1. 使用 ClassLoader.getResourceAsStream() 方法
InputStream inputStream = getClass().getClassLoader().getResourceAsStream(“file.txt”);
2.使用 Class.getResourceAsStream() 方法
InputStream inputStream = getClass().getResourceAsStream(“/file.txt”);
3.使用 ResourceLoader 加载文件
@Autowired private ResourceLoader resourceLoader;
Resource resource = resourceLoader.getResource(“classpath:file.txt”); InputStream inputStream = resource.getInputStream();
4.使用 ResourceUtils 加载文件
File file = ResourceUtils.getFile(“classpath:file.txt”);
5. 使用 ApplicationContext 加载文件
@Autowired private ApplicationContext applicationContext;
Resource resource = applicationContext.getResource(“classpath:file.txt”); InputStream inputStream = resource.getInputStream();
6.使用 ServletContext 加载文件
@Autowired private ServletContext servletContext;
InputStream inputStream = servletContext.getResourceAsStream(“/WEB-INF/classes/file.txt”);
7. 使用 File System 加载文件
File file = new File(“src/main/resources/file.txt”); InputStream inputStream = new FileInputStream(file);
8. 使用 Paths 和 Files 加载文件
Path path = Paths.get(“src/main/resources/file.txt”); InputStream inputStream = Files.newInputStream(path);
9. 使用 ClassPathResource 加载文件 (springboot项目 读取resources 推荐使用)
ClassPathResource resource = new ClassPathResource(“file.txt”); InputStream inputStream = resource.getInputStream();
案例： 模拟springboot 装配bean
配置文件
package com.ldj.springboot.importbean.selector; import org.springframework.context.annotation.ImportSelector; import org.springframework.core.io.ClassPathResource; import org.springframework.core.type.AnnotationMetadata; import org.springframework.util.CollectionUtils; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.LinkedList; import java.util.List; /** * User: ldj * Date: 2024/8/24 * Time: 23:54 * Description: No Description */ public class MyBeanSelector implements ImportSelector { @Override public String[] selectImports(AnnotationMetadata annotationMetadata) { List<String> springBeanPaths = SpringFactoriesLoader.getSpringBeanPaths("spring.factories"); if (CollectionUtils.isEmpty(springBeanPaths)) { throw new RuntimeException("spring.factories文件 缺少配置！"); } return springBeanPaths.toArray(new String[0]); } } // 读取要注入容器的类所在路径的配置文件 class SpringFactoriesLoader { public static List<String> getSpringBeanPaths(String path) { List<String> classPaths = new LinkedList<>(); InputStreamReader inputStreamReader = null; BufferedReader bufferedReader = null; InputStream inputStream = null; String str; try { ClassPathResource classPathResource = new ClassPathResource(path); inputStream = classPathResource.getInputStream(); inputStreamReader = new InputStreamReader(inputStream); bufferedReader = new BufferedReader(inputStreamReader); while ((str = bufferedReader.readLine()) != null) { System.out.println(str); classPaths.add(str); } } catch (Exception e) { e.printStackTrace(); return null; } finally { try { if (inputStream != null) { inputStream.close(); } if (bufferedReader != null) { bufferedReader.close(); } if (inputStreamReader != null) { inputStreamReader.close(); } } catch (IOException e) { e.printStackTrace(); } } return classPaths; } } package com.ldj.springboot.importbean; import com.ldj.springboot.importbean.config.ProductConfig; import com.ldj.springboot.importbean.config.StoreConfig; import com.ldj.springboot.importbean.selector.MyBeanSelector; import org.springframework.context.annotation.AnnotationConfigApplicationContext; import org.springframework.context.annotation.Import; @Import(value = {MyBeanSelector.class}) public class ImportBeanApplication { public static void main(String[] args) { AnnotationConfigApplicationContext annotationConfigApplicationContext = new AnnotationConfigApplicationContext(ImportBeanApplication.class); System.out.println(annotationConfigApplicationContext.getBean(ProductConfig.class)); System.out.println(annotationConfigApplicationContext.getBean(StoreConfig.class)); } }
