Servlet.service() 用於 servlet [dispatcherServlet] 在上下文中的路徑

Question

我在創建 spring maven rest Web 服務時遇到錯誤。 當我使用 postman 測試 ocbc 的 api 上的發布請求時，它工作正常。 但是，當我嘗試對 citi 進行發布請求時，出現以下錯誤： Servlet.service() for servlet [dispatcherServlet] in context with path [] throw exception [Request processing failed; 嵌套異常是 java.lang.NullPointerException] 的根本原因。 在我的 postman 中顯示錯誤：“內部服務器錯誤”，狀態：“500”

錯誤：

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.example.service.impl.PaymentServiceImpl.addCitiPayment(PaymentServiceImpl.java:22) ~[classes/:na]
        at com.example.controller.PaymentController.addCitiPayment(PaymentController.java:25) ~[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:564) ~[na:na]
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:197) ~[spring-web-5.3.4.jar:5.3.4]
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:141) ~[spring-web-5.3.4.jar:5.3.4]
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.3.4.jar:5.3.4]
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:894) ~[spring-webmvc-5.3.4.jar:5.3.4]
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.4.jar:5.3.4]
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.4.jar:5.3.4]    
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1060) ~[spring-webmvc-5.3.4.jar:5.3.4]
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:962) ~[spring-webmvc-5.3.4.jar:5.3.4]
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.4.jar:5.3.4]
        at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.3.4.jar:5.3.4]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:652) ~[tomcat-embed-core-9.0.43.jar:4.0.FR]
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.4.jar:5.3.4]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.43.jar:4.0.FR]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.4.jar:5.3.4]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.4.jar:5.3.4]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.4.jar:5.3.4]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.4.jar:5.3.4]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.4.jar:5.3.4]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.4.jar:5.3.4]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:887) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1684) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130) ~[na:na]
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630) ~[na:na]
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
        at java.base/java.lang.Thread.run(Thread.java:832) ~[na:na]

這是我的代碼：

銀行OCBCDAO

package com.example.repository;

import com.example.model.BankOCBC;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface BankOCBCDAO extends JpaRepository<BankOCBC, Integer>{

}

銀行花旗銀行DAO

package com.example.repository;

import com.example.model.BankCitiBank;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface BankCitiBankDAO extends JpaRepository<BankCitiBank, Integer>{

}

支付控制器

package com.example.controller;

import com.example.model.BankCitiBank;
import com.example.model.BankOCBC;
import com.example.service.PaymentService;
import com.example.dto.ApiResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;


@RestController
@RequestMapping(path="/payment")
public class PaymentController {
    
    @Autowired
    private PaymentService paymentService;

    
    @PostMapping("/citi")
    public ApiResponse addCitiPayment(@RequestBody BankCitiBank bankCitiBank) {
        return paymentService.addCitiPayment(bankCitiBank);
    }

    @PostMapping("/ocbc")
    public ApiResponse addOCBCPayment(@RequestBody BankOCBC bankOCBC) {
        return paymentService.addOCBCPayment(bankOCBC);
    }
}

支付服務

package com.example.service;

import com.example.model.BankCitiBank;
import com.example.model.BankOCBC;
import com.example.dto.ApiResponse;

public interface PaymentService {
    ApiResponse addCitiPayment(BankCitiBank bankCitiBank);
    ApiResponse addOCBCPayment(BankOCBC bankOCBC);
}

PaymentServiceImpl

package com.example.service.impl;

import com.example.dto.ApiResponse;
import com.example.model.BankCitiBank;
import com.example.model.BankOCBC;
import com.example.service.PaymentService;
import com.example.repository.BankCitiBankDAO;
import com.example.repository.BankOCBCDAO;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;


@Service
public class PaymentServiceImpl implements PaymentService{
    @Autowired
    private BankOCBCDAO bankOCBCDAO;
    private BankCitiBankDAO bankCitiBankDAO;
    
    @Override
    public ApiResponse addCitiPayment(BankCitiBank bankCitiBank) {
        bankCitiBankDAO.save(bankCitiBank);
        return new ApiResponse(200, "CitiBank Payment Successful", null); 
    }

    @Override
    public ApiResponse addOCBCPayment(BankOCBC bankOCBC) {
        bankOCBCDAO.save(bankOCBC);
        return new ApiResponse(200, "OCBC Payment Successful", null); 
        
    }
    
}

請告知我的代碼有什么問題。 提前致謝。

我也可以問是否有任何推薦的方法來加密從 api 獲得的數據值，然后再添加到數據庫中。

Answer 1

您還需要將@Autowired添加到bankCitiBankDAO ：

    @Autowired
    private BankOCBCDAO bankOCBCDAO;
    @Autowired
    private BankCitiBankDAO bankCitiBankDAO;

但是由於現場注入不是最好的事情（ https://www.vojtechruzicka.com/field-dependency-injection-considered-harmful/ ），您應該使用構造函數注入 go：

@Service
public class PaymentServiceImpl implements PaymentService{

    private BankOCBCDAO bankOCBCDAO;
    private BankCitiBankDAO bankCitiBankDAO;

    public PaymentServiceImpl(BankOCBCDAO bankOCBCDAO, BankCitiBankDAO bankCitiBankDAO){
       this.bankOCBCDAO = bankOCBCDAO;
       this.bankCitiBankDAO = bankCitiBankDAO;
    }
...
}

Answer 2

請在 Model Class 中添加正確的注釋，這將清除問題。

參考

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="bank_id")
private int bankId;