DATACOUCH-14 - Enable SLF4J as default logging.

If the whole system is constructed through the AbstractCouchbaseConfiguration or
the custom <couchbase> xml config, the logger is specified automatically.

Please note that this also changes the java config a little bit, but it should
also make it easier to construct it.

src/main/java/org/springframework/data/couchbase/config/AbstractCouchbaseConfiguration.java

@@ -23,6 +23,7 @@ import org.springframework.context.annotation.ClassPathScanningCandidateComponen
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.type.filter.AnnotationTypeFilter;
 import org.springframework.data.annotation.Persistent;
+import org.springframework.data.couchbase.core.CouchbaseFactoryBean;
 import org.springframework.data.couchbase.core.CouchbaseTemplate;
 import org.springframework.data.couchbase.core.convert.MappingCouchbaseConverter;
 import org.springframework.data.couchbase.core.convert.translation.JacksonTranslationService;
@@ -32,8 +33,9 @@ import org.springframework.data.couchbase.core.mapping.Document;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
-import java.util.HashSet;
-import java.util.Set;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.*;
 
 /**
  * Base class for Spring Data Couchbase configuration using JavaConfig.
@@ -43,13 +45,62 @@ import java.util.Set;
 @Configuration
 public abstract class AbstractCouchbaseConfiguration {
 
+  /**
+   * The list of hostnames (or IP addresses to bootstrap from).
+   *
+   * @return the list of bootstrap hosts.
+   */
+  protected abstract List<String> bootstrapHosts();
+
+  /**
+   * The name of the bucket to connect to.
+   *
+   * @return the name of the bucket.
+   */
+  protected abstract String getBucketName();
+
+  /**
+   * The password of the bucket (can be an empty string).
+   *
+   * @return the password of the bucket.
+   */
+  protected abstract String getBucketPassword();
+
   /**
    * Return the {@link CouchbaseClient} instance to connect to.
    *
    * @throws Exception on Bean construction failure.
    */
   @Bean(destroyMethod = "shutdown")
-  public abstract CouchbaseClient couchbaseClient() throws Exception;
+  public CouchbaseClient couchbaseClient() throws Exception {
+    setLoggerProperty(couchbaseLogger());
+
+    return new CouchbaseClient(
+      bootstrapUris(bootstrapHosts()),
+      getBucketName(),
+      getBucketPassword()
+    );
+  }
+
+  /**
+   * Specifies the logger to use (defaults to SLF4J).
+   *
+   * @return the logger property string.
+   */
+  protected String couchbaseLogger() {
+    return CouchbaseFactoryBean.DEFAULT_LOGGER_PROPERTY;
+  }
+
+  /**
+   * Prepare the logging property before initializing couchbase.
+   *
+   * @param logger
+   */
+  private void setLoggerProperty(String logger) {
+    Properties systemProperties = System.getProperties();
+    systemProperties.put("net.spy.log.LoggerImpl", logger);
+    System.setProperties(systemProperties);
+  }
 
   /**
    * Creates a {@link CouchbaseTemplate}.
@@ -130,4 +181,19 @@ public abstract class AbstractCouchbaseConfiguration {
     return getClass().getPackage().getName();
   }
 
+
+  /**
+   * Converts the given list of hostnames into parsable URIs.
+   *
+   * @param hosts the list of hosts to convert.
+   * @return the converted URIs.
+   */
+  private List<URI> bootstrapUris(List<String> hosts) throws URISyntaxException {
+    List<URI> uris = new ArrayList<URI>();
+    for (String host : hosts) {
+      uris.add(new URI("http://" + host + ":8091/pools"));
+    }
+    return uris;
+  }
+
 }

src/main/java/org/springframework/data/couchbase/config/CouchbaseParser.java

@@ -30,6 +30,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Properties;
 
 /**
  * Parser for "<couchbase:couchbase />" bean definitions.
@@ -68,6 +69,14 @@ public class CouchbaseParser extends AbstractSingleBeanDefinitionParser {
     bean.addConstructorArgValue(StringUtils.hasText(password) ? password : CouchbaseFactoryBean.DEFAULT_PASSWORD);
 
     bean.setDestroyMethodName(CouchbaseFactoryBean.DEFAULT_DESTROY_METHOD);
+
+    setLogger();
+  }
+
+  private void setLogger() {
+    Properties systemProperties = System.getProperties();
+    systemProperties.put("net.spy.log.LoggerImpl", CouchbaseFactoryBean.DEFAULT_LOGGER_PROPERTY);
+    System.setProperties(systemProperties);
   }
 
   /**

src/main/java/org/springframework/data/couchbase/core/CouchbaseFactoryBean.java

@@ -64,6 +64,11 @@ public class CouchbaseFactoryBean implements FactoryBean<CouchbaseClient>, Initi
    */
   public static final String DEFAULT_DESTROY_METHOD = "shutdown";
 
+  /**
+   * Use SLF4J as the default logger if not instructed otherwise.
+   */
+  public static final String DEFAULT_LOGGER_PROPERTY = "net.spy.memcached.compat.log.SLF4JLogger";
+
   /**
    * Holds the enclosed {@link CouchbaseClient}.
    */