Clean up BaseDBConfiguration class

This change isn't too big;  it mainly just attempts to clean up the
BaseDBConfiguration class using best practices.  For example:

* documentation is added surrounding public methods, public constants,
  protected variables, and class headers.
* code logic for parsing "optional" integer properties is abstracted
  into a separate private static function, which returns a default
  value if the given input property cannot be parsed or is not present.
* public functions where the NumberFormatException RuntimeException
  might be thrown have the appriorate "throws" modifier added to their
  function signatures to indicate that the consumer is responsible for
  exception handling.
* constants are extracted in place of "magic numbers"

This is really just code sanitation work.

Change-Id: Ifaf092e10b17f54c7cce0a888aa49bfe8377cdd3
Issue-Id: SDNC-79
Signed-off-by: Ryan Goulding <ryandgoulding@gmail.com>

1 files changed, 211 insertions, 78 deletions

diff --git a/dblib/provider/src/main/java/org/onap/ccsdk/sli/core/dblib/config/BaseDBConfiguration.java b/dblib/provider/src/main/java/org/onap/ccsdk/sli/core/dblib/config/BaseDBConfiguration.java
index 4b738d42..d53be0e7 100644
--- a/dblib/provider/src/main/java/org/onap/ccsdk/sli/core/dblib/config/BaseDBConfiguration.java
+++ b/dblib/provider/src/main/java/org/onap/ccsdk/sli/core/dblib/config/BaseDBConfiguration.java
@@ -22,83 +22,216 @@ package org.onap.ccsdk.sli.core.dblib.config;
 
 import java.util.Properties;
 
+/**
+ * Base class responsible for parsing business logic for database configuration from given <code>Properties</code>.
+ */
 public abstract class BaseDBConfiguration {
-	public static final String DATABASE_TYPE	= "org.onap.ccsdk.sli.dbtype";
-	public static final String DATABASE_URL		= "org.onap.ccsdk.sli.jdbc.url";
-	public static final String DATABASE_NAME	= "org.onap.ccsdk.sli.jdbc.database";
-	public static final String CONNECTION_NAME	= "org.onap.ccsdk.sli.jdbc.connection.name";
-	public static final String DATABASE_USER 	= "org.onap.ccsdk.sli.jdbc.user";
-	public static final String DATABASE_PSSWD	= "org.onap.ccsdk.sli.jdbc.password";
-	public static final String CONNECTION_TIMEOUT="org.onap.ccsdk.sli.jdbc.connection.timeout";
-	public static final String REQUEST_TIMEOUT	= "org.onap.ccsdk.sli.jdbc.request.timeout";
-	public static final String MIN_LIMIT		= "org.onap.ccsdk.sli.jdbc.limit.min";
-	public static final String MAX_LIMIT		= "org.onap.ccsdk.sli.jdbc.limit.max";
-	public static final String INIT_LIMIT		= "org.onap.ccsdk.sli.jdbc.limit.init";
-	public static final String DATABASE_HOSTS   = "org.onap.ccsdk.sli.jdbc.hosts";
-
-
-	protected final Properties props;
-
-	public BaseDBConfiguration(Properties properties) {
-		this.props = properties;
-	}
-
-	public int getConnTimeout() {
-		try {
-			String value = props.getProperty(CONNECTION_TIMEOUT);
-			return Integer.parseInt(value);
-		} catch(Exception exc) {
-			return -1;
-		}
-	}
-
-	public int getRequestTimeout() {
-		try {
-			String value = props.getProperty(REQUEST_TIMEOUT);
-			if(value == null)
-				return -1;
-			return Integer.parseInt(value);
-		} catch(Exception exc) {
-			return -1;
-		}
-	}
-
-	public String getDbConnectionName() {
-		return props.getProperty(CONNECTION_NAME);
-	}
-
-	public String getDatabaseName() {
-		return props.getProperty(DATABASE_NAME);
-	}
-
-	public String getDbUserId() {
-		return props.getProperty(DATABASE_USER);
-	}
-
-	public String getDbPasswd() {
-		return props.getProperty(DATABASE_PSSWD);
-	}
-
-	public int getDbMinLimit() {
-		String value = props.getProperty(MIN_LIMIT);
-		return Integer.parseInt(value);
-	}
-
-	public int getDbMaxLimit() {
-		String value = props.getProperty(MAX_LIMIT);
-		return Integer.parseInt(value);
-	}
-
-	public int getDbInitialLimit() {
-		String value = props.getProperty(INIT_LIMIT);
-		return Integer.parseInt(value);
-	}
-
-	public String getDbUrl() {
-		return props.getProperty(DATABASE_URL);
-	}
-
-	public String getServerGroup() {
-		return null;
-	}
+
+    /**
+     * Property key within a properties configuration File for db type
+     */
+    public static final String DATABASE_TYPE	= "org.onap.ccsdk.sli.dbtype";
+
+    /**
+     * Property key with a properties configuration File for db url
+     */
+    public static final String DATABASE_URL		= "org.onap.ccsdk.sli.jdbc.url";
+
+    /**
+     * Property key with a properties configuration File for database name
+     */
+    public static final String DATABASE_NAME	= "org.onap.ccsdk.sli.jdbc.database";
+
+    /**
+     * Property key with a properties configuration File for db database connection name
+     */
+    public static final String CONNECTION_NAME	= "org.onap.ccsdk.sli.jdbc.connection.name";
+
+    /**
+     * Property key with a properties configuration File for database user
+     */
+    public static final String DATABASE_USER 	= "org.onap.ccsdk.sli.jdbc.user";
+
+    /**
+     * Property key with a properties configuration File for database password for associated with
+     * <code>org.onap.ccsdk.sli.jdbc.user</code>.
+     */
+    public static final String DATABASE_PSSWD	= "org.onap.ccsdk.sli.jdbc.password";
+
+    /**
+     * Property key with a properties configuration File for database connection timeout
+     */
+    public static final String CONNECTION_TIMEOUT="org.onap.ccsdk.sli.jdbc.connection.timeout";
+
+    /**
+     * Property key with a properties configuration File for database request timeout
+     */
+    public static final String REQUEST_TIMEOUT	= "org.onap.ccsdk.sli.jdbc.request.timeout";
+
+    /**
+     * Property key with a properties configuration File for database minimum limit
+     */
+    public static final String MIN_LIMIT		= "org.onap.ccsdk.sli.jdbc.limit.min";
+
+    /**
+     * Property key with a properties configuration File for database maximum limit
+     */
+    public static final String MAX_LIMIT		= "org.onap.ccsdk.sli.jdbc.limit.max";
+
+    /**
+     * Property key with a properties configuration File for database initial limit
+     */
+    public static final String INIT_LIMIT		= "org.onap.ccsdk.sli.jdbc.limit.init";
+
+    /**
+     * Property key with a properties configuration File for database hosts
+     */
+    public static final String DATABASE_HOSTS   = "org.onap.ccsdk.sli.jdbc.hosts";
+
+    /**
+     * default value when the connection timeout is not present or cannot be parsed
+     */
+    private static final int DEFAULT_CONNECTION_TIMEOUT = -1;
+
+    /**
+     * default value when the request timeout is not present or cannot be parsed
+     */
+    private static final int DEFAULT_REQUEST_TIMEOUT = -1;
+
+    /**
+     * A set of properties with database configuration information.
+     */
+    protected final Properties properties;
+
+    /**
+     * Builds a configuration based on given properties
+     *
+     * @param properties properties represented by the public constant keys defined by this class
+     */
+    public BaseDBConfiguration(final Properties properties) {
+        this.properties = properties;
+    }
+
+    /**
+     * Extracts the connection timeout.
+     *
+     * @return the connection timeout, or <code>DEFAULT_CONNECTION_TIMEOUT</code> if not present
+     */
+    public int getConnTimeout() {
+        return extractProperty(properties, CONNECTION_TIMEOUT, DEFAULT_CONNECTION_TIMEOUT);
+    }
+
+    /**
+     * Extracts the request timeout.
+     *
+     * @return the request timeout, or <code>DEFAULT_REQUEST_TIMEOUT</code> if not present
+     */
+    public int getRequestTimeout() {
+        return extractProperty(properties, REQUEST_TIMEOUT, DEFAULT_REQUEST_TIMEOUT);
+    }
+
+    /**
+     * A utility method to extract int property from Properties.
+     *
+     * @param properties a set of <code>Properties</code>
+     * @param propertyKey the key in question
+     * @param defaultValue the value to return if the key does not exist
+     * @return Either the property value for <code>propertyKey</code> or <code>defaultValue</code> if not present
+     */
+    private static int extractProperty(final Properties properties, final String propertyKey, final int defaultValue) {
+        try {
+            final String valueString = properties.getProperty(propertyKey, Integer.toString(defaultValue));
+            return Integer.parseInt(valueString);
+        } catch(final NumberFormatException e) {
+            return defaultValue;
+        }
+    }
+
+    /**
+     * Extracts the db connection name.
+     *
+     * @return the db connection name, or <code>null</code> if not present
+     */
+    public String getDbConnectionName() {
+        return properties.getProperty(CONNECTION_NAME);
+    }
+
+    /**
+     * Extracts the db name.
+     *
+     * @return the db name, or <code>null</code> if not present
+     */
+    public String getDatabaseName() {
+        return properties.getProperty(DATABASE_NAME);
+    }
+
+    /**
+     * Extracts the db user id.
+     *
+     * @return the db user id, or <code>null</code> if not present
+     */
+    public String getDbUserId() {
+        return properties.getProperty(DATABASE_USER);
+    }
+
+    /**
+     * Extracts the db password.
+     *
+     * @return the db password, or <code>null</code> if not present
+     */
+    public String getDbPasswd() {
+        return properties.getProperty(DATABASE_PSSWD);
+    }
+
+    /**
+     * Extracts the db min limit.
+     *
+     * @return the db min limit
+     * @throws NumberFormatException if the property is not specified, or cannot be parsed as an <code>Integer</code>.
+     */
+    public int getDbMinLimit() throws NumberFormatException {
+        String value = properties.getProperty(MIN_LIMIT);
+        return Integer.parseInt(value);
+    }
+
+    /**
+     * Extracts the db max limit.
+     *
+     * @return the db max limit
+     * @throws NumberFormatException if the property is not specified, or cannot be parsed as an <code>Integer</code>.
+     */
+    public int getDbMaxLimit() throws NumberFormatException {
+        String value = properties.getProperty(MAX_LIMIT);
+        return Integer.parseInt(value);
+    }
+
+    /**
+     * Extracts the db initial limit.
+     *
+     * @return the db initial limit
+     * @throws NumberFormatException if the property is not specified, or cannot be parsed as an <code>Integer</code>.
+     */
+    public int getDbInitialLimit() throws NumberFormatException {
+        String value = properties.getProperty(INIT_LIMIT);
+        return Integer.parseInt(value);
+    }
+
+    /**
+     * Extracts the db url.
+     *
+     * @return the db url, or <code>null</code> if not present
+     */
+    public String getDbUrl() {
+        return properties.getProperty(DATABASE_URL);
+    }
+
+    /**
+     * Extracts the db server group.
+     *
+     * @return <code>null</code>
+     */
+    @Deprecated
+    public String getServerGroup() {
+        return null;
+    }
 }