Return appropriate HTTP status code

Return 404 instead of 500 when items are not found.  Bubble up other
HTTP error codes instead of changing them all to 500.

Change-Id: Ib614bb83f28cfb1ce2384679398f0a45058fc455
Issue-ID: POLICY-1686
Signed-off-by: Jim Hahn <jrh3@att.com>

7 files changed, 208 insertions, 192 deletions

diff --git a/main/src/main/java/org/onap/policy/pap/main/comm/PdpModifyRequestMap.java b/main/src/main/java/org/onap/policy/pap/main/comm/PdpModifyRequestMap.java
index 04bab743..3f0b5c11 100644
--- a/main/src/main/java/org/onap/policy/pap/main/comm/PdpModifyRequestMap.java
+++ b/main/src/main/java/org/onap/policy/pap/main/comm/PdpModifyRequestMap.java
@@ -221,7 +221,7 @@ public class PdpModifyRequestMap {
      * @param pdpName name of the PDP to be removed
      * @return {@code true} if the PDP was removed from a group, {@code false} if it was
      *         not assigned to a group
-     * @throws PfModelException if an error occurs
+     * @throws PfModelException if an error occurred
      */
     public boolean removeFromGroups(String pdpName) throws PfModelException {
 
diff --git a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeleteControllerV1.java b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeleteControllerV1.java
index 08781857..ad8b5081 100644
--- a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeleteControllerV1.java
+++ b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeleteControllerV1.java
@@ -35,15 +35,19 @@ import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.Status;
-import org.apache.commons.lang3.tuple.Pair;
+import org.onap.policy.models.base.PfModelException;
+import org.onap.policy.models.base.PfModelRuntimeException;
 import org.onap.policy.models.pap.concepts.PdpGroupDeleteResponse;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyIdentifierOptVersion;
 import org.onap.policy.pap.main.rest.PapRestControllerV1;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Class to provide REST end points for PAP component to delete a PDP group.
  */
 public class PdpGroupDeleteControllerV1 extends PapRestControllerV1 {
+    private static final Logger logger = LoggerFactory.getLogger(PdpGroupDeleteControllerV1.class);
 
     private final PdpGroupDeleteProvider provider = new PdpGroupDeleteProvider();
 
@@ -82,10 +86,18 @@ public class PdpGroupDeleteControllerV1 extends PapRestControllerV1 {
     public Response deleteGroup(@HeaderParam(REQUEST_ID_NAME) @ApiParam(REQUEST_ID_PARAM_DESCRIPTION) UUID requestId,
                     @ApiParam(value = "PDP Group Name", required = true) @PathParam("name") String groupName) {
 
-        Pair<Status, PdpGroupDeleteResponse> pair = provider.deleteGroup(groupName);
-
-        return addLoggingHeaders(addVersionControlHeaders(Response.status(pair.getLeft())), requestId)
-                        .entity(pair.getRight()).build();
+        try {
+            provider.deleteGroup(groupName);
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(Status.OK)), requestId)
+                            .entity(new PdpGroupDeleteResponse()).build();
+
+        } catch (PfModelException | PfModelRuntimeException e) {
+            logger.warn("delete group failed", e);
+            PdpGroupDeleteResponse resp = new PdpGroupDeleteResponse();
+            resp.setErrorDetails(e.getErrorResponse().getErrorMessage());
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(e.getErrorResponse().getResponseCode())),
+                            requestId).entity(resp).build();
+        }
     }
 
     /**
@@ -123,11 +135,18 @@ public class PdpGroupDeleteControllerV1 extends PapRestControllerV1 {
     public Response deletePolicy(@HeaderParam(REQUEST_ID_NAME) @ApiParam(REQUEST_ID_PARAM_DESCRIPTION) UUID requestId,
                     @ApiParam(value = "PDP Policy Name", required = true) @PathParam("name") String policyName) {
 
-        Pair<Status, PdpGroupDeleteResponse> pair =
-                        provider.undeploy(new ToscaPolicyIdentifierOptVersion(policyName, null));
-
-        return addLoggingHeaders(addVersionControlHeaders(Response.status(pair.getLeft())), requestId)
-                        .entity(pair.getRight()).build();
+        try {
+            provider.undeploy(new ToscaPolicyIdentifierOptVersion(policyName, null));
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(Status.OK)), requestId)
+                            .entity(new PdpGroupDeleteResponse()).build();
+
+        } catch (PfModelException | PfModelRuntimeException e) {
+            logger.warn("undeploy policy failed", e);
+            PdpGroupDeleteResponse resp = new PdpGroupDeleteResponse();
+            resp.setErrorDetails(e.getErrorResponse().getErrorMessage());
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(e.getErrorResponse().getResponseCode())),
+                            requestId).entity(resp).build();
+        }
     }
 
     /**
@@ -168,10 +187,17 @@ public class PdpGroupDeleteControllerV1 extends PapRestControllerV1 {
                     @ApiParam(value = "PDP Policy Name", required = true) @PathParam("name") String policyName,
                     @ApiParam(value = "PDP Policy Version", required = true) @PathParam("version") String version) {
 
-        Pair<Status, PdpGroupDeleteResponse> pair =
-                        provider.undeploy(new ToscaPolicyIdentifierOptVersion(policyName, version));
-
-        return addLoggingHeaders(addVersionControlHeaders(Response.status(pair.getLeft())), requestId)
-                        .entity(pair.getRight()).build();
+        try {
+            provider.undeploy(new ToscaPolicyIdentifierOptVersion(policyName, version));
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(Status.OK)), requestId)
+                            .entity(new PdpGroupDeleteResponse()).build();
+
+        } catch (PfModelException | PfModelRuntimeException e) {
+            logger.warn("undeploy policy failed", e);
+            PdpGroupDeleteResponse resp = new PdpGroupDeleteResponse();
+            resp.setErrorDetails(e.getErrorResponse().getErrorMessage());
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(e.getErrorResponse().getResponseCode())),
+                            requestId).entity(resp).build();
+        }
     }
 }
diff --git a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeleteProvider.java b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeleteProvider.java
index c64a0efe..6df713d3 100644
--- a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeleteProvider.java
+++ b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeleteProvider.java
@@ -21,24 +21,21 @@
 package org.onap.policy.pap.main.rest.depundep;
 
 import java.util.function.BiFunction;
-import javax.ws.rs.core.Response;
-import org.apache.commons.lang3.tuple.Pair;
+import javax.ws.rs.core.Response.Status;
 import org.onap.policy.models.base.PfModelException;
-import org.onap.policy.models.pap.concepts.PdpGroupDeleteResponse;
 import org.onap.policy.models.pdp.concepts.PdpGroup;
 import org.onap.policy.models.pdp.concepts.PdpSubGroup;
 import org.onap.policy.models.pdp.enums.PdpState;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicy;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyIdentifier;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyIdentifierOptVersion;
-import org.onap.policy.pap.main.PolicyPapRuntimeException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
  * Provider for PAP component to delete PDP groups.
  */
-public class PdpGroupDeleteProvider extends ProviderBase<PdpGroupDeleteResponse> {
+public class PdpGroupDeleteProvider extends ProviderBase {
     private static final Logger logger = LoggerFactory.getLogger(PdpGroupDeleteProvider.class);
 
 
@@ -53,11 +50,10 @@ public class PdpGroupDeleteProvider extends ProviderBase<PdpGroupDeleteResponse>
      * Deletes a PDP group.
      *
      * @param groupName name of the PDP group to be deleted
-     * @return a pair containing the status and the response
+     * @throws PfModelException if an error occurred
      */
-    public Pair<Response.Status, PdpGroupDeleteResponse> deleteGroup(String groupName) {
-
-        return process(groupName, this::deleteGroup);
+    public void deleteGroup(String groupName) throws PfModelException {
+        process(groupName, this::deleteGroup);
     }
 
     /**
@@ -65,27 +61,23 @@ public class PdpGroupDeleteProvider extends ProviderBase<PdpGroupDeleteResponse>
      *
      * @param data session data
      * @param groupName name of the PDP group to be deleted
+     * @throws PfModelException if an error occurred
      */
-    private void deleteGroup(SessionData data, String groupName) {
+    private void deleteGroup(SessionData data, String groupName) throws PfModelException {
         try {
             PdpGroup group = data.getGroup(groupName);
             if (group == null) {
-                throw new PolicyPapRuntimeException("group not found");
+                throw new PfModelException(Status.NOT_FOUND, "group not found");
             }
 
             if (group.getPdpGroupState() == PdpState.ACTIVE) {
-                throw new PolicyPapRuntimeException("group is still " + PdpState.ACTIVE);
+                throw new PfModelException(Status.BAD_REQUEST, "group is still " + PdpState.ACTIVE);
             }
 
             data.deleteGroupFromDb(group);
 
-        } catch (PfModelException e) {
-            // no need to log the error here, as it will be logged by the invoker
-            logger.warn("failed to delete group: {}", groupName);
-            throw new PolicyPapRuntimeException(DB_ERROR_MSG, e);
-
-        } catch (RuntimeException e) {
-            // no need to log the error here, as it will be logged by the invoker
+        } catch (PfModelException | RuntimeException e) {
+            // no need to log the error object here, as it will be logged by the invoker
             logger.warn("failed to delete group: {}", groupName);
             throw e;
         }
@@ -95,11 +87,10 @@ public class PdpGroupDeleteProvider extends ProviderBase<PdpGroupDeleteResponse>
      * Undeploys a policy.
      *
      * @param policyIdent identifier of the policy to be undeployed
-     * @return a pair containing the status and the response
+     * @throws PfModelException if an error occurred
      */
-    public Pair<Response.Status, PdpGroupDeleteResponse> undeploy(ToscaPolicyIdentifierOptVersion policyIdent) {
-
-        return process(policyIdent, this::undeployPolicy);
+    public void undeploy(ToscaPolicyIdentifierOptVersion policyIdent) throws PfModelException {
+        process(policyIdent, this::undeployPolicy);
     }
 
     /**
@@ -107,30 +98,19 @@ public class PdpGroupDeleteProvider extends ProviderBase<PdpGroupDeleteResponse>
      *
      * @param data session data
      * @param ident identifier of the policy to be deleted
+     * @throws PfModelException if an error occurred
      */
-    private void undeployPolicy(SessionData data, ToscaPolicyIdentifierOptVersion ident) {
+    private void undeployPolicy(SessionData data, ToscaPolicyIdentifierOptVersion ident) throws PfModelException {
         try {
             processPolicy(data, ident);
 
-        } catch (PfModelException e) {
-            // no need to log the error here, as it will be logged by the invoker
-            logger.warn("failed to undeploy policy: {}", ident);
-            throw new PolicyPapRuntimeException(DB_ERROR_MSG, e);
-
-        } catch (RuntimeException e) {
-            // no need to log the error here, as it will be logged by the invoker
+        } catch (PfModelException | RuntimeException e) {
+            // no need to log the error object here, as it will be logged by the invoker
             logger.warn("failed to undeploy policy: {}", ident);
             throw e;
         }
     }
 
-    @Override
-    public PdpGroupDeleteResponse makeResponse(String errorMsg) {
-        PdpGroupDeleteResponse resp = new PdpGroupDeleteResponse();
-        resp.setErrorDetails(errorMsg);
-        return resp;
-    }
-
     /**
      * Returns a function that will remove the specified policy from a subgroup.
      */
diff --git a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeployControllerV1.java b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeployControllerV1.java
index bdec3562..d3e6c006 100644
--- a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeployControllerV1.java
+++ b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeployControllerV1.java
@@ -34,16 +34,20 @@ import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.Status;
-import org.apache.commons.lang3.tuple.Pair;
+import org.onap.policy.models.base.PfModelException;
+import org.onap.policy.models.base.PfModelRuntimeException;
 import org.onap.policy.models.pap.concepts.PdpDeployPolicies;
 import org.onap.policy.models.pap.concepts.PdpGroupDeployResponse;
 import org.onap.policy.models.pdp.concepts.PdpGroups;
 import org.onap.policy.pap.main.rest.PapRestControllerV1;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Class to provide REST end points for PAP component to deploy a PDP group.
  */
 public class PdpGroupDeployControllerV1 extends PapRestControllerV1 {
+    private static final Logger logger = LoggerFactory.getLogger(PdpGroupDeployControllerV1.class);
 
     private final PdpGroupDeployProvider provider = new PdpGroupDeployProvider();
 
@@ -82,10 +86,18 @@ public class PdpGroupDeployControllerV1 extends PapRestControllerV1 {
     public Response deployGroup(@HeaderParam(REQUEST_ID_NAME) @ApiParam(REQUEST_ID_PARAM_DESCRIPTION) UUID requestId,
                     @ApiParam(value = "List of PDP Group Configuration", required = true) PdpGroups groups) {
 
-        Pair<Status, PdpGroupDeployResponse> pair = provider.createOrUpdateGroups(groups);
+        try {
+            provider.createOrUpdateGroups(groups);
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(Status.OK)), requestId)
+                            .entity(new PdpGroupDeployResponse()).build();
 
-        return addLoggingHeaders(addVersionControlHeaders(Response.status(pair.getLeft())), requestId)
-                        .entity(pair.getRight()).build();
+        } catch (PfModelException | PfModelRuntimeException e) {
+            logger.warn("create groups failed", e);
+            PdpGroupDeployResponse resp = new PdpGroupDeployResponse();
+            resp.setErrorDetails(e.getErrorResponse().getErrorMessage());
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(e.getErrorResponse().getResponseCode())),
+                            requestId).entity(resp).build();
+        }
     }
 
     /**
@@ -124,9 +136,17 @@ public class PdpGroupDeployControllerV1 extends PapRestControllerV1 {
                     @ApiParam(value = "PDP Policies; only the name is required",
                                     required = true) PdpDeployPolicies policies) {
 
-        Pair<Status, PdpGroupDeployResponse> pair = provider.deployPolicies(policies);
+        try {
+            provider.deployPolicies(policies);
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(Status.OK)), requestId)
+                            .entity(new PdpGroupDeployResponse()).build();
 
-        return addLoggingHeaders(addVersionControlHeaders(Response.status(pair.getLeft())), requestId)
-                        .entity(pair.getRight()).build();
+        } catch (PfModelException | PfModelRuntimeException e) {
+            logger.warn("deploy policies failed", e);
+            PdpGroupDeployResponse resp = new PdpGroupDeployResponse();
+            resp.setErrorDetails(e.getErrorResponse().getErrorMessage());
+            return addLoggingHeaders(addVersionControlHeaders(Response.status(e.getErrorResponse().getResponseCode())),
+                            requestId).entity(resp).build();
+        }
     }
 }
diff --git a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeployProvider.java b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeployProvider.java
index 5fd1213c..ee66b35c 100644
--- a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeployProvider.java
+++ b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/PdpGroupDeployProvider.java
@@ -30,16 +30,15 @@ import java.util.Map;
 import java.util.Set;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
-import javax.ws.rs.core.Response;
-import org.apache.commons.lang3.tuple.Pair;
+import javax.ws.rs.core.Response.Status;
 import org.onap.policy.common.parameters.BeanValidationResult;
 import org.onap.policy.common.parameters.ObjectValidationResult;
 import org.onap.policy.common.parameters.ValidationResult;
 import org.onap.policy.common.parameters.ValidationStatus;
 import org.onap.policy.common.utils.services.Registry;
 import org.onap.policy.models.base.PfModelException;
+import org.onap.policy.models.base.PfModelRuntimeException;
 import org.onap.policy.models.pap.concepts.PdpDeployPolicies;
-import org.onap.policy.models.pap.concepts.PdpGroupDeployResponse;
 import org.onap.policy.models.pdp.concepts.PdpGroup;
 import org.onap.policy.models.pdp.concepts.PdpGroups;
 import org.onap.policy.models.pdp.concepts.PdpSubGroup;
@@ -48,7 +47,6 @@ import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicy;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyIdentifier;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyIdentifierOptVersion;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyTypeIdentifier;
-import org.onap.policy.pap.main.PolicyPapRuntimeException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -61,7 +59,7 @@ import org.slf4j.LoggerFactory;
  * <li>PAP DAO Factory</li>
  * </ul>
  */
-public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse> {
+public class PdpGroupDeployProvider extends ProviderBase {
     private static final Logger logger = LoggerFactory.getLogger(PdpGroupDeployProvider.class);
 
 
@@ -76,18 +74,18 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * Creates or updates PDP groups.
      *
      * @param groups PDP group configurations to be created or updated
-     * @return a pair containing the status and the response
+     * @throws PfModelException if an error occurred
      */
-    public Pair<Response.Status, PdpGroupDeployResponse> createOrUpdateGroups(PdpGroups groups) {
+    public void createOrUpdateGroups(PdpGroups groups) throws PfModelException {
         ValidationResult result = groups.validatePapRest();
 
         if (!result.isValid()) {
             String msg = result.getResult().trim();
             logger.warn(msg);
-            return Pair.of(Response.Status.INTERNAL_SERVER_ERROR, makeResponse(msg));
+            throw new PfModelException(Status.BAD_REQUEST, msg);
         }
 
-        return process(groups, this::createOrUpdate);
+        process(groups, this::createOrUpdate);
     }
 
     /**
@@ -95,8 +93,9 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      *
      * @param data session data
      * @param groups PDP group configurations
+     * @throws PfModelException if an error occurred
      */
-    private void createOrUpdate(SessionData data, PdpGroups groups) {
+    private void createOrUpdate(SessionData data, PdpGroups groups) throws PfModelException {
         BeanValidationResult result = new BeanValidationResult("groups", groups);
 
         for (PdpGroup group : groups.getGroups()) {
@@ -111,7 +110,7 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
         }
 
         if (!result.isValid()) {
-            throw new PolicyPapRuntimeException(result.getResult().trim());
+            throw new PfModelException(Status.BAD_REQUEST, result.getResult().trim());
         }
     }
 
@@ -121,8 +120,9 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * @param data session data
      * @param group the group to be added
      * @return the validation result
+     * @throws PfModelException if an error occurred
      */
-    private ValidationResult addGroup(SessionData data, PdpGroup group) {
+    private ValidationResult addGroup(SessionData data, PdpGroup group) throws PfModelException {
         BeanValidationResult result = new BeanValidationResult(group.getName(), group);
 
         validateGroupOnly(group, result);
@@ -176,8 +176,9 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * @param dbgroup the group, as it appears within the DB
      * @param group the group to be added
      * @return the validation result
+     * @throws PfModelException if an error occurred
      */
-    private ValidationResult updateGroup(SessionData data, PdpGroup dbgroup, PdpGroup group) {
+    private ValidationResult updateGroup(SessionData data, PdpGroup dbgroup, PdpGroup group) throws PfModelException {
         BeanValidationResult result = new BeanValidationResult(group.getName(), group);
 
         if (!ObjectUtils.equals(dbgroup.getProperties(), group.getProperties())) {
@@ -242,8 +243,9 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * @param data session data
      * @param subgrp the subgroup to be added
      * @return the validation result
+     * @throws PfModelException if an error occurred
      */
-    private ValidationResult addSubGroup(SessionData data, PdpSubGroup subgrp) {
+    private ValidationResult addSubGroup(SessionData data, PdpSubGroup subgrp) throws PfModelException {
         subgrp.setCurrentInstanceCount(0);
         subgrp.setPdpInstances(Collections.emptyList());
 
@@ -264,9 +266,10 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * @param container container for additional validation results
      * @return {@code true} if the subgroup content was changed, {@code false} if there
      *         were no changes
+     * @throws PfModelException if an error occurred
      */
     private boolean updateSubGroup(SessionData data, PdpGroup dbgroup, PdpSubGroup dbsub, PdpSubGroup subgrp,
-                    BeanValidationResult container) {
+                    BeanValidationResult container) throws PfModelException {
 
         // perform additional validations first
         if (!validateSubGroup(data, dbsub, subgrp, container)) {
@@ -301,9 +304,10 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * @param subgrp the subgroup to be validated
      * @param container container for additional validation results
      * @return {@code true} if the subgroup is valid, {@code false} otherwise
+     * @throws PfModelException if an error occurred
      */
     private boolean validateSubGroup(SessionData data, PdpSubGroup dbsub, PdpSubGroup subgrp,
-                    BeanValidationResult container) {
+                    BeanValidationResult container) throws PfModelException {
 
         BeanValidationResult result = new BeanValidationResult(subgrp.getPdpType(), subgrp);
 
@@ -346,16 +350,27 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * @param data session data
      * @param subgrp the subgroup to be validated
      * @param result the validation result
+     * @throws PfModelException if an error occurred
      */
-    private ValidationResult validatePolicies(SessionData data, PdpSubGroup subgrp) {
+    private ValidationResult validatePolicies(SessionData data, PdpSubGroup subgrp) throws PfModelException {
         BeanValidationResult result = new BeanValidationResult(subgrp.getPdpType(), subgrp);
 
         for (ToscaPolicyIdentifier ident : subgrp.getPolicies()) {
-            ToscaPolicy policy = data.getPolicy(new ToscaPolicyIdentifierOptVersion(ident));
+            try {
+                ToscaPolicy policy = data.getPolicy(new ToscaPolicyIdentifierOptVersion(ident));
+
+                if (!subgrp.getSupportedPolicyTypes().contains(policy.getTypeIdentifier())) {
+                    result.addResult(new ObjectValidationResult("policy", ident, ValidationStatus.INVALID,
+                                    "not a supported policy for the subgroup"));
+                }
+
+            } catch (PfModelException e) {
+                if (e.getErrorResponse().getResponseCode() != Status.NOT_FOUND) {
+                    throw e;
+                }
 
-            if (!subgrp.getSupportedPolicyTypes().contains(policy.getTypeIdentifier())) {
                 result.addResult(new ObjectValidationResult("policy", ident, ValidationStatus.INVALID,
-                                "not a supported policy for the subgroup"));
+                                "unknown policy"));
             }
         }
 
@@ -366,10 +381,10 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * Deploys or updates PDP policies using the simple API.
      *
      * @param policies PDP policies
-     * @return a pair containing the status and the response
+     * @throws PfModelException if an error occurred
      */
-    public Pair<Response.Status, PdpGroupDeployResponse> deployPolicies(PdpDeployPolicies policies) {
-        return process(policies, this::deploySimplePolicies);
+    public void deployPolicies(PdpDeployPolicies policies) throws PfModelException {
+        process(policies, this::deploySimplePolicies);
     }
 
     /**
@@ -379,20 +394,16 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
      * @param data session data
      * @param extPolicies external PDP policies
      * @return a list of requests that should be sent to configure the PDPs
+     * @throws PfModelException if an error occurred
      */
-    private void deploySimplePolicies(SessionData data, PdpDeployPolicies policies) {
+    private void deploySimplePolicies(SessionData data, PdpDeployPolicies policies) throws PfModelException {
 
         for (ToscaPolicyIdentifierOptVersion desiredPolicy : policies.getPolicies()) {
 
             try {
                 processPolicy(data, desiredPolicy);
 
-            } catch (PfModelException e) {
-                // no need to log the error here, as it will be logged by the invoker
-                logger.warn("failed to deploy policy: {}", desiredPolicy);
-                throw new PolicyPapRuntimeException(DB_ERROR_MSG, e);
-
-            } catch (RuntimeException e) {
+            } catch (PfModelException | RuntimeException e) {
                 // no need to log the error here, as it will be logged by the invoker
                 logger.warn("failed to deploy policy: {}", desiredPolicy);
                 throw e;
@@ -421,8 +432,8 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
             }
 
             if (subgroup.getPdpInstances().isEmpty()) {
-                throw new PolicyPapRuntimeException("group " + group.getName() + " subgroup " + subgroup.getPdpType()
-                                + " has no active PDPs");
+                throw new PfModelRuntimeException(Status.BAD_REQUEST, "group " + group.getName() + " subgroup "
+                                + subgroup.getPdpType() + " has no active PDPs");
             }
 
 
@@ -431,11 +442,4 @@ public class PdpGroupDeployProvider extends ProviderBase<PdpGroupDeployResponse>
             return true;
         };
     }
-
-    @Override
-    public PdpGroupDeployResponse makeResponse(String errorMsg) {
-        PdpGroupDeployResponse resp = new PdpGroupDeployResponse();
-        resp.setErrorDetails(errorMsg);
-        return resp;
-    }
 }
diff --git a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/ProviderBase.java b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/ProviderBase.java
index 07d04c24..a66b03d2 100644
--- a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/ProviderBase.java
+++ b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/ProviderBase.java
@@ -22,14 +22,13 @@ package org.onap.policy.pap.main.rest.depundep;
 
 import java.util.Collection;
 import java.util.Collections;
-import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
 import java.util.stream.Collectors;
-import javax.ws.rs.core.Response;
+import javax.ws.rs.core.Response.Status;
 import org.apache.commons.lang3.tuple.Pair;
 import org.onap.policy.common.utils.services.Registry;
 import org.onap.policy.models.base.PfModelException;
-import org.onap.policy.models.pap.concepts.SimpleResponse;
+import org.onap.policy.models.base.PfModelRuntimeException;
 import org.onap.policy.models.pdp.concepts.Pdp;
 import org.onap.policy.models.pdp.concepts.PdpGroup;
 import org.onap.policy.models.pdp.concepts.PdpStateChange;
@@ -41,7 +40,6 @@ import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyIdentifierOp
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyTypeIdentifier;
 import org.onap.policy.pap.main.PapConstants;
 import org.onap.policy.pap.main.PolicyModelsProviderFactoryWrapper;
-import org.onap.policy.pap.main.PolicyPapRuntimeException;
 import org.onap.policy.pap.main.comm.PdpModifyRequestMap;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -54,10 +52,8 @@ import org.slf4j.LoggerFactory;
  * <li>PDP Modify Request Map</li>
  * <li>PAP DAO Factory</li>
  * </ul>
- *
- * @param <R> the response type
  */
-public abstract class ProviderBase<R extends SimpleResponse> {
+public abstract class ProviderBase {
     private static final String DEPLOY_FAILED = "failed to deploy/undeploy policies";
     public static final String DB_ERROR_MSG = "DB error";
 
@@ -93,9 +89,9 @@ public abstract class ProviderBase<R extends SimpleResponse> {
      *
      * @param request PDP policy request
      * @param processor function that processes the request
-     * @return a pair containing the status and the response
+     * @throws PfModelException if an error occurred
      */
-    protected <T> Pair<Response.Status, R> process(T request, BiConsumer<SessionData, T> processor) {
+    protected <T> void process(T request, BiConsumerWithEx<SessionData, T> processor) throws PfModelException {
 
         synchronized (updateLock) {
             // list of requests to be published to the PDPs
@@ -111,49 +107,19 @@ public abstract class ProviderBase<R extends SimpleResponse> {
 
                 requests = data.getPdpRequests();
 
-            } catch (PfModelException e) {
-                logger.warn(DEPLOY_FAILED, e);
-                return Pair.of(Response.Status.INTERNAL_SERVER_ERROR, makeResponse(DB_ERROR_MSG));
-
-            } catch (PolicyPapRuntimeException e) {
+            } catch (PfModelException | PfModelRuntimeException e) {
                 logger.warn(DEPLOY_FAILED, e);
-                return Pair.of(Response.Status.INTERNAL_SERVER_ERROR, makeResponse(e.getMessage()));
+                throw e;
 
             } catch (RuntimeException e) {
                 logger.warn(DEPLOY_FAILED, e);
-                return Pair.of(Response.Status.INTERNAL_SERVER_ERROR, makeResponse("request failed"));
+                throw new PfModelException(Status.INTERNAL_SERVER_ERROR, "request failed", e);
             }
 
 
             // publish the requests
             requests.forEach(pair -> requestMap.addRequest(pair.getLeft(), pair.getRight()));
         }
-
-        return Pair.of(Response.Status.OK, makeResponse(null));
-    }
-
-    /**
-     * Makes a response.
-     *
-     * @param errorMsg error message, or {@code null} if there was no error
-     * @return a new response
-     */
-    public abstract R makeResponse(String errorMsg);
-
-    /**
-     * Finds a Policy having the given name and version. If the specified version is
-     * {@code null}, then it finds the matching Policy with the latest version.
-     *
-     * @param data session data
-     * @param desiredPolicy the policy desired, with the "name" and optional
-     *        "policyVersion" populated
-     * @return the matching Policy type
-     * @throws PolicyPapRuntimeException if there is no matching policy type or a DAO
-     *         error occurs
-     */
-    private ToscaPolicy getPolicy(SessionData data, ToscaPolicyIdentifierOptVersion desiredPolicy) {
-
-        return data.getPolicy(desiredPolicy);
     }
 
     /**
@@ -161,8 +127,7 @@ public abstract class ProviderBase<R extends SimpleResponse> {
      *
      * @param data session data
      * @param desiredPolicy request policy
-     * @throws PolicyPapRuntimeException if an error occurs
-     * @throws PfModelException if a DAO error occurred
+     * @throws PfModelException if an error occurred
      */
     protected void processPolicy(SessionData data, ToscaPolicyIdentifierOptVersion desiredPolicy)
                     throws PfModelException {
@@ -171,8 +136,8 @@ public abstract class ProviderBase<R extends SimpleResponse> {
 
         Collection<PdpGroup> groups = getGroups(data, policy.getTypeIdentifier());
         if (groups.isEmpty()) {
-            throw new PolicyPapRuntimeException("policy not supported by any PDP group: " + desiredPolicy.getName()
-                            + " " + desiredPolicy.getVersion());
+            throw new PfModelException(Status.BAD_REQUEST, "policy not supported by any PDP group: "
+                            + desiredPolicy.getName() + " " + desiredPolicy.getVersion());
         }
 
         BiFunction<PdpGroup, PdpSubGroup, Boolean> updater = makeUpdater(policy);
@@ -199,7 +164,7 @@ public abstract class ProviderBase<R extends SimpleResponse> {
      * @param policyType the policy type of interest
      * @return the matching PDP group, or {@code null} if no active group supports the
      *         given PDP types
-     * @throws PfModelException if an error occurs
+     * @throws PfModelException if an error occurred
      */
     private Collection<PdpGroup> getGroups(SessionData data, ToscaPolicyTypeIdentifier policyType)
                     throws PfModelException {
@@ -213,9 +178,9 @@ public abstract class ProviderBase<R extends SimpleResponse> {
      * @param data session data
      * @param group the original group, to be updated
      * @param updater function to update a group
+     * @throws PfModelRuntimeException if an error occurred
      */
-    private void upgradeGroup(SessionData data, PdpGroup group,
-                    BiFunction<PdpGroup, PdpSubGroup, Boolean> updater) {
+    private void upgradeGroup(SessionData data, PdpGroup group, BiFunction<PdpGroup, PdpSubGroup, Boolean> updater) {
 
         boolean updated = false;
 
@@ -268,8 +233,38 @@ public abstract class ProviderBase<R extends SimpleResponse> {
         update.setPdpGroup(group.getName());
         update.setPdpSubgroup(subgroup.getPdpType());
         update.setPolicies(subgroup.getPolicies().stream().map(ToscaPolicyIdentifierOptVersion::new)
-                        .map(data::getPolicy).collect(Collectors.toList()));
+                        .map(ident -> getPolicy(data, ident)).collect(Collectors.toList()));
 
         return update;
     }
+
+    /**
+     * Gets the specified policy.
+     *
+     * @param data session data
+     * @param ident policy identifier, with an optional version
+     * @return the policy of interest
+     * @throws PfModelRuntimeException if an error occurred or the policy was not found
+     */
+    private ToscaPolicy getPolicy(SessionData data, ToscaPolicyIdentifierOptVersion ident) {
+        try {
+            return data.getPolicy(ident);
+
+        } catch (PfModelException e) {
+            throw new PfModelRuntimeException(e.getErrorResponse().getResponseCode(),
+                            e.getErrorResponse().getErrorMessage(), e);
+        }
+    }
+
+    @FunctionalInterface
+    public static interface BiConsumerWithEx<F, S> {
+        /**
+         * Performs this operation on the given arguments.
+         *
+         * @param firstArg the first input argument
+         * @param secondArg the second input argument
+         * @throws PfModelException if an error occurred
+         */
+        void accept(F firstArg, S secondArg) throws PfModelException;
+    }
 }
diff --git a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/SessionData.java b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/SessionData.java
index 5cd2f803..98a5e675 100644
--- a/main/src/main/java/org/onap/policy/pap/main/rest/depundep/SessionData.java
+++ b/main/src/main/java/org/onap/policy/pap/main/rest/depundep/SessionData.java
@@ -27,6 +27,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
+import javax.ws.rs.core.Response.Status;
 import org.apache.commons.lang3.tuple.Pair;
 import org.onap.policy.models.base.PfModelException;
 import org.onap.policy.models.pdp.concepts.PdpGroup;
@@ -40,14 +41,14 @@ import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyFilter;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyFilter.ToscaPolicyFilterBuilder;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyIdentifierOptVersion;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyTypeIdentifier;
-import org.onap.policy.pap.main.PolicyPapRuntimeException;
 
 /**
  * Data used during a single REST call when updating PDP policies.
  */
 public class SessionData {
     /**
-     * If a version string matches this, then it is just a prefix (i.e., major or major.minor).
+     * If a version string matches this, then it is just a prefix (i.e., major or
+     * major.minor).
      */
     private static final Pattern VERSION_PREFIX_PAT = Pattern.compile("[^.]+(?:[.][^.]*)?");
 
@@ -94,29 +95,24 @@ public class SessionData {
      *
      * @param desiredPolicy policy identifier
      * @return the specified policy
-     * @throws PolicyPapRuntimeException if an error occurs
+     * @throws PfModelException if an error occurred
      */
-    public ToscaPolicy getPolicy(ToscaPolicyIdentifierOptVersion desiredPolicy) {
+    public ToscaPolicy getPolicy(ToscaPolicyIdentifierOptVersion desiredPolicy) throws PfModelException {
 
-        ToscaPolicy policy = policyCache.computeIfAbsent(desiredPolicy, key -> {
+        ToscaPolicy policy = policyCache.get(desiredPolicy);
+        if (policy == null) {
+            ToscaPolicyFilterBuilder filterBuilder = ToscaPolicyFilter.builder().name(desiredPolicy.getName());
+            setPolicyFilterVersion(filterBuilder, desiredPolicy.getVersion());
 
-            try {
-                ToscaPolicyFilterBuilder filterBuilder = ToscaPolicyFilter.builder().name(desiredPolicy.getName());
-                setPolicyFilterVersion(filterBuilder, desiredPolicy.getVersion());
-
-                List<ToscaPolicy> lst = dao.getFilteredPolicyList(filterBuilder.build());
-                if (lst.isEmpty()) {
-                    throw new PolicyPapRuntimeException("cannot find policy: " + desiredPolicy.getName() + " "
-                                    + desiredPolicy.getVersion());
-                }
-
-                return lst.get(0);
-
-            } catch (PfModelException e) {
-                throw new PolicyPapRuntimeException(
-                                "cannot get policy: " + desiredPolicy.getName() + " " + desiredPolicy.getVersion(), e);
+            List<ToscaPolicy> lst = dao.getFilteredPolicyList(filterBuilder.build());
+            if (lst.isEmpty()) {
+                throw new PfModelException(Status.NOT_FOUND,
+                                "cannot find policy: " + desiredPolicy.getName() + " " + desiredPolicy.getVersion());
             }
-        });
+
+            policy = lst.get(0);
+            policyCache.put(desiredPolicy, policy);
+        }
 
         // desired version may have only been a prefix - cache with full identifier, too
         policyCache.putIfAbsent(new ToscaPolicyIdentifierOptVersion(policy.getIdentifier()), policy);
@@ -172,8 +168,8 @@ public class SessionData {
     }
 
     /**
-     * Adds a state-change to the set of state-change requests, replacing any previous entry for the given
-     * PDP.
+     * Adds a state-change to the set of state-change requests, replacing any previous
+     * entry for the given PDP.
      *
      * @param change the state-change to be added
      */
@@ -243,27 +239,22 @@ public class SessionData {
      *
      * @param name name of the group to get
      * @return the group, or {@code null} if it does not exist
-     * @throws PolicyPapRuntimeException if an error occurs
+     * @throws PfModelException if an error occurred
      */
-    public PdpGroup getGroup(String name) {
+    public PdpGroup getGroup(String name) throws PfModelException {
 
-        GroupData data = groupCache.computeIfAbsent(name, key -> {
-
-            try {
-                List<PdpGroup> lst = dao.getPdpGroups(key);
-                if (lst.isEmpty()) {
-                    return null;
-                }
-
-                return new GroupData(lst.get(0));
-
-            } catch (PfModelException e) {
-                throw new PolicyPapRuntimeException("cannot get group: " + name, e);
+        GroupData data = groupCache.get(name);
+        if (data == null) {
+            List<PdpGroup> lst = dao.getPdpGroups(name);
+            if (lst.isEmpty()) {
+                return null;
             }
 
-        });
+            data = new GroupData(lst.get(0));
+            groupCache.put(name, data);
+        }
 
-        return (data == null ? null : data.getGroup());
+        return data.getGroup();
     }
 
     /**
@@ -271,7 +262,7 @@ public class SessionData {
      *
      * @param type desired policy type
      * @return the active groups supporting the given policy
-     * @throws PfModelException if an error occurs
+     * @throws PfModelException if an error occurred
      */
     public List<PdpGroup> getActivePdpGroupsByPolicyType(ToscaPolicyTypeIdentifier type) throws PfModelException {
         List<GroupData> data = type2groups.get(type);
@@ -311,7 +302,7 @@ public class SessionData {
     /**
      * Update the DB with the changes.
      *
-     * @throws PfModelException if an error occurs
+     * @throws PfModelException if an error occurred
      */
     public void updateDb() throws PfModelException {
         // create new groups
@@ -333,7 +324,7 @@ public class SessionData {
      * executed later).
      *
      * @param group the group to be deleted
-     * @throws PfModelException if an error occurs
+     * @throws PfModelException if an error occurred
      */
     public void deleteGroupFromDb(PdpGroup group) throws PfModelException {
         dao.deletePdpGroup(group.getName());