src/main/org/apache/tools/ant/taskdefs/optional/PropertyFile.java - ant - Git at Google

 /*
  *  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.optional;

 import java.io.BufferedInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.file.Files;
 import java.text.DateFormat;
 import java.text.DecimalFormat;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Vector;

 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Task;
 import org.apache.tools.ant.types.EnumeratedAttribute;
 import org.apache.tools.ant.util.FileUtils;
 import org.apache.tools.ant.util.LayoutPreservingProperties;

 /**
  * Modifies settings in a property file.
  *
  * <p>The following is an example of its usage:</p>
  * <pre>
  *    &lt;target name="setState"&gt;
  *      &lt;property
  *        name="header"
  *        value="##Generated file - do not modify!"/&gt;
  *      &lt;propertyfile file="apropfile.properties" comment="${header}"&gt;
  *        &lt;entry key="product.version.major" type="int"  value="5"/&gt;
  *        &lt;entry key="product.version.minor" type="int"  value="0"/&gt;
  *        &lt;entry key="product.build.major"   type="int"  value="0" /&gt;
  *        &lt;entry key="product.build.minor"   type="int"  operation="+"/&gt;
  *        &lt;entry key="product.build.date"    type="date" value="now"/&gt;
  *        &lt;entry key="intSet" type="int" operation="=" value="681"/&gt;
  *        &lt;entry key="intDec" type="int" operation="-"/&gt;
  *        &lt;entry key="StringEquals" type="string" value="testValue"/&gt;
  *     &lt;/propertyfile&gt;
  *   &lt;/target&gt;
  * </pre>
  * <p>
  * The &lt;propertyfile&gt; task must have:
  * </p>
  * <ul>
  *   <li>file</li>
  * </ul>
  * Other parameters are:
  * <ul>
  *   <li>comment</li>
  *   <li>key</li>
  *   <li>operation</li>
  *   <li>type</li>
  *   <li>value (the final four being eliminated shortly)</li>
  * </ul>
  * <p>
  * The &lt;entry&gt; task must have:
  * </p>
  * <ul>
  *   <li>key</li>
  * </ul>
  * Other parameters are:
  * <ul>
  *   <li>operation</li>
  *   <li>type</li>
  *   <li>value</li>
  *   <li>default</li>
  *   <li>unit</li>
  * </ul>
  * <p>
  * If type is unspecified, it defaults to string.
  * </p>
  * Parameter values:
  * <dl>
  *   <dt>operation:</dt>
  *   <dd>
  *   <ul>
  *     <li>"=" (set -- default)</li>
  *     <li>"-" (dec)</li>
  *     <li>"+" (inc)</li>
  *   </ul>
  *   </dd>
  *   <dt>type:</dt>
  *   <dd>
  *   <ul>
  *     <li>"int"</li>
  *     <li>"date"</li>
  *     <li>"string"</li>
  *   </ul>
  *   </dd>
  *   <dt>value:</dt>
  *   <dd>
  *   <ul>
  *     <li>holds the default value, if the property
  *              was not found in property file</li>
  *     <li>"now" In case of type "date", the
  *              value "now" will be replaced by the current
  *              date/time and used even if a valid date was
  *              found in the property file.</li>
  *   </ul>
  *   </dd>
  * </dl>
  *
  * <p>String property types can only use the "=" operation.
  * Int property types can only use the "=", "-" or "+" operations.<p>
  *
  * The message property is used for the property file header, with "\\" being
  * a newline delimiter character.
  *
  */
 public class PropertyFile extends Task {

     /* ========================================================================
      *
      * Instance variables.
      */

     // Use this to prepend a message to the properties file
     private String              comment;

     private Properties          properties;
     private File                propertyfile;
     private boolean             useJDKProperties;

     private Vector<Entry> entries = new Vector<>();

     /* ========================================================================
      *
      * Constructors
      */

     /* ========================================================================
      *
      * Methods
      */

     /**
      * Execute the task.
      * @throws BuildException on error.
      */
     @Override
     public void execute() throws BuildException {
         checkParameters();
         readFile();
         executeOperation();
         writeFile();
     }

     /**
      * The entry nested element.
      * @return an entry nested element to be configured.
      */
     public Entry createEntry() {
         Entry e = new Entry();
         entries.addElement(e);
         return e;
     }

     private void executeOperation() throws BuildException {
         entries.forEach(e -> e.executeOn(properties));
     }

     private void readFile() throws BuildException {
         if (useJDKProperties) {
             // user chose to use standard Java properties, which loose
             // comments and layout
             properties = new Properties();
         } else {
             properties = new LayoutPreservingProperties();
         }
         try {
             if (propertyfile.exists()) {
                 log("Updating property file: "
                     + propertyfile.getAbsolutePath());
                 try (InputStream fis = Files.newInputStream(propertyfile.toPath());
                      BufferedInputStream bis = new BufferedInputStream(fis)) {
                     properties.load(bis);
                 }
             } else {
                 log("Creating new property file: "
                     + propertyfile.getAbsolutePath());
                 try (OutputStream out =
                      Files.newOutputStream(propertyfile.toPath())) {
                     out.flush();
                 }
             }
         } catch (IOException ioe) {
             throw new BuildException(ioe.toString());
         }
     }

     private void checkParameters() throws BuildException {
         if (!checkParam(propertyfile)) {
             throw new BuildException("file token must not be null.",
                                      getLocation());
         }
     }

     /**
      * Location of the property file to be edited; required.
      * @param file the property file.
      */
     public void setFile(File file) {
         propertyfile = file;
     }

     /**
      * optional header comment for the file
      * @param hdr the string to use for the comment.
      */
     public void setComment(String hdr) {
         comment = hdr;
     }

     /**
      * optional flag to use original Java properties (as opposed to
      * layout preserving properties)
      * @param val boolean
      */
     public void setJDKProperties(boolean val) {
         useJDKProperties = val;
     }

     private void writeFile() throws BuildException {
         // Write to RAM first, as an OOME could otherwise produce a truncated file:
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         try {
             properties.store(baos, comment);
         } catch (IOException x) { // should not happen
             throw new BuildException(x, getLocation());
         }
         try {
             try (OutputStream os = Files.newOutputStream(propertyfile.toPath())) {
                 os.write(baos.toByteArray());
             } catch (IOException x) { // possibly corrupt
                 FileUtils.getFileUtils().tryHardToDelete(propertyfile);
                 throw x;
             }
         } catch (IOException x) { // opening, writing, or closing
             throw new BuildException(x, getLocation());
         }
     }

     private boolean checkParam(File param) {
         return param != null;
     }

     /**
      * Instance of this class represents nested elements of
      * a task propertyfile.
      */
     public static class Entry {
         private static final int DEFAULT_INT_VALUE = 0;
         private static final String DEFAULT_DATE_VALUE = "now";
         private static final String DEFAULT_STRING_VALUE = "";

         private String key = null;
         private int    type = Type.STRING_TYPE;
         private int    operation = Operation.EQUALS_OPER;
         private String value = null;
         private String defaultValue = null;
         private String newValue = null;
         private String pattern = null;
         private int    field = Calendar.DATE;

         /**
          * Name of the property name/value pair
          * @param value the key.
          */
         public void setKey(String value) {
             this.key = value;
         }

         /**
          * Value to set (=), to add (+) or subtract (-)
          * @param value the value.
          */
         public void setValue(String value) {
             this.value = value;
         }

         /**
          * operation to apply.
          * &quot;+&quot; or &quot;=&quot;
          *(default) for all datatypes; &quot;-&quot; for date and int only)\.
          * @param value the operation enumerated value.
          */
         public void setOperation(Operation value) {
             this.operation = Operation.toOperation(value.getValue());
         }

         /**
          * Regard the value as : int, date or string (default)
          * @param value the type enumerated value.
          */
         public void setType(Type value) {
             this.type = Type.toType(value.getValue());
         }

         /**
          * Initial value to set for a property if it is not
          * already defined in the property file.
          * For type date, an additional keyword is allowed: &quot;now&quot;
          * @param value the default value.
          */
         public void setDefault(String value) {
             this.defaultValue = value;
         }

         /**
          * For int and date type only. If present, Values will
          * be parsed and formatted accordingly.
          * @param value the pattern to use.
          */
         public void setPattern(String value) {
             this.pattern = value;
         }

         /**
          * The unit of the value to be applied to date +/- operations.
          *            Valid Values are:
          *            <ul>
          *               <li>millisecond</li>
          *               <li>second</li>
          *               <li>minute</li>
          *               <li>hour</li>
          *               <li>day (default)</li>
          *               <li>week</li>
          *               <li>month</li>
          *               <li>year</li>
          *            </ul>
          *            This only applies to date types using a +/- operation.
          * @param unit the unit enumerated value.
          * @since Ant 1.5
          */
         public void setUnit(PropertyFile.Unit unit) {
             field = unit.getCalendarField();
         }

         /**
          * Apply the nested element to the properties.
          * @param props the properties to apply the entry on.
          * @throws BuildException if there is an error.
          */
         protected void executeOn(Properties props) throws BuildException {
             checkParameters();

             if (operation == Operation.DELETE_OPER) {
                 props.remove(key);
                 return;
             }

             // type may be null because it wasn't set
             String oldValue = (String) props.get(key);
             try {
                 if (type == Type.INTEGER_TYPE) {
                     executeInteger(oldValue);
                 } else if (type == Type.DATE_TYPE) {
                     executeDate(oldValue);
                 } else if (type == Type.STRING_TYPE) {
                     executeString(oldValue);
                 } else {
                     throw new BuildException("Unknown operation type: %d", type);
                 }
             } catch (NullPointerException npe) {
                 // Default to string type
                 // which means do nothing
                 npe.printStackTrace(); //NOSONAR
             }

             if (newValue == null) {
                 newValue = "";
             }

             // Insert as a string by default
             props.put(key, newValue);
         }

         /**
          * Handle operations for type <code>date</code>.
          *
          * @param oldValue the current value read from the property file or
          *                 <code>null</code> if the <code>key</code> was
          *                 not contained in the property file.
          */
         private void executeDate(String oldValue) throws BuildException {
             Calendar currentValue = Calendar.getInstance();

             if (pattern == null) {
                 pattern = "yyyy/MM/dd HH:mm";
             }
             DateFormat fmt = new SimpleDateFormat(pattern);

             String currentStringValue = getCurrentValue(oldValue);
             if (currentStringValue == null) {
                 currentStringValue = DEFAULT_DATE_VALUE;
             }

             if ("now".equals(currentStringValue)) {
                 currentValue.setTime(new Date());
             } else {
                 try {
                     currentValue.setTime(fmt.parse(currentStringValue));
                 } catch (ParseException pe)  {
                     // swallow
                 }
             }

             if (operation != Operation.EQUALS_OPER) {
                 int offset = 0;
                 try {
                     offset = Integer.parseInt(value);
                     if (operation == Operation.DECREMENT_OPER) {
                         offset = -1 * offset;
                     }
                 } catch (NumberFormatException e) {
                     throw new BuildException("Value not an integer on " + key);
                 }
                 currentValue.add(field, offset);
             }

             newValue = fmt.format(currentValue.getTime());
         }

         /**
          * Handle operations for type <code>int</code>.
          *
          * @param oldValue the current value read from the property file or
          *                 <code>null</code> if the <code>key</code> was
          *                 not contained in the property file.
          */
         private void executeInteger(String oldValue) throws BuildException {
             int currentValue = DEFAULT_INT_VALUE;
             int newV  = DEFAULT_INT_VALUE;

             DecimalFormat fmt = (pattern != null) ? new DecimalFormat(pattern)
                 : new DecimalFormat();
             try {
                 String curval = getCurrentValue(oldValue);
                 if (curval != null) {
                     currentValue = fmt.parse(curval).intValue();
                 } else {
                     currentValue = 0;
                 }
             } catch (NumberFormatException | ParseException nfe) {
                 // swallow
             }

             if (operation == Operation.EQUALS_OPER) {
                 newV = currentValue;
             } else {
                 int operationValue = 1;
                 if (value != null) {
                     try {
                         operationValue = fmt.parse(value).intValue();
                     } catch (NumberFormatException | ParseException nfe) {
                         // swallow
                     }
                 }

                 if (operation == Operation.INCREMENT_OPER) {
                     newV = currentValue + operationValue;
                 } else if (operation == Operation.DECREMENT_OPER) {
                     newV = currentValue - operationValue;
                 }
             }

             this.newValue = fmt.format(newV);
         }

         /**
          * Handle operations for type <code>string</code>.
          *
          * @param oldValue the current value read from the property file or
          *                 <code>null</code> if the <code>key</code> was
          *                 not contained in the property file.
          */
         private void executeString(String oldValue) throws BuildException {
             String newV  = DEFAULT_STRING_VALUE;

             String currentValue = getCurrentValue(oldValue);

             if (currentValue == null) {
                 currentValue = DEFAULT_STRING_VALUE;
             }

             if (operation == Operation.EQUALS_OPER) {
                 newV = currentValue;
             } else if (operation == Operation.INCREMENT_OPER) {
                 newV = currentValue + value;
             }
             this.newValue = newV;
         }

         /**
          * Check if parameter combinations can be supported
          * @todo make sure the 'unit' attribute is only specified on date
          *      fields
          */
         private void checkParameters() throws BuildException {
             if (type == Type.STRING_TYPE
                 && operation == Operation.DECREMENT_OPER) {
                 throw new BuildException("- is not supported for string "
                                          + "properties (key:" + key + ")");
             }
             if (value == null && defaultValue == null  && operation != Operation.DELETE_OPER) {
                 throw new BuildException(
                     "\"value\" and/or \"default\" attribute must be specified (key: %s)",
                     key);
             }
             if (key == null) {
                 throw new BuildException("key is mandatory");
             }
             if (type == Type.STRING_TYPE && pattern != null) {
                 throw new BuildException(
                     "pattern is not supported for string properties (key: %s)",
                     key);
             }
         }

         private String getCurrentValue(String oldValue) {
             String ret = null;
             if (operation == Operation.EQUALS_OPER) {
                 // If only value is specified, the property is set to it
                 // regardless of its previous value.
                 if (value != null && defaultValue == null) {
                     ret = value;
                 }

                 // If only default is specified and the property previously
                 // existed in the property file, it is unchanged.
                 if (value == null && defaultValue != null && oldValue != null) {
                     ret = oldValue;
                 }

                 // If only default is specified and the property did not
                 // exist in the property file, the property is set to default.
                 if (value == null && defaultValue != null && oldValue == null) {
                     ret = defaultValue;
                 }

                 // If value and default are both specified and the property
                 // previously existed in the property file, the property
                 // is set to value.
                 if (value != null && defaultValue != null && oldValue != null) {
                     ret = value;
                 }

                 // If value and default are both specified and the property
                 // did not exist in the property file, the property is set
                 // to default.
                 if (value != null && defaultValue != null && oldValue == null) {
                     ret = defaultValue;
                 }
             } else {
                 ret = oldValue == null ? defaultValue : oldValue;
             }

             return ret;
         }

         /**
          * Enumerated attribute with the values "+", "-", "="
          */
         public static class Operation extends EnumeratedAttribute {

             // Property type operations
             /** + */
             public static final int INCREMENT_OPER = 0;
             /** - */
             public static final int DECREMENT_OPER = 1;
             /** = */
             public static final int EQUALS_OPER =    2;
             /** del */
             public static final int DELETE_OPER =    3;

             /** {@inheritDoc}. */
             @Override
             public String[] getValues() {
                 return new String[] {"+", "-", "=", "del"};
             }

             /**
              * Convert string to index.
              * @param oper the string to convert.
              * @return the index.
              */
             public static int toOperation(String oper) {
                 if ("+".equals(oper)) {
                     return INCREMENT_OPER;
                 }
                 if ("-".equals(oper)) {
                     return DECREMENT_OPER;
                 }
                 if ("del".equals(oper)) {
                     return DELETE_OPER;
                 }
                 return EQUALS_OPER;
             }
         }

         /**
          * Enumerated attribute with the values "int", "date" and "string".
          */
         public static class Type extends EnumeratedAttribute {

             // Property types
             /** int */
             public static final int INTEGER_TYPE = 0;
             /** date */
             public static final int DATE_TYPE =    1;
             /** string */
             public static final int STRING_TYPE =  2;

             /** {@inheritDoc} */
             @Override
             public String[] getValues() {
                 return new String[] {"int", "date", "string"};
             }

             /**
              * Convert string to index.
              * @param type the string to convert.
              * @return the index.
              */
             public static int toType(String type) {
                 if ("int".equals(type)) {
                     return INTEGER_TYPE;
                 }
                 if ("date".equals(type)) {
                     return DATE_TYPE;
                 }
                 return STRING_TYPE;
             }
         }
     }

     /**
      * Borrowed from Tstamp
      * @todo share all this time stuff across many tasks as a datetime datatype
      * @since Ant 1.5
      */
     public static class Unit extends EnumeratedAttribute {

         private static final String MILLISECOND = "millisecond";
         private static final String SECOND = "second";
         private static final String MINUTE = "minute";
         private static final String HOUR = "hour";
         private static final String DAY = "day";
         private static final String WEEK = "week";
         private static final String MONTH = "month";
         private static final String YEAR = "year";

         private static final String[] UNITS = {MILLISECOND, SECOND, MINUTE, HOUR, DAY, WEEK, MONTH,
                 YEAR};

         private Map<String, Integer> calendarFields = new HashMap<>();

         /** no arg constructor */
         public Unit() {
             calendarFields.put(MILLISECOND,
                     Calendar.MILLISECOND);
             calendarFields.put(SECOND, Calendar.SECOND);
             calendarFields.put(MINUTE, Calendar.MINUTE);
             calendarFields.put(HOUR, Calendar.HOUR_OF_DAY);
             calendarFields.put(DAY, Calendar.DATE);
             calendarFields.put(WEEK, Calendar.WEEK_OF_YEAR);
             calendarFields.put(MONTH, Calendar.MONTH);
             calendarFields.put(YEAR, Calendar.YEAR);
         }

         /**
          * Convert the value to a Calendar field index.
          * @return the calendar value.
          */
         public int getCalendarField() {
             return calendarFields.get(getValue().toLowerCase());
         }

         /** {@inheritDoc}. */
         @Override
         public String[] getValues() {
             return UNITS;
         }
     }
 }
	/*
	* 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.optional;

	import java.io.BufferedInputStream;
	import java.io.ByteArrayOutputStream;
	import java.io.File;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.nio.file.Files;
	import java.text.DateFormat;
	import java.text.DecimalFormat;
	import java.text.ParseException;
	import java.text.SimpleDateFormat;
	import java.util.Calendar;
	import java.util.Date;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Properties;
	import java.util.Vector;

	import org.apache.tools.ant.BuildException;
	import org.apache.tools.ant.Task;
	import org.apache.tools.ant.types.EnumeratedAttribute;
	import org.apache.tools.ant.util.FileUtils;
	import org.apache.tools.ant.util.LayoutPreservingProperties;

	/**
	* Modifies settings in a property file.
	*
	* <p>The following is an example of its usage:</p>
	* <pre>
	* <target name="setState">
	* <property
	* name="header"
	* value="##Generated file - do not modify!"/>
	* <propertyfile file="apropfile.properties" comment="${header}">
	* <entry key="product.version.major" type="int" value="5"/>
	* <entry key="product.version.minor" type="int" value="0"/>
	* <entry key="product.build.major" type="int" value="0" />
	* <entry key="product.build.minor" type="int" operation="+"/>
	* <entry key="product.build.date" type="date" value="now"/>
	* <entry key="intSet" type="int" operation="=" value="681"/>
	* <entry key="intDec" type="int" operation="-"/>
	* <entry key="StringEquals" type="string" value="testValue"/>
	* </propertyfile>
	* </target>
	* </pre>
	* <p>
	* The <propertyfile> task must have:
	* </p>
	* <ul>
	* <li>file</li>
	* </ul>
	* Other parameters are:
	* <ul>
	* <li>comment</li>
	* <li>key</li>
	* <li>operation</li>
	* <li>type</li>
	* <li>value (the final four being eliminated shortly)</li>
	* </ul>
	* <p>
	* The <entry> task must have:
	* </p>
	* <ul>
	* <li>key</li>
	* </ul>
	* Other parameters are:
	* <ul>
	* <li>operation</li>
	* <li>type</li>
	* <li>value</li>
	* <li>default</li>
	* <li>unit</li>
	* </ul>
	* <p>
	* If type is unspecified, it defaults to string.
	* </p>
	* Parameter values:
	* <dl>
	* <dt>operation:</dt>
	* <dd>
	* <ul>
	* <li>"=" (set -- default)</li>
	* <li>"-" (dec)</li>
	* <li>"+" (inc)</li>
	* </ul>
	* </dd>
	* <dt>type:</dt>
	* <dd>
	* <ul>
	* <li>"int"</li>
	* <li>"date"</li>
	* <li>"string"</li>
	* </ul>
	* </dd>
	* <dt>value:</dt>
	* <dd>
	* <ul>
	* <li>holds the default value, if the property
	* was not found in property file</li>
	* <li>"now" In case of type "date", the
	* value "now" will be replaced by the current
	* date/time and used even if a valid date was
	* found in the property file.</li>
	* </ul>
	* </dd>
	* </dl>
	*
	* <p>String property types can only use the "=" operation.
	* Int property types can only use the "=", "-" or "+" operations.<p>
	*
	* The message property is used for the property file header, with "\\" being
	* a newline delimiter character.
	*
	*/
	public class PropertyFile extends Task {

	/* ========================================================================
	*
	* Instance variables.
	*/

	// Use this to prepend a message to the properties file
	private String comment;

	private Properties properties;
	private File propertyfile;
	private boolean useJDKProperties;

	private Vector<Entry> entries = new Vector<>();

	/* ========================================================================
	*
	* Constructors
	*/

	/* ========================================================================
	*
	* Methods
	*/

	/**
	* Execute the task.
	* @throws BuildException on error.
	*/
	@Override
	public void execute() throws BuildException {
	checkParameters();
	readFile();
	executeOperation();
	writeFile();
	}

	/**
	* The entry nested element.
	* @return an entry nested element to be configured.
	*/
	public Entry createEntry() {
	Entry e = new Entry();
	entries.addElement(e);
	return e;
	}

	private void executeOperation() throws BuildException {
	entries.forEach(e -> e.executeOn(properties));
	}

	private void readFile() throws BuildException {
	if (useJDKProperties) {
	// user chose to use standard Java properties, which loose
	// comments and layout
	properties = new Properties();
	} else {
	properties = new LayoutPreservingProperties();
	}
	try {
	if (propertyfile.exists()) {
	log("Updating property file: "
	+ propertyfile.getAbsolutePath());
	try (InputStream fis = Files.newInputStream(propertyfile.toPath());
	BufferedInputStream bis = new BufferedInputStream(fis)) {
	properties.load(bis);
	}
	} else {
	log("Creating new property file: "
	+ propertyfile.getAbsolutePath());
	try (OutputStream out =
	Files.newOutputStream(propertyfile.toPath())) {
	out.flush();
	}
	}
	} catch (IOException ioe) {
	throw new BuildException(ioe.toString());
	}
	}

	private void checkParameters() throws BuildException {
	if (!checkParam(propertyfile)) {
	throw new BuildException("file token must not be null.",
	getLocation());
	}
	}

	/**
	* Location of the property file to be edited; required.
	* @param file the property file.
	*/
	public void setFile(File file) {
	propertyfile = file;
	}

	/**
	* optional header comment for the file
	* @param hdr the string to use for the comment.
	*/
	public void setComment(String hdr) {
	comment = hdr;
	}

	/**
	* optional flag to use original Java properties (as opposed to
	* layout preserving properties)
	* @param val boolean
	*/
	public void setJDKProperties(boolean val) {
	useJDKProperties = val;
	}

	private void writeFile() throws BuildException {
	// Write to RAM first, as an OOME could otherwise produce a truncated file:
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	try {
	properties.store(baos, comment);
	} catch (IOException x) { // should not happen
	throw new BuildException(x, getLocation());
	}
	try {
	try (OutputStream os = Files.newOutputStream(propertyfile.toPath())) {
	os.write(baos.toByteArray());
	} catch (IOException x) { // possibly corrupt
	FileUtils.getFileUtils().tryHardToDelete(propertyfile);
	throw x;
	}
	} catch (IOException x) { // opening, writing, or closing
	throw new BuildException(x, getLocation());
	}
	}

	private boolean checkParam(File param) {
	return param != null;
	}

	/**
	* Instance of this class represents nested elements of
	* a task propertyfile.
	*/
	public static class Entry {
	private static final int DEFAULT_INT_VALUE = 0;
	private static final String DEFAULT_DATE_VALUE = "now";
	private static final String DEFAULT_STRING_VALUE = "";

	private String key = null;
	private int type = Type.STRING_TYPE;
	private int operation = Operation.EQUALS_OPER;
	private String value = null;
	private String defaultValue = null;
	private String newValue = null;
	private String pattern = null;
	private int field = Calendar.DATE;

	/**
	* Name of the property name/value pair
	* @param value the key.
	*/
	public void setKey(String value) {
	this.key = value;
	}

	/**
	* Value to set (=), to add (+) or subtract (-)
	* @param value the value.
	*/
	public void setValue(String value) {
	this.value = value;
	}

	/**
	* operation to apply.
	* "+" or "="
	*(default) for all datatypes; "-" for date and int only)\.
	* @param value the operation enumerated value.
	*/
	public void setOperation(Operation value) {
	this.operation = Operation.toOperation(value.getValue());
	}

	/**
	* Regard the value as : int, date or string (default)
	* @param value the type enumerated value.
	*/
	public void setType(Type value) {
	this.type = Type.toType(value.getValue());
	}

	/**
	* Initial value to set for a property if it is not
	* already defined in the property file.
	* For type date, an additional keyword is allowed: "now"
	* @param value the default value.
	*/
	public void setDefault(String value) {
	this.defaultValue = value;
	}

	/**
	* For int and date type only. If present, Values will
	* be parsed and formatted accordingly.
	* @param value the pattern to use.
	*/
	public void setPattern(String value) {
	this.pattern = value;
	}

	/**
	* The unit of the value to be applied to date +/- operations.
	* Valid Values are:
	* <ul>
	* <li>millisecond</li>
	* <li>second</li>
	* <li>minute</li>
	* <li>hour</li>
	* <li>day (default)</li>
	* <li>week</li>
	* <li>month</li>
	* <li>year</li>
	* </ul>
	* This only applies to date types using a +/- operation.
	* @param unit the unit enumerated value.
	* @since Ant 1.5
	*/
	public void setUnit(PropertyFile.Unit unit) {
	field = unit.getCalendarField();
	}

	/**
	* Apply the nested element to the properties.
	* @param props the properties to apply the entry on.
	* @throws BuildException if there is an error.
	*/
	protected void executeOn(Properties props) throws BuildException {
	checkParameters();

	if (operation == Operation.DELETE_OPER) {
	props.remove(key);
	return;
	}

	// type may be null because it wasn't set
	String oldValue = (String) props.get(key);
	try {
	if (type == Type.INTEGER_TYPE) {
	executeInteger(oldValue);
	} else if (type == Type.DATE_TYPE) {
	executeDate(oldValue);
	} else if (type == Type.STRING_TYPE) {
	executeString(oldValue);
	} else {
	throw new BuildException("Unknown operation type: %d", type);
	}
	} catch (NullPointerException npe) {
	// Default to string type
	// which means do nothing
	npe.printStackTrace(); //NOSONAR
	}

	if (newValue == null) {
	newValue = "";
	}

	// Insert as a string by default
	props.put(key, newValue);
	}

	/**
	* Handle operations for type <code>date</code>.
	*
	* @param oldValue the current value read from the property file or
	* <code>null</code> if the <code>key</code> was
	* not contained in the property file.
	*/
	private void executeDate(String oldValue) throws BuildException {
	Calendar currentValue = Calendar.getInstance();

	if (pattern == null) {
	pattern = "yyyy/MM/dd HH:mm";
	}
	DateFormat fmt = new SimpleDateFormat(pattern);

	String currentStringValue = getCurrentValue(oldValue);
	if (currentStringValue == null) {
	currentStringValue = DEFAULT_DATE_VALUE;
	}

	if ("now".equals(currentStringValue)) {
	currentValue.setTime(new Date());
	} else {
	try {
	currentValue.setTime(fmt.parse(currentStringValue));
	} catch (ParseException pe) {
	// swallow
	}
	}

	if (operation != Operation.EQUALS_OPER) {
	int offset = 0;
	try {
	offset = Integer.parseInt(value);
	if (operation == Operation.DECREMENT_OPER) {
	offset = -1 * offset;
	}
	} catch (NumberFormatException e) {
	throw new BuildException("Value not an integer on " + key);
	}
	currentValue.add(field, offset);
	}

	newValue = fmt.format(currentValue.getTime());
	}

	/**
	* Handle operations for type <code>int</code>.
	*
	* @param oldValue the current value read from the property file or
	* <code>null</code> if the <code>key</code> was
	* not contained in the property file.
	*/
	private void executeInteger(String oldValue) throws BuildException {
	int currentValue = DEFAULT_INT_VALUE;
	int newV = DEFAULT_INT_VALUE;

	DecimalFormat fmt = (pattern != null) ? new DecimalFormat(pattern)
	: new DecimalFormat();
	try {
	String curval = getCurrentValue(oldValue);
	if (curval != null) {
	currentValue = fmt.parse(curval).intValue();
	} else {
	currentValue = 0;
	}
	} catch (NumberFormatException \| ParseException nfe) {
	// swallow
	}

	if (operation == Operation.EQUALS_OPER) {
	newV = currentValue;
	} else {
	int operationValue = 1;
	if (value != null) {
	try {
	operationValue = fmt.parse(value).intValue();
	} catch (NumberFormatException \| ParseException nfe) {
	// swallow
	}
	}

	if (operation == Operation.INCREMENT_OPER) {
	newV = currentValue + operationValue;
	} else if (operation == Operation.DECREMENT_OPER) {
	newV = currentValue - operationValue;
	}
	}

	this.newValue = fmt.format(newV);
	}

	/**
	* Handle operations for type <code>string</code>.
	*
	* @param oldValue the current value read from the property file or
	* <code>null</code> if the <code>key</code> was
	* not contained in the property file.
	*/
	private void executeString(String oldValue) throws BuildException {
	String newV = DEFAULT_STRING_VALUE;

	String currentValue = getCurrentValue(oldValue);

	if (currentValue == null) {
	currentValue = DEFAULT_STRING_VALUE;
	}

	if (operation == Operation.EQUALS_OPER) {
	newV = currentValue;
	} else if (operation == Operation.INCREMENT_OPER) {
	newV = currentValue + value;
	}
	this.newValue = newV;
	}

	/**
	* Check if parameter combinations can be supported
	* @todo make sure the 'unit' attribute is only specified on date
	* fields
	*/
	private void checkParameters() throws BuildException {
	if (type == Type.STRING_TYPE
	&& operation == Operation.DECREMENT_OPER) {
	throw new BuildException("- is not supported for string "
	+ "properties (key:" + key + ")");
	}
	if (value == null && defaultValue == null && operation != Operation.DELETE_OPER) {
	throw new BuildException(
	"\"value\" and/or \"default\" attribute must be specified (key: %s)",
	key);
	}
	if (key == null) {
	throw new BuildException("key is mandatory");
	}
	if (type == Type.STRING_TYPE && pattern != null) {
	throw new BuildException(
	"pattern is not supported for string properties (key: %s)",
	key);
	}
	}

	private String getCurrentValue(String oldValue) {
	String ret = null;
	if (operation == Operation.EQUALS_OPER) {
	// If only value is specified, the property is set to it
	// regardless of its previous value.
	if (value != null && defaultValue == null) {
	ret = value;
	}

	// If only default is specified and the property previously
	// existed in the property file, it is unchanged.
	if (value == null && defaultValue != null && oldValue != null) {
	ret = oldValue;
	}

	// If only default is specified and the property did not
	// exist in the property file, the property is set to default.
	if (value == null && defaultValue != null && oldValue == null) {
	ret = defaultValue;
	}

	// If value and default are both specified and the property
	// previously existed in the property file, the property
	// is set to value.
	if (value != null && defaultValue != null && oldValue != null) {
	ret = value;
	}

	// If value and default are both specified and the property
	// did not exist in the property file, the property is set
	// to default.
	if (value != null && defaultValue != null && oldValue == null) {
	ret = defaultValue;
	}
	} else {
	ret = oldValue == null ? defaultValue : oldValue;
	}

	return ret;
	}

	/**
	* Enumerated attribute with the values "+", "-", "="
	*/
	public static class Operation extends EnumeratedAttribute {

	// Property type operations
	/** + */
	public static final int INCREMENT_OPER = 0;
	/** - */
	public static final int DECREMENT_OPER = 1;
	/** = */
	public static final int EQUALS_OPER = 2;
	/** del */
	public static final int DELETE_OPER = 3;

	/** {@inheritDoc}. */
	@Override
	public String[] getValues() {
	return new String[] {"+", "-", "=", "del"};
	}

	/**
	* Convert string to index.
	* @param oper the string to convert.
	* @return the index.
	*/
	public static int toOperation(String oper) {
	if ("+".equals(oper)) {
	return INCREMENT_OPER;
	}
	if ("-".equals(oper)) {
	return DECREMENT_OPER;
	}
	if ("del".equals(oper)) {
	return DELETE_OPER;
	}
	return EQUALS_OPER;
	}
	}

	/**
	* Enumerated attribute with the values "int", "date" and "string".
	*/
	public static class Type extends EnumeratedAttribute {

	// Property types
	/** int */
	public static final int INTEGER_TYPE = 0;
	/** date */
	public static final int DATE_TYPE = 1;
	/** string */
	public static final int STRING_TYPE = 2;

	/** {@inheritDoc} */
	@Override
	public String[] getValues() {
	return new String[] {"int", "date", "string"};
	}

	/**
	* Convert string to index.
	* @param type the string to convert.
	* @return the index.
	*/
	public static int toType(String type) {
	if ("int".equals(type)) {
	return INTEGER_TYPE;
	}
	if ("date".equals(type)) {
	return DATE_TYPE;
	}
	return STRING_TYPE;
	}
	}
	}

	/**
	* Borrowed from Tstamp
	* @todo share all this time stuff across many tasks as a datetime datatype
	* @since Ant 1.5
	*/
	public static class Unit extends EnumeratedAttribute {

	private static final String MILLISECOND = "millisecond";
	private static final String SECOND = "second";
	private static final String MINUTE = "minute";
	private static final String HOUR = "hour";
	private static final String DAY = "day";
	private static final String WEEK = "week";
	private static final String MONTH = "month";
	private static final String YEAR = "year";

	private static final String[] UNITS = {MILLISECOND, SECOND, MINUTE, HOUR, DAY, WEEK, MONTH,
	YEAR};

	private Map<String, Integer> calendarFields = new HashMap<>();

	/** no arg constructor */
	public Unit() {
	calendarFields.put(MILLISECOND,
	Calendar.MILLISECOND);
	calendarFields.put(SECOND, Calendar.SECOND);
	calendarFields.put(MINUTE, Calendar.MINUTE);
	calendarFields.put(HOUR, Calendar.HOUR_OF_DAY);
	calendarFields.put(DAY, Calendar.DATE);
	calendarFields.put(WEEK, Calendar.WEEK_OF_YEAR);
	calendarFields.put(MONTH, Calendar.MONTH);
	calendarFields.put(YEAR, Calendar.YEAR);
	}

	/**
	* Convert the value to a Calendar field index.
	* @return the calendar value.
	*/
	public int getCalendarField() {
	return calendarFields.get(getValue().toLowerCase());
	}

	/** {@inheritDoc}. */
	@Override
	public String[] getValues() {
	return UNITS;
	}
	}
	}