# [Bld](https://github.com/rife2/rife2/wiki/What-Is-Bld) Extension to Create or Modify Properties Files
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[](https://www.oracle.com/java/technologies/javase/jdk17-archive-downloads.html)
[](https://repo.rife2.com/#/releases/com/uwyn/rife2/bld-property-file)
[](https://repo.rife2.com/#/snapshots/com/uwyn/rife2/bld-property-file)
[](https://github.com/rife2/bld-property-file/actions/workflows/bld.yml)
An extension for creating or modifying [property files](https://docs.oracle.com/javase/tutorial/essential/environment/properties.html) with [bld](https://github.com/rife2/rife2/wiki/What-Is-Bld). It is inspired by the [ant PropertyFile task](https://ant.apache.org/manual/Tasks/propertyfile.html).
```java
@BuildCommand
public void updateMajor() throws Exception {
new PropertyFileOperation(this)
.file("version.properties")
.entry(new EntryInt("version.major").defaultValue(0).calc(ADD))
.entry(new EntryInt("version.minor").set(0))
.entry(new EntryInt("version.patch").set(0))
.entry(new EntryDate("build.date").now().pattern("yyyy-MM-dd"))
.execute();
}
```
Invoking the `updateMajor` command, will create the `version.propertees`file:
```sh
./bld updateMajor ...
```
```ini
# version.properties
build.date=2023-04-02
version.major=1
version.minor=0
version.patch=0
```
Invoking the `updateMajor` command again, will increase the `version.major` property:
```sh
./bld updateMajor ...
```
```ini
# version.properties
build.date=2023-04-02
version.major=2
version.minor=0
version.patch=0
```
- [View Examples](https://github.com/rife2/bld-property-file/tree/master/examples)
## Property File
The [PropertyFileOperation](https://rife2.github.io/bld-property-file/rife/bld/extension/propertyfile/PropertyFileOperation.html) class is used to configure the [properties file](https://docs.oracle.com/javase/tutorial/essential/environment/properties.html) location, etc.
| Function | Description | Required |
|:------------------|:----------------------------------------------------------------|:---------|
| `file()` | The location of the properties files to modify. | Yes |
| `comment()` | Comment to be inserted at the top of the properties file. | No |
| `failOnWarning()` | If set to `true`, will cause execution to fail on any warnings. | No |
## Entry
The [Entry](https://rife2.github.io/bld-property-file/rife/bld/extension/propertyfile/Entry.html) class is used to specify modifications to a [String property](https://docs.oracle.com/javase/tutorial/essential/environment/properties.html).
| Function | Description/Example |
|:-----------------|:--------------------------------------------------------------------------------------------------------|
| `defaultValue()` | The value to be used if the property doesn't exist. |
| `delete()` | Delete the property. |
| `modify()` | `modify("-foo", String::concat)`
`modify("-foo", (v, s) -> v + s)`
`modify((v, s) -> v.trim())` | Modify an entry value. |
| `set()` | The value to set the property to, regardless of its previous value. |
## EntryDate
The [EntryDate](https://rife2.github.io/bld-property-file/rife/bld/extension/propertyfile/EntryDate.html) class is used to specify modifications to a [date property](https://docs.oracle.com/javase/tutorial/essential/environment/properties.html).
| Function | Description/Example |
|:-----------------|:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `calc()` | `calc(ADD)`
`calc(v -> v + 1)`
`calc(SUB)`
`calc(v -> v - 1)` |
| `delete()` | Delete the property. |
| `now()` | Set the entry to the current date/time. |
| `pattern()` | If present, will parse the value as a [DateTimeFormatter](https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/time/format/DateTimeFormatter.html) pattern. |
| `set()` | The [Calendar](https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Calendar.html), [Date](https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Date.html), or [java.time](https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/time/package-summary.html) value to set the property to, regardless of its previous value. |
| `unit()` | The unit to be used calculations. See [Units](#units). |
- `set` or `now` are required.
### Units
The following [Units](https://rife2.github.io/bld-property-file/rife/bld/extension/propertyfile/EntryDate.Units.html) are available:
* `Units.MILLISECOND`
* `Units.SECOND`
* `Units.MINUTE`
* `Units.HOUR`
* `Units.DAY`
* `Units.WEEK`
* `Units.MONTH`
* `Units.YEAR`
## EntryInt
The [EntryInt](https://rife2.github.io/bld-property-file/rife/bld/extension/propertyfile/EntryInt.html) class is used to specify modifications to a [integer property](https://docs.oracle.com/javase/tutorial/essential/environment/properties.html).
| Function | Description/Example |
|:-----------------|:-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `defaultValue()` | The value to be used if the property doesn't exist. |
| `calc()` | `calc(ADD)`
`calc(v -> v + 1)`
`calc(SUB)`
`calc(v -> v - 1)` |
| `delete()` | Delete the property. |
| `pattern()` | If present, will parse the value as a [DecimalFormat](https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/text/DecimalFormat.html) pattern. |
| `set()` | The [integer value](https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Integer.html) to set the property to, regardless of its previous value. |