Polish

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/DataSourceHealthIndicator.java

@@ -20,12 +20,14 @@ import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import javax.sql.DataSource;
 
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.support.DataAccessUtils;
 import org.springframework.jdbc.IncorrectResultSetColumnCountException;
@@ -33,6 +35,7 @@ import org.springframework.jdbc.core.ConnectionCallback;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.RowMapper;
 import org.springframework.jdbc.support.JdbcUtils;
+import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
@@ -45,24 +48,26 @@ import org.springframework.util.StringUtils;
  * @author Stephane Nicoll
  * @since 1.1.0
  */
-public class DataSourceHealthIndicator extends AbstractHealthIndicator {
-
-	private DataSource dataSource;
-
-	private JdbcTemplate jdbcTemplate;
-
-	private static final Map<String, String> queries = new HashMap<String, String>();
+public class DataSourceHealthIndicator extends AbstractHealthIndicator implements
+		InitializingBean {
 
+	private static final Map<String, String> PRODUCT_SPECIFIC_QUERIES;
 	static {
+		Map<String, String> queries = new HashMap<String, String>();
 		queries.put("HSQL Database Engine", "SELECT COUNT(*) FROM "
 				+ "INFORMATION_SCHEMA.SYSTEM_USERS");
 		queries.put("Oracle", "SELECT 'Hello' from DUAL");
 		queries.put("Apache Derby", "SELECT 1 FROM SYSIBM.SYSDUMMY1");
+		PRODUCT_SPECIFIC_QUERIES = Collections.unmodifiableMap(queries);
 	}
 
 	private static final String DEFAULT_QUERY = "SELECT 1";
 
-	private String query = null;
+	private DataSource dataSource;
+
+	private String query;
+
+	private JdbcTemplate jdbcTemplate;
 
 	/**
 	 * Create a new {@link DataSourceHealthIndicator} instance.
@@ -71,7 +76,17 @@ public class DataSourceHealthIndicator extends AbstractHealthIndicator {
 	}
 
 	/**
-	 * Create a new {@link DataSourceHealthIndicator} using the specified datasource.
+	 * Create a new {@link DataSourceHealthIndicator} using the specified
+	 * {@link DataSource}.
+	 * @param dataSource the data source
+	 */
+	public DataSourceHealthIndicator(DataSource dataSource) {
+		this(dataSource, null);
+	}
+
+	/**
+	 * Create a new {@link DataSourceHealthIndicator} using the specified
+	 * {@link DataSource} and validation query.
 	 * @param dataSource the data source
 	 * @param query the validation query to use (can be {@code null})
 	 */
@@ -81,12 +96,10 @@ public class DataSourceHealthIndicator extends AbstractHealthIndicator {
 		this.jdbcTemplate = new JdbcTemplate(dataSource);
 	}
 
-	/**
-	 * Create a new {@link DataSourceHealthIndicator} using the specified datasource.
-	 * @param dataSource the data source
-	 */
-	public DataSourceHealthIndicator(DataSource dataSource) {
-		this(dataSource, null);
+	@Override
+	public void afterPropertiesSet() throws Exception {
+		Assert.state(this.dataSource != null,
+				"DataSource for DataSourceHealthIndicator must be specified");
 	}
 
 	@Override
@@ -102,11 +115,11 @@ public class DataSourceHealthIndicator extends AbstractHealthIndicator {
 	private void doDataSourceHealthCheck(Health.Builder builder) throws Exception {
 		String product = getProduct();
 		builder.up().withDetail("database", product);
-		String query = detectQuery(product);
-		if (StringUtils.hasText(query)) {
+		String validationQuery = getValidationQuery(product);
+		if (StringUtils.hasText(validationQuery)) {
 			try {
 				// Avoid calling getObject as it breaks MySQL on Java 7
-				List<Object> results = this.jdbcTemplate.query(query,
+				List<Object> results = this.jdbcTemplate.query(validationQuery,
 						new SingleColumnRowMapper());
 				Object result = DataAccessUtils.requiredSingleResult(results);
 				builder.withDetail("hello", result);
@@ -127,10 +140,10 @@ public class DataSourceHealthIndicator extends AbstractHealthIndicator {
 		});
 	}
 
-	protected String detectQuery(String product) {
+	protected String getValidationQuery(String product) {
 		String query = this.query;
 		if (!StringUtils.hasText(query)) {
-			query = queries.get(product);
+			query = PRODUCT_SPECIFIC_QUERIES.get(product);
 		}
 		if (!StringUtils.hasText(query)) {
 			query = DEFAULT_QUERY;
@@ -147,18 +160,18 @@ public class DataSourceHealthIndicator extends AbstractHealthIndicator {
 	}
 
 	/**
-	 * Set a specific validation query to use to validate a connection. If
-	 * none is set, a default validation query is used.
+	 * Set a specific validation query to use to validate a connection. If none is set, a
+	 * default validation query is used.
 	 */
 	public void setQuery(String query) {
 		this.query = query;
 	}
 
 	/**
-	 * Return the specific validation query, if any.
+	 * Return the validation query or {@code null}.
 	 */
 	public String getQuery() {
-		return query;
+		return this.query;
 	}
 
 	/**

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/autoconfigure/HealthIndicatorAutoConfigurationTests.java

@@ -23,13 +23,13 @@ import javax.sql.DataSource;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+import org.springframework.boot.actuate.health.ApplicationHealthIndicator;
 import org.springframework.boot.actuate.health.DataSourceHealthIndicator;
 import org.springframework.boot.actuate.health.HealthIndicator;
 import org.springframework.boot.actuate.health.MongoHealthIndicator;
 import org.springframework.boot.actuate.health.RabbitHealthIndicator;
 import org.springframework.boot.actuate.health.RedisHealthIndicator;
 import org.springframework.boot.actuate.health.SolrHealthIndicator;
-import org.springframework.boot.actuate.health.ApplicationHealthIndicator;
 import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
 import org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration;
 import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
@@ -166,12 +166,15 @@ public class HealthIndicatorAutoConfigurationTests {
 	@Test
 	public void dataSourceHealthIndicatorWithCustomValidationQuery() {
 		this.context = new AnnotationConfigApplicationContext();
-		this.context.register(PropertyPlaceholderAutoConfiguration.class, DataSourceProperties.class,
-				DataSourceConfig.class, DataSourcePoolMetadataProvidersConfiguration.class,
+		this.context.register(PropertyPlaceholderAutoConfiguration.class,
+				DataSourceProperties.class, DataSourceConfig.class,
+				DataSourcePoolMetadataProvidersConfiguration.class,
 				HealthIndicatorAutoConfiguration.class);
-		EnvironmentTestUtils.addEnvironment(this.context, "spring.datasource.validation-query:SELECT from FOOBAR");
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.datasource.validation-query:SELECT from FOOBAR");
 		this.context.refresh();
-		Map<String, HealthIndicator> beans = this.context.getBeansOfType(HealthIndicator.class);
+		Map<String, HealthIndicator> beans = this.context
+				.getBeansOfType(HealthIndicator.class);
 		assertEquals(1, beans.size());
 		HealthIndicator healthIndicator = beans.values().iterator().next();
 		assertEquals(DataSourceHealthIndicator.class, healthIndicator.getClass());
@@ -247,7 +250,6 @@ public class HealthIndicatorAutoConfigurationTests {
 				.getClass());
 	}
 
-
 	@Configuration
 	@EnableConfigurationProperties
 	protected static class DataSourceConfig {
@@ -257,8 +259,9 @@ public class HealthIndicatorAutoConfigurationTests {
 		public DataSource dataSource() {
 			return DataSourceBuilder.create()
 					.driverClassName("org.hsqldb.jdbc.JDBCDriver")
-					.url("jdbc:hsqldb:mem:test")
-					.username("sa").build();
+					.url("jdbc:hsqldb:mem:test").username("sa").build();
 		}
+
 	}
+
 }