Polish DataSourceMetrics code

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

@@ -43,8 +43,8 @@ public class DataSourceMetricsAutoConfiguration {
 
 	@Bean
 	@ConditionalOnBean(DataSourceMetadataProvider.class)
-	@ConditionalOnMissingBean(DataSourcePublicMetrics.class)
-	DataSourcePublicMetrics dataSourcePublicMetrics() {
+	@ConditionalOnMissingBean
+	public DataSourcePublicMetrics dataSourcePublicMetrics() {
 		return new DataSourcePublicMetrics();
 	}
 

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/DataSourcePublicMetrics.java

@@ -20,6 +20,7 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.Map;
+import java.util.Set;
 
 import javax.annotation.PostConstruct;
 import javax.sql.DataSource;
@@ -47,88 +48,63 @@ public class DataSourcePublicMetrics implements PublicMetrics {
 	private ApplicationContext applicationContext;
 
 	@Autowired
-	private Collection<DataSourceMetadataProvider> dataSourceMetadataProviders;
+	private Collection<DataSourceMetadataProvider> providers;
 
-	private final Map<String, DataSourceMetadata> dataSourceMetadataByPrefix = new HashMap<String, DataSourceMetadata>();
+	private final Map<String, DataSourceMetadata> metadataByPrefix = new HashMap<String, DataSourceMetadata>();
 
 	@PostConstruct
 	public void initialize() {
-		Map<String, DataSource> dataSources = this.applicationContext
-				.getBeansOfType(DataSource.class);
 		DataSource primaryDataSource = getPrimaryDataSource();
-
 		DataSourceMetadataProvider provider = new CompositeDataSourceMetadataProvider(
-				this.dataSourceMetadataProviders);
-		for (Map.Entry<String, DataSource> entry : dataSources.entrySet()) {
-			String prefix = createPrefix(entry.getKey(), entry.getValue(), entry
-					.getValue().equals(primaryDataSource));
-			DataSourceMetadata dataSourceMetadata = provider.getDataSourceMetadata(entry
-					.getValue());
+				this.providers);
+		for (Map.Entry<String, DataSource> entry : this.applicationContext
+				.getBeansOfType(DataSource.class).entrySet()) {
+			String beanName = entry.getKey();
+			DataSource bean = entry.getValue();
+			String prefix = createPrefix(beanName, bean, bean.equals(primaryDataSource));
+			DataSourceMetadata dataSourceMetadata = provider.getDataSourceMetadata(bean);
 			if (dataSourceMetadata != null) {
-				this.dataSourceMetadataByPrefix.put(prefix, dataSourceMetadata);
+				this.metadataByPrefix.put(prefix, dataSourceMetadata);
 			}
 		}
 	}
 
 	@Override
 	public Collection<Metric<?>> metrics() {
-		Collection<Metric<?>> result = new LinkedHashSet<Metric<?>>();
-		for (Map.Entry<String, DataSourceMetadata> entry : this.dataSourceMetadataByPrefix
+		Set<Metric<?>> metrics = new LinkedHashSet<Metric<?>>();
+		for (Map.Entry<String, DataSourceMetadata> entry : this.metadataByPrefix
 				.entrySet()) {
 			String prefix = entry.getKey();
-			// Make sure the prefix ends with a dot
-			if (!prefix.endsWith(".")) {
-				prefix = prefix + ".";
-			}
+			prefix = (prefix.endsWith(".") ? prefix : prefix + ".");
 			DataSourceMetadata dataSourceMetadata = entry.getValue();
-			Integer poolSize = dataSourceMetadata.getPoolSize();
-			if (poolSize != null) {
-				result.add(new Metric<Integer>(prefix + "active", poolSize));
-			}
-			Float poolUsage = dataSourceMetadata.getPoolUsage();
-			if (poolUsage != null) {
-				result.add(new Metric<Float>(prefix + "usage", poolUsage));
-			}
+			addMetric(metrics, prefix + "active", dataSourceMetadata.getPoolSize());
+			addMetric(metrics, prefix + "usage", dataSourceMetadata.getPoolUsage());
+		}
+		return metrics;
+	}
+
+	private <T extends Number> void addMetric(Set<Metric<?>> metrics, String name, T value) {
+		if (value != null) {
+			metrics.add(new Metric<T>(name, value));
 		}
-		return result;
 	}
 
 	/**
 	 * Create the prefix to use for the metrics to associate with the given
 	 * {@link DataSource}.
-	 * @param dataSourceName the name of the data source bean
+	 * @param name the name of the data source bean
 	 * @param dataSource the data source to configure
 	 * @param primary if this data source is the primary data source
 	 * @return a prefix for the given data source
 	 */
-	protected String createPrefix(String dataSourceName, DataSource dataSource,
-			boolean primary) {
-		StringBuilder sb = new StringBuilder("datasource.");
+	protected String createPrefix(String name, DataSource dataSource, boolean primary) {
 		if (primary) {
-			sb.append("primary");
+			return "datasource.primary";
 		}
-		else if (endWithDataSource(dataSourceName)) { // Strip the data source part out of
-														// the name
-			sb.append(dataSourceName.substring(0, dataSourceName.length()
-					- DATASOURCE_SUFFIX.length()));
-		}
-		else {
-			sb.append(dataSourceName);
-		}
-		return sb.toString();
-	}
-
-	/**
-	 * Specify if the given value ends with {@code dataSource}.
-	 */
-	protected boolean endWithDataSource(String value) {
-		int suffixLength = DATASOURCE_SUFFIX.length();
-		int valueLength = value.length();
-		if (valueLength > suffixLength) {
-			String suffix = value.substring(valueLength - suffixLength, valueLength);
-			return suffix.equalsIgnoreCase(DATASOURCE_SUFFIX);
+		if (name.toLowerCase().endsWith(DATASOURCE_SUFFIX.toLowerCase())) {
+			name = name.substring(0, name.length() - DATASOURCE_SUFFIX.length());
 		}
-		return false;
+		return "datasource." + name;
 	}
 
 	/**
@@ -140,7 +116,7 @@ public class DataSourcePublicMetrics implements PublicMetrics {
 		try {
 			return this.applicationContext.getBean(DataSource.class);
 		}
-		catch (NoSuchBeanDefinitionException e) {
+		catch (NoSuchBeanDefinitionException ex) {
 			return null;
 		}
 	}

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/AbstractDataSourceMetadata.java

@@ -24,38 +24,35 @@ import javax.sql.DataSource;
  * @author Stephane Nicoll
  * @since 1.2.0
  */
-public abstract class AbstractDataSourceMetadata<D extends DataSource> implements
+public abstract class AbstractDataSourceMetadata<T extends DataSource> implements
 		DataSourceMetadata {
 
-	private final D dataSource;
+	private final T dataSource;
 
 	/**
 	 * Create an instance with the data source to use.
 	 */
-	protected AbstractDataSourceMetadata(D dataSource) {
+	protected AbstractDataSourceMetadata(T dataSource) {
 		this.dataSource = dataSource;
 	}
 
 	@Override
 	public Float getPoolUsage() {
-		Integer max = getMaxPoolSize();
-		if (max == null) {
+		Integer maxSize = getMaxPoolSize();
+		Integer currentSize = getPoolSize();
+		if (maxSize == null || currentSize == null) {
 			return null;
 		}
-		if (max < 0) {
+		if (maxSize < 0) {
 			return -1F;
 		}
-		Integer current = getPoolSize();
-		if (current == null) {
-			return null;
-		}
-		if (current == 0) {
+		if (currentSize == 0) {
 			return 0F;
 		}
-		return (float) current / max; // something like that
+		return (float) currentSize / (float) maxSize;
 	}
 
-	protected final D getDataSource() {
+	protected final T getDataSource() {
 		return this.dataSource;
 	}
 

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/CommonsDbcpDataSourceMetadata.java

@@ -16,10 +16,12 @@
 
 package org.springframework.boot.autoconfigure.jdbc;
 
+import javax.sql.DataSource;
+
 import org.apache.commons.dbcp.BasicDataSource;
 
 /**
- * A {@link DataSourceMetadata} implementation for the commons dbcp data source.
+ * {@link DataSourceMetadata} for a Apache Commons DBCP {@link DataSource}.
  *
  * @author Stephane Nicoll
  * @since 1.2.0

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/CompositeDataSourceMetadataProvider.java

@@ -18,6 +18,7 @@ package org.springframework.boot.autoconfigure.jdbc;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 
 import javax.sql.DataSource;
 
@@ -30,30 +31,30 @@ import javax.sql.DataSource;
  */
 public class CompositeDataSourceMetadataProvider implements DataSourceMetadataProvider {
 
-	private final Collection<DataSourceMetadataProvider> providers;
+	private final List<DataSourceMetadataProvider> providers;
 
 	/**
-	 * Create an instance with an initial collection of delegates to use.
+	 * Create a {@link CompositeDataSourceMetadataProvider} instance with no delegate.
 	 */
-	public CompositeDataSourceMetadataProvider(
-			Collection<DataSourceMetadataProvider> providers) {
-		this.providers = providers;
+	public CompositeDataSourceMetadataProvider() {
+		this(new ArrayList<DataSourceMetadataProvider>());
 	}
 
 	/**
-	 * Create an instance with no delegate.
+	 * Create a {@link CompositeDataSourceMetadataProvider} instance with an initial
+	 * collection of delegates to use.
 	 */
-	public CompositeDataSourceMetadataProvider() {
-		this(new ArrayList<DataSourceMetadataProvider>());
+	public CompositeDataSourceMetadataProvider(
+			Collection<? extends DataSourceMetadataProvider> providers) {
+		this.providers = new ArrayList<DataSourceMetadataProvider>(providers);
 	}
 
 	@Override
 	public DataSourceMetadata getDataSourceMetadata(DataSource dataSource) {
 		for (DataSourceMetadataProvider provider : this.providers) {
-			DataSourceMetadata dataSourceMetadata = provider
-					.getDataSourceMetadata(dataSource);
-			if (dataSourceMetadata != null) {
-				return dataSourceMetadata;
+			DataSourceMetadata metadata = provider.getDataSourceMetadata(dataSource);
+			if (metadata != null) {
+				return metadata;
 			}
 		}
 		return null;

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/DataSourceMetadata.java

@@ -19,8 +19,8 @@ package org.springframework.boot.autoconfigure.jdbc;
 import javax.sql.DataSource;
 
 /**
- * Provide various metadata regarding a {@link DataSource} that are shared by most data
- * source types but not accessible in a standard manner.
+ * Provides access meta-data that is commonly available from most {@link DataSource}
+ * implementations.
  *
  * @author Stephane Nicoll
  * @since 1.2.0
@@ -28,7 +28,8 @@ import javax.sql.DataSource;
 public interface DataSourceMetadata {
 
 	/**
-	 * Return the usage of the pool as a double value between 0 and 1.
+	 * Return the usage of the pool as value between 0 and 1 (or -1 if the pool is not
+	 * limited).
 	 * <ul>
 	 * <li>1 means that the maximum number of connections have been allocated</li>
 	 * <li>0 means that no connection is currently active</li>

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/HikariDataSourceMetadata.java

@@ -16,14 +16,15 @@
 
 package org.springframework.boot.autoconfigure.jdbc;
 
-import org.springframework.beans.BeansException;
+import javax.sql.DataSource;
+
 import org.springframework.beans.DirectFieldAccessor;
 
 import com.zaxxer.hikari.HikariDataSource;
 import com.zaxxer.hikari.pool.HikariPool;
 
 /**
- * A {@link DataSourceMetadata} implementation for the hikari data source.
+ * {@link DataSourceMetadata} for a Hikari {@link DataSource}.
  *
  * @author Stephane Nicoll
  * @since 1.2.0
@@ -31,20 +32,23 @@ import com.zaxxer.hikari.pool.HikariPool;
 public class HikariDataSourceMetadata extends
 		AbstractDataSourceMetadata<HikariDataSource> {
 
-	private final HikariPoolProvider hikariPoolProvider;
-
 	public HikariDataSourceMetadata(HikariDataSource dataSource) {
 		super(dataSource);
-		this.hikariPoolProvider = new HikariPoolProvider(dataSource);
 	}
 
 	@Override
 	public Integer getPoolSize() {
-		HikariPool hikariPool = this.hikariPoolProvider.getHikariPool();
-		if (hikariPool != null) {
-			return hikariPool.getActiveConnections();
+		try {
+			return getHikariPool().getActiveConnections();
 		}
-		return null;
+		catch (Exception ex) {
+			return null;
+		}
+	}
+
+	private HikariPool getHikariPool() {
+		return (HikariPool) new DirectFieldAccessor(getDataSource())
+				.getPropertyValue("pool");
 	}
 
 	@Override
@@ -62,50 +66,4 @@ public class HikariDataSourceMetadata extends
 		return getDataSource().getConnectionTestQuery();
 	}
 
-	/**
-	 * Provide the {@link HikariPool} instance managed internally by the
-	 * {@link HikariDataSource} as there is no other way to retrieve that information
-	 * except JMX access.
-	 */
-	private static class HikariPoolProvider {
-		private final HikariDataSource dataSource;
-
-		private boolean poolAvailable;
-
-		private HikariPoolProvider(HikariDataSource dataSource) {
-			this.dataSource = dataSource;
-			this.poolAvailable = isHikariPoolAvailable();
-		}
-
-		public HikariPool getHikariPool() {
-			if (!this.poolAvailable) {
-				return null;
-			}
-
-			Object value = doGetValue();
-			if (value instanceof HikariPool) {
-				return (HikariPool) value;
-			}
-			return null;
-		}
-
-		private boolean isHikariPoolAvailable() {
-			try {
-				doGetValue();
-				return true;
-			}
-			catch (BeansException e) { // No such field
-				return false;
-			}
-			catch (SecurityException e) { // Security manager prevents to read the value
-				return false;
-			}
-		}
-
-		private Object doGetValue() {
-			DirectFieldAccessor accessor = new DirectFieldAccessor(this.dataSource);
-			return accessor.getPropertyValue("pool");
-		}
-	}
-
 }

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/TomcatDataSourceMetadata.java

@@ -20,8 +20,7 @@ import org.apache.tomcat.jdbc.pool.ConnectionPool;
 import org.apache.tomcat.jdbc.pool.DataSource;
 
 /**
- *
- * A {@link DataSourceMetadata} implementation for the tomcat data source.
+ * {@link DataSourceMetadata} for a Tomcat {@link DataSource}.
  *
  * @author Stephane Nicoll
  */

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/AbstractDataSourceMetadataTests.java

@@ -27,9 +27,11 @@ import org.springframework.jdbc.core.JdbcTemplate;
 import static org.junit.Assert.assertEquals;
 
 /**
+ * Abstract base class for {@link DataSourceMetadata} tests.
+ *
  * @author Stephane Nicoll
  */
-public abstract class AbstractDataSourceMetadataTests<D extends AbstractDataSourceMetadata> {
+public abstract class AbstractDataSourceMetadataTests<D extends AbstractDataSourceMetadata<?>> {
 
 	/**
 	 * Return a data source metadata instance with a min size of 0 and max size of 2.

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/CommonsDbcpDataSourceMetadataTests.java

@@ -24,6 +24,8 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 
 /**
+ * Tests for {@link CommonsDbcpDataSourceMetadata}.
+ *
  * @author Stephane Nicoll
  */
 public class CommonsDbcpDataSourceMetadataTests extends

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/CompositeDataSourceMetadataProviderTests.java

@@ -30,6 +30,8 @@ import static org.junit.Assert.assertSame;
 import static org.mockito.BDDMockito.given;
 
 /**
+ * Tests for {@link CompositeDataSourceMetadataProvider}.
+ *
  * @author Stephane Nicoll
  */
 public class CompositeDataSourceMetadataProviderTests {

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/HikariDataSourceMetadataTests.java

@@ -23,6 +23,8 @@ import com.zaxxer.hikari.HikariDataSource;
 import static org.junit.Assert.assertEquals;
 
 /**
+ * Tests for {@link HikariDataSourceMetadata}.
+ *
  * @author Stephane Nicoll
  */
 public class HikariDataSourceMetadataTests extends

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/TomcatDataSourceMetadataTests.java

@@ -22,6 +22,8 @@ import org.junit.Before;
 import static org.junit.Assert.assertEquals;
 
 /**
+ * Tests for {@link TomcatDataSourceMetadata}.
+ *
  * @author Stephane Nicoll
  */
 public class TomcatDataSourceMetadataTests extends