com.davidbracewell.io.resource.BaseResource Maven / Gradle / Ivy

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A set of utilities and tools to speed up and ease programming in Java.
There is a newer version: 0.5
/*
 * (c) 2005 David B. Bracewell
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.davidbracewell.io.resource;

import com.davidbracewell.io.FileUtils;
import com.davidbracewell.string.StringUtils;
import com.google.common.base.Preconditions;

import javax.annotation.Nonnull;
import java.io.*;
import java.net.URI;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Optional;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

/**
 * @author David B. Bracewell
 */
public abstract class BaseResource implements Resource, Serializable {
  private static final long serialVersionUID = 1L;

  private Charset charset = StandardCharsets.UTF_8;
  private boolean isCompressed = false;

  @Override
  public final Charset getCharset() {
    if( charset == null ){
      return StandardCharsets.UTF_8;
    }
    return charset;
  }

  @Override
  public final boolean isCompressed() {
    return isCompressed;
  }

  @Override
  public final Resource setIsCompressed(boolean isCompressed) {
    this.isCompressed = isCompressed;
    return this;
  }

  @Override
  public final Resource setCharset(@Nonnull Charset charset) {
    this.charset = charset;
    return this;
  }

  @Override
  public final Resource compressed() {
    return setIsCompressed(true);
  }

  @Override
  public final Resource uncompressed() {
    return setIsCompressed(false);
  }

  @Override
  public InputStream inputStream() throws IOException {
    Preconditions.checkState(canRead(), "This is resource cannot be read from.");
    PushbackInputStream is = new PushbackInputStream(createInputStream(), 2);
    if (FileUtils.isCompressed(is)) {
      setIsCompressed(true);
      return new GZIPInputStream(is);
    }
    return is;
  }

  @Override
  public OutputStream outputStream() throws IOException {
    Preconditions.checkState(canWrite(), "This is resource cannot be written to.");
    if (isCompressed) {
      return new GZIPOutputStream(createOutputStream());
    }
    return createOutputStream();
  }

  protected OutputStream createOutputStream() throws IOException {
    return null;
  }

  protected InputStream createInputStream() throws IOException {
    return null;
  }

  @Override
  public boolean canRead() {
    return true;
  }

  @Override
  public boolean canWrite() {
    return true;
  }

  @Override
  public final String toString() {
    return descriptor();
  }

  @Override
  public Optional asFile() {
    return Optional.empty();
  }

  @Override
  public Optional asURI() {
    return Optional.empty();
  }

  @Override
  public String baseName() {
    return StringUtils.EMPTY;
  }

  @Override
  public String descriptor() {
    return super.toString();
  }

  @Override
  public boolean isDirectory() {
    return false;
  }

  @Override
  public String path() {
    return StringUtils.EMPTY;
  }

}//END OF BaseResource