springboot打成jar後獲取classpath下文件失敗的解決方案
springboot打成jar後獲取classpath下文件
代碼如下：
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
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
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);
}
}
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 並使用maven 管理依賴。在springboot+maven項目下怎麼讀取resources下的文件實現文件下載？
怎麼獲取resources目錄下的文件？（相對路徑）
方法一：
File sourceFile = ResourceUtils.getFile("classpath:templateFile/test.xlsx"); //這種方法在linux下無法工作
方法二：
Resource resource = new ClassPathResource("templateFile/test.xlsx"); File sourceFile = resource.getFile();
我使用的是第二種。
@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後發現還是找不到文件，錯誤日志：
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)
因為我知道Resource resource = new ClassPathResource(“templateFile/test.xlsx”);就是到classPath*（註意這裡有個*）下去找，然後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），就發現並沒有這個文件在。
後面仔細想想這是Maven項目啊，所以就找pom.xml文件去看看，突然想起：springboot的maven默認隻會加載classPath同級目錄下文件（配置那些），其他的需要配置<resources>標簽：
<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，發現有瞭這個文件瞭，同時也能獲取瞭。如果文件名為中文的話就會出現亂碼的情況。
怎麼解決文件名中文亂碼？
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測試中文亂碼response響應頭相關信息。
後面怎麼改都亂碼，然後我就試著到瀏覽器中請求試試，結果發現隻是postman的原因，隻要文件名編碼跟返回內容編碼一致（”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("\"");
//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，希望能給大傢一個參考，也希望大傢多多支持WalkonNet。
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