SpringBoot核心
读取顺序
(1)与jar同级的config文件夹内
(2)与jar同级的文件夹
(3)读取jar包内的resources目录
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
@Component
public class FileLoader ...
@Autowired
private ResourceLoader resourceLoader;
/**
* 读取顺序：
* （1）与jar同级的config文件夹内
* （2）与jar同级的文件夹
* （3）读取jar包内的resources目录
*/
public InputStream getResource(String fileName) {
Resource resource = resourceLoader.getResource("file:config/" + fileName);
if (resource.exists()) {
LOGGER.debug("{}在与jar的同级目录config目录下", fileName);
return getInputStream(resource);
}
//这里是与JAR包同级目录下
resource = resourceLoader.getResource("file:" + fileName);
if (resource.exists()) {
LOGGER.debug("{}在与JAR包同级目录下", fileName);
return getInputStream(resource);
}
resource = resourceLoader.getResource("classpath:/" + fileName);
if (resource.exists()) {
LOGGER.debug("{}在jar里面的resources目录", fileName);
return getInputStream(resource);
}
throw new RuntimeException("Resource Not Found:" + fileName);
}
private InputStream getInputStream(Resource resource) {
try {
return resource.getInputStream();
} catch (IOException ex) {
throw new RuntimeException(ex);
}
}
读取springboot # resources下文件
import org.springframework.util.ResourceUtils;
File path = new File(ResourceUtils.getURL("classpath:").getPath());
File file1 = new File(path.getAbsolutePath() +
"/templates/testUpload.html");
File file2 = new File(path.getAbsolutePath() +"/application.yaml");
读取当前应用下resource下的文件
public static String getPath() {
return TestFileUtil.class.getResource("/").getPath();
}
//读取resources目录下demo包内的xlsx文件
String fileName = "demo_has_error.xlsx";
String filePath = TestFileUtil.getPath() + "demo"
+ File.separator + fileName;
File file = new File(filePath);
创建可能不存在的文件
@SneakyThrows
private File createFile(String fileAbsolutePath) {
File file = new File(fileAbsolutePath);
if (!file.exists()) {
createParentPath(file);
file.createNewFile();
}
return file;
}
public void createParentPath(File file) {
File parentFile = file.getParentFile();
if (null != parentFile && !parentFile.exists()) {
// 创建文件夹
parentFile.mkdirs();
// 递归创建父级目录
createParentPath(parentFile);
}
}
本地读取资源文件
File file =new File("src/main/resources/properties/test.properties");
其它示例
此时我想读取 jar 包中根路径下的 HelloServiceEncryptFile.txt 文件，然后重新写入到根路径下的 com.study/service 路径下！
InputStream inputStream =
EncryptUtil.class.getResourceAsStream("/HelloServiceEncryptFile.txt");
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line = reader.readLine();
// 获取类路径下的文件路径
File path = new File(ResourceUtils.getURL("classpath:").getPath());
if (!path.exists()) {
path = new File("");
}
log.info("path = {}", path.getAbsolutePath());
File upload = new File(path.getAbsolutePath(), "com/study/service");
if (!upload.exists()) {
upload.mkdirs();
}
FileOutputStream fos = new FileOutputStream(upload.getAbsolutePath()
+ File.separator + "hello.txt");
IoUtil.copy(inputStream, fos);
fos.close();
inputStream.close();
读取jar包内文件
使用Spring提供的ClassPathResource类能够读取到那个JAR包中的resources目录下的ffmpeg文件。比如下面的复制业务，通过ClassPathResource类就能读取到该JAR中的文件。
try {
org.springframework.core.io.ClassPathResource resource =
new ClassPathResource("ffmpeg/ffmpeg.exe");
InputStream fis = resource.getInputStream();
FileOutputStream outputStream = new FileOutputStream( new File('目标文件路径') );
org.apache.tomcat.util.http.fileupload.IOUtils.copy(fis, outputStream);
//一定要关闭，不然复制的文件会报被占用错误
outputStream.close();
} catch (Exception ex) {
LOGGER.error("复制文件出错");
throw new FfmpegException("复制文件出错");
}
LOGGER.info("文件复制结束");```
