springboot打成jar后获取classpath下文件失败

电玩女神 2021-09-11 19:56 809阅读 0赞

# springboot打成jar后获取classpath下文件失败 #

## springboot打成jar后获取classpath下文件失败 ##

之前的方式：

//读取的关键步骤
      InputStream fis = CmsApplication.class.getResourceAsStream("application.yml");
    File file = ResourceUtils.getFile("classpath:application.yml");
    InputStream fis = new FileInputStream(file);

未打包时可以获取到文件，打包后报错

Caused by: java.io.FileNotFoundException: class path resource [application.yml] cannot be resolved to absolute file path because it does not reside in the file system: jar:file:/D:/sunmnet/JetBrains/workspace/bigdata-parse-table/target/bigdata-parse-table-1.0-SNAPSHOT.jar!/BOOT-INF/classes!/application.yml
            at org.springframework.util.ResourceUtils.getFile(ResourceUtils.java:215) ~[spring-core-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
            at org.springframework.core.io.AbstractFileResolvingResource.getFile(AbstractFileResolvingResource.java:53) ~[spring-core-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
            at hello.whz.Application.lambda$lookup$0(Application.java:30) [classes!/:1.0-SNAPSHOT]
            at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:732) [spring-boot-1.5.8.RELEASE.jar!/:1.5.8.RELEASE]
            ... 14 common frames omitted

**这是因为打包后Spring试图访问文件系统路径，但无法访问JAR中的路径。  
因此必须使用resource.getInputStream()**

解决：

private static void createFile() { 
            try { 
                File dbFile = new File("./config/application.yml");
                if (!dbFile.exists()) { 
                    ClassPathResource resource = new ClassPathResource("application.yml");
                    InputStream fis = resource.getInputStream();
    
                    //创建目录
                    File db = new File("./config/application.yml");
                    if (!db.exists()) { 
                        db.getParentFile().mkdirs();
                    }
                    dbFile.createNewFile();
                   // FileOutputStream fos = new FileOutputStream("./repository/cms.yml");
    
                    OutputStream fos = new FileOutputStream("./config/application.yml");
    
    
                    List<String> lines = IOUtils.readLines(fis);
                    for(String line : lines){ 
                    //读取yml换行
                        line = line+"\r\n";
                        byte[] bytes = line.getBytes();
                        fos.write(bytes);
                    }
    
    
                    fis.close();
                    fos.close();
                }
    
    
            } catch (Exception e) { 
                e.printStackTrace();
            }
        }