How to convert from application.properties to application.yml in Spring Boot?

Question

I have a very simple Spring Boot app and I have application.properties, and now I want to move to application.yml

This is the application.yml file:

spring:
    datasource:
        url: jdbc:mysql://localhost:3306/employee_directory
        username: student
        password: Password123

So I've deleted application.properties file and I've written the application.yml file. If I run the app I get this exception:

   20:31:22.446 [restartedMain] ERROR org.springframework.boot.SpringApplication - Application run failed
java.lang.IllegalStateException: Failed to load property source from location 'classpath:/application.yml'
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:524)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadForFileExtension(ConfigFileApplicationListener.java:473)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:443)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.lambda$null$6(ConfigFileApplicationListener.java:425)
    at java.lang.Iterable.forEach(Iterable.java:75)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.lambda$load$7(ConfigFileApplicationListener.java:425)
    at java.lang.Iterable.forEach(Iterable.java:75)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:422)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:321)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.addPropertySources(ConfigFileApplicationListener.java:202)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:186)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:176)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:164)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:75)
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:53)
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:340)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:304)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1213)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1202)
    at com.dgs.springboot.SpringBootRESTJPA.SpringBootRestJPAApplication.main(SpringBootRestJPAApplication.java:10)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
Caused by: org.yaml.snakeyaml.scanner.ScannerException: while scanning for the next token
found character '\t(TAB)' that cannot start any token. (Do not use \t(TAB) for indentation)
 in 'reader', line 2, column 1:
        datasource:
    ^

    at org.yaml.snakeyaml.scanner.ScannerImpl.fetchMoreTokens(ScannerImpl.java:419)
    at org.yaml.snakeyaml.scanner.ScannerImpl.checkToken(ScannerImpl.java:227)
    at org.yaml.snakeyaml.parser.ParserImpl$ParseBlockMappingValue.produce(ParserImpl.java:586)
    at org.yaml.snakeyaml.parser.ParserImpl.peekEvent(ParserImpl.java:158)
    at org.yaml.snakeyaml.parser.ParserImpl.checkEvent(ParserImpl.java:148)
    at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:124)
    at org.yaml.snakeyaml.composer.Composer.composeValueNode(Composer.java:236)
    at org.yaml.snakeyaml.composer.Composer.composeMappingChildren(Composer.java:227)
    at org.yaml.snakeyaml.composer.Composer.composeMappingNode(Composer.java:215)
    at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:144)
    at org.yaml.snakeyaml.composer.Composer.getNode(Composer.java:85)
    at org.yaml.snakeyaml.constructor.BaseConstructor.getData(BaseConstructor.java:123)
    at org.yaml.snakeyaml.Yaml$1.next(Yaml.java:547)
    at org.springframework.beans.factory.config.YamlProcessor.process(YamlProcessor.java:160)
    at org.springframework.beans.factory.config.YamlProcessor.process(YamlProcessor.java:134)
    at org.springframework.boot.env.OriginTrackedYamlLoader.load(OriginTrackedYamlLoader.java:75)
    at org.springframework.boot.env.YamlPropertySourceLoader.load(YamlPropertySourceLoader.java:49)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadDocuments(ConfigFileApplicationListener.java:542)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:497)
    ... 28 common frames omitted

I think I need to make other modification to my code to use this application.yml file but I don't know what to do?

This is pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.dgs.springboot</groupId>
    <artifactId>SpringBootRESTHibernate</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>SpringBootRESTHibernate</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <!-- Add work around for Eclipse bug -->
        <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
          <groupId>org.projectlombok</groupId>
          <artifactId>lombok</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <!-- This is used for packaging and running our app -->
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Any feedback will be appreciated. Thank you!

The message is quite clear: `found character '\t(TAB)' that cannot start any token. (Do not use \t(TAB) for indentation)`. — JB Nizet, Aug 12 '19 at 17:51

sdoxsee · Answer 1 · 2022-03-02T00:04:33.450

39

I built an online conversion tool (https://env.simplestep.ca/) that converts between spring boot yaml, properties and environment variables--using spring boot's relaxed binding rules

edited Mar 02 '22 at 00:04

answered Jun 11 '21 at 13:30

sdoxsee

4,451
1
25
60

1

**There's [this online converter](http://mageddo.com/tools/yaml-converter) also**, if someone needs it. – Maicon Mauricio Oct 05 '21 at 11:27
works great, you just need to handle comments, had to remove them in order to work ;) – rmpt Nov 02 '22 at 09:57
1

This literally is a life saver, thank you! – RogueGingerz Mar 09 '23 at 18:24
1

Good contribution, but does not accept comments and doesn't properly convert indexed properties (`my.property[0]=x`, `my.property[1]=y`, etc.) – Paulo Merson May 05 '23 at 18:52
@PauloMerson, should handle the indexed properties (see the properties example). I have an open issue for ignoring comments. PR welcome! – sdoxsee May 05 '23 at 19:53
Be carefull. with sending sensitive information to an online tool. – Martijn Jan Jaap de Bruin Jul 16 '23 at 08:26

Md.Habibur Rahman · Answer 2 · 2022-07-17T04:52:10.213

4

for intellij-IDEA : go to file > settings > plugins then search for a plugin called: Properties to YAML Converter. Install it and After that restart your IDE then right click the application.properties file and you will get an option called "convert to yaml"

edited Jul 17 '22 at 04:52

answered Mar 02 '22 at 07:09

Md.Habibur Rahman

307
3
9

score 3 · Answer 3 · answered Aug 12 '19 at 18:02

Check if you are using tabs for indentation. This is not permitted by the YAML spec:

To maintain portability, tab characters must not be used in indentation, since different systems treat tabs differently. Note that most modern editors may be configured so that pressing the tab key results in the insertion of an appropriate number of spaces.

score 3 · Answer 4 · answered Mar 20 '20 at 14:08

3

You can use the command line tool props2yaml for generic automatic (and correct) translation from properties to yaml.

answered Mar 20 '20 at 14:08

vboerchers

767
1
6
16

score 3 · Answer 5 · answered Jul 25 '22 at 11:55

3

Found a good online tool to convert properties to YAML -

Properties to YAML online converter

answered Jul 25 '22 at 11:55

Batman Rises

597
6
9

This online converter unfortunately repositions the **properties in alphabetical order**. – Paulo Merson May 05 '23 at 17:59

Shadyar · Answer 6 · 2022-01-23T05:38:51.240

1

If you use Eclipse or STS it's very simple.

Just open the context menu on the .properties file and choose "Convert to Yaml file".

The file will be converted automatically. If there is not this feature on your context menu you need to install Yaml plugin from

Help menu-> Eclipse market place.

edited Jan 23 '22 at 05:38

answered Apr 15 '20 at 06:39

Shadyar

709
8
16

Which yaml plugin on the market place? There are a bunch. – ScrappyDev May 05 '20 at 14:54
1

I had Spring Boot project and Plug in & it was very easy to convert using this option , thx ! – Sabir Khan May 17 '22 at 09:45

score 0 · Answer 7 · answered Aug 12 '19 at 17:53

I think your datasource.url value needs to be in quotes, due to the ':'. Try this:

  ...
  url: 'jdbc:mysql://localhost:3306/employee_directory'
  ...

Also, as was pointed about above, you should use spaces for indentation; typically, two spaces per level.

Good luck!

score 0 · Answer 8 · answered May 10 '21 at 18:14

0

This is just an additional answer, might help other developers.

I found a better and easy tool to convert properties file to YML file. convert from properties to yml

You have to upload your .properties file and then Choose To YML file option and it will generate a pretty good yml file. This tool supports many other formats also like Yml to XML, Yml to Properties, CSV, JSON, etc.

answered May 10 '21 at 18:14

bharatpatel

1,203
11
22

Unfortunately, it removes all comments and doesn't properly convert indexed properties (`my.property[0]=x`, `my.property[1]=y`, etc.) – Paulo Merson May 05 '23 at 19:18

score 0 · Answer 9 · edited Sep 08 '21 at 12:24

0

File application.yml must be in the root folder resources.

edited Sep 08 '21 at 12:24

bad_coder

11,289
20
44
72

answered Sep 08 '21 at 10:32

Andrey

1

2

Since the location of the file wasn't mentioned, I'd rather comment and ask instead of answering immediately. – TimSch Sep 08 '21 at 12:13

score -2 · Answer 10 · answered Aug 26 '20 at 05:16

Just for others looking a similar answer, in a Spring project running in IntelliJ, it works just change the extension of the application.properties to application.yml. In my case the file was empty, so I didn't have to change anything and I could use application.yml propertly.

How to convert from application.properties to application.yml in Spring Boot?

10 Answers10

Linked