https://ant.apache.org/: master POM (The Apache Software Foundation) 
/*
 *  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
 *
 *      https://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.tools.ant.taskdefs;

import java.util.Hashtable;
import java.util.Map;

import org.apache.tools.ant.BuildEvent;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.SubBuildListener;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.types.EnumeratedAttribute;
import org.apache.tools.ant.types.LogLevel;


Adds a listener to the current build process that records the
output to a file.

Several recorders can exist at the same time.  Each recorder is
associated with a file.  The filename is used as a unique identifier for
the recorders.  The first call to the recorder task with an unused filename
will create a recorder (using the parameters provided) and add it to the
listeners of the build.  All subsequent calls to the recorder task using
this filename will modify that recorders state (recording or not) or other
properties (like logging level).


Some technical issues: the file's print stream is flushed for "finished"
events (buildFinished, targetFinished and taskFinished), and is closed on
a buildFinished event.


See Also:
  • RecorderEntry
Version:0.5
Since:Ant 1.4
@ant.taskname="record" category="utility"
/**
 * Adds a listener to the current build process that records the
 * output to a file.
 * <p>Several recorders can exist at the same time.  Each recorder is
 * associated with a file.  The filename is used as a unique identifier for
 * the recorders.  The first call to the recorder task with an unused filename
 * will create a recorder (using the parameters provided) and add it to the
 * listeners of the build.  All subsequent calls to the recorder task using
 * this filename will modify that recorders state (recording or not) or other
 * properties (like logging level).</p>
 * <p>Some technical issues: the file's print stream is flushed for &quot;finished&quot;
 * events (buildFinished, targetFinished and taskFinished), and is closed on
 * a buildFinished event.</p>
 * @see RecorderEntry
 * @version 0.5
 * @since Ant 1.4
 * @ant.task name="record" category="utility"
 */
public class Recorder extends Task implements SubBuildListener {

    //////////////////////////////////////////////////////////////////////
    // ATTRIBUTES

    
The name of the file to record to. 
/** The name of the file to record to. */
    private String filename = null;
    
Whether or not to append. Need Boolean to record an unset state (null).

/**
     * Whether or not to append. Need Boolean to record an unset state (null).
     */
    private Boolean append = null;
    
Whether to start or stop recording. Need Boolean to record an unset
state (null).

/**
     * Whether to start or stop recording. Need Boolean to record an unset
     * state (null).
     */
    private Boolean start = null;
    
The level to log at. A level of -1 means not initialized yet. 
/** The level to log at. A level of -1 means not initialized yet. */
    private int loglevel = -1;
    
Strip task banners if true.  
/** Strip task banners if true.  */
    private boolean emacsMode = false;
    
The list of recorder entries. 
/** The list of recorder entries. */
    private static Map<String, RecorderEntry> recorderEntries = new Hashtable<>();

    //////////////////////////////////////////////////////////////////////
    // CONSTRUCTORS / INITIALIZERS

    
Overridden so we can add the task as build listener.

Since:Ant 1.7
/**
     * Overridden so we can add the task as build listener.
     *
     * @since Ant 1.7
     */
    public void init() {
        getProject().addBuildListener(this);
    }

    //////////////////////////////////////////////////////////////////////
    // ACCESSOR METHODS

    
Sets the name of the file to log to, and the name of the recorder
entry.

Params:
  • fname – File name of logfile.
/**
     * Sets the name of the file to log to, and the name of the recorder
     * entry.
     *
     * @param fname File name of logfile.
     */
    public void setName(String fname) {
        filename = fname;
    }


    
Sets the action for the associated recorder entry.

Params:
  • action – The action for the entry to take: start or stop.
/**
     * Sets the action for the associated recorder entry.
     *
     * @param action The action for the entry to take: start or stop.
     */
    public void setAction(ActionChoices action) {
        if (action.getValue().equalsIgnoreCase("start")) {
            start = Boolean.TRUE;
        } else {
            start = Boolean.FALSE;
        }
    }


    
Whether or not the logger should append to a previous file.

Params:
  • append – if true, append to a previous file.
/**
     * Whether or not the logger should append to a previous file.
     * @param append if true, append to a previous file.
     */
    public void setAppend(boolean append) {
        this.append = (append ? Boolean.TRUE : Boolean.FALSE);
    }


    
Set emacs mode.

Params:
  • emacsMode – if true use emacs mode
/**
     * Set emacs mode.
     * @param emacsMode if true use emacs mode
     */
    public void setEmacsMode(boolean emacsMode) {
        this.emacsMode = emacsMode;
    }


    
Sets the level to which this recorder entry should log to.

Params:
  • level – the level to set.
See Also:
/**
     * Sets the level to which this recorder entry should log to.
     * @param level the level to set.
     * @see VerbosityLevelChoices
     */
    public void setLoglevel(VerbosityLevelChoices level) {
        loglevel = level.getLevel();
    }

    //////////////////////////////////////////////////////////////////////
    // CORE / MAIN BODY

    
The main execution.

Throws:
  • BuildException – on error
/**
     * The main execution.
     * @throws BuildException on error
     */
    public void execute() throws BuildException {
        if (filename == null) {
            throw new BuildException("No filename specified");
        }

        getProject().log("setting a recorder for name " + filename,
            Project.MSG_DEBUG);

        // get the recorder entry
        RecorderEntry recorder = getRecorder(filename, getProject());
        // set the values on the recorder
        recorder.setMessageOutputLevel(loglevel);
        recorder.setEmacsMode(emacsMode);
        if (start != null) {
            if (start) {
                recorder.reopenFile();
                recorder.setRecordState(start);
            } else {
                recorder.setRecordState(start);
                recorder.closeFile();
            }
        }
    }

    //////////////////////////////////////////////////////////////////////
    // INNER CLASSES

    
A list of possible values for the setAction() method.
Possible values include: start and stop.

/**
     * A list of possible values for the <code>setAction()</code> method.
     * Possible values include: start and stop.
     */
    public static class ActionChoices extends EnumeratedAttribute {
        private static final String[] VALUES = {"start", "stop"};

        
See Also:
  • 
{@inheritDoc}.
/**
         * @see EnumeratedAttribute#getValues()
         * {@inheritDoc}.
         */
        public String[] getValues() {
            return VALUES;
        }
    }


    
A list of possible values for the setLoglevel() method.
Possible values include: error, warn, info, verbose, debug.

/**
     * A list of possible values for the <code>setLoglevel()</code> method.
     * Possible values include: error, warn, info, verbose, debug.
     */
    public static class VerbosityLevelChoices extends LogLevel {
    }


    
Gets the recorder that's associated with the passed in name. If the
recorder doesn't exist, then a new one is created.

Params:
  • name – the name of the recorder
  • proj – the current project
Throws:
Returns:a recorder
/**
     * Gets the recorder that's associated with the passed in name. If the
     * recorder doesn't exist, then a new one is created.
     * @param name the name of the recorder
     * @param proj the current project
     * @return a recorder
     * @throws BuildException on error
     */
    protected RecorderEntry getRecorder(String name, Project proj)
         throws BuildException {
        RecorderEntry entry = recorderEntries.get(name);

        if (entry == null) {
            // create a recorder entry
            entry = new RecorderEntry(name);

            if (append == null) {
                entry.openFile(false);
            } else {
                entry.openFile(append);
            }
            entry.setProject(proj);
            recorderEntries.put(name, entry);
        }

        return entry;
    }

    
Empty implementation required by SubBuildListener interface.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Empty implementation required by SubBuildListener interface.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void buildStarted(BuildEvent event) {
    }

    
Empty implementation required by SubBuildListener interface.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Empty implementation required by SubBuildListener interface.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void subBuildStarted(BuildEvent event) {
    }

    
Empty implementation required by SubBuildListener interface.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Empty implementation required by SubBuildListener interface.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void targetStarted(BuildEvent event) {
    }

    
Empty implementation required by SubBuildListener interface.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Empty implementation required by SubBuildListener interface.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void targetFinished(BuildEvent event) {
    }

    
Empty implementation required by SubBuildListener interface.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Empty implementation required by SubBuildListener interface.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void taskStarted(BuildEvent event) {
    }

    
Empty implementation required by SubBuildListener interface.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Empty implementation required by SubBuildListener interface.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void taskFinished(BuildEvent event) {
    }

    
Empty implementation required by SubBuildListener interface.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Empty implementation required by SubBuildListener interface.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void messageLogged(BuildEvent event) {
    }

    
Cleans recorder registry.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Cleans recorder registry.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void buildFinished(BuildEvent event) {
        cleanup();
    }

    
Cleans recorder registry, if this is the subbuild the task has
been created in.

Params:
  • event – ignored.
Since:Ant 1.7
/**
     * Cleans recorder registry, if this is the subbuild the task has
     * been created in.
     * @param event ignored.
     * @since Ant 1.7
     */
    public void subBuildFinished(BuildEvent event) {
        if (event.getProject() == getProject()) {
            cleanup();
        }
    }

    
cleans recorder registry and removes itself from BuildListener list.

Since:Ant 1.7
/**
     * cleans recorder registry and removes itself from BuildListener list.
     *
     * @since Ant 1.7
     */
    private void cleanup() {
        recorderEntries.entrySet().removeIf(e -> e.getValue().getProject() == getProject());
        getProject().removeBuildListener(this);
    }
}