move type based service finder to sse bundles (create new com.sap.sse.osgi bundle)

java/com.sap.sse.common/src/com/sap/sse/common/NoCorrespondingServiceRegisteredException.java

@@ -0,0 +1,26 @@
+package com.sap.sse.common;
+
+import java.io.Serializable;
+
+public class NoCorrespondingServiceRegisteredException extends RuntimeException implements Serializable {
+    public String type;
+    public String serviceInterface;
+    private static final long serialVersionUID = -358955216089477585L;
+    
+    protected NoCorrespondingServiceRegisteredException() {}
+
+    public NoCorrespondingServiceRegisteredException(String message, String type, String serviceInterface) {
+        super(message);
+        this.type = type;
+        this.serviceInterface = serviceInterface;
+    }
+
+    public String getDeviceType() {
+        return type;
+    }
+
+    @Override
+    public String toString() {
+        return super.toString() + " (Service: " + serviceInterface + ", Type: " + type + ")";
+    }
+}

java/com.sap.sse.common/src/com/sap/sse/common/TypeBasedServiceFinder.java

@@ -0,0 +1,30 @@
+package com.sap.sse.common;
+
+
+/**
+ * @author Fredrik Teschke
+ *
+ * @param <ServiceType> Specifies desired the service interface
+ */
+public interface TypeBasedServiceFinder<ServiceType> {
+    public static final String TYPE = "type";
+
+    /**
+     * Find a service that implements the <ServiceType> interface for the specified {@code type}
+     * of object (e.g. type of a {@link GPSFix}).
+     * @param type A {@link String} that specifies for which type the service should be registered
+     * @throws NoCorrespondingServiceRegisteredException Thrown, if no service is registered for this type.
+     */
+    ServiceType findService(String type) throws NoCorrespondingServiceRegisteredException;
+    
+    /**
+     * Sets a fallback service (optional), that is used if no service is registered for a {@code type}.
+     * This should be a generic service, that can deal with any {@code type}, and provides a
+     * "better-than-nothing" implementation, which will be returned instead of throwing a
+     * {@link NoCorrespondingServiceRegisteredException}.
+     * <p>
+     * This method does not need to be implemented, but can remain a stub, if no fallback behaviour
+     * is desired.
+     */
+    void setFallbackService(ServiceType fallback);
+}

java/com.sap.sse.common/src/com/sap/sse/common/TypeBasedServiceFinderFactory.java

@@ -0,0 +1,18 @@
+package com.sap.sse.common;
+
+
+/**
+ * A factory for creating {@link TypeBasedServiceFinder}s, for a specific type of service.
+ * The desired service type is specified by the {@link Class} object passed to the
+ * {@link #createServiceFinder(Class)} method.
+ * 
+ * The created {@link TypeBasedServiceFinder} can then be used to find the desired
+ * service for a specific type. E.g., there may be a persistence service interface for
+ * {@link GPSFix}es, and there are several different service registered, depending on the type
+ * of {@link GPSFix}. The service finder then can find the appropriate service for each fix.
+ * @author Fredrik Teschke
+ *
+ */
+public interface TypeBasedServiceFinderFactory {
+    <ServiceT> TypeBasedServiceFinder<ServiceT> createServiceFinder(Class<ServiceT> clazz);
+}

java/com.sap.sse.common/src/com/sap/sse/common/impl/SingleTypeBasedServiceFinderImpl.java

@@ -0,0 +1,40 @@
+package com.sap.sse.common.impl;
+
+import com.sap.sse.common.NoCorrespondingServiceRegisteredException;
+import com.sap.sse.common.TypeBasedServiceFinder;
+
+/**
+ * Only can provide the service for a single {@code type}, e.g. on smartphones with no OSGi context.
+ * Optionally, a {@link #setFallbackService(Object) fallback} can be set.
+ * @author Fredrik Teschke
+ */
+public class SingleTypeBasedServiceFinderImpl<ServiceType> implements
+TypeBasedServiceFinder<ServiceType> {
+    private final ServiceType service;
+    private final String type;
+    private ServiceType fallback;
+
+    public SingleTypeBasedServiceFinderImpl(ServiceType service, ServiceType fallback, String type) {
+        this.service = service;
+        this.type = type;
+        this.fallback = fallback;
+    }
+
+    public SingleTypeBasedServiceFinderImpl(ServiceType service, String type) {
+        this(service, null, type);
+    }
+
+    @Override
+    public ServiceType findService(String type)
+            throws NoCorrespondingServiceRegisteredException {
+        if (type.equals(this.type)) return service;
+        if (fallback != null) return fallback;
+        throw new NoCorrespondingServiceRegisteredException("Only one service registered", type, service.getClass().getSimpleName());
+    }
+
+    @Override
+    public void setFallbackService(ServiceType fallback) {
+        this.fallback = fallback;
+    }
+
+}