java - 从 REST API get 调用读取 InputStream

Question

我正在尝试使用 get 调用来调用其余 Controller ，该调用从文件系统读取文件并返回该文件的 InputStream。

客户端代码:

website = new URL(configurationFileUrl + "/stream/" + key.getReportRawDataId());
            URLConnection connection = website.openConnection();
            connection.setConnectTimeout(60 * 1000);
            connection.setReadTimeout(60 * 1000);
            stream = connection.getInputStream();

Controller 代码:

@RestController
@RequestMapping(value = "/blueprintConfig", produces = {"application/octet-stream", "application/json"}, headers = "Accept=*/*")
public class ReportConfigurationController {

@ResponseBody
    @RequestMapping(value = "/stream/{id:.+}", method = RequestMethod.GET)
    public ResponseEntity<?> getFilesAsStream(@PathVariable("id") String id) throws Exception {
        return configurationService.getFilesAsStream(id);
    }

}

服务:

@Override
    public ResponseEntity<?> getFilesAsStream(String id) throws Exception {
        String filePath = resourcePath + id;
        InputStream is = null;
        try {
            is = new FileInputStream(filePath);
        } catch (FileNotFoundException e) {
            LOGGER.error("can not read file: {}", e);
        }
        return new ResponseEntity<InputStream>(is, HttpStatus.OK);
    }

在调试时，我看到服务正在返回输入流，没有任何异常，但客户端抛出以下 IO 异常:

java.io.IOException: Server returned HTTP response code: 406 for URL: http://localhost:8091/blueprintConfig/stream/1_check.png

at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1839)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1440)
    at com.jasper.wrapper.service.ReportServiceImpl.putInCache(ReportServiceImpl.java:128)
    at com.jasper.wrapper.service.ReportServiceImpl.populateCache(ReportServiceImpl.java:110)
    at com.jasper.wrapper.service.ReportServiceImpl.lambda$generateReport$0(ReportServiceImpl.java:64)
    at com.jasper.wrapper.service.ReportServiceImpl$$Lambda$8/819977316.accept(Unknown Source)
    at java.util.LinkedHashMap.forEach(LinkedHashMap.java:676)
    at com.jasper.wrapper.service.ReportServiceImpl.generateReport(ReportServiceImpl.java:64)
    at com.jasper.wrapper.controller.JasperReportController.generateReport(JasperReportController.java:27)
    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:497)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:775)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:869)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

我在这里做错了什么，我尝试设置

connection.setRequestProperty("accept", "application/octet-stream");

但运气不佳，请帮忙

Answer 1

406 意味着您的客户端不接受从服务器获得的响应，因此服务器不知道(因此服务器上没有错误)。

这实际上取决于服务器所说的数据是什么。

只需远程登录到您的服务器:

telnet localhost:8091

并发出:

GET /blueprintConfig/stream/1_check.png HTTP/1.1

(按两次返回键)

然后查看响应 header 以了解服务器发送回客户端的内容。

或者，如果您安装了 curl，只需执行以下操作:

curl -I http://localhost:8091/blueprintConfig/stream/1_check.png

然后查看标题。