springboot打成jar后獲取classpath下文件
代碼如下：
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ClassPathResource resource = new ClassPathResource("app.keystore");File file = resource.getFile();FileUtils.readLines(file).forEach(System.out::println); |
解決方式如下：
1. Spring framework
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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);} |
2.use a file
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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);} |
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Resource resource = new ClassPathResource("data.sql");BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream()));reader.lines().forEach(System.out::println); |
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String content = new ClassPathResourceReader("data.sql").getContent(); |
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@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); }} |
springboot-項目獲取resources下文件碰到的問題（classPath下找不到文件和文件名亂碼）
項目是spring-boot + spring-cloud 并使用maven 管理依賴。在springboot+maven項目下怎么讀取resources下的文件實現文件下載？
怎么獲取resources目錄下的文件？（相對路徑）
方法一：
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File sourceFile = ResourceUtils.getFile("classpath:templateFile/test.xlsx"); //這種方法在linux下無法工作 |
方法二：
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Resource resource = new ClassPathResource("templateFile/test.xlsx"); File sourceFile = resource.getFile(); |
我使用的是第二種。
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@PostMapping("/downloadTemplateFile") public JSONData downloadTemplateFile(HttpServletResponse response) { String filePath = "templateFile/test.xlsx"; Resource resource = new ClassPathResource(filePath);//用來讀取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); //設置響應頭信息 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()); //邊讀邊寫 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("模板文件下載成功"); } |
高高興興的啟動項目后發現還是找不到文件，錯誤日志：
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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) |
因為我知道Resource resource = new ClassPathResource("templateFile/test.xlsx");就是到classPath*（注意這里有個*）下去找，然后就去項目本地的目錄下找classPath下是否有這個文件（maven的classPath在 “target\classes”目錄下），就發現并沒有這個文件在。
后面仔細想想這是Maven項目啊，所以就找pom.xml文件去看看，突然想起：springboot的maven默認只會加載classPath同級目錄下文件（配置那些），其他的需要配置<resources>標簽：
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<build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <!--是否替換資源中的屬性--> <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> <!--是否替換資源中的屬性--> <filtering>false</filtering> </resource> </resources></build> |
重新啟動，再到classPath下看，發現有了這個文件了，同時也能獲取了。如果文件名為中文的話就會出現亂碼的情況。
怎么解決文件名中文亂碼？
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Access-Control-Allow-Origin →*Access-Control-Allow-Credentials →trueAccess-Control-Allow-Headers →accessToken,Access-Control-Allow-Origin,Content-Type,X-Requested-With,accept,Origin,Access-Control-Request-Method,Access-Control-Request-HeadersAccess-Control-Allow-Methods →POST,GET,PUT,PATCH,DELETE,OPTIONS,HEADAccess-Control-Max-Age →360Content-disposition →attachment; filename="????????-??????????.xlsx"Content-Type →application/octet-stream;charset=UTF-8Transfer-Encoding →chunkedDate →Fri, 19 Apr 2019 06:47:34 GMT |
上面是使用postman測試中文亂碼response響應頭相關信息。
后面怎么改都亂碼，然后我就試著到瀏覽器中請求試試，結果發現只是postman的原因，只要文件名編碼跟返回內容編碼一致（"Content-disposition"和“ContentType”）就行：
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this.response.setContentType("application/octet-stream; charset=iso-8859-1");StringBuffer contentDisposition = new StringBuffer("attachment; filename=\"");String fileName = file.getName();contentDisposition.append(fileName).append("\"");//設置文件名編碼String contentDispositionStr = new String(contentDisposition.toString().getBytes(), "iso-8859-1");this.response.setHeader("Content-disposition", contentDispositionStr); |
到此全部結束！
以上為個人經驗，希望能給大家一個參考，也希望大家多多支持服務器之家。
原文鏈接：https://blog.csdn.net/qq_27384769/article/details/99877083
