报错代码：
java.lang.IllegalStateException: Failed to load property source from location 'classpath:/application.yml'
at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:538)
at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadForFileExtension(ConfigFileApplicationListener.java:497)
at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:465)
at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.lambda$null$6(ConfigFileApplicationListener.java:447)
at java.lang.Iterable.forEach(Iterable.java:75)
at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.lambda$load$7(ConfigFileApplicationListener.java:446)
at java.lang.Iterable.forEach(Iterable.java:75)
at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:443)
at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:335)
at org.springframework.boot.context.config.ConfigFileApplicationListener.addPropertySources(ConfigFileApplicationListener.java:214)
at org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:197)
at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:184)
at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:170)
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:358)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:317)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243)
at com.suviky.demo.DemoApplication.main(DemoApplication.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:556)
at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:518)
... 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 omitted
Process finished with exit code 1
第一种可能是你的application.yml文件编码格式有问题，改为UTF-8，如下：
第二种可能就是你的application.yml文件是通过把其他类型的文件后缀名直接改为yml生成的，这时就需要你把application.yml中的内容全部复制，然后删除，再新建一个application.yml文件，将复制的内容拷贝进去再运行项目就不会报错了。