Add exception handling

.checkstyle

@@ -6,5 +6,6 @@
   </local-check-config>
   <fileset name="all" enabled="true" check-config-name="Shibboleth" local="true">
     <file-match-pattern match-pattern="^src/main/java/" include-pattern="true"/>
+    <file-match-pattern match-pattern="ValidatorsApi.java" include-pattern="false"/>
   </fileset>
 </fileset-config>

.springBeans

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beansProjectDescription>
+	<version>1</version>
+	<pluginVersion><![CDATA[3.9.4.201804120850-RELEASE]]></pluginVersion>
+	<configSuffixes>
+		<configSuffix><![CDATA[xml]]></configSuffix>
+	</configSuffixes>
+	<enableImports><![CDATA[false]]></enableImports>
+	<configs>
+	</configs>
+	<autoconfigs>
+	</autoconfigs>
+	<configSets>
+	</configSets>
+</beansProjectDescription>

src/main/java/uk/org/iay/incommon/validator/api/ApiException.java

@@ -0,0 +1,73 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package uk.org.iay.incommon.validator.api;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.joda.time.DateTime;
+import org.springframework.http.HttpStatus;
+
+/**
+ * Exception class for use within the API.
+ */
+public class ApiException extends Exception {
+
+    /** Serial version UID. */
+    private static final long serialVersionUID = -5046975083822313941L;
+
+    /** HTTP Status to be reported by this exception. */
+    private final HttpStatus status;
+
+    /** When the exception was created. */
+    private final DateTime when;
+
+    /**
+     * Constructor.
+     *
+     * @param stat HTTP status
+     * @param msg message
+     */
+    public ApiException(final HttpStatus stat, final String msg) {
+        super(msg);
+        status = stat;
+        when = DateTime.now();
+    }
+
+    /**
+     * Reuturns the wrapped {@link HttpStatus} value.
+     *
+     * @return an {@link HttpStatus}
+     */
+    public HttpStatus getStatus() {
+        return status;
+    }
+
+    /**
+     * Convert to a {@link Map} so that the data can be turned into
+     * a JSON response.
+     *
+     * @return a new {@link Map} containing the exception information
+     */
+    public Map<String, Object> toMap() {
+        final Map<String, Object> m = new HashMap<>();
+        m.put("status", Integer.valueOf(getStatus().value()));
+        m.put("error", getStatus().getReasonPhrase());
+        m.put("message", getMessage());
+        m.put("exception", getClass().getName());
+        m.put("timestamp", when);
+        return m;
+    }
+}

src/main/java/uk/org/iay/incommon/validator/api/NotFoundException.java

@@ -0,0 +1,36 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package uk.org.iay.incommon.validator.api;
+
+import org.springframework.http.HttpStatus;
+
+/**
+ * {@link ApiException} representing a "not found" condition.
+ */
+public class NotFoundException extends ApiException {
+
+    /** Serial version UID. */
+    private static final long serialVersionUID = 424520235843161978L;
+
+    /**
+     * Constructor.
+     *
+     * @param msg message to be included in the exception
+     */
+    public NotFoundException(final String msg) {
+        super(HttpStatus.NOT_FOUND, msg);
+    }
+
+}

src/main/java/uk/org/iay/incommon/validator/api/ValidatorsApi.java

@@ -0,0 +1,52 @@
+/**
+ * NOTE: This class is auto generated by the swagger code generator program (2.3.1).
+ * https://github.com/swagger-api/swagger-codegen
+ * Do not edit the class manually.
+ *
+ * **IAY**: The only changes here from the generated file have been to clean up the imports
+ * list and to add "throws ApiException" to the validate method.
+ */
+package uk.org.iay.incommon.validator.api;
+
+import java.util.List;
+
+import javax.validation.Valid;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+
+import io.swagger.annotations.Api;
+import io.swagger.annotations.ApiOperation;
+import io.swagger.annotations.ApiParam;
+import io.swagger.annotations.ApiResponse;
+import io.swagger.annotations.ApiResponses;
+import uk.org.iay.incommon.validator.models.Status;
+import uk.org.iay.incommon.validator.models.Validator;
+@javax.annotation.Generated(value = "io.swagger.codegen.languages.SpringCodegen", date = "2018-05-12T13:33:10.546+01:00")
+
+@Api(value = "validators", description = "the validators API")
+public interface ValidatorsApi {
+
+    @ApiOperation(value = "lists available validators", nickname = "getValidators", notes = "Lists all of the available validator pipelines. ", response = Validator.class, responseContainer = "List", tags={ "validation", })
+    @ApiResponses(value = { 
+        @ApiResponse(code = 200, message = "list of validator identifiers and descriptions", response = Validator.class, responseContainer = "List") })
+    @RequestMapping(value = "/validators",
+        produces = { "application/json" }, 
+        method = RequestMethod.GET)
+    ResponseEntity<List<Validator>> getValidators();
+
+
+    @ApiOperation(value = "performs a validation", nickname = "validate", notes = "", response = Status.class, responseContainer = "List", tags={ "validation", })
+    @ApiResponses(value = { 
+        @ApiResponse(code = 200, message = "The result of a validation operation is a (possibly empty) array of `Status` objects derived from the `StatusMetadata` instances attached to the item being validated.  These may include errors, and it is up to the client to determine what constitues a \"pass\" or \"fail\". ", response = Status.class, responseContainer = "List") })
+    @RequestMapping(value = "/validators/{validator_id}/validate",
+        produces = { "application/json" }, 
+        consumes = { "application/xml+samlmetadata" },
+        method = RequestMethod.POST)
+    ResponseEntity<List<Status>> validate(@ApiParam(value = "An identifier for the validation to be performed. ",required=true) @PathVariable("validator_id") String validatorId,@ApiParam(value = "The metadata to be validated." ,required=true )  @Valid @RequestBody String metadata)
+        throws ApiException;
+
+}

src/main/java/uk/org/iay/incommon/validator/api/ValidatorsApiController.java

@@ -16,7 +16,9 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 
+import javax.servlet.http.HttpServletRequest;
 import javax.validation.Valid;
 
 import org.slf4j.Logger;
@@ -25,6 +27,7 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestBody;
 
@@ -88,10 +91,26 @@ public ResponseEntity<List<Status>> validate(
                 @PathVariable("validator_id")
                 final String validatorId,
             @ApiParam(value = "The metadata to be validated.", required = true) @Valid @RequestBody
-                final String metadata) {
+                final String metadata) throws ApiException {
         final List<Status> statuses = new ArrayList<>();
         statuses.add(makeStatus(StatusEnum.ERROR, "component", "message"));
         statuses.add(makeStatus(StatusEnum.WARNING, "component/sub", "another message"));
-        return new ResponseEntity<List<Status>>(statuses, HttpStatus.NOT_IMPLEMENTED);
+        //return new ResponseEntity<List<Status>>(statuses, HttpStatus.NOT_IMPLEMENTED);
+        throw new NotFoundException("bad validator identifier '" + validatorId + "'");
+    }
+
+    /**
+     * Handle an {@link ApiException} by converting it to a {@link Map}, which will
+     * in turn be converted to a JSON object.
+     *
+     * @param req the {@link HttpServletRequest} being handled
+     * @param ex the {@link ApiException} being handled
+     * @return a {@link ResponseEntity} equivalent to the {@link ApiException}
+     */
+    @ExceptionHandler(ApiException.class)
+    public ResponseEntity<Map<String, Object>> handleApiException(final HttpServletRequest req, final ApiException ex) {
+        final Map<String, Object> m = ex.toMap();
+        m.put("path", req.getRequestURI());
+        return new ResponseEntity<>(m, ex.getStatus());
     }
 }

swagger/.swagger-codegen-ignore

@@ -15,3 +15,14 @@ README.md
 # Don't generate dummy controllers once we have implemented them.
 #
 **/ValidatorsApiController.java
+
+#
+# Turns out we need to make changes to the API classes as well, to
+# allow for exceptions.
+#
+**/ValidatorsApi.java
+
+#
+# In turn, that means we don't need to generate the exception classes.
+#
+**/*Exception.java