解决：IllegalStateException: Failed to load property source from location classpath:/application.ymljavaJav-

java.lang.IllegalStateException: Failed to load property source from location 'classpath:/application.yml'  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:549) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadForFileExtension(ConfigFileApplicationListener.java:500) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:468) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.lambda$null$6(ConfigFileApplicationListener.java:450) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at java.lang.Iterable.forEach(Iterable.java:75) ~[na:1.8.0_181]  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.lambda$load$7(ConfigFileApplicationListener.java:449) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at java.lang.Iterable.forEach(Iterable.java:75) ~[na:1.8.0_181]  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:446) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:336) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener.addPropertySources(ConfigFileApplicationListener.java:215) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:198) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:185) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:171) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]  at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]  at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]  at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]  at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:74) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:361) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.SpringApplication.run(SpringApplication.java:320) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.SpringApplication.run(SpringApplication.java:1258) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at com.leyou10086.gateway.LyGateway.main(LyGateway.java:15) [classes/:na] Caused by: org.yaml.snakeyaml.error.YAMLException: java.nio.charset.MalformedInputException: Input length = 1  at org.yaml.snakeyaml.reader.StreamReader.update(StreamReader.java:254) ~[snakeyaml-1.19.jar:na]  at org.yaml.snakeyaml.reader.StreamReader.<init>(StreamReader.java:58) ~[snakeyaml-1.19.jar:na]  at org.yaml.snakeyaml.Yaml.loadAll(Yaml.java:537) ~[snakeyaml-1.19.jar:na]  at org.springframework.beans.factory.config.YamlProcessor.process(YamlProcessor.java:166) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]  at org.springframework.beans.factory.config.YamlProcessor.process(YamlProcessor.java:139) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]  at org.springframework.boot.env.OriginTrackedYamlLoader.load(OriginTrackedYamlLoader.java:75) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.env.YamlPropertySourceLoader.load(YamlPropertySourceLoader.java:50) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadDocuments(ConfigFileApplicationListener.java:567) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]  at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:523) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE] ... 23 common frames omitted Caused by: java.nio.charset.MalformedInputException: Input length = 1  at java.nio.charset.CoderResult.throwException(CoderResult.java:281) ~[na:1.8.0_181]  at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:339) ~[na:1.8.0_181]  at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178) ~[na:1.8.0_181]  at java.io.InputStreamReader.read(InputStreamReader.java:184) ~[na:1.8.0_181]  at org.yaml.snakeyaml.reader.UnicodeReader.read(UnicodeReader.java:125) ~[snakeyaml-1.19.jar:na]  at org.yaml.snakeyaml.reader.StreamReader.update(StreamReader.java:223) ~[snakeyaml-1.19.jar:na] ... 31 common frames omitted  

原因：
我的application.yml是没有配置错误的，而且我的文件名称是完全正常的，编译后的target文件里面也有application.yml，我就很纳闷问题出在哪儿了！打开target文件，查看application.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

解决：

1. 修改你的编码格式
2. 删除注释