implement get chaining, cover by tests

src/main/java/com/mykola2312/retracker/bencode/BDict.java

@@ -41,13 +41,12 @@ public class BDict extends BList {
 	}
 	
 	@SuppressWarnings("unchecked")
-	public <T extends BValue> T get(String key) throws BValueError {
-		T value = (T)get(new BString(key));
-		System.out.println("sedsed " + value.getClass().getName());
-		if (!(value instanceof T)) {
-			throw new BErrorValueCast(this, key, value.getClass());
+	public <T extends BValue> T get(BType type, String key) throws BValueError {
+		BValue value = get(new BString(key));
+		if (!value.getType().equals(type)) {
+			throw new BErrorValueCast(this, key, type, value.getType());
 		}
 		
-		return value;
+		return (T)value;
 	}
 }

src/main/java/com/mykola2312/retracker/bencode/error/BErrorValueCast.java

@@ -1,11 +1,12 @@
 package com.mykola2312.retracker.bencode.error;
 
+import com.mykola2312.retracker.bencode.BType;
 import com.mykola2312.retracker.bencode.BValue;
 
 public class BErrorValueCast extends BValueError {
 	private static final long serialVersionUID = 6790204193944478194L;
 
-	public BErrorValueCast(BValue node, String key, Class cause) {
-		super(node, String.format("cast error: %s is instance of %s", key, cause.getName()));
+	public BErrorValueCast(BValue node, String key, BType wanted, BType found) {
+		super(node, String.format("cast error: %s is type %s instead of %s", key, found, wanted));
 	}
 }

src/test/java/com/mykola2312/retracker/bencode/BDictTest.java

@@ -4,6 +4,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 import org.junit.jupiter.api.Test;
 
@@ -52,7 +53,23 @@ public class BDictTest {
 		dict.set("key", new BInteger(4));
 		
 		assertThrows(BErrorValueCast.class, () -> {
-			dict.<BString>get("key").get();
+			dict.<BString>get(BType.STRING, "key");
+		});
+	}
+	
+	@Test
+	public void testGetChained() {
+		BDict dict = new BDict()
+			.set("first", new BDict()
+					.set("second", new BInteger(3)));
+		
+		assertDoesNotThrow(() -> {
+			BInteger value = dict
+					.<BDict>get(BType.DICT, "first")
+					.<BInteger>get(BType.INTEGER, "second");
+			
+			assertNotNull(value);
+			assertEquals(value, new BInteger(3));
 		});
 	}
 }