2_08_StAX

JavaWebinar · JavaWebinar · commit 98bce9dca220 · 2017-10-24T00:29:15.000+03:00
diff --git a/src/main/java/ru/javaops/masterjava/xml/util/StaxStreamProcessor.java b/src/main/java/ru/javaops/masterjava/xml/util/StaxStreamProcessor.java
@@ -0,0 +1,56 @@
+package ru.javaops.masterjava.xml.util;
+
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.events.XMLEvent;
+import java.io.InputStream;
+
+public class StaxStreamProcessor implements AutoCloseable {
+    private static final XMLInputFactory FACTORY = XMLInputFactory.newInstance();
+
+    private final XMLStreamReader reader;
+
+    public StaxStreamProcessor(InputStream is) throws XMLStreamException {
+        reader = FACTORY.createXMLStreamReader(is);
+    }
+
+    public XMLStreamReader getReader() {
+        return reader;
+    }
+
+    public boolean doUntil(int stopEvent, String value) throws XMLStreamException {
+        while (reader.hasNext()) {
+            int event = reader.next();
+            if (event == stopEvent) {
+                if (value.equals(getValue(event))) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    public String getValue(int event) throws XMLStreamException {
+        return (event == XMLEvent.CHARACTERS) ? reader.getText() : reader.getLocalName();
+    }
+
+    public String getElementValue(String element) throws XMLStreamException {
+        return doUntil(XMLEvent.START_ELEMENT, element) ? reader.getElementText() : null;
+    }
+
+    public String getText() throws XMLStreamException {
+        return reader.getElementText();
+    }
+
+    @Override
+    public void close() {
+        if (reader != null) {
+            try {
+                reader.close();
+            } catch (XMLStreamException e) {
+                // empty
+            }
+        }
+    }
+}
diff --git a/src/test/java/ru/javaops/masterjava/xml/util/StaxStreamProcessorTest.java b/src/test/java/ru/javaops/masterjava/xml/util/StaxStreamProcessorTest.java
@@ -0,0 +1,36 @@
+package ru.javaops.masterjava.xml.util;
+
+import com.google.common.io.Resources;
+import org.junit.Test;
+
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.events.XMLEvent;
+
+public class StaxStreamProcessorTest {
+    @Test
+    public void readCities() throws Exception {
+        try (StaxStreamProcessor processor =
+                     new StaxStreamProcessor(Resources.getResource("payload.xml").openStream())) {
+            XMLStreamReader reader = processor.getReader();
+            while (reader.hasNext()) {
+                int event = reader.next();
+                if (event == XMLEvent.START_ELEMENT) {
+                    if ("City".equals(reader.getLocalName())) {
+                        System.out.println(reader.getElementText());
+                    }
+                }
+            }
+        }
+    }
+
+    @Test
+    public void readCities2() throws Exception {
+        try (StaxStreamProcessor processor =
+                     new StaxStreamProcessor(Resources.getResource("payload.xml").openStream())) {
+            String city;
+            while ((city = processor.getElementValue("City")) != null) {
+                System.out.println(city);
+            }
+        }
+    }
+}
