【发布时间】：2018-05-03 02:18:22
【问题描述】：
我正在用 Java 程序编写代码，使用 Spring 数据库管理进行数据存储
问题：我在尝试访问存储库时不断收到 NullPointerException。
相关部分代码如下......
控制器：
@RestController
public class AssetDiscoveryInfoController {
@Autowired
private static ScanItemInfo scanItem;
@Autowired
private static ScanItemRepository scanItemRepository;
//for testing
public static void addScanItem(String ip, String discoveryMethod, String dt)
{
scanItem.setIP(ip);
scanItem.setDiscoveryMethod(discoveryMethod);
scanItem.setDate(dt);
scanItemRepository.save(scanItem);
}
public static String convertArrayListtoString(ArrayList<ArrayList> arrList)
{
String xmlString = "";
java.util.Date dt = new java.util.Date();
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String currentTime = sdf.format(dt);
Iterator<ArrayList> iterator = arrList.iterator();
while (iterator.hasNext())
{
ArrayList newArray = new ArrayList();
newArray = iterator.next();
String hostIP = newArray.get(0).toString();
String sourceName = newArray.get(1).toString();
addScanItem(hostIP, sourceName, currentTime);
xmlString = xmlString+"<host>"//
+ "<ip>" + hostIP + "</ip>"//
+ "<scanSource>" + sourceName + "</scanSource>"//
+ "<dateTime>" + currentTime + "</dateTime>"//
+ "</host>";
}
return xmlString;
}
@RequestMapping(value = "/map/{mapSource}", method = RequestMethod.GET)
public String getMap(@PathVariable String mapSource) throws JSONException
{
String mapSourceURL="";
String jsonStr="";
ArrayList<ArrayList> mapStr = new ArrayList<ArrayList>();
String ref="";
String mapURL="";
String reportID="";
String XMLString="";
if(mapSource.equalsIgnoreCase(tenable))
{
AssetDiscoveryTenableApiWrapper taw = new AssetDiscoveryTenableApiWrapper();
ArrayList rowDetailArrayList = new ArrayList<ArrayList>();
mapSourceURL = loadConfig("tenableBaseURL");
reportID = loadConfig("tenableReportID");
mapURL = mapSourceURL+reportID;
JSONObject mapListJSON = new JSONObject(taw.getMapData(mapURL));
JSONArray mapListJSONEntries = mapListJSON.getJSONArray("hosts");
for (int i = 0; i < mapListJSONEntries.length(); i++)
{
List rowDetailList = new ArrayList<String>();
String hostIP = mapListJSONEntries.getJSONObject(i).get("hostname").toString();
String mapSourceName = tenable;
rowDetailList.add(hostIP);
rowDetailList.add(mapSourceName);
rowDetailArrayList.add(rowDetailList);
}
mapStr = rowDetailArrayList;
}
XMLString = convertArrayListtoString(mapStr);
return "<?xml version='1.0' encoding='UTF-8' standalone='no' ?><hosts>"+XMLString+"</hosts>";
}
}
存储库：
@Repository("scanRepository")
public interface ScanItemRepository extends JpaRepository<ScanItemInfo, Long>{
}
型号：
@Entity
public class ScanItemInfo {
@Id
@GeneratedValue
private Long id;
private String ip;
@Column(name = "discovery_method")
private String discoveryMethod;
private String dt;
public ScanItemInfo() {
super();
}
public ScanItemInfo(String ip, String discoveryMethod, String dt) {
super();
this.ip = ip;
this.discoveryMethod = discoveryMethod;
this.dt = dt;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getIP() {
return ip;
}
public void setIP(String ip) {
System.out.println("IP: "+ip);
this.ip = ip;
}
public void setDiscoveryMethod(String discoveryMethod) {
System.out.println("METHOD: "+discoveryMethod);
this.discoveryMethod = discoveryMethod;
}
public String getDiscoveryMethod() {
return discoveryMethod;
}
public String getDate() {
return dt;
}
public void setDate(String dt) {
System.out.println("DATE: "+dt);
this.dt = dt;
}
}
我得到的错误日志是
[nio-8080-exec-5] 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.macquarie.assetdiscovery.controller.AssetDiscoveryInfoController.addScanItem(AssetDiscoveryInfoController.java:89) ~[classes!/:0.0.1-SNAPSHOT]
at com.macquarie.assetdiscovery.controller.AssetDiscoveryInfoController.convertArrayListtoString(AssetDiscoveryInfoController.java:215) ~[classes!/:0.0.1-SNAPSHOT]
at com.macquarie.assetdiscovery.controller.AssetDiscoveryInfoController.getMap(AssetDiscoveryInfoController.java:355) ~[classes!/:0.0.1-SNAPSHOT]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:158) ~[spring-boot-actuator-2.0.1.RELEASE.jar!/:2.0.1.RELEASE]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:126) ~[spring-boot-actuator-2.0.1.RELEASE.jar!/:2.0.1.RELEASE]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:111) ~[spring-boot-actuator-2.0.1.RELEASE.jar!/:2.0.1.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:84) ~[spring-boot-actuator-2.0.1.RELEASE.jar!/:2.0.1.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar!/:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_171]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_171]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.29.jar!/:8.5.29]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_171]
我可以登录到数据库并查看创建的表。只是每当我尝试插入新行时...弹出此错误...任何帮助将不胜感激...谢谢
【问题讨论】：
-
您正在使用静态方法来使用自动装配的实例？请使用调试工具了解为什么它为空。
-
从您的存储库中删除
@Repository("scanRepository")，并从您的自动连接字段中删除static关键字。
标签： java database hibernate spring-boot spring-data-jpa