今天在开发中遇到了这样一个问题：

java.lang.IllegalStateException: Failed to load property source from location ‘classpath:/application-dev.yml’

从这个报错里，我们可以清晰的看出是加载文件出了问题，我们需要先排查下配置文件是否出现了问题。比如格式错误，拼写错误等等这种低级的错误。

再给大家看下完整的报错信息，是不是这样的

java.lang.IllegalStateException: Failed to load property source from location 'classpath:/application-dev.yml'
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:549)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadForFileExtension(ConfigFileApplicationListener.java:488)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:468)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.lambda$null$6(ConfigFileApplicationListener.java:450)
    at java.lang.Iterable.forEach(Iterable.java:75)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.lambda$load$7(ConfigFileApplicationListener.java:449)
    at java.lang.Iterable.forEach(Iterable.java:75)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:446)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:336)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.addPropertySources(ConfigFileApplicationListener.java:215)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:198)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:185)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:171)
    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:74)
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:361)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1258)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246)
    at com.dawn.rockcandy.RockCandyApplication.main(RockCandyApplication.java:11)
Caused by: org.yaml.snakeyaml.error.YAMLException: java.nio.charset.MalformedInputException: Input length = 1
    at org.yaml.snakeyaml.reader.StreamReader.update(StreamReader.java:254)
    at org.yaml.snakeyaml.reader.StreamReader.<init>(StreamReader.java:58)
    at org.yaml.snakeyaml.Yaml.loadAll(Yaml.java:537)
    at org.springframework.beans.factory.config.YamlProcessor.process(YamlProcessor.java:166)
    at org.springframework.beans.factory.config.YamlProcessor.process(YamlProcessor.java:139)
    at org.springframework.boot.env.OriginTrackedYamlLoader.load(OriginTrackedYamlLoader.java:75)
    at org.springframework.boot.env.YamlPropertySourceLoader.load(YamlPropertySourceLoader.java:50)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadDocuments(ConfigFileApplicationListener.java:567)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:523)
    ... 23 common frames omitted
Caused by: java.nio.charset.MalformedInputException: Input length = 1
    at java.nio.charset.CoderResult.throwException(CoderResult.java:281)
    at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:339)
    at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
    at java.io.InputStreamReader.read(InputStreamReader.java:184)
    at org.yaml.snakeyaml.reader.UnicodeReader.read(UnicodeReader.java:125)
    at org.yaml.snakeyaml.reader.StreamReader.update(StreamReader.java:223)
    ... 31 common frames omitte

如果你的文件名称是完全正常的，编译后的target文件里面也有application-dev.yml，那你

打开target文件，查看application-dev.yml文件，发现这个文件居然是空的，说明这个文件编译失败了！！！

最后找到问题，因为这个文件的编码格式是GBK，项目的编码格式是UTF-8，里面有注释，注释乱码，导致编译失败