Android cannot validate XML with XSD. WTF

APED/.idea/gradle.xml

@@ -10,8 +10,8 @@
         <option name="gradleJvm" value="1.8" />
         <option name="modules">
           <set>
-            <option value="$PROJECT_DIR$" />
+            <option value="$USER_HOME$/Storage/Programs/TH/MO_Mobile_Systeme/aped_app/APED" />
-            <option value="$PROJECT_DIR$/app" />
+            <option value="$USER_HOME$/Storage/Programs/TH/MO_Mobile_Systeme/aped_app/APED/app" />
           </set>
         </option>
         <option name="resolveModulePerSourceSet" value="false" />

APED/app/src/main/assets/XML

@@ -1 +1 @@
-Subproject commit ce8ce41609a1a7ef9282cbcdda3358f9c2ec6939
+Subproject commit 594fc1ea61264673706a2e26120e3b4b95af4f2f

APED/app/src/main/java/com/example/aped/MainActivity.java

@@ -2,7 +2,9 @@ package com.example.aped;
 
 import android.Manifest;
 import android.app.AlertDialog;
+import android.content.res.AssetManager;
 import android.os.Bundle;
+import android.os.Environment;
 import android.util.Log;
 import android.view.MenuItem;
 
@@ -10,8 +12,10 @@ import android.view.Menu;
 import android.widget.Toast;
 
 import com.example.aped.communication.IIO;
+import com.example.aped.utils.ExternalStorageHandler;
 import com.example.aped.utils.IXML;
 import com.example.aped.utils.TestXML;
+import com.example.aped.utils.XMLHandler;
 import com.google.android.material.navigation.NavigationView;
 
 import androidx.annotation.NonNull;
@@ -25,6 +29,16 @@ import androidx.drawerlayout.widget.DrawerLayout;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
 
+import org.xml.sax.SAXException;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.xml.parsers.ParserConfigurationException;
+
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 
 public class MainActivity extends AppCompatActivity {
@@ -42,6 +56,7 @@ public class MainActivity extends AppCompatActivity {
         super.onCreate(savedInstanceState);
         //checks that the permission to read and write the xml is granted
         ensurePermissions();
+        setXML();
         setContentView(R.layout.activity_main);
         Toolbar toolbar = findViewById(R.id.toolbar);
         setSupportActionBar(toolbar);
@@ -59,8 +74,6 @@ public class MainActivity extends AppCompatActivity {
         NavigationUI.setupActionBarWithNavController(this,
                                         navController, mAppBarConfiguration);
         NavigationUI.setupWithNavController(navigationView, navController);
-
-        xml = new TestXML();
     }
     /** Fügt Elemente zur Aktionsleiste hinzu, wenn diese vorhanden ist.*/
     @Override
@@ -117,13 +130,7 @@ public class MainActivity extends AppCompatActivity {
         if (ContextCompat.checkSelfPermission(
                         this,
                         Manifest.permission.WRITE_EXTERNAL_STORAGE)
-                == PERMISSION_GRANTED) {
+                != PERMISSION_GRANTED) {
-            Toast.makeText(
-                    this,
-                    "You have already granted this permission",
-                    Toast.LENGTH_LONG)
-                    .show();
-        } else {
             if (ActivityCompat.shouldShowRequestPermissionRationale(
                     this,
                     Manifest.permission.READ_EXTERNAL_STORAGE)) {
@@ -176,4 +183,29 @@ public class MainActivity extends AppCompatActivity {
             }
         }
     }
+
+    private void setXML(){
+        try {
+            String xmlPath = ExternalStorageHandler.getExternalPrivateStorageDir(MainActivity.this);
+            File xmlFile = new File(xmlPath,"config.xml");
+
+            //create the default XML config by using the default.xml from the assets folder
+            if (xmlFile.exists()){
+                xmlFile.delete();
+            }
+            InputStream inputStream = getAssets().open("XML/default.xml");
+            byte[] buffer = new byte[inputStream.available()];
+            inputStream.read(buffer);
+            inputStream.close();
+            FileOutputStream fileOutputStream = new FileOutputStream(xmlFile);
+            fileOutputStream.write(buffer);
+            fileOutputStream.close();
+
+            xml = new XMLHandler(xmlFile);
+        } catch (FileNotFoundException e) {
+            Log.e("Main Activity","Exception while reading the external private storage dir: " + e.getMessage());
+        } catch (ParserConfigurationException | IOException | SAXException e){
+            Log.e("Main Activity","XMLHandler failed to initialise: " + e.getMessage());
+        }
+    }
 }

APED/app/src/main/java/com/example/aped/utils/XMLHandler.java

@@ -15,14 +15,9 @@ import java.util.Dictionary;
 import java.util.Hashtable;
 import java.util.List;
 
-import javax.xml.XMLConstants;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
-import javax.xml.transform.stream.StreamSource;
-import javax.xml.validation.Schema;
-import javax.xml.validation.SchemaFactory;
-import javax.xml.validation.Validator;
 import javax.xml.xpath.XPath;
 import javax.xml.xpath.XPathConstants;
 import javax.xml.xpath.XPathExpression;
@@ -38,44 +33,17 @@ public class XMLHandler implements IXML {
 
     /**
      * constructor for the XMLHandler.
-     * @param xmlPath the path to the XML file
+     * @param xmlFile the XML file
-     * @param xsdPath the path to the XSD file
      * @throws ParserConfigurationException the XML parser configuration failed
      * @throws IOException the XML file could not be accessed
      * @throws SAXException the XML parse failed
      */
-    public XMLHandler(final String xmlPath, final String xsdPath)
+    public XMLHandler(final File xmlFile)
         throws ParserConfigurationException, IOException, SAXException {
-        if (!validate(xmlPath, xsdPath)) {
+        //parse the root document from the XML file
-            throw new VerifyError("the XML file is invalid");
-        }
-        //parse the root document fromt the XML file
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
-        root = builder.parse(new File(xmlPath));
+        root = builder.parse(xmlFile);
-    }
-
-    /**
-     * validates a XML file against a XSD file.
-     * @param xmlPath the path to the XML file
-     * @param xsdPath the path to the XSD file
-     * @return true if XML is valid
-     */
-    private boolean validate(final String xmlPath, final String xsdPath) {
-        try {
-            SchemaFactory factory = SchemaFactory.newInstance(
-                    XMLConstants.W3C_XML_SCHEMA_NS_URI
-            );
-            Schema schema = factory.newSchema(new File(xsdPath));
-            Validator validator = schema.newValidator();
-            validator.validate(new StreamSource(new File(xmlPath)));
-        } catch (IOException | SAXException e) {
-            Log.e("XMLHandler",
-                    "Error while validating the XML file"
-                        + e.getMessage());
-            return false;
-        }
-        return true;
     }
 
     @Override

APED/app/src/test/java/com/example/aped/XMLHandlerUnitTest.java

@@ -16,14 +16,12 @@ import static org.junit.Assert.*;
 
 public class XMLHandlerUnitTest {
     private String xmlPath="src/main/assets/XML/Test.xml";
-    private String xsdPath="src/main/assets/XML/config.xsd";
     private File xmlFile = new File(xmlPath);
-    private File xsdFile = new File(xsdPath);
 
     @Test
     public void TestFiles_AreValid(){
         try{
-            XMLHandler xmlHandler = new XMLHandler(xmlFile,xsdFile);
+            XMLHandler xmlHandler = new XMLHandler(xmlFile);
         }catch(IOException | ParserConfigurationException | SAXException e){
             System.out.println("XMLHandler failed");
             assert(false);
@@ -36,7 +34,7 @@ public class XMLHandlerUnitTest {
     @Test
     public void Test_getDeviceNames(){
         try{
-            XMLHandler xmlHandler = new XMLHandler(xmlFile,xsdFile);
+            XMLHandler xmlHandler = new XMLHandler(xmlFile);
             List<String> deviceNames = xmlHandler.getDeviceNames();
             assertArrayEquals(new String[]{"example","sensorarray"},deviceNames.toArray());
         }catch(IOException | ParserConfigurationException | SAXException e){
@@ -48,7 +46,7 @@ public class XMLHandlerUnitTest {
     @Test
     public void TestInput_SimpleValueInfo(){
         try{
-            XMLHandler xmlHandler = new XMLHandler(xmlFile,xsdFile);
+            XMLHandler xmlHandler = new XMLHandler(xmlFile);
             Dictionary<String, Object> valueInfo = xmlHandler.getValueInfo("example");
             assertEquals("{factor=1.0, type=boolean, unit=, offset=0.0}",valueInfo.toString());
         }catch(IOException | ParserConfigurationException | SAXException e){
@@ -60,7 +58,7 @@ public class XMLHandlerUnitTest {
     @Test
     public void TestInput_ComplexValueInfo(){
         try{
-            XMLHandler xmlHandler = new XMLHandler(xmlFile,xsdFile);
+            XMLHandler xmlHandler = new XMLHandler(xmlFile);
             Dictionary<String, Object> valueInfo = xmlHandler.getValueInfo("sensorarray");
             assertEquals("{factor=2.5, type=int, unit=°C, offset=1.2}",valueInfo.toString());
         }catch(IOException | ParserConfigurationException | SAXException e){
@@ -72,7 +70,7 @@ public class XMLHandlerUnitTest {
     @Test
     public void TestInput_SimplePort(){
         try{
-            XMLHandler xmlHandler = new XMLHandler(xmlFile,xsdFile);
+            XMLHandler xmlHandler = new XMLHandler(xmlFile);
             Dictionary<String, Object> port = xmlHandler.getPort("example");
             assertEquals("{pins=[GPIO_2], protocol=DI}",port.toString());
         }catch(IOException | ParserConfigurationException | SAXException e){
@@ -84,7 +82,7 @@ public class XMLHandlerUnitTest {
     @Test
     public void TestInput_ComplexPort(){
         try{
-            XMLHandler xmlHandler = new XMLHandler(xmlFile,xsdFile);
+            XMLHandler xmlHandler = new XMLHandler(xmlFile);
             Dictionary<String, Object> port = xmlHandler.getPort("sensorarray");
             assertEquals("{pins=[GPIO_3, GPIO_4, GPIO_5, GPIO_6], protocol=DI}",port.toString());
         }catch(IOException | ParserConfigurationException | SAXException e){