有人可以告诉我这段代码有什么问题吗
我得到了空指针异常，并且由于多个请求而承担
@Service
public class GernericMockingServiceImpl implements GenericMockingService {
private static final Logger LOG = LoggerFactory.getLogger(GernericMockingServiceImpl.class);
@Override
public String getJsonResponse(GenericMockingForm genericMockingForm, String requestURI) throws Exception {
LOG.info("printing requestURI : "+requestURI);
String path = new URI(requestURI).getPath();
//resolves to a folder name in src/main/resources
String folderName = path.substring(path.lastIndexOf('/') + 1);
LOG.info("printing folderName : " + folderName);
String jsonResponse = null;
StringBuilder sb = new StringBuilder();
//check if the request body has prodcut id's which means that the request is for products else check for sku's which means that the request is for price or stock
if(!Objects.isNull(genericMockingForm.getProductIds()) && !genericMockingForm.getProductIds().isEmpty()){
//currently it iterates over all the product id's/sku's in the request and appends the content of all the id's
//TODO: the content of the file is not exactly how we want it to be for multiple ids' But for the single id it just works.
// TODO: Needs to be refactored later when we handle multiple id's in request
for(String productId : genericMockingForm.getProductIds()){
jsonResponse = getJson(folderName, productId, sb);
}
}else{
for (String sku : genericMockingForm.getSkus()) {
jsonResponse = getJson(folderName, sku, sb);
}
}
LOG.info("printing jsonResponse : " + jsonResponse);
return jsonResponse;
}
private String getJson(String folderName, String id, StringBuilder sb) throws Exception {
String responseJson = null;
String filePath = "data" + File.separator + folderName + File.separator + id + ".json";
LOG.info("printing filePath : " + filePath);
LOG.info("printing id : " + id);
File f = new File(filePath);
if(f.exists()){
try (InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream(filePath)) {
LOG.info("printing inputStream : " + inputStream);
if (inputStream != null) {
responseJson = IOUtils.toString(inputStream, StandardCharsets.UTF_8.name());
}
if (responseJson == null || responseJson.isEmpty()) {
LOG.info("json response is null : ");
throw new JsonNotFoundException(Constant.JSON_NOT_FOUND);
}
sb.append(responseJson);
} catch (IOException e) {
LOG.info("IO exception : ");
throw new IOException(e);
} catch (Exception e) {
LOG.info(" exception : ");
throw new Exception(e);
}
}
else{
LOG.info("file doesnt exists : " + filePath);
}
return sb.toString();
}
}
**我有3个并行请求，该请求访问包含3个不同文件的文件夹并尝试从文件中读取
这是我的堆栈跟踪**
2019-03-05 17:30:29.335 INFO 82 --- [nio-8080-exec-1] c.k.m.controller.ProductController : Received request for Mocking Controller
2019-03-05 17:30:29.335 INFO 82 --- [nio-8080-exec-3] c.k.m.controller.ProductController : Received request for Mocking Controller
2019-03-05 17:30:29.335 INFO 82 --- [nio-8080-exec-2] c.k.m.controller.ProductController : Received request for Mocking Controller
2019-03-05 17:30:29.336 INFO 82 --- [nio-8080-exec-2] c.k.m.s.impl.GernericMockingServiceImpl : printing requestURI : /mocking/api/stocks
2019-03-05 17:30:29.336 INFO 82 --- [nio-8080-exec-3] c.k.m.s.impl.GernericMockingServiceImpl : printing requestURI : /mocking/get-products
2019-03-05 17:30:29.337 INFO 82 --- [nio-8080-exec-3] c.k.m.s.impl.GernericMockingServiceImpl : printing folderName : get-products
2019-03-05 17:30:29.338 INFO 82 --- [nio-8080-exec-3] c.k.m.s.impl.GernericMockingServiceImpl : printing filePath : data/get-products/1610-17637-319.json
2019-03-05 17:30:29.338 INFO 82 --- [nio-8080-exec-3] c.k.m.s.impl.GernericMockingServiceImpl : printing id : 1610-17637-319
2019-03-05 17:30:29.338 INFO 82 --- [nio-8080-exec-3] c.k.m.s.impl.GernericMockingServiceImpl : file doesnt exists : data/get-products/1610-17637-319.json
2019-03-05 17:30:29.338 INFO 82 --- [nio-8080-exec-3] c.k.m.s.impl.GernericMockingServiceImpl : printing jsonResponse :
2019-03-05 17:30:29.336 INFO 82 --- [nio-8080-exec-1] c.k.m.s.impl.GernericMockingServiceImpl : printing requestURI : /mocking/api/prices
2019-03-05 17:30:29.338 INFO 82 --- [nio-8080-exec-1] c.k.m.s.impl.GernericMockingServiceImpl : printing folderName : prices
2019-03-05 17:30:29.337 INFO 82 --- [nio-8080-exec-2] c.k.m.s.impl.GernericMockingServiceImpl : printing folderName : stocks
2019-03-05 17:30:29.343 INFO 82 --- [nio-8080-exec-2] c.k.m.s.impl.GernericMockingServiceImpl : printing filePath : data/stocks/1610-17637.json
2019-03-05 17:30:29.343 INFO 82 --- [nio-8080-exec-2] c.k.m.s.impl.GernericMockingServiceImpl : printing id : 1610-17637
2019-03-05 17:30:29.343 INFO 82 --- [nio-8080-exec-2] c.k.m.s.impl.GernericMockingServiceImpl : file doesnt exists : data/stocks/1610-17637.json
2019-03-05 17:30:29.343 INFO 82 --- [nio-8080-exec-2] c.k.m.s.impl.GernericMockingServiceImpl : printing jsonResponse :
2019-03-05 17:30:29.354 ERROR 82 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
java.lang.NullPointerException: null
at com.kfz24.mockingservice.service.impl.GernericMockingServiceImpl.getJsonResponse(GernericMockingServiceImpl.java:45) ~[classes/:na]
at com.kfz24.mockingservice.controller.GenericMockingController.processRequest(GenericMockingController.java:32) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:189) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800) ~[spring-webmvc-5.1.4.RELEASE.jar:5.1.4.RELEASE]
**at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038) ~[spring-webmvc-5.1.4.RELEASE.jar:5.1.4.RELEASE]**
答案 0 :(得分：1)
我得到了空指针异常，并且由于多个请求而承担
我认为您的假设是错误的。
[来自评论：null为]这行
strtok
这似乎表明tokens返回for (String sku : genericMockingForm.getSkus()) {，因为那里唯一使用的其他对象是经过测试的genericMockingForm.getSkus()。
您应该在表单测试中放置相同的null检查：
null如果两个都是genericMockingForm，则应该吐出某种使用错误。