[OLINGO-1630] Add support for Segment as Path from Odata v4.01

Add support for Segment as Path from Odata v4.01

Author: mibo

lib/commons-api/src/main/java/org/apache/olingo/commons/api/edm/EdmEntitySet.java

@@ -31,4 +31,8 @@ public interface EdmEntitySet extends EdmBindingTarget {
    */
   boolean isIncludeInServiceDocument();
 
+  /**
+   * @return true if the entity set allows for the next segment to be the key.
+   */
+  boolean isKeyAsSegmentAllowed();
 }

lib/commons-api/src/main/java/org/apache/olingo/commons/api/edm/EdmNavigationProperty.java

@@ -60,4 +60,9 @@ public interface EdmNavigationProperty extends EdmElement, EdmAnnotatable {
 
   EdmOnDelete getOnDelete();
 
+  /**
+   * @return true if the entity set allows for the next segment to be the key.
+   */
+  boolean isKeyAsSegmentAllowed();
+
 }

lib/commons-api/src/main/java/org/apache/olingo/commons/api/edm/provider/CsdlEntitySet.java

@@ -30,6 +30,9 @@ public class CsdlEntitySet extends CsdlBindingTarget {
   // Default for EntitySets is true
   private boolean includeInServiceDocument = true;
 
+  // Default for EntitySets is false
+  private boolean keyAsSegmentAllowed = false;
+
   @Override
   public CsdlEntitySet setName(final String name) {
     this.name = name;
@@ -81,7 +84,27 @@ public CsdlEntitySet setIncludeInServiceDocument(final boolean includeInServiceD
     this.includeInServiceDocument = includeInServiceDocument;
     return this;
   }
-  
+
+  /**
+   * Is this entity set allowed to be followed by a path variable.
+   *
+   * @return the boolean
+   */
+  public boolean isKeyAsSegmentAllowed() {
+    return keyAsSegmentAllowed;
+  }
+
+  /**
+   * Sets the path variable allowed parameter.
+   *
+   * @param keyAsSegmentAllowed whether path variables are allowed
+   * @return EntitySet with path variable boolean set.
+   */
+  public CsdlEntitySet setKeyAsSegmentAllowed(boolean keyAsSegmentAllowed) {
+    this.keyAsSegmentAllowed = keyAsSegmentAllowed;
+    return this;
+  }
+
   @Override
   public CsdlEntitySet setTitle(String title) {
     super.setTitle(title);

lib/commons-api/src/main/java/org/apache/olingo/commons/api/edm/provider/CsdlNavigationProperty.java

@@ -47,6 +47,9 @@ public class CsdlNavigationProperty extends CsdlAbstractEdmItem implements CsdlN
 
   private List<CsdlAnnotation> annotations = new ArrayList<CsdlAnnotation>();
 
+  // Default for EntitySets is false
+  private boolean keyAsSegmentAllowed = false;
+
   @Override
   public String getName() {
     return name;
@@ -241,4 +244,24 @@ public CsdlNavigationProperty setAnnotations(final List<CsdlAnnotation> annotati
     this.annotations = annotations;
     return this;
   }
+
+  /**
+   * Is this entity set allowed to be followed by a path variable.
+   *
+   * @return the boolean
+   */
+  public boolean isKeyAsSegmentAllowed() {
+    return keyAsSegmentAllowed;
+  }
+
+  /**
+   * Sets the path variable allowed parameter.
+   *
+   * @param keyAsSegmentAllowed whether path variables are allowed
+   * @return EntitySet with path variable boolean set.
+   */
+  public CsdlNavigationProperty setKeyAsSegmentAllowed(boolean keyAsSegmentAllowed) {
+    this.keyAsSegmentAllowed = keyAsSegmentAllowed;
+    return this;
+  }
 }

lib/commons-core/src/main/java/org/apache/olingo/commons/core/edm/EdmEntitySetImpl.java

@@ -37,4 +37,8 @@ public boolean isIncludeInServiceDocument() {
     return entitySet.isIncludeInServiceDocument();
   }
 
+  @Override
+  public boolean isKeyAsSegmentAllowed() {
+    return entitySet.isKeyAsSegmentAllowed();
+  }
 }

lib/commons-core/src/main/java/org/apache/olingo/commons/core/edm/EdmNavigationPropertyImpl.java

@@ -127,4 +127,9 @@ public EdmOnDelete getOnDelete() {
     CsdlOnDelete csdlOnDelete = navigationProperty.getOnDelete();
     return csdlOnDelete != null ? new EdmOnDeleteImpl(edm, csdlOnDelete) : null;
   }
+
+  @Override
+  public boolean isKeyAsSegmentAllowed() {
+    return navigationProperty.isKeyAsSegmentAllowed();
+  }
 }

lib/server-core/src/main/java/org/apache/olingo/server/core/uri/parser/ResourcePathParser.java

@@ -36,7 +36,9 @@
 import org.apache.olingo.commons.api.edm.EdmStructuredType;
 import org.apache.olingo.commons.api.edm.EdmType;
 import org.apache.olingo.commons.api.edm.FullQualifiedName;
+import org.apache.olingo.commons.api.edm.EdmKeyPropertyRef;
 import org.apache.olingo.commons.api.edm.constants.EdmTypeKind;
+import org.apache.olingo.commons.core.edm.primitivetype.EdmString;
 import org.apache.olingo.server.api.uri.UriParameter;
 import org.apache.olingo.server.api.uri.UriResource;
 import org.apache.olingo.server.api.uri.UriResourceEntitySet;
@@ -56,6 +58,7 @@
 import org.apache.olingo.server.core.uri.UriResourceTypedImpl;
 import org.apache.olingo.server.core.uri.UriResourceValueImpl;
 import org.apache.olingo.server.core.uri.UriResourceWithKeysImpl;
+import org.apache.olingo.server.core.uri.UriParameterImpl;
 import org.apache.olingo.server.core.uri.parser.UriTokenizer.TokenKind;
 import org.apache.olingo.server.core.uri.validator.UriValidationException;
 
@@ -89,16 +92,35 @@ public UriResource parsePathSegment(final String pathSegment, UriResource previo
       }
 
     } else {
-      if (tokenizer.next(TokenKind.REF)) {
-        return ref(previous);
-      } else if (tokenizer.next(TokenKind.VALUE)) {
-        return value(previous);
-      } else if (tokenizer.next(TokenKind.COUNT)) {
-        return count(previous);
-      } else if (tokenizer.next(TokenKind.QualifiedName)) {
-        return boundOperationOrTypeCast(previous);
-      } else if (tokenizer.next(TokenKind.ODataIdentifier)) {
-        return navigationOrProperty(previous);
+      try {
+        if (tokenizer.next(TokenKind.REF)) {
+          return ref(previous);
+        } else if (tokenizer.next(TokenKind.VALUE)) {
+          return value(previous);
+        } else if (tokenizer.next(TokenKind.COUNT)) {
+          return count(previous);
+        } else if (tokenizer.next(TokenKind.QualifiedName)) {
+          return boundOperationOrTypeCast(previous);
+        } else if (tokenizer.next(TokenKind.ODataIdentifier)) {
+          return navigationOrProperty(previous);
+        } else if (canParseKeyFromSegment(pathSegment, previous)) {
+          /*
+           * This should only be reached if the path segment is an integer. If it can be parsed as a key segment,
+           * null is returned so that this portion of the path is skipped.
+           */
+          return null;
+        }
+      } catch (UriParserException e) {
+        /*
+         * This exception will be caught if the path segment is a string. It will first try to be parsed as a navigation
+         * or property. That will fail if the path segment is not part of the schema. If it can be parsed as a key
+         * segment, null is returned so that this portion of the path is skipped. If it can not be parsed as a key
+         * segment, then the original exception is re-thrown.
+         */
+        if (canParseKeyFromSegment(pathSegment,previous)) {
+          return null;
+        }
+        throw e;
       }
     }
 
@@ -141,6 +163,30 @@ public List<String> parseCrossjoinSegment(final String pathSegment) throws UriPa
     return entitySetNames;
   }
 
+  /*
+   * This logic is to handle our use case of supporting keys as segments.
+   * If all the existing parsing fails, then we check if the previous segment is an entity set, or navigation.
+   * If it is, and it has the flag set allow keys as segments, then we check if the entity set already has
+   * the key parameter set. If it does, then we return the original parse exception (ie /entitySet('key')/un-parseable).
+   * If there is no key set, then we pass the current segment back to the previous segment as the key.
+   * With this logic, /entitySet('key') and /entitySet/key should be equivalent.
+   */
+  private boolean canParseKeyFromSegment(final String pathSegment, UriResource previous) {
+    if (previous instanceof UriResourceEntitySetImpl) {
+      UriResourceEntitySetImpl entitySet = (UriResourceEntitySetImpl) previous;
+      if (entitySet.getEntitySet().isKeyAsSegmentAllowed()) {
+        return didSetKeySegmentAsKey(pathSegment, entitySet, entitySet.getEntitySet().getEntityType());
+      }
+    } else if (previous instanceof UriResourceNavigationPropertyImpl) {
+      UriResourceNavigationPropertyImpl navProp = (UriResourceNavigationPropertyImpl) previous;
+      EdmNavigationProperty edmNavProperty = navProp.getProperty();
+      if (edmNavProperty.isKeyAsSegmentAllowed()) {
+        return didSetKeySegmentAsKey(pathSegment, navProp, edmNavProperty.getType());
+      }
+    }
+    return false;
+  }
+
   private UriResource ref(final UriResource previous) throws UriParserException {
     ParserHelper.requireTokenEnd(tokenizer);
     requireTyped(previous, "$ref");
@@ -423,4 +469,28 @@ private UriResource functionCall(final EdmFunctionImport edmFunctionImport,
     ParserHelper.requireTokenEnd(tokenizer);
     return resource;
   }
+
+  private boolean didSetKeySegmentAsKey(
+    final String pathSegment,
+    UriResourceWithKeysImpl resourceWithKeys,
+    EdmEntityType entityType) {
+    List<EdmKeyPropertyRef> keys = entityType.getKeyPropertyRefs();
+    if (keys != null && keys.size() == 1) {
+      // Currently only supports types with a single key.
+      EdmKeyPropertyRef propertyRef = keys.get(0);
+      String keyName = propertyRef.getName();
+      List<UriParameter> parameterList = new ArrayList<>(resourceWithKeys.getKeyPredicates());
+      if (parameterList.stream().noneMatch(u -> keyName.equals(u.getName()))) {
+        String value = pathSegment;
+        if (propertyRef.getProperty().getType() instanceof EdmString) {
+          value = "'" + value + "'";
+        }
+        parameterList.add(new UriParameterImpl().setName(keyName).setText(value));
+        resourceWithKeys.setKeyPredicates(parameterList);
+        return true;
+      }
+    }
+
+    return false;
+  }
 }

lib/server-tecsvc/src/main/java/org/apache/olingo/server/tecsvc/provider/ContainerProvider.java

@@ -730,7 +730,31 @@ public CsdlEntitySet getEntitySet(final FullQualifiedName entityContainer, final
       return new CsdlEntitySet()
           .setName("ESStreamOnComplexProp")
           .setType(EntityTypeProvider.nameETStreamOnComplexProp);
-      } 
+    } else if (name.equals("ESKeyAsSegmentString")) {
+      return new CsdlEntitySet()
+          .setName("ESKeyAsSegmentString")
+          .setType(EntityTypeProvider.nameETKeyAsSegmentString)
+          .setKeyAsSegmentAllowed(true);
+    } else if (name.equals("ESKeyAsSegmentInt")) {
+      return new CsdlEntitySet()
+          .setName("ESKeyAsSegmentInt")
+          .setType(EntityTypeProvider.nameETKeyAsSegmentInt)
+          .setKeyAsSegmentAllowed(true);
+    } else if (name.equals("ESComplexKeyAsSegment")) {
+      return new CsdlEntitySet()
+          .setName("ESComplexKeyAsSegment")
+          .setType(EntityTypeProvider.nameETComplexKeyAsSegment)
+          .setKeyAsSegmentAllowed(true);
+      } else if (name.equals("ESKeyAsSegmentStringNavKeyAsSegment")) {
+      return new CsdlEntitySet()
+          .setName("ESKeyAsSegmentStringNavKeyAsSegment")
+          .setType(EntityTypeProvider.nameETKeyAsSegmentStringNavKeyAsSegment)
+          .setKeyAsSegmentAllowed(true)
+          .setNavigationPropertyBindings(Arrays.asList(new CsdlNavigationPropertyBinding()
+            .setPath(PropertyProvider.navPropertyKeyAsSegment.getName())
+            .setTarget("ESKeyAsSegmentString")
+          ));
+      }
     }
     return null;
   }

lib/server-tecsvc/src/main/java/org/apache/olingo/server/tecsvc/provider/EntityTypeProvider.java

@@ -100,6 +100,18 @@ public class EntityTypeProvider {
 
   public static final FullQualifiedName nameETStreamOnComplexProp = 
       new FullQualifiedName(SchemaProvider.NAMESPACE, "ETStreamOnComplexProp");
+
+  public static final FullQualifiedName nameETKeyAsSegmentString =
+          new FullQualifiedName(SchemaProvider.NAMESPACE, "ETKeyAsSegmentString");
+
+  public static final FullQualifiedName nameETKeyAsSegmentInt =
+          new FullQualifiedName(SchemaProvider.NAMESPACE, "ETKeyAsSegmentInt");
+
+  public static final FullQualifiedName nameETComplexKeyAsSegment =
+          new FullQualifiedName(SchemaProvider.NAMESPACE, "ETComplexKeyAsSegment");
+
+  public static final FullQualifiedName nameETKeyAsSegmentStringNavKeyAsSegment =
+          new FullQualifiedName(SchemaProvider.NAMESPACE, "ETKeyAsSegmentStringNavKeyAsSegment");
 
   public CsdlEntityType getEntityType(final FullQualifiedName entityTypeName) throws ODataException {
     if(entityTypeName.equals(nameETAllPrimDefaultValues)){        
@@ -574,6 +586,37 @@ public CsdlEntityType getEntityType(final FullQualifiedName entityTypeName) thro
               PropertyProvider.propertyInt32, PropertyProvider.propertyEntityStream,
               PropertyProvider.propertyCompWithStream_CTWithStreamProp
               ));
+    } else if (entityTypeName.equals(nameETKeyAsSegmentString)) {
+      return new CsdlEntityType()
+              .setName("ETKeyAsSegmentString")
+              .setKey(Arrays.asList(
+                      new CsdlPropertyRef().setName("PropertyString")))
+              .setProperties(Arrays.asList(
+                      PropertyProvider.propertyString_NotNullable));
+    } else if (entityTypeName.equals(nameETKeyAsSegmentInt)) {
+      return new CsdlEntityType()
+              .setName("ETKeyAsSegmentInt")
+              .setKey(Arrays.asList(
+                      new CsdlPropertyRef().setName("PropertyInt16")))
+              .setProperties(Arrays.asList(
+                      PropertyProvider.propertyInt16_NotNullable));
+    } else if (entityTypeName.equals(nameETComplexKeyAsSegment)) {
+      return new CsdlEntityType()
+              .setName("ETComplexKeyAsSegment")
+              .setKey(Arrays.asList(
+                      new CsdlPropertyRef().setName("PropertyString"),
+                      new CsdlPropertyRef().setName("PropertyInt16")))
+              .setProperties(Arrays.asList(
+                      PropertyProvider.propertyString_NotNullable,
+                      PropertyProvider.propertyInt16_NotNullable));
+    } else if(entityTypeName.equals(nameETKeyAsSegmentStringNavKeyAsSegment)) {
+      return new CsdlEntityType()
+              .setName(nameETKeyAsSegmentStringNavKeyAsSegment.getName())
+              .setKey(Arrays.asList(
+                      new CsdlPropertyRef().setName("PropertyString")))
+              .setProperties(Arrays.asList(
+                      PropertyProvider.propertyString_NotNullable))
+              .setNavigationProperties(Arrays.asList(PropertyProvider.navPropertyKeyAsSegment));
     }
     return null;
   }

lib/server-tecsvc/src/main/java/org/apache/olingo/server/tecsvc/provider/PropertyProvider.java

@@ -1051,4 +1051,9 @@ public class PropertyProvider {
       .setName("NavPropertyETStreamOnComplexPropMany")
       .setType(EntityTypeProvider.nameETStream)
       .setCollection(true);
-}
+
+  public static final CsdlNavigationProperty navPropertyKeyAsSegment = new CsdlNavigationProperty()
+      .setName("NavPropertyKeyAsSegment")
+      .setType(EntityTypeProvider.nameETKeyAsSegmentStringNavKeyAsSegment)
+      .setKeyAsSegmentAllowed(true);
+  }