Clean and optimize code

Integrated most of the optimisation/improvements proposed by @nowheresly
in PR #23, making use of Java 8 lambdas and streams when possible.

Author: nowheresly

.gitignore

@@ -11,3 +11,6 @@
 # properties file holding connection data for integration test
 demodb.properties
 
+# Intellij IDEA stuff
+.idea/*
+*.iml

src/main/java/com/debortoliwines/odoo/api/ObjectAdapter.java

@@ -23,8 +23,11 @@
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.TimeZone;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Stream;
 
 import org.apache.xmlrpc.XmlRpcException;
 
@@ -50,17 +53,17 @@ public class ObjectAdapter {
 	// the database for every new object.
 	// Bulk loads/reads can become very slow if every adapter requires a call
 	// back to the server
-	private static ArrayList<String> objectNameCache = new ArrayList<>();
+	private static final List<String> objectNameCache = new ArrayList<>();
 
 	// Object workflow signal cache so the adapter doesn't have to reread signal
 	// names from the database for every workflow call.
-	private static ArrayList<String> signalCache = new ArrayList<>();
+	private static final List<String> signalCache = new ArrayList<>();
 
 	// Cache used to store the name_get result of an model to cater for
 	// many2many relations in the import function
 	// It is cleared every time the import function is called for a specific
 	// object
-	private HashMap<String, HashMap<String, String>> modelNameCache = new HashMap<>();
+	private final Map<String, Map<String, String>> modelNameCache = new ConcurrentHashMap<>();
 
 	/**
 	 * Default constructor
@@ -238,9 +241,7 @@ public RowCollection readObject(Object[] ids, String[] fields) throws XmlRpcExce
 		 * sortedResults[idList.indexOf(id)] = result; }
 		 ****/
 
-		RowCollection rows = new RowCollection(results, fieldCol);
-
-		return rows;
+		return new RowCollection(results, fieldCol);
 	}
 
 	/***
@@ -487,9 +488,9 @@ private Object[] fixImportData(Row inputRow) throws OpeneERPApiException, XmlRpc
 				 * import. Replace the ID list passed in with a Name list for
 				 * the import_data function that we are about to call
 				 */
-				HashMap<String, String> idToName = null;
+				Map<String, String> idToName;
 				if (!modelNameCache.containsKey(fld.getRelation())) {
-					idToName = new HashMap<String, String>();
+					idToName = new HashMap<>();
 					Object[] ids = command.searchObject(fld.getRelation(), new Object[] {});
 					Object[] names = command.nameGet(fld.getRelation(), ids);
 					for (int j = 0; j < ids.length; j++) {
@@ -533,19 +534,17 @@ private Object[] fixImportData(Row inputRow) throws OpeneERPApiException, XmlRpc
 	}
 
 	private String[] getFieldListForImport(FieldCollection currentFields) {
+		return Stream
+				.concat(Stream.of(".id"),
+						currentFields.stream().map(ObjectAdapter::getFieldNameForImport))
+				.toArray(String[]::new);
 
-		ArrayList<String> fieldList = new ArrayList<String>();
-		fieldList.add(".id");
-
-		for (Field field : currentFields) {
-			if (field.getType() == FieldType.MANY2ONE)
-				fieldList.add(field.getName() + ".id");
-			else
-				fieldList.add(field.getName());
-		}
-
-		return fieldList.toArray(new String[fieldList.size()]);
+	}
 
+	private static String getFieldNameForImport(Field field) {
+		// Return field name, adding ".id" if type is MANY2ONE
+		return field.getType() == FieldType.MANY2ONE ? field.getName() + ".id"
+				: field.getName();
 	}
 
 	/**
@@ -723,7 +722,7 @@ public RowCollection searchAndReadObject(FilterCollection filter, String[] field
 	public RowCollection searchAndReadObject(final FilterCollection filter, final String[] fields, int offset,
 			int limit, String order) throws XmlRpcException, OpeneERPApiException {
 
-		String[] fieldArray = (fields == null ? new String[] {} : fields);
+		String[] fieldArray = fields == null ? new String[] {} : fields;
 		Object[] preparedFilters = validateFilters(filter);
 		Object[] idList = (Object[]) command.searchObject(modelName, preparedFilters, offset, limit, order, false);
 
@@ -938,7 +937,7 @@ public FieldCollection callFieldsFunction(String functionName, Object[] paramete
 				}
 
 				if (fldDetails == null)
-					fldDetails = new HashMap<String, Object>();
+					fldDetails = new HashMap<>();
 
 				if (!fldDetails.containsKey("name"))
 					fldDetails.put("name", field);
@@ -991,9 +990,7 @@ public RowCollection callFunction(String functionName, Object[] parameters, Fiel
 		if (fieldCol == null)
 			fieldCol = callFieldsFunction(functionName, parameters);
 
-		RowCollection rows = new RowCollection(results, fieldCol);
-
-		return rows;
+		return new RowCollection(results, fieldCol);
 	}
 
 	/**

src/main/java/com/debortoliwines/odoo/api/Session.java

@@ -36,6 +36,8 @@
  */
 public class Session {
 
+	private static final String LINE_SEPARATOR_SYSTEM_PROPERTY = "line.separator";
+	private static final String LINE_SEPARATOR = System.getProperty(LINE_SEPARATOR_SYSTEM_PROPERTY);
 	private String host;
 	private int port;
 	private String databaseName;
@@ -162,24 +164,23 @@ void checkDatabasePresenceSafe() {
 		  }
 	}
 
-	void checkDatabasePresence() throws XmlRpcException, Exception {
+	void checkDatabasePresence() throws XmlRpcException {
 		ArrayList<String> dbList = getDatabaseList(protocol, host, port);
-		if (dbList.indexOf(databaseName) < 0) {
-			StringBuffer dbListBuff = new StringBuffer();
-			for (String dbName : dbList)
-				dbListBuff.append(dbName + System.getProperty("line.separator"));
+		if (!dbList.contains(databaseName)) {
+			StringBuilder messageBuilder = new StringBuilder("Error while connecting to Odoo.  Database [")
+					.append(databaseName).append("]  was not found in the following list: ").append(LINE_SEPARATOR)
+					.append(LINE_SEPARATOR).append(String.join(LINE_SEPARATOR, dbList)).append(LINE_SEPARATOR);
 
-			throw new Exception("Error while connecting to Odoo.  Database [" + databaseName + "] "
-					+ " was not found in the following list: " + System.getProperty("line.separator")
-					+ System.getProperty("line.separator") + dbListBuff.toString());
+			throw new IllegalStateException(messageBuilder.toString());
 		}
 	}
 
 	private synchronized static void startConnecting(){
 		while (Session.connecting){
 			try {
 				Thread.sleep(100);
-			} catch (Exception e) {
+			} catch (InterruptedException e) {
+				e.printStackTrace();
 			}
 		}
 		Session.connecting = true;

src/main/java/com/debortoliwines/odoo/api/helpers/FlatViewHelper.java

@@ -23,6 +23,7 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Date;
+import java.util.stream.Collectors;
 
 import org.apache.xmlrpc.XmlRpcException;
 
@@ -112,31 +113,24 @@ public static FlatViewFieldCollection getFields(String objectName, FieldCollecti
 	 */
 	public static String[] getFieldNames(String objectName, FieldCollection fields) throws XmlRpcException {
 
-		ArrayList<String> fieldNames = new ArrayList<String>();
-		
-		for (FlatViewField fld : getFields(objectName, fields)){
-			fieldNames.add(fld.getName());
-		}
-		
-		return fieldNames.toArray(new String[0]);
+		return getFields(objectName, fields).stream()
+				.map(f -> f.getName())
+				.toArray(String[]::new);
 	}
 
 	/**
 	 * Returns the original field names from a flattened out view collection 
-	 * @param objectName Object that the fields are for, for eg res.partner
 	 * @param fields Flattened out field collection 
 	 * @return Original list of fields that the flattened out collection was built on
 	 */
-	public static String[] getOriginalFieldNames(String objectName, FlatViewFieldCollection fields){
-		ArrayList<String> fieldNames = new ArrayList<String>();
-		
-		for (FlatViewField fld : fields){
-			if (fieldNames.indexOf(fld.getSourceField().getName()) < 0){
-				fieldNames.add(fld.getName());
-			}
-		}
+	public static String[] getOriginalFieldNames(FlatViewFieldCollection fields){
 
-		return fieldNames.toArray(new String[0]);
+		return fields.stream()
+				.collect(Collectors.toMap(
+						f -> f.getSourceField().getName(), 
+						f -> f.getName(), 
+						(f1, f2) -> f1))
+				.values().toArray(new String[0]);
 	}
 
 	/**