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代码如下：
ClassPathResource resource = new ClassPathResource("app.keystore");
File file = resource.getFile();
FileUtils.readLines(file).forEach(System.out::println);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);
}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);
}Resource resource = new ClassPathResource("data.sql");
BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream()));
reader.lines().forEach(System.out::println);String content = new ClassPathResourceReader("data.sql").getContent();@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);
}
}项目是spring-boot + spring-cloud 并使用maven 管理依赖。在springboot+maven项目下怎么读取resources下的文件实现文件下载？
File sourceFile = ResourceUtils.getFile("classpath:templateFile/test.xlsx"); //这种方法在linux下无法工作Resource resource = new ClassPathResource("templateFile/test.xlsx"); File sourceFile = resource.getFile();我使用的是第二种。
@PostMapping("/downloadTemplateFile")
public JSONData downloadTemplateFile(HttpServletResponse response) {
String filePath = "templateFile/test.xlsx";
Resource resource = new ClassPathResource(filePath);//用来读取resources下的文件
InputStream is = null;
BufferedInputStream bis = null;
OutputStream os = null;
try {
File file = resource.getFile();
if (!file.exists()) {
return new JSONData(false,"模板文件不存在");
}
is = new FileInputStream(file);
os = response.getOutputStream();
bis = new BufferedInputStream(is);
//设置响应头信息
response.setCharacterEncoding("UTF-8");
this.response.setContentType("application/octet-stream; charset=UTF-8");
StringBuffer contentDisposition = new StringBuffer("attachment; filename=\"");
String fileName = new String(file.getName().getBytes(), "utf-8");
contentDisposition.append(fileName).append("\"");
this.response.setHeader("Content-disposition", contentDisposition.toString());
//边读边写
byte[] buffer = new byte[500];
int i;
while ((i = bis.read(buffer)) != -1) {
os.write(buffer, 0, i);
}
os.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
return new JSONData(false,"模板文件不存在");
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if(os != null) os.close();
if(bis != null) bis.close();
if(is != null) is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return new JSONData("模板文件下载成功");
}高高兴兴的启动项目后发现还是找不到文件，错误日志：
java.io.FileNotFoundException: class path resource [templateFile/test.xlsx] cannot be resolved to URL because it does not exist at org.springframework.core.io.ClassPathResource.getURL(ClassPathResource.java:195) at org.springframework.core.io.AbstractFileResolvingResource.getFile(AbstractFileResolvingResource.java:129) at com.citycloud.parking.support.controller.operate.OperateBusinessUserController.downloadTemplateFile(OperateBusinessUserController.java:215) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877) at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:158) at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:126) at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:111) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
因为我知道Resource resource = new ClassPathResource("templateFile/test.xlsx");就是到classPath*（注意这里有个*）下去找，然后就去项目本地的目录下找classPath下是否有这个文件（maven的classPath在 “target\classes”目录下），就发现并没有这个文件在。
后面仔细想想这是Maven项目啊，所以就找pom.xml文件去看看，突然想起：springboot的maven默认只会加载classPath同级目录下文件（配置那些），其他的需要配置<resources>标签：
<build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <!--是否替换资源中的属性--> <filtering>false</filtering> </resource> <resource> <directory>src/main/resources</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> <include>**/*.yml</include> <include>**/Dockerfile</include> <include>**/*.xlsx</include> </includes> <!--是否替换资源中的属性--> <filtering>false</filtering> </resource> </resources> </build>
重新启动，再到classPath下看，发现有了这个文件了，同时也能获取了。如果文件名为中文的话就会出现乱码的情况。
Access-Control-Allow-Origin →* Access-Control-Allow-Credentials →true Access-Control-Allow-Headers →accessToken,Access-Control-Allow-Origin,Content-Type,X-Requested-With,accept,Origin,Access-Control-Request-Method,Access-Control-Request-Headers Access-Control-Allow-Methods →POST,GET,PUT,PATCH,DELETE,OPTIONS,HEAD Access-Control-Max-Age →360 Content-disposition →attachment; filename="????????-??????????.xlsx" Content-Type →application/octet-stream;charset=UTF-8 Transfer-Encoding →chunked Date →Fri, 19 Apr 2019 06:47:34 GMT
上面是使用postman测试中文乱码response响应头相关信息。
后面怎么改都乱码，然后我就试着到浏览器中请求试试，结果发现只是postman的原因，只要文件名编码跟返回内容编码一致（"Content-disposition"和“ContentType”）就行：
this.response.setContentType("application/octet-stream; charset=iso-8859-1");
StringBuffer contentDisposition = new StringBuffer("attachment; filename=\"");
String fileName = file.getName();
contentDisposition.append(fileName).append("\"");
//设置文件名编码
String contentDispositionStr = new String(contentDisposition.toString().getBytes(), "iso-8859-1");
this.response.setHeader("Content-disposition", contentDispositionStr);以上是“springboot打成jar后获取classpath下文件失败怎么办”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注亿速云行业资讯频道！
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