Java example source code file (LineNumbersTest.java)

This example Java source code file (LineNumbersTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

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Java - Java tags/keywords

abstractmodule, class, creationexception, generatingclassloader, injector, linenumberstest, object, reflection, source, string, testcase

The LineNumbersTest.java Java example source code

/**
 * Copyright (C) 2008 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.inject.internal.util;

import static com.google.inject.Asserts.assertContains;
import static com.google.inject.Asserts.getDeclaringSourcePart;

import com.google.inject.AbstractModule;
import com.google.inject.CreationException;
import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.matcher.Matchers;

import junit.framework.TestCase;

import java.lang.reflect.Modifier;

import javax.inject.Inject;

/**
 * @author jessewilson@google.com (Jesse Wilson)
 */
public class LineNumbersTest extends TestCase {

  public void testLineNumbers() {
    try {
      Guice.createInjector(new AbstractModule() {
        protected void configure() {
          bind(A.class);
        }
      });
      fail();
    } catch (CreationException expected) {
      assertContains(
          expected.getMessage(),
          "1) No implementation for " + B.class.getName() + " was bound.",
          "for the 1st parameter of " + A.class.getName() + ".<init>(LineNumbersTest.java:",
          "at " + LineNumbersTest.class.getName(),
          getDeclaringSourcePart(getClass()));
    }
  }

  static class A {
    @Inject A(B b) {}
  }
  public interface B {}

  /*if[AOP]*/
  public void testCanHandleLineNumbersForGuiceGeneratedClasses() {
    try {
      Guice.createInjector(new AbstractModule() {
        protected void configure() {
          bindInterceptor(Matchers.only(A.class), Matchers.any(),
              new org.aopalliance.intercept.MethodInterceptor() {
                public Object invoke(org.aopalliance.intercept.MethodInvocation methodInvocation) {
                  return null;
                }
              });

          bind(A.class);
        }
      });
      fail();
    } catch (CreationException expected) {
      assertContains(
          expected.getMessage(),
          "1) No implementation for " + B.class.getName() + " was bound.",
          "for the 1st parameter of " + A.class.getName() + ".<init>(LineNumbersTest.java:",
          "at " + LineNumbersTest.class.getName(),
          getDeclaringSourcePart(getClass()));
    }
  }

  static class GeneratingClassLoader extends ClassLoader {
    static String name = "__generated";

    GeneratingClassLoader() {
      super(B.class.getClassLoader());
    }

    Class<?> generate() {
      org.objectweb.asm.ClassWriter cw =
          new org.objectweb.asm.ClassWriter(org.objectweb.asm.ClassWriter.COMPUTE_MAXS);
      cw.visit(org.objectweb.asm.Opcodes.V1_5,
          Modifier.PUBLIC, name, null,
          org.objectweb.asm.Type.getInternalName(Object.class), null);

      String sig = "("+org.objectweb.asm.Type.getDescriptor(B.class)+")V";

      org.objectweb.asm.MethodVisitor mv = cw.visitMethod(Modifier.PUBLIC, "<init>", sig, null, null);

      mv.visitAnnotation(org.objectweb.asm.Type.getDescriptor(Inject.class), true);
      mv.visitCode();
      mv.visitVarInsn(org.objectweb.asm.Opcodes.ALOAD, 0);
      mv.visitMethodInsn(org.objectweb.asm.Opcodes.INVOKESPECIAL,
          org.objectweb.asm.Type.getInternalName(Object.class), "<init>", "()V" );
      mv.visitInsn(org.objectweb.asm.Opcodes.RETURN);
      mv.visitMaxs(0, 0);
      mv.visitEnd();
      cw.visitEnd();

      byte[] buf = cw.toByteArray();

      return defineClass(name.replace('/', '.'), buf, 0, buf.length);
    }
  }

  public void testUnavailableByteCodeShowsUnknownSource() {
    try {
      Guice.createInjector(new AbstractModule() {
        protected void configure() {
          bind(new GeneratingClassLoader().generate());
        }
      });
      fail();
    } catch (CreationException expected) {
      assertContains(
          expected.getMessage(),
          "1) No implementation for " + B.class.getName() + " was bound.",
          "for the 1st parameter of " + GeneratingClassLoader.name + ".<init>(Unknown Source)",
          "at " + LineNumbersTest.class.getName(),
          getDeclaringSourcePart(getClass()));
    }
  }
  
  public void testGeneratedClassesCanSucceed() {
    final Class<?> generated = new GeneratingClassLoader().generate();
    Injector injector = Guice.createInjector(new AbstractModule() {
      protected void configure() {
        bind(generated);
        bind(B.class).toInstance(new B() {});
      }
    });
    Object instance = injector.getInstance(generated);
    assertEquals(instance.getClass(), generated);
  }
  /*end[AOP]*/
}