Prelimary stuff for REST error reporting
Change-Id: Ie562498d0a9394c3e839ceb463e9beab9e1ecff2
diff --git a/src/main/java/net/onrc/onos/api/rest/RestError.java b/src/main/java/net/onrc/onos/api/rest/RestError.java
new file mode 100644
index 0000000..8b958de
--- /dev/null
+++ b/src/main/java/net/onrc/onos/api/rest/RestError.java
@@ -0,0 +1,60 @@
+package net.onrc.onos.api.rest;
+
+/**
+ * Describes a REST error.
+ * code is a unique identifier for the error.
+ * summary is indended to be a short description of what happened.
+ * description is a long description of the problem, and can be formatted using
+ * variable replacement. Variable placeholders are indicated with the string
+ * "{}" in the description.
+ * Objects of this class are immutable.
+ */
+
+public final class RestError {
+
+ private final RestErrorCodes.RestErrorCode code;
+ private final String summary;
+ private final String description;
+
+ /**
+ * Constructs a new RestError object from a code, summary and description.
+ *
+ * @param newCode code for the new error
+ * @param newSummary short summary for the new error
+ * @param newDescription formatable description for the new error
+ */
+ public RestError(final RestErrorCodes.RestErrorCode newCode,
+ final String newSummary,
+ final String newDescription) {
+ code = newCode;
+ summary = newSummary;
+ description = newDescription;
+ }
+
+ /**
+ * Gets the summary of the error.
+ *
+ * @return string for the summary
+ */
+ public String getSummary() {
+ return summary;
+ }
+
+ /**
+ * Gets the unique code for this error.
+ *
+ * @return unique code
+ */
+ public RestErrorCodes.RestErrorCode getCode() {
+ return code;
+ }
+
+ /**
+ * Gets the unformatted description string for the error.
+ *
+ * @return the unformatted description string.
+ */
+ public String getDescription() {
+ return description;
+ }
+}
diff --git a/src/main/java/net/onrc/onos/api/rest/RestErrorCatalog.java b/src/main/java/net/onrc/onos/api/rest/RestErrorCatalog.java
new file mode 100644
index 0000000..d81805f
--- /dev/null
+++ b/src/main/java/net/onrc/onos/api/rest/RestErrorCatalog.java
@@ -0,0 +1,84 @@
+package net.onrc.onos.api.rest;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Maintains a catalog of RestErrors and allows lookup by error code.
+ */
+public final class RestErrorCatalog {
+
+ /**
+ * Hide the default constructor of a utility class.
+ */
+ private RestErrorCatalog() { }
+
+ /**
+ * Static list of known errors. Someday this will be read in from an
+ * external file.
+ */
+ private static final RestError[] ERROR_LIST = {
+ new RestError(RestErrorCodes.RestErrorCode.INTENT_NOT_FOUND,
+ "Intent not found",
+ "An intent with the identifier {} was not found."),
+ new RestError(RestErrorCodes.RestErrorCode.INTENT_ALREADY_EXISTS,
+ "Intent already exists",
+ "An intent with the identifier {} could not be created " +
+ "because one already exists."),
+ new RestError(RestErrorCodes.RestErrorCode.INTENT_NO_PATH,
+ "No path found",
+ "No path found between {} and {}"),
+
+ };
+
+ /**
+ * Singleton implementation using the demand holder idiom.
+ */
+ private static class RestErrorMapHolder {
+ /**
+ * Load up the error map.
+ *
+ * @return REST error map
+ */
+ private static Map<Integer, RestError> initializeRestErrorMap() {
+ restErrorMap = new HashMap<>();
+ for (final RestError restError : ERROR_LIST) {
+ restErrorMap.put(restError.getCode().ordinal(), restError);
+ }
+ return restErrorMap;
+ }
+
+ /**
+ * Fetch the singleton map.
+ *
+ * @return map of the Rest Errors that was created from the known error
+ * list.
+ */
+ public static Map<Integer, RestError> getRestErrorMap() {
+ return restErrorMap;
+ }
+
+
+ private static Map<Integer, RestError> restErrorMap = initializeRestErrorMap();
+ }
+
+ /**
+ * Fetch the map of REST errors.
+ *
+ * @return map of possible REST errors.
+ */
+ public static Map<Integer, RestError> getRestErrorMap() {
+ return RestErrorMapHolder.getRestErrorMap();
+ }
+
+ /**
+ * Fetch the RestError for the given code.
+ *
+ * @param code the code for the message to look up.
+ * @return the REST error for the code if one exists, null if it does not
+ * exist.
+ */
+ public static RestError getRestError(final RestErrorCodes.RestErrorCode code) {
+ return getRestErrorMap().get(code.ordinal());
+ }
+}
diff --git a/src/main/java/net/onrc/onos/api/rest/RestErrorCodes.java b/src/main/java/net/onrc/onos/api/rest/RestErrorCodes.java
new file mode 100644
index 0000000..1d34615
--- /dev/null
+++ b/src/main/java/net/onrc/onos/api/rest/RestErrorCodes.java
@@ -0,0 +1,30 @@
+package net.onrc.onos.api.rest;
+
+/**
+ * Holder class for constants that describe the REST error codes.
+ */
+public final class RestErrorCodes {
+
+ /**
+ * Hidden default constructor for utility class.
+ */
+ private RestErrorCodes() { }
+
+ /**
+ * Enumeration of the ONOS defined error codes.
+ */
+ public enum RestErrorCode {
+
+ // TODO: These are made up just for testing purposes.
+
+ /** Intent not found. */
+ INTENT_NOT_FOUND,
+
+ /** Intent already exists. */
+ INTENT_ALREADY_EXISTS,
+
+ /** No path available for the Intent. */
+ INTENT_NO_PATH
+ }
+
+}
diff --git a/src/main/java/net/onrc/onos/api/rest/RestErrorFormatter.java b/src/main/java/net/onrc/onos/api/rest/RestErrorFormatter.java
new file mode 100644
index 0000000..edc39b2
--- /dev/null
+++ b/src/main/java/net/onrc/onos/api/rest/RestErrorFormatter.java
@@ -0,0 +1,32 @@
+package net.onrc.onos.api.rest;
+
+import org.slf4j.helpers.FormattingTuple;
+import org.slf4j.helpers.MessageFormatter;
+
+/**
+ * Utility class used for formatting Rest Error descriptions.
+ */
+public final class RestErrorFormatter {
+
+ /**
+ * Hide default constructor for utility classes.
+ */
+ private RestErrorFormatter() { }
+
+ /**
+ * Takes a RestError template and formats the description using a supplied
+ * list of replacement parameters.
+ *
+ * @param error the RestError to format
+ * @param parameters parameter list to use as positional parameters in the
+ * result string
+ *
+ * @return the String object for the formatted message.
+ */
+ static String formatErrorMessage(final RestError error,
+ final Object... parameters) {
+ final FormattingTuple formattingResult =
+ MessageFormatter.arrayFormat(error.getDescription(), parameters);
+ return formattingResult.getMessage();
+ }
+}
diff --git a/src/test/java/net/onrc/onos/api/rest/RestErrorTest.java b/src/test/java/net/onrc/onos/api/rest/RestErrorTest.java
new file mode 100644
index 0000000..f505740
--- /dev/null
+++ b/src/test/java/net/onrc/onos/api/rest/RestErrorTest.java
@@ -0,0 +1,81 @@
+package net.onrc.onos.api.rest;
+
+import org.junit.Test;
+
+import static net.onrc.onos.core.util.UtilityClassChecker.assertThatClassIsUtility;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.*;
+
+
+/**
+ * Unit tests for REST error handling classes.
+ */
+public class RestErrorTest {
+
+ /**
+ * Test the formatting of a REST error that contains a single
+ * positional parameter.
+ */
+ @Test
+ public void testRestErrorFormatting1Parameter() {
+ final RestError restError =
+ RestErrorCatalog.getRestError(RestErrorCodes.RestErrorCode.INTENT_ALREADY_EXISTS);
+ assertThat(restError, is(notNullValue()));
+
+ final String formattedError =
+ RestErrorFormatter.formatErrorMessage(restError,
+ "INTENT-ID");
+ assertThat(formattedError, is(notNullValue()));
+
+ final String expectedFormattedString =
+ "An intent with the identifier INTENT-ID could not be created " +
+ "because one already exists.";
+ assertThat(formattedError, is(equalTo(expectedFormattedString)));
+
+ }
+
+ /**
+ * Test the formatting of a REST error that contains two
+ * positional parameters.
+ */
+ @Test
+ public void testRestErrorFormatting2Parameters() {
+ final RestError restError =
+ RestErrorCatalog.getRestError(RestErrorCodes.RestErrorCode.INTENT_NO_PATH);
+ assertThat(restError, is(notNullValue()));
+
+ final String formattedError =
+ RestErrorFormatter.formatErrorMessage(restError,
+ "Switch1", "Switch2");
+ assertThat(formattedError, is(notNullValue()));
+
+ final String expectedFormattedString =
+ "No path found between Switch1 and Switch2";
+ assertThat(formattedError, is(equalTo(expectedFormattedString)));
+
+ }
+
+ /**
+ * Make sure that the error formatter is a utility class.
+ */
+ @Test
+ public void assureThatErrorFormatterIsUtility() {
+ assertThatClassIsUtility(RestErrorFormatter.class);
+ }
+
+ /**
+ * Make sure that the error catalog is a utility class.
+ */
+ @Test
+ public void assureThatErrorCatalogIsUtility() {
+ assertThatClassIsUtility(RestErrorCatalog.class);
+ }
+
+ /**
+ * Make sure that the error codes is a utility class.
+ */
+ @Test
+ public void assureThatErrorCodesIsUtility() {
+ assertThatClassIsUtility(RestErrorCodes.class);
+ }
+}