home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (Message.java)

This example Java source code file (Message.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

element, list, message, object, objectstreamexception, override, serializable, string, throwable, util

The Message.java Java example source code

/**
 * Copyright (C) 2006 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.spi;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.base.Objects;
import com.google.common.collect.ImmutableList;
import com.google.inject.Binder;
import com.google.inject.internal.Errors;
import com.google.inject.internal.util.SourceProvider;

import java.io.ObjectStreamException;
import java.io.Serializable;
import java.util.List;

/**
 * An error message and the context in which it occured. Messages are usually created internally by
 * Guice and its extensions. Messages can be created explicitly in a module using {@link
 * com.google.inject.Binder#addError(Throwable) addError()} statements:
 * <pre>
 *     try {
 *       bindPropertiesFromFile();
 *     } catch (IOException e) {
 *       addError(e);
 *     }</pre>
 *
 * @author crazybob@google.com (Bob Lee)
 */
public final class Message implements Serializable, Element {
  private final String message;
  private final Throwable cause;
  private final List<Object> sources;

  /**
   * @since 2.0
   */
  public Message(List<Object> sources, String message, Throwable cause) {
    this.sources = ImmutableList.copyOf(sources);
    this.message = checkNotNull(message, "message");
    this.cause = cause;
  }

  /**
   * @since 4.0
   */
  public Message(String message, Throwable cause) {
    this(ImmutableList.of(), message, cause);
  }

  public Message(Object source, String message) {
    this(ImmutableList.of(source), message, null);
  }

  public Message(String message) {
    this(ImmutableList.of(), message, null);
  }

  public String getSource() {
    return sources.isEmpty()
        ? SourceProvider.UNKNOWN_SOURCE.toString()
        : Errors.convert(sources.get(sources.size() - 1)).toString();
  }

  /** @since 2.0 */
  public List<Object> getSources() {
    return sources;
  }

  /**
   * Gets the error message text.
   */
  public String getMessage() {
    return message;
  }

  /** @since 2.0 */
  public <T> T acceptVisitor(ElementVisitor visitor) {
    return visitor.visit(this);
  }

  /**
   * Returns the throwable that caused this message, or {@code null} if this
   * message was not caused by a throwable.
   *
   * @since 2.0
   */
  public Throwable getCause() {
    return cause;
  }

  @Override public String toString() {
    return message;
  }

  @Override public int hashCode() {
    return Objects.hashCode(message, cause, sources);
  }

  @Override public boolean equals(Object o) {
    if (!(o instanceof Message)) {
      return false;
    }
    Message e = (Message) o;
    return message.equals(e.message) && Objects.equal(cause, e.cause) && sources.equals(e.sources);
  }

  /** @since 2.0 */
  public void applyTo(Binder binder) {
    binder.withSource(getSource()).addError(this);
  }

  /**
   * When serialized, we eagerly convert sources to strings. This hurts our formatting, but it
   * guarantees that the receiving end will be able to read the message.
   */
  private Object writeReplace() throws ObjectStreamException {
    Object[] sourcesAsStrings = sources.toArray();
    for (int i = 0; i < sourcesAsStrings.length; i++) {
      sourcesAsStrings[i] = Errors.convert(sourcesAsStrings[i]).toString();
    }
    return new Message(ImmutableList.copyOf(sourcesAsStrings), message, cause);
  }

  private static final long serialVersionUID = 0;
}

Other Java examples (source code examples)

Here is a short list of links related to this Java Message.java source code file:



my book on functional programming

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.