Implement JAX-RS flit exception mapper

Author: jlisam

runtime/jaxrs/build.gradle

@@ -11,5 +11,11 @@ repositories {
 }
 
 dependencies {
+    compile project(':runtime:core')
+    compile group: 'javax.servlet', name: 'javax.servlet-api', version: '4.0.1'
+    compile group: 'javax.ws.rs', name: 'javax.ws.rs-api', version: '2.1.1'
+    compile group: 'org.slf4j', name: 'slf4j-api', version: '1.7.25'
     testCompile group: 'junit', name: 'junit', version: '4.12'
+    testCompile group: 'org.glassfish.jersey.core', name: 'jersey-common', version: '2.22.2'
+    testCompile group: 'org.mockito', name: 'mockito-all', version: '1.10.19'
 }

runtime/jaxrs/src/main/java/com/flit/runtime/jaxrs/FlitExceptionMapper.java

@@ -0,0 +1,38 @@
+package com.flit.runtime.jaxrs;
+
+import com.flit.runtime.FlitException;
+import java.util.HashMap;
+import java.util.Map;
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.ext.ExceptionMapper;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class FlitExceptionMapper implements ExceptionMapper<FlitException> {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(FlitExceptionMapper.class);
+
+  @Context private HttpServletRequest request;
+
+  @Override
+  public Response toResponse(FlitException exception) {
+    LOGGER.error("Flit exception: request = {}, method = {}, code = {}, msg = {}",
+        request.getRequestURI(), request.getMethod(), exception.getErrorCode(),
+        exception.getMessage(), exception);
+
+    Map<String, Object> response = new HashMap<>();
+    response.put("code", exception.getErrorCode().getErrorCode());
+    response.put("msg", exception.getMessage());
+
+    if (exception.hasMeta()) {
+      response.put("meta", exception.getMeta());
+    }
+    return Response.status(exception.getErrorCode().getHttpStatus())
+        .type(MediaType.APPLICATION_JSON)
+        .entity(response)
+        .build();
+  }
+}

runtime/jaxrs/src/test/java/com/flit/runtime/jaxrs/FlitExceptionMapperTest.java

@@ -0,0 +1,43 @@
+package com.flit.runtime.jaxrs;
+
+import static org.junit.Assert.assertEquals;
+
+import com.flit.runtime.ErrorCode;
+import com.flit.runtime.FlitException;
+import java.util.Map;
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+public class FlitExceptionMapperTest {
+
+  @Mock
+  private HttpServletRequest request;
+
+  @InjectMocks
+  private FlitExceptionMapper flitExceptionMapper = new FlitExceptionMapper();
+
+  @Before
+  public void setup() {
+    MockitoAnnotations.initMocks(this);
+  }
+
+  @Test
+  public void testToResponse() {
+    FlitException flit = FlitException.builder()
+        .withCause(new RuntimeException("Failed"))
+        .withErrorCode(ErrorCode.INTERNAL)
+        .withMessage("with this message")
+        .build();
+    Response response = flitExceptionMapper.toResponse(flit);
+    assertEquals(response.getStatus(), 500);
+    Map<String, Object> expectedResult = Map.of("msg", "with this message", "code", "internal");
+    assertEquals(response.getEntity(), expectedResult);
+    assertEquals(response.getMediaType(), MediaType.APPLICATION_JSON_TYPE);
+  }
+}