Java example source code file (ProvisionExceptionsTest.java)

This example Java source code file (ProvisionExceptionsTest.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, error, exploder, explosion, illegalstateexception, injector, ioexception, override, provider, provides, provisionexceptionstest, testcase, tracer, tracerimpl

The ProvisionExceptionsTest.java Java example source code

/**
 * Copyright (C) 2010 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;

import com.google.inject.internal.Errors;
import com.google.inject.name.Named;
import com.google.inject.name.Names;

import junit.framework.TestCase;

import java.io.IOException;

/**
 * Tests that ProvisionExceptions are readable and clearly indicate to the user what went wrong with
 * their code.
 *
 * @author sameb@google.com (Sam Berlin)
 */
public class ProvisionExceptionsTest extends TestCase {
  
  public void testConstructorRuntimeException() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        bindConstant().annotatedWith(Names.named("runtime")).to(true);
        bind(Exploder.class).to(Explosion.class);
        bind(Tracer.class).to(TracerImpl.class);        
      }
    });
    try {
      injector.getInstance(Tracer.class);
      fail();
    } catch(ProvisionException pe) {
      // Make sure our initial error message gives the user exception.
      Asserts.assertContains(pe.getMessage(),
          "1) Error injecting constructor", "java.lang.IllegalStateException: boom!");
      assertEquals(1, pe.getErrorMessages().size());
      assertEquals(IllegalStateException.class, pe.getCause().getClass());
      assertEquals(IllegalStateException.class, Errors.getOnlyCause(pe.getErrorMessages()).getClass());
    }
  }
  
  public void testConstructorCheckedException() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        bindConstant().annotatedWith(Names.named("runtime")).to(false);
        bind(Exploder.class).to(Explosion.class);
        bind(Tracer.class).to(TracerImpl.class);        
      }
    });
    try {
      injector.getInstance(Tracer.class);
      fail();
    } catch(ProvisionException pe) {
      // Make sure our initial error message gives the user exception.
      Asserts.assertContains(pe.getMessage(),
          "1) Error injecting constructor", "java.io.IOException: boom!");
      assertEquals(1, pe.getErrorMessages().size());
      assertEquals(IOException.class, pe.getCause().getClass());
      assertEquals(IOException.class, Errors.getOnlyCause(pe.getErrorMessages()).getClass());
    }
  }
  
  public void testCustomProvidersRuntimeException() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        bind(Exploder.class).toProvider(new Provider<Exploder>() {
          public Exploder get() {
            return Explosion.createRuntime();
          }
        });
        bind(Tracer.class).to(TracerImpl.class);        
      }
    });
    try {
      injector.getInstance(Tracer.class);
      fail();
    } catch(ProvisionException pe) {
      // Make sure our initial error message gives the user exception.
      Asserts.assertContains(pe.getMessage(),
          "1) Error in custom provider", "java.lang.IllegalStateException: boom!");
      assertEquals(1, pe.getErrorMessages().size());
      assertEquals(IllegalStateException.class, pe.getCause().getClass());
      assertEquals(IllegalStateException.class, Errors.getOnlyCause(pe.getErrorMessages()).getClass());
    }
  }
  
  public void testProviderMethodRuntimeException() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        bind(Tracer.class).to(TracerImpl.class);        
      }
      @Provides Exploder exploder() {
        return Explosion.createRuntime();
      }
    });
    try {
      injector.getInstance(Tracer.class);
      fail();
    } catch(ProvisionException pe) {
      // Make sure our initial error message gives the user exception.
      Asserts.assertContains(pe.getMessage(),
          "1) Error in custom provider", "java.lang.IllegalStateException: boom!");
      assertEquals(1, pe.getErrorMessages().size());
      assertEquals(IllegalStateException.class, pe.getCause().getClass());
      assertEquals(IllegalStateException.class, Errors.getOnlyCause(pe.getErrorMessages()).getClass());
    }
  }
  
  public void testProviderMethodCheckedException() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        bind(Tracer.class).to(TracerImpl.class);        
      }
      @Provides Exploder exploder() throws IOException {
        return Explosion.createChecked();
      }
    });
    try {
      injector.getInstance(Tracer.class);
      fail();
    } catch(ProvisionException pe) {
      pe.printStackTrace();
      // Make sure our initial error message gives the user exception.
      Asserts.assertContains(pe.getMessage(),
          "1) Error in custom provider", "java.io.IOException: boom!");
      assertEquals(1, pe.getErrorMessages().size());
      assertEquals(IOException.class, pe.getCause().getClass());
      assertEquals(IOException.class, Errors.getOnlyCause(pe.getErrorMessages()).getClass());
    }
  }
  
  private static interface Exploder {}
  public static class Explosion implements Exploder {
    @Inject public Explosion(@Named("runtime") boolean runtime) throws IOException {
      if(runtime) {
        throw new IllegalStateException("boom!");
      } else {
        throw new IOException("boom!");
      }
    }
    
    public static Explosion createRuntime() {
      try {
        return new Explosion(true);
      } catch(IOException iox) {
        throw new RuntimeException();
      }      
    }
    
    public static Explosion createChecked() throws IOException {
      return new Explosion(false);
    }
  }
  private static interface Tracer {}
  private static class TracerImpl implements Tracer {
    @Inject TracerImpl(Exploder explosion) {
    }
  }
}