Ensure redis export properties are actually set using a @Value()

Previously the @Value annotation was not on a top level @Bean field
(it was nested inside). Manually constructing the bean in a separate
configuration class seems like the best way to get it to actually bind
at runtime.

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/MetricExportAutoConfiguration.java

@@ -22,6 +22,7 @@ import java.util.List;
 import java.util.Map;
 
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.actuate.endpoint.MetricsEndpointMetricReader;
 import org.springframework.boot.actuate.metrics.export.MetricExportProperties;
 import org.springframework.boot.actuate.metrics.export.MetricExporters;
@@ -43,7 +44,7 @@ import org.springframework.scheduling.config.ScheduledTaskRegistrar;
 @Configuration
 @EnableScheduling
 @ConditionalOnProperty(value = "spring.metrics.export.enabled", matchIfMissing = true)
-@EnableConfigurationProperties(MetricExportProperties.class)
+@EnableConfigurationProperties
 public class MetricExportAutoConfiguration {
 
 	@Autowired(required = false)
@@ -60,6 +61,20 @@ public class MetricExportAutoConfiguration {
 	@Autowired(required = false)
 	private MetricsEndpointMetricReader endpointReader;
 
+	@Configuration
+	protected static class MetricExportPropertiesConfiguration {
+		@Value("spring.metrics.${random.value:0000}.${spring.application.name:application}")
+		private String prefix = "spring.metrics";
+
+		@Bean(name = "spring.metrics.export.CONFIGURATION_PROPERTIES")
+		@ConditionalOnMissingBean
+		public MetricExportProperties metricExportProperties() {
+			MetricExportProperties export = new MetricExportProperties();
+			export.getRedis().setPrefix(prefix);
+			return export;
+		}
+	}
+
 	@Bean
 	@ConditionalOnMissingBean(name = "metricWritersMetricExporter")
 	public SchedulingConfigurer metricWritersMetricExporter() {

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/MetricRepositoryAutoConfiguration.java

@@ -26,7 +26,6 @@ import org.springframework.boot.actuate.metrics.buffer.CounterBuffers;
 import org.springframework.boot.actuate.metrics.buffer.GaugeBuffers;
 import org.springframework.boot.actuate.metrics.export.Exporter;
 import org.springframework.boot.actuate.metrics.export.MetricCopyExporter;
-import org.springframework.boot.actuate.metrics.export.MetricExportProperties;
 import org.springframework.boot.actuate.metrics.repository.InMemoryMetricRepository;
 import org.springframework.boot.actuate.metrics.repository.MetricRepository;
 import org.springframework.boot.actuate.metrics.writer.DefaultCounterService;
@@ -37,7 +36,6 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnJava;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnJava.JavaVersion;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnJava.Range;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.messaging.MessageChannel;
@@ -81,7 +79,6 @@ import com.codahale.metrics.MetricRegistry;
  * @author Dave Syer
  */
 @Configuration
-@EnableConfigurationProperties(MetricExportProperties.class)
 public class MetricRepositoryAutoConfiguration {
 
 	@Configuration

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/export/MetricExportProperties.java

@@ -22,7 +22,6 @@ import java.util.Map.Entry;
 
 import javax.annotation.PostConstruct;
 
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.util.PatternMatchUtils;
 import org.springframework.util.StringUtils;
@@ -149,7 +148,6 @@ public class MetricExportProperties extends Trigger {
 		 * set spring.application.name elsewhere, then the default will be in the right
 		 * form.
 		 */
-		@Value("spring.metrics.${random.value:0000}.${spring.application.name:application}")
 		private String prefix = "spring.metrics";
 
 		/**
@@ -179,6 +177,7 @@ public class MetricExportProperties extends Trigger {
 			if (tokens.length > 1) {
 				if (StringUtils.hasText(tokens[1])) {
 					// If the prefix has 2 or more non-trivial parts, use the first 1
+					// (the aggregator strips a further 2 by default).
 					return tokens[0];
 				}
 			}

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/repository/redis/RedisMetricRepository.java

@@ -100,11 +100,6 @@ public class RedisMetricRepository implements MetricRepository {
 			prefix = prefix + ".";
 		}
 		this.prefix = prefix;
-		if (!DEFAULT_METRICS_PREFIX.equals(this.prefix)) {
-			if (DEFAULT_KEY.equals(key)) {
-				key = "keys." + prefix;
-			}
-		}
 		if (key.endsWith(".")) {
 			key = key.substring(0, key.length() - 1);
 		}