How to convert .yml to .properties with a gradle task? - spring

Question

The only supported i18n formats for Spring are .properties and .xml, but it's not really optimal.
What I'd like is to have a complex Yaml file (messages.yml and messages_xx.yml) that get converted to .properties in a Gradle task so I can queue it before Build task.
For example, a messages.yml would look like:
group1:
group2:
group3:
message1: hello
message2: how are you?
group4:
message3: good
group5:
group6:
message4: let's party
And the output .properties would be:
group1.group2.group3.message1: hello
group1.group2.group3.message2: how are you?
group1.group2.group4.message3: good
group1.group5.group6.message4: let's party
Is there a way to achieve this?
I didn't find existing converters.

Answer 1

import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Map;
import java.util.TreeMap;
import org.yaml.snakeyaml.Yaml;
public class YamlBackToProperties {
public static void main(String[] args) throws IOException {
Yaml yaml = new Yaml();
try (InputStream in = Files.newInputStream(Paths.get("test.yml"))) {
TreeMap<String, Map<String, Object>> config = yaml.loadAs(in, TreeMap.class);
System.out.println(String.format("%s%n\nConverts to Properties:%n%n%s", config.toString(), toProperties(config)));
}
}
private static String toProperties(TreeMap<String, Map<String, Object>> config) {
StringBuilder sb = new StringBuilder();
for (String key : config.keySet()) {
sb.append(toString(key, config.get(key)));
}
return sb.toString();
}
private static String toString(String key, Map<String, Object> map) {
StringBuilder sb = new StringBuilder();
for (String mapKey : map.keySet()) {
if (map.get(mapKey) instanceof Map) {
sb.append(toString(String.format("%s.%s", key, mapKey), (Map<String, Object>) map.get(mapKey)));
} else {
sb.append(String.format("%s.%s=%s%n", key, mapKey, map.get(mapKey).toString()));
}
}
return sb.toString();
}
}

Answer 2

Made some changes to the first answer. Now works for me for all cases:
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Map;
import java.util.TreeMap;
import org.yaml.snakeyaml.Yaml;
public class YamlConverter {
public static void main(String[] args) throws IOException {
Yaml yaml = new Yaml();
try (InputStream in = Files.newInputStream(Paths.get("yourpath/application.yml"))) {
TreeMap<String, Map<String, Object>> config = yaml.loadAs(in, TreeMap.class);
System.out.println(String.format("%s%n\nConverts to Properties:%n%n%s", config.toString(), toProperties(config)));
}
}
private static String toProperties(TreeMap<String, Map<String, Object>> config) {
StringBuilder sb = new StringBuilder();
for (String key : config.keySet()) {
sb.append(toString(key, config.get(key)));
}
return sb.toString();
}
private static String toString(String key, Object mapr) {
StringBuilder sb = new StringBuilder();
if(!(mapr instanceof Map)) {
sb.append(key+"="+mapr+"\n");
return sb.toString();
}
Map<String, Object> map = (Map<String, Object>)mapr;
for (String mapKey : map.keySet()) {
if (map.get(mapKey) instanceof Map) {
sb.append(toString(key+"."+mapKey, map.get(mapKey)));
} else {
sb.append(String.format("%s.%s=%s%n", key, mapKey, map.get(mapKey).toString()));
}
}
return sb.toString();
}
}

Answer 3

Here's a straighforward implementation in Kotlin:
Once you have a Map with the parsed Yaml just call flatten():
fun flatten(map: Map<String, *>): MutableMap<String, Any> {
val processed = mutableMapOf<String, Any>()
map.forEach { key, value ->
doFlatten(key, value as Any, processed)
}
return processed
}
fun doFlatten(parentKey: String, value: Any, processed: MutableMap<String, Any>) {
if (value is Map<*, *>) {
value.forEach {
doFlatten("$parentKey.${it.key}", it.value as Any, processed)
}
} else {
processed[parentKey] = value
}
}

Answer 4

You can try like this
package com.example.yaml;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import org.yaml.snakeyaml.Yaml;
public class YamlConfigRunner {
public static void main(String[] args) throws IOException {
if( args.length != 1 ) {
System.out.println( "Usage: <file.yml>" );
return;
}
Yaml yaml = new Yaml();
try( InputStream in = Files.newInputStream( Paths.get( args[ 0 ] ) ) ) {
Configuration config = yaml.loadAs( in, Configuration.class );
System.out.println( config.toString() );
}
}
}
reference: https://dzone.com/articles/using-yaml-java-application