运行jar时找不到类路径资源

8 回答

• 0

  resource.getFile()期望资源本身在文件系统上可用，即，一旦您构建了应用程序并从可执行jar运行它，它就可以工作 . 而不是使用 getFile() 来访问资源's contents, I'建议使用getInputStream()代替 . 那个'll allow you to read the resource'的内容无论它位于何处 .

  回复于 2024-04-17T06:15:17+08:00
• 2

  如果您正在使用Spring框架，那么使用Spring framework's FileCopyUtils将 ClassPathResource 读入 String 非常简单：

  String data = "";
  ClassPathResource cpr = new ClassPathResource("static/file.txt");
  try {
      byte[] bdata = FileCopyUtils.copyToByteArray(cpr.getInputStream());
      data = new String(bdata, StandardCharsets.UTF_8);
  } catch (IOException e) {
      LOG.warn("IOException", e);
  }
  

  回复于 2024-04-17T06:15:17+08:00
• 29

  如果要使用文件：

  ClassPathResource classPathResource = new ClassPathResource("static/something.txt");
  
  InputStream inputStream = classPathResource.getInputStream();
  File somethingFile = File.createTempFile("test", ".txt");
  try {
      FileUtils.copyInputStreamToFile(inputStream, somethingFile);
  } finally {
      IOUtils.closeQuietly(inputStream);
  }
  

  回复于 2024-04-17T06:15:17+08:00
• 2

  当spring boot项目作为jar运行并且需要在classpath中读取一些文件时，我通过下面的代码实现它

  Resource resource = new ClassPathResource("data.sql");
  BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream()));
  reader.lines().forEach(System.out::println);
  

  回复于 2024-04-17T06:15:17+08:00
• 6

  我也遇到了这个限制并创建了这个库来克服这个问题：spring-boot-jar-resources它基本上允许你用Spring Boot注册一个自定义ResourceLoader，它可以根据需要透明地从JAR中提取类路径资源 .

  回复于 2024-04-17T06:15:17+08:00
• 119

  我以java 8方式创建了一个ClassPathResourceReader类，以便从类路径中轻松读取文件

  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.stream.Collectors;
  
  import org.springframework.core.io.ClassPathResource;
  
  public final class ClassPathResourceReader {
  
      private final String path;
  
      private String content;
  
      public ClassPathResourceReader(String path) {
          this.path = path;
      }
  
      public String getContent() {
          if (content == null) {
              try {
                  ClassPathResource resource = new ClassPathResource(path);
                  BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream()));
                  content = reader.lines().collect(Collectors.joining("\n"));
                  reader.close();
              } catch (IOException ex) {
                  throw new RuntimeException(ex);
              }
          }
          return content;
      }
  }
  

  利用：

  String content = new ClassPathResourceReader("data.sql").getContent();
  

  回复于 2024-04-17T06:15:17+08:00
• 38

  to get list of data from src/main/resources/data folder --
  first of all mention your folder location in properties file as - 
  resourceLoader.file.location=data
  
  inside class declare your location. 
  
  @Value("${resourceLoader.file.location}")
      @Setter
      private String location;
  
      private final ResourceLoader resourceLoader;
  
  public void readallfilesfromresources() {
         Resource[] resources;
  
          try {
              resources = ResourcePatternUtils.getResourcePatternResolver(resourceLoader).getResources("classpath:" + location + "/*.json");
              for (int i = 0; i < resources.length; i++) {
                  try {
                  InputStream is = resources[i].getInputStream();
                  byte[] encoded = IOUtils.toByteArray(is);
                  String content = new String(encoded, Charset.forName("UTF-8"));
                  }
              }
          } catch (IOException e) {
              throw new UncheckedIOException(e);
          }
  }
  

  回复于 2024-04-17T06:15:17+08:00
• 1

  Jersey 需要打开包装 .

  <build>  
      <plugins>
          <plugin>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-maven-plugin</artifactId>
              <configuration>
                  <requiresUnpack>
                      <dependency>
                          <groupId>com.myapp</groupId>
                          <artifactId>rest-api</artifactId>
                      </dependency>
                  </requiresUnpack>
              </configuration>
          </plugin>
      </plugins>
  </build>
  

  回复于 2024-04-17T06:15:17+08:00