Finished config parser to read race info from external xml file

- created config parser unit test.
- modified config.xml file
- write unit test for config parser

#story[422]

doc/examples/config.xml

@@ -4,5 +4,6 @@
     <race-name>AC35</race-name>
     <race-size>6</race-size>
     <time-scale>1.0</time-scale>
+    <wind-direction>135</wind-direction>
 </configurations>
 

src/main/java/seng302/models/parsers/ConfigParser.java

@@ -0,0 +1,80 @@
+package seng302.models.parsers;
+
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+
+import java.util.DoubleSummaryStatistics;
+
+public class ConfigParser extends FileParser {
+
+	private Document doc;
+
+	public ConfigParser(String path) {
+		super(path);
+		this.doc = this.parseFile();
+	}
+
+	/**
+	 * Gets wind direction from config file.
+	 *
+	 * @return a double type degree, or 0 if no value or invalid value is found
+	 */
+	public double getWindDirection() {
+		return getDoubleByTagName("wind-direction", 0.0);
+	}
+
+	/**
+	 * Gets a non negative time scale for the race
+	 *
+	 * @return a double type scale, or 0 if no scale or invalid scale is found
+	 */
+	public double getTimeScale() {
+		return getDoubleByTagName("time-scale", 1.0);
+	}
+
+	/**
+	 * Gets a double type number by given tag name found in xml file
+	 *
+	 * @param tagName    a string of tag name
+	 * @param defaultVal value returned if no value or invalid value is found
+	 * @return value found
+	 */
+	public double getDoubleByTagName(String tagName, double defaultVal) {
+		double val = defaultVal;
+		try {
+			Node node = this.doc.getElementsByTagName(tagName).item(0);
+			if (node.getNodeType() == Node.ELEMENT_NODE) {
+				Element element = (Element) node;
+				val = Double.valueOf(element.getTextContent());
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		} finally {
+			return val;
+		}
+	}
+
+	/**
+	 * Gets a string by given tag name found in xml file
+	 *
+	 * @param tagName    a string of tag name
+	 * @param defaultVal a string returned if no value or invalid value is found
+	 * @return string found
+	 */
+	public String getStringByTagName(String tagName, String defaultVal) {
+		String string = defaultVal;
+		try {
+			Node node = this.doc.getElementsByTagName(tagName).item(0);
+			if (node.getNodeType() == Node.ELEMENT_NODE) {
+				Element element = (Element) node;
+				string = element.getTextContent();
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		} finally {
+			return string;
+		}
+	}
+}

src/test/java/seng302/models/parsers/ConfigParserTest.java

@@ -0,0 +1,42 @@
+package seng302.models.parsers;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Haoming on 23/03/17.
+ */
+public class ConfigParserTest {
+
+	private ConfigParser cp;
+
+	@Before
+	public void initializeParser() throws Exception {
+		cp = new ConfigParser("doc/examples/config.xml");
+	}
+
+	@Test
+	public void getWindDirection() throws Exception {
+		assertEquals(135, cp.getWindDirection(), 1e-10);
+	}
+
+	@Test
+	public void getTimeScale() throws Exception {
+		assertEquals(1.0, cp.getTimeScale(), 1e-10);
+	}
+
+	@Test
+	public void getDoubleByTagName() throws Exception {
+		assertEquals(6, cp.getDoubleByTagName("race-size", 0), 1e-10);
+		assertEquals(100, cp.getDoubleByTagName("noTag", 100), 1e-10);
+	}
+
+	@Test
+	public void getStringByTagName() throws Exception {
+		assertEquals("AC35", cp.getStringByTagName("race-name", "11"));
+		assertEquals("oops", cp.getStringByTagName("noTag", "oops"));
+	}
+
+}