diff --git a/libraries/pom.xml b/libraries/pom.xml index 6be4980b93..c23b6ef912 100644 --- a/libraries/pom.xml +++ b/libraries/pom.xml @@ -530,6 +530,16 @@ hll ${hll.version} + + net.bytebuddy + byte-buddy + ${bytebuddy.version} + + + net.bytebuddy + byte-buddy-agent + ${bytebuddy.version} + 0.7.0 @@ -572,6 +582,7 @@ mytheme 1.6.0 + 1.7.1 diff --git a/libraries/src/main/java/com/baeldung/bytebuddy/Bar.java b/libraries/src/main/java/com/baeldung/bytebuddy/Bar.java new file mode 100644 index 0000000000..d0362a6c92 --- /dev/null +++ b/libraries/src/main/java/com/baeldung/bytebuddy/Bar.java @@ -0,0 +1,16 @@ +package com.baeldung.bytebuddy; + +import net.bytebuddy.implementation.bind.annotation.BindingPriority; + +public class Bar { + + @BindingPriority(3) + public static String sayHelloBar() { return "Holla in Bar!"; } + + @BindingPriority(2) + public static String sayBar() { return "bar"; } + + public String bar() { return Bar.class.getSimpleName() + " - Bar"; } + + +} diff --git a/libraries/src/main/java/com/baeldung/bytebuddy/Foo.java b/libraries/src/main/java/com/baeldung/bytebuddy/Foo.java new file mode 100644 index 0000000000..4be06785b1 --- /dev/null +++ b/libraries/src/main/java/com/baeldung/bytebuddy/Foo.java @@ -0,0 +1,7 @@ +package com.baeldung.bytebuddy; + +public class Foo { + + public String sayHelloFoo() { return "Hello in Foo!"; } + +} diff --git a/libraries/src/test/java/com/baeldung/bytebuddy/ByteBuddyUnitTest.java b/libraries/src/test/java/com/baeldung/bytebuddy/ByteBuddyUnitTest.java new file mode 100644 index 0000000000..6b7364a0a5 --- /dev/null +++ b/libraries/src/test/java/com/baeldung/bytebuddy/ByteBuddyUnitTest.java @@ -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")); + + } + + +}