Logging added

Author: sklarman

README.md

@@ -41,7 +41,7 @@ To minimise the number of return trips between HyperGraphQL server and RDF store
 ```
 
 ### HyperGraphQL response:
-```json
+```js
 {
   "extensions": {},
   "data": {
@@ -98,7 +98,7 @@ Clone the Git repository into a local directory. Then in the root of the project
 
 Basic settings are defined in the *properties.json* file. The defaults are:
 
-```json
+```js
 {
     "schemaFile": "schema.graphql",
     "contextFile": "context.json",
@@ -173,7 +173,7 @@ The context specification consists of three components:
 
 The following example presents a possible context associated with the schema above, where all predicates are associated with the *http://dbpedia.org* graph.
 
-```json
+```js
 {
   "@predicates": {
     "person": {

log4j.properties

@@ -0,0 +1,14 @@
+# Root logger option
+log4j.rootLogger=DEBUG, file
+
+# Direct log messages to a log file
+log4j.appender.file=org.apache.log4j.RollingFileAppender
+
+#Redirect to Tomcat logs folder
+#log4j.appender.file.File=${catalina.home}/logs/logging.log
+
+log4j.appender.file.File=logging.log
+log4j.appender.file.MaxFileSize=10MB
+log4j.appender.file.MaxBackupIndex=10
+log4j.appender.file.layout=org.apache.log4j.PatternLayout
+log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

src/main/java/uk/co/semanticintegration/hypergraphql/Converter.java

@@ -3,6 +3,7 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import graphql.language.TypeDefinition;
+import org.apache.log4j.Logger;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -19,7 +20,7 @@
  * This class contains jsonRewrite methods between different query/response formats
  */
 public class Converter {
-
+    static Logger logger = Logger.getLogger(Converter.class);
 
     private JsonNode globalContext;
     private Map<String, String> JSONLD_VOC = new HashMap<String, String>() {{
@@ -115,7 +116,7 @@ public List<String> graphql2sparql(String query) {
                 String constructQuery = getConstructQuery(nextQuery);
                 output.add(constructQuery);
             } catch (Exception e) {
-                System.out.println(e.fillInStackTrace());
+                logger.error(e);
             }
         }
 
@@ -249,7 +250,6 @@ private String[] getSubquery(JsonNode node, String parentNode, String parentGrap
 
                         childConstruct.add(nodeMark);
 
-                        // childOptionalPattern = String.format(servicePattern, endpointId, childOptionalPattern);
                     } else {
 
                         String[] grandChildPatterns = getSubquery(field, childNode, graphId, endpointId);
@@ -353,7 +353,7 @@ public JsonNode query2json(String query) {
         try {
             JsonNode object = mapper.readTree(query);
 
-            // System.out.println(object.toString()); //debug message
+             logger.debug("Generated query JSON: " + object.toString()); //debug message
 
             return object;
         } catch (IOException e) {
@@ -389,7 +389,7 @@ public JsonNode definitionToJson(TypeDefinition type) {
 
             return object;
         } catch (IOException e) {
-            e.printStackTrace();
+            logger.error(e);
         }
 
         return null;

src/main/java/uk/co/semanticintegration/hypergraphql/GraphqlService.java

@@ -2,6 +2,7 @@
 
 import graphql.*;
 import graphql.language.SourceLocation;
+import org.apache.log4j.Logger;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -15,6 +16,9 @@
 public class GraphqlService {
     private GraphQL graphQL;
     private Config config;
+    static Logger logger = Logger.getLogger(GraphqlService.class);
+
+
 
     public GraphqlService(Config config, GraphQL graphQL) {
         this.graphQL = graphQL;
@@ -51,26 +55,7 @@ public Map<String, Object> results(String query) {
             try {
                 data = converter.jsonLDdata(query, qlResult.getData());
             } catch (IOException e) {
-
-                GraphQLError error = new GraphQLError() {
-                    @Override
-                    public String getMessage() {
-                        return e.getMessage();
-                    }
-
-                    @Override
-                    public List<SourceLocation> getLocations() {
-                        return null;
-                    }
-
-                    @Override
-                    public ErrorType getErrorType() {
-                        return null ;
-                    }
-                };
-
-                errors.add(error);
-
+                logger.error(e);
             }
 
         } else {

src/main/java/uk/co/semanticintegration/hypergraphql/GraphqlWiring.java

@@ -26,6 +26,7 @@
 import java.util.*;
 
 import org.apache.jena.rdf.model.RDFNode;
+import org.apache.log4j.Logger;
 
 /**
  * Created by szymon on 24/08/2017.
@@ -39,6 +40,10 @@ public class GraphqlWiring {
     private GraphQLSchema schema;
     private Converter converter;
 
+    static Logger logger = Logger.getLogger(GraphqlWiring.class);
+
+
+
     private Map<String, GraphQLArgument> defaultArguments = new HashMap<String, GraphQLArgument>() {{
         put("limit", new GraphQLArgument("limit", GraphQLInt));
         put("offset", new GraphQLArgument("offset", GraphQLInt));
@@ -227,12 +232,12 @@ public GraphQLFieldDefinition registerGraphQLField(Boolean isQueryType, JsonNode
             if (refType.isList) {
                 return getBuiltField(isQueryType, fieldDef, refType, instancesOfTypeFetcher);
             } else {
-                System.out.println("All queries must return array types.");
+                logger.error("Wrong schema: all fields in the Query type must return array types. This is not the case for: " + fieldDef.get("name"));
                 System.exit(1);
             }
         } else {
 
-            String fieldName = refType.dataType;
+            String targetDataTypeName = refType.dataType;
 
             final Set<String> allowedTypes = new HashSet<String>() {{
                 add("String");
@@ -241,8 +246,8 @@ public GraphQLFieldDefinition registerGraphQLField(Boolean isQueryType, JsonNode
                 add("Boolean");
             }};
 
-//      if (fieldName.equals("String") || fieldName.equals("Int") || fieldName.equals("ID") || fieldName.equals("Boolean")) {
-            if (allowedTypes.contains(fieldName)) {
+//      if (targetDataTypeName.equals("String") || targetDataTypeName.equals("Int") || targetDataTypeName.equals("ID") || targetDataTypeName.equals("Boolean")) {
+            if (allowedTypes.contains(targetDataTypeName)) {
                 return getBuiltField(isQueryType, fieldDef, refType, literalFetchers.get(refType.isList));
             } else {
                 return getBuiltField(isQueryType, fieldDef, refType, objectFetchers.get(refType.isList));

src/main/java/uk/co/semanticintegration/hypergraphql/Main.java

@@ -1,16 +1,17 @@
 package uk.co.semanticintegration.hypergraphql;
 
 import graphql.GraphQL;
-import org.apache.log4j.BasicConfigurator;
-import org.apache.log4j.Level;
 import org.apache.log4j.Logger;
+import org.apache.log4j.PropertyConfigurator;
 
 public class Main {
 
+    static Logger logger = Logger.getLogger(Main.class);
+
+
     public static void main(String[] args) {
 
-        BasicConfigurator.configure();
-        Logger.getRootLogger().setLevel(Level.OFF);
+        PropertyConfigurator.configure("log4j.properties");
 
         Config config = new Config("properties.json");
 
@@ -21,6 +22,8 @@ public static void main(String[] args) {
         System.out.println("GraphQL server started at: http://localhost:" + config.graphql().port() + config.graphql().path());
         System.out.println("GraphiQL UI available at: http://localhost:" + config.graphql().port() + config.graphql().graphiql());
 
+        logger.info("Server started at http://localhost:" + config.graphql().port() + config.graphql().path());
+
         Controller.start(config, graphQL);
 
     }

src/main/java/uk/co/semanticintegration/hypergraphql/SparqlClient.java

@@ -12,6 +12,7 @@
 import org.apache.jena.sparql.ARQConstants;
 import org.apache.jena.sparql.util.Context;
 import org.apache.jena.sparql.util.Symbol;
+import org.apache.log4j.Logger;
 
 /**
  * Created by szymon on 22/08/2017.
@@ -25,12 +26,18 @@ public class SparqlClient {
 
     private Model model;
 
+    private static Logger logger = Logger.getLogger(SparqlClient.class);
+
+
+
     public SparqlClient(List<String> queries, Map<String, Context> sparqlEndpointsContext) {
 
         model = ModelFactory.createDefaultModel();
 
         for (String constructQuery : queries) {
 
+            logger.debug("Executing construct query: " + constructQuery);
+
             QueryExecution qexec = QueryExecutionFactory.create(constructQuery, model);
 
             Context mycxt = qexec.getContext();
@@ -39,9 +46,8 @@ public SparqlClient(List<String> queries, Map<String, Context> sparqlEndpointsCo
 
             try {
                 qexec.execConstruct(model);
-
             } catch (Exception e) {
-                System.out.println(e.fillInStackTrace());
+                logger.error(e);
             }
         }
 
@@ -50,14 +56,14 @@ public SparqlClient(List<String> queries, Map<String, Context> sparqlEndpointsCo
 
     public ResultSet sparqlSelect(String queryString) {
 
-        // System.out.println(queryString);
+        logger.debug("Executing SPARQL fetchquery: " + queryString);
         QueryExecution qexec = QueryExecutionFactory.create(queryString, model);
         try {
             ResultSet results = qexec.execSelect();
             return results;
         } catch (Exception e) {
-            System.out.println("Failed to return the response on query: " + queryString);
-            System.out.println(e);
+            logger.error("Failed to return the response on query: " + queryString);
+            logger.error(e);
             return null;
         }
     }