Java example source code file (ResourcesTest.java)

This example Java source code file (ResourcesTest.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.

Learn more about this Java project at its project page.

Java - Java tags/keywords

adventures, bytearrayoutputstream, illegalargumentexception, ioexception, iotestcase, lineprocessor, list, net, network, override, printwriter, should, testsuite, url, urlclassloader, utf-8, util

The ResourcesTest.java Java example source code

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * 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.common.io;

import static com.google.common.base.CharMatcher.whitespace;
import static com.google.common.truth.Truth.assertThat;

import com.google.common.base.Charsets;
import com.google.common.collect.ImmutableList;
import com.google.common.testing.NullPointerTester;

import junit.framework.TestSuite;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;

/**
 * Unit test for {@link Resources}.
 *
 * @author Chris Nokleberg
 */

public class ResourcesTest extends IoTestCase {

  public static TestSuite suite() {
    TestSuite suite = new TestSuite();
    suite.addTest(ByteSourceTester.tests("Resources.asByteSource[URL]",
        SourceSinkFactories.urlByteSourceFactory(), true));
    suite.addTest(CharSourceTester.tests("Resources.asCharSource[URL, Charset]",
        SourceSinkFactories.urlCharSourceFactory(), false));
    suite.addTestSuite(ResourcesTest.class);
    return suite;
  }

  public void testToString() throws IOException {
    URL resource = getClass().getResource("testdata/i18n.txt");
    assertEquals(I18N, Resources.toString(resource, Charsets.UTF_8));
    assertThat(Resources.toString(resource, Charsets.US_ASCII))
        .isNotEqualTo(I18N);
  }

  public void testToToByteArray() throws IOException {
    byte[] data = Resources.toByteArray(classfile(Resources.class));
    assertEquals(0xCAFEBABE,
        new DataInputStream(new ByteArrayInputStream(data)).readInt());
  }

  public void testReadLines() throws IOException {
    // TODO(chrisn): Check in a better resource
    URL resource = getClass().getResource("testdata/i18n.txt");
    assertEquals(ImmutableList.of(I18N),
        Resources.readLines(resource, Charsets.UTF_8));
  }

  public void testReadLines_withLineProcessor() throws IOException {
    URL resource = getClass().getResource("testdata/alice_in_wonderland.txt");
    LineProcessor<List collectAndLowercaseAndTrim =
        new LineProcessor<List() {
          List<String> collector = new ArrayList();
          @Override
          public boolean processLine(String line) {
            collector.add(whitespace().trimFrom(line));
            return true;
          }

          @Override
          public List<String> getResult() {
            return collector;
          }
        };
    List<String> result = Resources.readLines(resource, Charsets.US_ASCII,
        collectAndLowercaseAndTrim);
    assertEquals(3600, result.size());
    assertEquals("ALICE'S ADVENTURES IN WONDERLAND", result.get(0));
    assertEquals("THE END", result.get(result.size() - 1));
  }

  public void testCopyToOutputStream() throws IOException {
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    URL resource = getClass().getResource("testdata/i18n.txt");
    Resources.copy(resource, out);
    assertEquals(I18N, out.toString("UTF-8"));
  }

  public void testGetResource_notFound() {
    try {
      Resources.getResource("no such resource");
      fail();
    } catch (IllegalArgumentException e) {
      assertThat(e).hasMessage("resource no such resource not found.");
    }
  }

  public void testGetResource() {
    assertNotNull(
        Resources.getResource("com/google/common/io/testdata/i18n.txt"));
  }

  public void testGetResource_relativePath_notFound() {
    try {
      Resources.getResource(
          getClass(), "com/google/common/io/testdata/i18n.txt");
      fail();
    } catch (IllegalArgumentException e) {
      assertThat(e)
          .hasMessage(
              "resource com/google/common/io/testdata/i18n.txt"
                  + " relative to com.google.common.io.ResourcesTest not found.");
    }
  }

  public void testGetResource_relativePath() {
    assertNotNull(Resources.getResource(getClass(), "testdata/i18n.txt"));
  }

  public void testGetResource_contextClassLoader() throws IOException {
    // Check that we can find a resource if it is visible to the context class
    // loader, even if it is not visible to the loader of the Resources class.

    File tempFile = createTempFile();
    PrintWriter writer = new PrintWriter(tempFile, "UTF-8");
    writer.println("rud a chur ar an méar fhada");
    writer.close();

    // First check that we can't find it without setting the context loader.
    // This is a sanity check that the test doesn't spuriously pass because
    // the resource is visible to the system class loader.
    try {
      Resources.getResource(tempFile.getName());
      fail("Should get IllegalArgumentException");
    } catch (IllegalArgumentException expected) {
    }

    // Now set the context loader to one that should find the resource.
    URL baseUrl = tempFile.getParentFile().toURI().toURL();
    URLClassLoader loader = new URLClassLoader(new URL[] {baseUrl});
    ClassLoader oldContextLoader =
        Thread.currentThread().getContextClassLoader();
    try {
      Thread.currentThread().setContextClassLoader(loader);
      URL url = Resources.getResource(tempFile.getName());
      String text = Resources.toString(url, Charsets.UTF_8);
      assertEquals("rud a chur ar an méar fhada\n", text);
    } finally {
      Thread.currentThread().setContextClassLoader(oldContextLoader);
    }
  }

  public void testGetResource_contextClassLoaderNull() {
    ClassLoader oldContextLoader =
        Thread.currentThread().getContextClassLoader();
    try {
      Thread.currentThread().setContextClassLoader(null);
      assertNotNull(
          Resources.getResource("com/google/common/io/testdata/i18n.txt"));
      try {
        Resources.getResource("no such resource");
        fail("Should get IllegalArgumentException");
      } catch (IllegalArgumentException expected) {
      }
    } finally {
      Thread.currentThread().setContextClassLoader(oldContextLoader);
    }
  }

  public void testNulls() {
    new NullPointerTester()
        .setDefault(URL.class, classfile(ResourcesTest.class))
        .testAllPublicStaticMethods(Resources.class);
  }

  private static URL classfile(Class<?> c) {
    return c.getResource(c.getSimpleName() + ".class");
  }
}