External Application Properties
Spring Boot will automatically find and load application.properties
and application.yaml
files from the following locations when your application starts:
-
From the classpath
-
The classpath root
-
The classpath
/config
package
-
-
From the current directory
-
The current directory
-
The
config/
subdirectory in the current directory -
Immediate child directories of the
config/
subdirectory
-
The list is ordered by precedence (with values from lower items overriding earlier ones).
Documents from the loaded files are added as PropertySources
to the Spring Environment
.
If you do not like application
as the configuration file name, you can switch to another file name by specifying a spring.config.name
environment property.
For example, to look for myproject.properties
and myproject.yaml
files you can run your application as follows:
$ java -jar myproject.jar --spring.config.name=myproject
You can also refer to an explicit location by using the spring.config.location
environment property.
This property accepts a comma-separated list of one or more locations to check.
The following example shows how to specify two distinct files:
$ java -jar myproject.jar --spring.config.location=\
optional:classpath:/default.properties,\
optional:classpath:/override.properties
Use the prefix optional: if the locations are optional and you do not mind if they do not exist.
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spring.config.name , spring.config.location , and spring.config.additional-location are used very early to determine which files have to be loaded.
They must be defined as an environment property (typically an OS environment variable, a system property, or a command-line argument).
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If spring.config.location
contains directories (as opposed to files), they should end in /
.
At runtime they will be appended with the names generated from spring.config.name
before being loaded.
Files specified in spring.config.location
are imported directly.
Both directory and file location values are also expanded to check for profile-specific files.
For example, if you have a spring.config.location of classpath:myconfig.properties , you will also find appropriate classpath:myconfig-<profile>.properties files are loaded.
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In most situations, each spring.config.location
item you add will reference a single file or directory.
Locations are processed in the order that they are defined and later ones can override the values of earlier ones.
If you have a complex location setup, and you use profile-specific configuration files, you may need to provide further hints so that Spring Boot knows how they should be grouped.
A location group is a collection of locations that are all considered at the same level.
For example, you might want to group all classpath locations, then all external locations.
Items within a location group should be separated with ;
.
See the example in the “Profile Specific Files” section for more details.
Locations configured by using spring.config.location
replace the default locations.
For example, if spring.config.location
is configured with the value optional:classpath:/custom-config/,optional:file:./custom-config/
, the complete set of locations considered is:
-
optional:classpath:custom-config/
-
optional:file:./custom-config/
If you prefer to add additional locations, rather than replacing them, you can use spring.config.additional-location
.
Properties loaded from additional locations can override those in the default locations.
For example, if spring.config.additional-location
is configured with the value optional:classpath:/custom-config/,optional:file:./custom-config/
, the complete set of locations considered is:
-
optional:classpath:/;optional:classpath:/config/
-
optional:file:./;optional:file:./config/;optional:file:./config/*/
-
optional:classpath:custom-config/
-
optional:file:./custom-config/
This search ordering lets you specify default values in one configuration file and then selectively override those values in another.
You can provide default values for your application in application.properties
(or whatever other basename you choose with spring.config.name
) in one of the default locations.
These default values can then be overridden at runtime with a different file located in one of the custom locations.
If you use environment variables rather than system properties, most operating systems disallow period-separated key names, but you can use underscores instead (for example, SPRING_CONFIG_NAME instead of spring.config.name ).
See Binding From Environment Variables for details.
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If your application runs in a servlet container or application server, then JNDI properties (in java:comp/env ) or servlet context initialization parameters can be used instead of, or as well as, environment variables or system properties.
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