PropertiesLauncher (Spring Boot 2.6.14 API)

java.lang.Object
- org.springframework.boot.loader.Launcher
- - org.springframework.boot.loader.PropertiesLauncher

```
public class PropertiesLauncher
extends Launcher
```
Launcher for archives with user-configured classpath and main class via a properties file. This model is often more flexible and more amenable to creating well-behaved OS-level services than a model based on executable jars.
Looks in various places for a properties file to extract loader settings, defaulting to loader.properties either on the current classpath or in the current working directory. The name of the properties file can be changed by setting a System property loader.config.name (e.g. -Dloader.config.name=foo will look for foo.properties. If that file doesn't exist then tries loader.config.location (with allowed prefixes classpath: and file: or any valid URL). Once that file is located turns it into Properties and extracts optional values (which can also be provided overridden as System properties in case the file doesn't exist):
- loader.path: a comma-separated list of directories (containing file resources and/or nested archives in *.jar or *.zip or archives) or archives to append to the classpath. BOOT-INF/classes,BOOT-INF/lib in the application archive are always used
- loader.main: the main method to delegate execution to once the class loader is set up. No default, but will fall back to looking for a Start-Class in a MANIFEST.MF, if there is one in ${loader.home}/META-INF.
Since:

1.0.0

Author:

Dave Syer, Janne Valkealahti, Andy Wilkinson

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`ARGS` Properties key for default command line arguments.
`static String`	`CONFIG_LOCATION` Properties key for config file location (including optional classpath:, file: or URL prefix).
`static String`	`CONFIG_NAME` Properties key for name of external configuration file (excluding suffix).
`static String`	`HOME` Properties key for home directory.
`static String`	`MAIN` Properties key for main class.
`static String`	`PATH` Properties key for classpath entries (directories possibly containing jars or jars).
`static String`	`SET_SYSTEM_PROPERTIES` Properties key for boolean flag (default false) which, if set, will cause the external configuration properties to be copied to System properties (assuming that is allowed by Java security).

Constructor Summary

Constructors
Constructor and Description

PropertiesLauncher()

Constructors
Constructor and Description
`PropertiesLauncher()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected ClassLoader`	`createClassLoader(Iterator<Archive> archives)` Create a classloader for the specified archives.
`protected String[]`	`getArgs(String... args)`
`protected Iterator<Archive>`	`getClassPathArchivesIterator()` Returns the archives that will be used to construct the class path.
`protected File`	`getHomeDirectory()`
`protected String`	`getMainClass()` Returns the main class that should be launched.
`static void`	`main(String[] args)`
`static String`	`toCamelCase(CharSequence string)`

Methods inherited from class org.springframework.boot.loader.Launcher
createArchive, createClassLoader, createClassLoader, createMainMethodRunner, getArchive, getClassPathArchives, isExploded, launch, launch

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - MAIN
```
public static final String MAIN
```
    Properties key for main class. As a manifest entry can also be specified as Start-Class.
    
    See Also:
    
    Constant Field Values
  - PATH
```
public static final String PATH
```
    Properties key for classpath entries (directories possibly containing jars or jars). Multiple entries can be specified using a comma-separated list. BOOT-INF/classes,BOOT-INF/lib in the application archive are always used.
    
    See Also:
    
    Constant Field Values
  - HOME
```
public static final String HOME
```
    Properties key for home directory. This is the location of external configuration if not on classpath, and also the base path for any relative paths in the loader path. Defaults to current working directory ( ${user.dir}).
    
    See Also:
    
    Constant Field Values
  - ARGS
```
public static final String ARGS
```
    Properties key for default command line arguments. These arguments (if present) are prepended to the main method arguments before launching.
    
    See Also:
    
    Constant Field Values
  - CONFIG_NAME
```
public static final String CONFIG_NAME
```
    Properties key for name of external configuration file (excluding suffix). Defaults to "application". Ignored if loader config location is provided instead.
    
    See Also:
    
    Constant Field Values
  - CONFIG_LOCATION
```
public static final String CONFIG_LOCATION
```
    Properties key for config file location (including optional classpath:, file: or URL prefix).
    
    See Also:
    
    Constant Field Values
  - SET_SYSTEM_PROPERTIES
```
public static final String SET_SYSTEM_PROPERTIES
```
    Properties key for boolean flag (default false) which, if set, will cause the external configuration properties to be copied to System properties (assuming that is allowed by Java security).
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - PropertiesLauncher
```
public PropertiesLauncher()
```
- Method Detail
  - getHomeDirectory
```
protected File getHomeDirectory()
```
  - getArgs
```
protected String[] getArgs(String... args)
                    throws Exception
```
    Throws:
    
    Exception
  - getMainClass
```
protected String getMainClass()
                       throws Exception
```
    Description copied from class: Launcher
    
    Returns the main class that should be launched.
    
    Specified by:
    
    getMainClass in class Launcher
    
    Returns:
    
    the name of the main class
    
    Throws:
    
    Exception - if the main class cannot be obtained
  - createClassLoader
```
protected ClassLoader createClassLoader(Iterator<Archive> archives)
                                 throws Exception
```
    Description copied from class: Launcher
    
    Create a classloader for the specified archives.
    
    Overrides:
    
    createClassLoader in class Launcher
    
    Parameters:
    
    archives - the archives
    
    Returns:
    
    the classloader
    
    Throws:
    
    Exception - if the classloader cannot be created
  - getClassPathArchivesIterator
```
protected Iterator<Archive> getClassPathArchivesIterator()
                                                  throws Exception
```
    Description copied from class: Launcher
    
    Returns the archives that will be used to construct the class path.
    
    Overrides:
    
    getClassPathArchivesIterator in class Launcher
    
    Returns:
    
    the class path archives
    
    Throws:
    
    Exception - if the class path archives cannot be obtained
  - main
```
public static void main(String[] args)
                 throws Exception
```
    Throws:
    
    Exception
  - toCamelCase
```
public static String toCamelCase(CharSequence string)
```

Class PropertiesLauncher

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.springframework.boot.loader.Launcher

Methods inherited from class java.lang.Object

Field Detail

MAIN

PATH

HOME

ARGS

CONFIG_NAME

CONFIG_LOCATION

SET_SYSTEM_PROPERTIES

Constructor Detail

PropertiesLauncher

Method Detail

getHomeDirectory

getArgs

getMainClass

createClassLoader

getClassPathArchivesIterator

main

toCamelCase