframework.boot.convert.DurationStyle}.
+ *
+ * @author Phillip Webb
+ * @since 2.2
+ */
+enum DurationStyle {
+
+	/**
+	 * Simple formatting, for example '1s'.
+	 */
+	SIMPLE("^([\\+\\-]?\\d+)([a-zA-Z]{0,2})$") {
+
+		@Override
+		public Duration parse(String value, @Nullable ChronoUnit unit) {
+			try {
+				Matcher matcher = matcher(value);
+				Assert.state(matcher.matches(), "Does not match simple duration pattern");
+				String suffix = matcher.group(2);
+				return (StringUtils.hasLength(suffix) ? Unit.fromSuffix(suffix) : Unit.fromChronoUnit(unit))
+						.parse(matcher.group(1));
+			} catch (Exception ex) {
+				throw new IllegalArgumentException("'" + value + "' is not a valid simple duration", ex);
+			}
+		}
+	},
+
+	/**
+	 * ISO-8601 formatting.
+	 */
+	ISO8601("^[\\+\\-]?P.*$") {
+
+		@Override
+		public Duration parse(String value, @Nullable ChronoUnit unit) {
+			try {
+				return Duration.parse(value);
+			} catch (Exception ex) {
+				throw new IllegalArgumentException("'" + value + "' is not a valid ISO-8601 duration", ex);
+			}
+		}
+	};
+
+	private final Pattern pattern;
+
+	DurationStyle(String pattern) {
+		this.pattern = Pattern.compile(pattern);
+	}
+
+	protected final boolean matches(String value) {
+		return this.pattern.matcher(value).matches();
+	}
+
+	protected final Matcher matcher(String value) {
+		return this.pattern.matcher(value);
+	}
+
+	/**
+	 * Parse the given value to a duration.
+	 *
+	 * @param value the value to parse
+	 * @return a duration
+	 */
+	public Duration parse(String value) {
+		return parse(value, null);
+	}
+
+	/**
+	 * Parse the given value to a duration.
+	 *
+	 * @param value the value to parse
+	 * @param unit the duration unit to use if the value doesn't specify one ({@code null} will default to ms)
+	 * @return a duration
+	 */
+	public abstract Duration parse(String value, @Nullable ChronoUnit unit);
+
+	/**
+	 * Detect the style then parse the value to return a duration.
+	 *
+	 * @param value the value to parse
+	 * @return the parsed duration
+	 * @throws IllegalStateException if the value is not a known style or cannot be parsed
+	 */
+	public static Duration detectAndParse(String value) {
+		return detectAndParse(value, null);
+	}
+
+	/**
+	 * Detect the style then parse the value to return a duration.
+	 *
+	 * @param value the value to parse
+	 * @param unit the duration unit to use if the value doesn't specify one ({@code null} will default to ms)
+	 * @return the parsed duration
+	 * @throws IllegalStateException if the value is not a known style or cannot be parsed
+	 */
+	public static Duration detectAndParse(String value, @Nullable ChronoUnit unit) {
+		return detect(value).parse(value, unit);
+	}
+
+	/**
+	 * Detect the style from the given source value.
+	 *
+	 * @param value the source value
+	 * @return the duration style
+	 * @throws IllegalStateException if the value is not a known style
+	 */
+	public static DurationStyle detect(String value) {
+		Assert.notNull(value, "Value must not be null");
+		for (DurationStyle candidate : values()) {
+			if (candidate.matches(value)) {
+				return candidate;
+			}
+		}
+		throw new IllegalArgumentException("'" + value + "' is not a valid duration");
+	}
+
+	/**
+	 * Units that we support.
+	 */
+	enum Unit {
+
+		/**
+		 * Milliseconds.
+		 */
+		MILLIS(ChronoUnit.MILLIS, "ms", Duration::toMillis),
+
+		/**
+		 * Seconds.
+		 */
+		SECONDS(ChronoUnit.SECONDS, "s", Duration::getSeconds),
+
+		/**
+		 * Minutes.
+		 */
+		MINUTES(ChronoUnit.MINUTES, "m", Duration::toMinutes),
+
+		/**
+		 * Hours.
+		 */
+		HOURS(ChronoUnit.HOURS, "h", Duration::toHours),
+
+		/**
+		 * Days.
+		 */
+		DAYS(ChronoUnit.DAYS, "d", Duration::toDays);
+
+		private final ChronoUnit chronoUnit;
+
+		private final String suffix;
+
+		private Function<Duration, Long> longValue;
+
+		Unit(ChronoUnit chronoUnit, String suffix, Function<Duration, Long> toUnit) {
+			this.chronoUnit = chronoUnit;
+			this.suffix = suffix;
+			this.longValue = toUnit;
+		}
+
+		public Duration parse(String value) {
+			return Duration.of(Long.valueOf(value), this.chronoUnit);
+		}
+
+		public long longValue(Duration value) {
+			return this.longValue.apply(value);
+		}
+
+		public static Unit fromChronoUnit(ChronoUnit chronoUnit) {
+			if (chronoUnit == null) {
+				return Unit.MILLIS;
+			}
+			for (Unit candidate : values()) {
+				if (candidate.chronoUnit == chronoUnit) {
+					return candidate;
+				}
+			}
+			throw new IllegalArgumentException("Unknown unit " + chronoUnit);
+		}
+
+		public static Unit fromSuffix(String suffix) {
+			for (Unit candidate : values()) {
+				if (candidate.suffix.equalsIgnoreCase(suffix)) {
+					return candidate;
+				}
+			}
+			throw new IllegalArgumentException("Unknown unit '" + suffix + "'");
+		}
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java

@@ -30,6 +30,7 @@
  * @author Thomas Darimont
  * @author Christoph Strobl
  * @author Jordi Llach
+ * @author Mark Paluch
  */
 @Target({ ElementType.ANNOTATION_TYPE, ElementType.FIELD })
 @Retention(RetentionPolicy.RUNTIME)
@@ -136,27 +137,32 @@
 	int expireAfterSeconds() default -1;
 
 	/**
-	 * Alternative for {@link #expireAfterSeconds()} to configure the timeout after which the collection should expire.
-	 * Defaults to an empty String for no expiry. Accepts numeric values followed by their unit of measure (d(ays),
-	 * h(ours), m(inutes), s(seconds)) or a Spring {@literal template expression}. The expression can result in a a valid
-	 * expiration {@link String} following the conventions already mentioned or a {@link java.time.Duration}.
+	 * Alternative for {@link #expireAfterSeconds()} to configure the timeout after which the document should expire.
+	 * Defaults to an empty {@link String} for no expiry. Accepts numeric values followed by their unit of measure:
+	 * <ul>
+	 * <li><b>d</b>: Days</li>
+	 * <li><b>h</b>: Hours</li>
+	 * <li><b>m</b>: Minutes</li>
+	 * <li><b>s</b>: Seconds</li>
+	 * <li>Alternatively: A Spring {@literal template expression}. The expression can result in a
+	 * {@link java.time.Duration} or a valid expiration {@link String} according to the already mentioned
+	 * conventions.</li>
+	 * </ul>
+	 * Supports ISO-8601 style.
 	 *
-	 * <pre>
-	 *     <code>
+	 * <pre class="code">
+	 *
+	 * &#0064;Indexed(expireAfter = "10s") String expireAfterTenSeconds;
 	 *
-	 * &#0064;Indexed(expireAfter = "10s")
-	 * String expireAfterTenSeconds;
+	 * &#0064;Indexed(expireAfter = "1d") String expireAfterOneDay;
 	 *
-	 * &#0064;Indexed(expireAfter = "1d")
-	 * String expireAfterOneDay;
+	 * &#0064;Indexed(expireAfter = "P2D") String expireAfterTwoDays;
 	 *
-	 * &#0064;Indexed(expireAfter = "#{&#0064;mySpringBean.timeout}")
-	 * String expireAfterTimeoutObtainedFromSpringBean;
-	 *     </code>
+	 * &#0064;Indexed(expireAfter = "#{&#0064;mySpringBean.timeout}") String expireAfterTimeoutObtainedFromSpringBean;
 	 * </pre>
 	 *
-	 * @return {@literal 0s} by default.
+	 * @return empty by default.
 	 * @since 2.2
 	 */
-	String expireAfter() default "0s";
+	String expireAfter() default "";
 }