基本上，我想使用OKHttp客户端对外部服务器进行几次API调用，以检索一些将在我的应用程序端缓存的数据。我想在服务器启动后自动进行这些调用，以便在调用控制器时，可以使用缓存的数据返回一些响应。
我已经使用了以下内容-此链接中所示的SmartInitializingSingleton和ApplicationReadyEvent方法-Run code on startup，但是它不起作用
我具有以下结构-
主控制器的结构如下-
@RequestMapping("/v1")
@RestController
public class MainController {
@Autowired
public Helper helper;
String vcap_services;
JSONObject vcap;
@PostConstruct
public void init() {
vcap_services = System.getenv("VCAP_SERVICES");
// The next line is ine 65
vcap = new JSONObject(vcap_services);
}
@GetMapping(path="/test", produces = "application/json")
public String test() {
return "test";
}
@GetMapping(path="/batch", produces = "application/json")
public String batch() {
return helper.some_function();
}
}
但是，每次编译时，都会收到以下错误-
Field helper in com.sap.destination.controller.MainController required a bean of type 'service.Helper' that could not be found.
发生这种情况是因为我试图通过覆盖它来覆盖Spring Boot的正常负载吗？
编辑-
***************************
APPLICATION FAILED TO START
***************************
Description:
Field helper in com.sap.destination.controller.MainController required a bean of type 'service.Helper' that could not be found.
The injection point has the following annotations:
- @org.springframework.beans.factory.annotation.Autowired(required=true)
Action:
Consider defining a bean of type 'service.Helper' in your configuration.
编辑2 -
package com.sap.destination.service;
import java.net.InetSocketAddress;
import java.net.Proxy;
import org.json.JSONObject;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;
import okhttp3.FormBody;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
@Component
public class Helper {
// JWT Tokens needed to use Connectivity and Destination services
public String getAccessToken(String credentials, String clientid, String URL) {
OkHttpClient client = new OkHttpClient();
RequestBody formBody = new FormBody.Builder()
.add("client_id", clientid)
.add("grant_type", "client_credentials")
.build();
Request request = new Request.Builder()
.url(URL)
.post(formBody)
.addHeader("content-type", "application/x-www-form-urlencoded")
.addHeader("Authorization", "Basic "+credentials)
.build();
try {
Response response = client.newCall(request).execute();
return response.body().string();
} catch (Exception e) {
return e.getMessage();
}
}
// Gets the URL from destination tab
public String getDestinationURL(String token, String URL, String destination_name) {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url(URL+"/destination-configuration/v1/destinations/"+destination_name)
.addHeader("Authorization", "Bearer "+token)
.build();
try {
Response response = client.newCall(request).execute();
return response.body().string();
} catch (Exception e) {
return e.getMessage();
}
}
// Makes the ODATA call for .
public String makeRequest(String onprem_host, int onprem_port, String connectivity_token, String destination_url, String auth, String payload) {
OkHttpClient.Builder builder = new OkHttpClient
.Builder()
.proxy(new Proxy(Proxy.Type.HTTP, new InetSocketAddress(onprem_host, onprem_port)));
OkHttpClient client = builder.build();
MediaType mediaType = MediaType.parse("multipart/mixed;boundary=batch_1");
RequestBody body = RequestBody.create(mediaType, payload);
Request request = new Request.Builder()
/.....
try {
Response response = client.newCall(request).execute();
return response.body().string();
} catch (Exception e) {
return e.getMessage();
}
}
// Parses batch response and returns JSON object out of the JSON payload
public JSONObject parseResponse(String response) {
// .. code
JSONObject res = new JSONObject(response.substring(start, end+1));
return res;
}
}
错误-
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-05-01 17:06:01.812 ERROR 98920 --- [ main] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mainController': Invocation of init method failed; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:139) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:414) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1770) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:849) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:127) [spring-boot-test-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:117) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:108) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:190) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:132) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:246) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:227) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) [junit-4.12.jar:4.12]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:246) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) [junit-4.12.jar:4.12]
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) [junit-4.12.jar:4.12]
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) [junit-4.12.jar:4.12]
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) [junit-4.12.jar:4.12]
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) [junit-4.12.jar:4.12]
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.junit.runners.ParentRunner.run(ParentRunner.java:363) [junit-4.12.jar:4.12]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:365) [surefire-junit4-2.22.1.jar:2.22.1]
at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:273) [surefire-junit4-2.22.1.jar:2.22.1]
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238) [surefire-junit4-2.22.1.jar:2.22.1]
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:159) [surefire-junit4-2.22.1.jar:2.22.1]
at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:384) [surefire-booter-2.22.1.jar:2.22.1]
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:345) [surefire-booter-2.22.1.jar:2.22.1]
at org.apache.maven.surefire.booter.ForkedBooter.execute(ForkedBooter.java:126) [surefire-booter-2.22.1.jar:2.22.1]
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:418) [surefire-booter-2.22.1.jar:2.22.1]
Caused by: java.lang.NullPointerException: null
at java.io.StringReader.<init>(StringReader.java:50) ~[na:1.8.0_191]
at org.json.JSONTokener.<init>(JSONTokener.java:94) ~[json-20180813.jar:na]
at org.json.JSONObject.<init>(JSONObject.java:399) ~[json-20180813.jar:na]
at com.sap.destination.controller.MainController.init(MainController.java:65) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_191]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_191]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:363) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:307) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
... 44 common frames omitted