Complete Example Code for BAEL-782 (#2270)

* added updated example codes * updated example code StringToCharStream * deleted StringToCharStream.java locally * removed redundant file * added code for apache commons collection SetUtils * refactored example code * added example code for bytebuddy
2017-07-17 23:44:10 +01:00
parent 3671427d5e
commit 2ce547d4cd
4 changed files with 123 additions and 0 deletions
@@ -0,0 +1,89 @@
+package com.baeldung.bytebuddy;
+
+import net.bytebuddy.ByteBuddy;
+import net.bytebuddy.agent.ByteBuddyAgent;
+import net.bytebuddy.dynamic.DynamicType;
+import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
+import net.bytebuddy.dynamic.loading.ClassReloadingStrategy;
+import net.bytebuddy.implementation.FixedValue;
+import net.bytebuddy.implementation.MethodDelegation;
+import net.bytebuddy.matcher.ElementMatchers;
+import org.junit.Test;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+
+import static net.bytebuddy.matcher.ElementMatchers.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class ByteBuddyUnitTest {
+
+    @Test
+    public void givenObject_whenToString_thenReturnHelloWorldString() throws InstantiationException, IllegalAccessException {
+        DynamicType.Unloaded unloadedType = new ByteBuddy()
+          .subclass(Object.class)
+          .method(ElementMatchers.isToString())
+          .intercept(FixedValue.value("Hello World ByteBuddy!"))
+          .make();
+
+        Class<?> dynamicType = unloadedType.load(getClass().getClassLoader())
+          .getLoaded();
+
+        assertEquals(dynamicType.newInstance().toString(), "Hello World ByteBuddy!");
+    }
+
+    @Test
+    public void givenFoo_whenRedefined_thenReturnFooRedefined() throws Exception {
+        ByteBuddyAgent.install();
+        new ByteBuddy()
+            .redefine(Foo.class)
+            .method(named("sayHelloFoo"))
+            .intercept(FixedValue.value("Hello Foo Redefined"))
+            .make()
+            .load(Foo.class.getClassLoader(), ClassReloadingStrategy.fromInstalledAgent());
+        Foo f = new Foo();
+        assertEquals(f.sayHelloFoo(), "Hello Foo Redefined");
+    }
+
+    @Test
+    public void givenSayHelloFoo_whenMethodDelegation_thenSayHelloBar() throws IllegalAccessException, InstantiationException {
+
+        String r = new ByteBuddy()
+          .subclass(Foo.class)
+          .method(
+            named("sayHelloFoo")
+            .and(isDeclaredBy(Foo.class)
+            .and(returns(String.class)))
+          )
+          .intercept(MethodDelegation.to(Bar.class))
+          .make()
+          .load(getClass().getClassLoader())
+          .getLoaded()
+          .newInstance()
+          .sayHelloFoo();
+
+        assertEquals(r, Bar.sayHelloBar());
+    }
+
+    @Test
+    public void givenMethodName_whenDefineMethod_thenCreateMethod() throws Exception {
+        Class<?> type = new ByteBuddy()
+            .subclass(Object.class)
+            .name("MyClassName")
+            .defineMethod("custom", String.class, Modifier.PUBLIC)
+            .intercept(MethodDelegation.to(Bar.class))
+            .defineField("x", String.class, Modifier.PUBLIC)
+            .make()
+            .load(getClass().getClassLoader(), ClassLoadingStrategy.Default.WRAPPER)
+            .getLoaded();
+
+        Method m = type.getDeclaredMethod("custom", null);
+
+        assertEquals(m.invoke(type.newInstance()), Bar.sayHelloBar());
+        assertNotNull(type.getDeclaredField("x"));
+
+    }
+
+
+}