commons-vfs2/src/main/java/org/apache/commons/vfs2/tasks/ShowFileTask.java

/*
 * 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 org.apache.commons.vfs2.tasks;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.Date;

import org.apache.commons.vfs2.FileContent;
import org.apache.commons.vfs2.FileObject;
import org.apache.tools.ant.BuildException;

/**
 * An Ant task that writes the details of a file to Ant's log.
 */
public class ShowFileTask extends VfsTask {

    private static final String INDENT = "  ";
    private String url;
    private boolean showContent;
    private boolean recursive;

    /**
     * The URL of the file to display.
     *
     * @param url The url of the file.
     */
    public void setFile(final String url) {
        this.url = url;
    }

    /**
     * Shows the content. Assumes the content is text, encoded using the platform's default encoding.
     *
     * @param showContent true if the content should be shown.
     */
    public void setShowContent(final boolean showContent) {
        this.showContent = showContent;
    }

    /**
     * Recursively shows the descendants of the file.
     *
     * @param recursive true if descendants should be shown.
     */
    public void setRecursive(final boolean recursive) {
        this.recursive = recursive;
    }

    /**
     * Executes the task.
     *
     * @throws BuildException if any exception is thrown.
     */
    @Override
    public void execute() throws BuildException {
        try {
            try (final FileObject file = resolveFile(url)) {
                log("Details of " + file.getPublicURIString());
                showFile(file, INDENT);
            }
        } catch (final Exception e) {
            throw new BuildException(e);
        }
    }

    /**
     * Logs the details of a file.
     */
    private void showFile(final FileObject file, final String prefix) throws Exception {
        // Write details
        final StringBuilder msg = new StringBuilder(prefix);
        msg.append(file.getName().getBaseName());
        if (file.exists()) {
            msg.append(" (");
            msg.append(file.getType().getName());
            msg.append(")");
        } else {
            msg.append(" (unknown)");
        }
        log(msg.toString());

        if (file.exists()) {
            final String newPrefix = prefix + INDENT;
            if (file.getType().hasContent()) {
                try (final FileContent content = file.getContent()) {
                    log(newPrefix + "Content-Length: " + content.getSize());
                    log(newPrefix + "Last-Modified" + new Date(content.getLastModifiedTime()));
                }
                if (showContent) {
                    log(newPrefix + "Content:");
                    logContent(file, newPrefix);
                }
            }
            if (file.getType().hasChildren()) {
                final FileObject[] children = file.getChildren();
                for (final FileObject child : children) {
                    if (recursive) {
                        showFile(child, newPrefix);
                    } else {
                        log(newPrefix + child.getName().getBaseName());
                    }
                }
            }
        }
    }

    /**
     * Writes the content of the file to Ant log.
     */
    private void logContent(final FileObject file, final String prefix) throws Exception {
        try (final FileContent content = file.getContent();
            final InputStream instr = content.getInputStream();
            final BufferedReader reader = new BufferedReader(new InputStreamReader(instr, Charset.defaultCharset()))) {
            while (true) {
                final String line = reader.readLine();
                if (line == null) {
                    break;
                }
                log(prefix + line);
            }
        }
    }
}