maven - 当我尝试从另一个包访问我的控制器类时，RESTEasy JAX-RS Nullpointer
问题描述
我正在基于基本 BCE 模式设置一个 Maven 项目（在 Java EE 中）。在“边界”包中，我开始使用 RESTeasy 指定几个 JAX-RS API。如果我向这个 API 发送 POST、GET 或其他任何内容，他们应该将请求委托给控制器类，然后控制器类基本上完成所有工作。
但是每当边界（Api）向控制器（服务）发送请求时，我都会遇到 Nullpointer 异常，例如：
2020-07-02T13:45:15.987+0200|Info: Try to post User alexhuckerman
2020-07-02T13:45:15.994+0200|Warning: StandardWrapperValve[Resteasy]: Servlet.service() for servlet Resteasy threw exception
org.jboss.resteasy.spi.UnhandledException: java.lang.NullPointerException
at org.jboss.resteasy.core.ExceptionHandler.handleApplicationException(ExceptionHandler.java:106)
at org.jboss.resteasy.core.ExceptionHandler.handleException(ExceptionHandler.java:372)
at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:216)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:515)
at org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:259)
at org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:160)
at org.jboss.resteasy.core.interception.jaxrs.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:364)
at org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:163)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:245)
at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:249)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:60)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:55)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:750)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1540)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:119)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:611)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:550)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:114)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:332)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:199)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:463)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:168)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:242)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:539)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:593)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:573)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at boundary.UserApi.postUser(UserApi.java:57)
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:498)
at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:167)
at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:130)
at org.jboss.resteasy.core.ResourceMethodInvoker.internalInvokeOnTarget(ResourceMethodInvoker.java:638)
at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTargetAfterFilter(ResourceMethodInvoker.java:504)
at org.jboss.resteasy.core.ResourceMethodInvoker.lambda$invokeOnTarget$2(ResourceMethodInvoker.java:454)
at org.jboss.resteasy.core.interception.jaxrs.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:364)
at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:456)
at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:417)
at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:391)
at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:68)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:488)
... 37 more
我的 POM.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.wm</groupId>
<artifactId>workflowManager</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>workflowManager Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.jboss.resteasy/resteasy-core -->
<dependency>
<groupId>org.jboss.resteasy</groupId>
<artifactId>resteasy-core</artifactId>
<version>4.5.5.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.jboss.resteasy/resteasy-client -->
<dependency>
<groupId>org.jboss.resteasy</groupId>
<artifactId>resteasy-client</artifactId>
<version>4.5.5.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.jboss.resteasy/resteasy-servlet-initializer -->
<dependency>
<groupId>org.jboss.resteasy</groupId>
<artifactId>resteasy-servlet-initializer</artifactId>
<version>4.5.5.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.jboss.resteasy/resteasy-jaxrs -->
<dependency>
<groupId>org.jboss.resteasy</groupId>
<artifactId>resteasy-jaxrs</artifactId>
<version>3.12.1.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.jboss.resteasy/resteasy-jackson-provider -->
<dependency>
<groupId>org.jboss.resteasy</groupId>
<artifactId>resteasy-jackson-provider</artifactId>
<version>3.12.1.Final</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.ws.rs/javax.ws.rs-api -->
<dependency>
<groupId>javax.ws.rs</groupId>
<artifactId>javax.ws.rs-api</artifactId>
<version>2.1.1</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.persistence/javax.persistence-api -->
<dependency>
<groupId>javax.persistence</groupId>
<artifactId>javax.persistence-api</artifactId>
<version>2.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.ibm.db2/jcc -->
<dependency>
<groupId>com.ibm.db2</groupId>
<artifactId>db2jcc</artifactId>
<version>1.0.2</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<configuration>
<source>1.8</source> <!-- or higher, depending on your project -->
<target>1.8</target> <!-- or higher, depending on your project -->
</configuration>
</plugin>
<plugin>
<groupId>org.glassfish.maven.plugin</groupId>
<artifactId>maven-glassfish-plugin</artifactId>
<version>2.1</version>
<configuration>
<glassfishDirectory>C:\Users\AlexanderCimander\Documents\Master@IBM\Uni\glassfish5\glassfish</glassfishDirectory>
<user>admin</user>
<passwordFile>files\password.txt</passwordFile>
<domain>
<name>domain1</name>
<host>localhost</host>
<adminPort>4848</adminPort>
</domain>
<components>
<component>
<name>${project.artifactId}</name>
<artifact>${project.build.directory}/${project.build.finalName}.war</artifact>
</component>
</components>
</configuration>
<executions>
<execution>
<goals>
<goal>deploy</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.3.0</version>
<configuration>
<archive>
<addMavenDescriptor>false</addMavenDescriptor>
</archive>
<strong>
<archiveClasses>false</archiveClasses>
</strong>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.2.1</version>
<configuration>
<executable>C:XXXXX\glassfish5\glassfish\bin\asadmin.bat</executable>
<arguments>
<argument>--host=localhost</argument>
<argument>--port=4848</argument>
<argument>--user=admin</argument>
<argument>--passwordfile=files/password.txt</argument>
<argument>--interactive=false</argument>
<argument>--echo=true</argument>
<argument>--terse=true</argument>
<argument>add-resources</argument>
<argument>--upload=true</argument>
<argument>files/glassfish-resources.xml</argument>
</arguments>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
我的 Web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0">
<display-name>workflowmanager</display-name>
<welcome-file-list>
<welcome-file>index.xhtml</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Resteasy</servlet-name>
<servlet-class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>
<init-param>
<param-name>javax.ws.rs.Application</param-name>
<param-value>boundary.ApplicationServlet</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Resteasy</servlet-name>
<url-pattern>/api/*</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
<context-param>
<param-name>resteasy.wider.request.matching</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<param-name>resteasy.servlet.mapping.prefix</param-name>
<param-value>/api</param-value>
</context-param>
</web-app>
我的 Beans.xml（放在 scr/main/webapp/WEB-INF 下）
<?xml version="1.0"?>
<beans bean-discovery-mode="all"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.jcp.org/xml/ns/javaee">
</beans>
我的应用程序Servlet
package boundary;
import java.util.HashSet;
import java.util.Set;
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
public class ApplicationServlet extends Application{
private Set<Object> singletons = new HashSet<Object>();
private Set<Class<?>> classes = new HashSet<Class<?>>();
public ApplicationServlet() {
singletons.add(new UserApi());
}
@Override
public Set<Class<?>> getClasses() {
return classes;
}
@Override
public Set<Object> getSingletons() {
return singletons;
}
}
我的用户接口
package boundary;
import java.util.logging.Logger;
import javax.inject.Inject;
import javax.transaction.Transactional;
import javax.validation.Valid;
import javax.ws.rs.BadRequestException;
import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;
import control.UserService;
import entity.User;
@Path("user")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
public class UserApi{
@Inject
UserService userService;
// Create a Logger
private final static Logger LOGGER = Logger.getLogger(UserApi.class.getName());
/*
* Will be called by a Rest-Client. This userApi then redirects the call from the client to the userService.
* After Processing the call this userApi will then respond to the client.
*
* Example Path to make a call: http://localhost:8080/workflowmanager/api/user/
*/
/**
* API method to post an user
*
* @param user
* @return {@link Response} containing the status of the request and (in case of
* success) also the requested contract information
* @throws Exception
*/
@Transactional(rollbackOn = Exception.class)
@POST
@Consumes(MediaType.APPLICATION_JSON)
public Response postUser(@Context final UriInfo uriInfo, @Valid final User user) throws Exception {
// create User
LOGGER.info(String.format("Try to post User %s", user.getUsername()));
final User createdUser = userService.createUser(user);
LOGGER.info(String.format("User %s successfully created", createdUser.getUsername()));
return Response.created(null).build();
}
/**
* API method to update an user
*
* @param user
* @return {@link Response} containing the status of the request and (in case of
* success) also the requested contract information
* @throws Exception
*/
@Transactional(rollbackOn = Exception.class)
@PUT
@Consumes(MediaType.APPLICATION_JSON)
@Path("/{username}")
public Response putUser(@Context final UriInfo uriInfo, @Valid final User user,
@PathParam("username") final String userName) throws Exception {
// avoid change of username
if (!userName.equals(user.getUsername())) {
throw new BadRequestException("Not allowed to change username!");
}
// update User
final User updatedUser = userService.updateUser(user);
LOGGER.info(String.format("User %s successfully updated", updatedUser.getUsername()));
return Response.ok().build();
}
/**
* API method to get an user
*
* @param userName
* @return {@link Response} containing the status of the request and (in case of
* success) also the requested contract information
* @throws Exception
*/
@GET
@Consumes(MediaType.APPLICATION_JSON)
@Path("/{userName}")
public Response getUser(@PathParam("userName") final String userName) throws Exception {
LOGGER.info(String.format("Looking up User %s", userName));
final User user = userService.getUser(userName);
return Response.ok(user).build();
}
/**
* API method to deregister an user
*
* @param username
* @return {@link Response} containing the status of the request and (in case of
* success) also the requested contract information
* @throws Exception
*/
@Transactional(rollbackOn =Exception.class)
@DELETE
@Consumes(MediaType.APPLICATION_JSON)
@Path("/{userName}")
public Response deleteUser(@PathParam("userName") final String userName) throws Exception {
userService.deleteContract(userName);
return Response.noContent().build();
}
}
我的用户服务
package control;
import java.util.List;
import java.util.logging.Logger;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.PersistenceContext;
import javax.ws.rs.NotFoundException;
import entity.User;
@Stateless
public class UserService {
@PersistenceContext(unitName = "workflowManager")
EntityManager entityManager;
// Create a Logger
private final static Logger LOGGER = Logger.getLogger(UserService.class.getName());
/*
* Hier werden die Anfragen von der userApi (Boundary) ankommen und die Daten
* manipuliert. Ebenfalls wird hier mit der Datenbank gesprochen
*/
/**
* Creates a new User
*
* @param user
* @throws Exception
*/
public User createUser(final User user) throws Exception {
// check preconditions
LOGGER.info(String.format("Checking if user with name %s already exists ", user.getUsername()));
if (getUser(user.getUsername()) != null) {
LOGGER.info(String.format("User %s already exists! Persisting process aborted.", user.getUsername()));
throw new Exception(new InternalError("Something went wrong during the creation of an user"));
}
// save
LOGGER.info(String.format("Creating user with name ", user.getUsername()));
this.entityManager.persist(user);
LOGGER.info(String.format("User %s successfully persisted", user.getUsername()));
return user;
}
/**
* Updates a given user
*
* @param user
* @throws ElcException
*/
public User updateUser(final User user) throws Exception {
User existingUser = null;
final String userName = user.getUsername();
if (userName != null) {
LOGGER.info(String.format("Searching for User with userName %s before updating", user.getUsername()));
existingUser = getUser(userName);
} else {
throw new Exception(new InternalError("Something went wrong during the update of an user"));
}
user.setId(existingUser.getId());
LOGGER.info(String.format("Merging user with username ", user.getUsername()));
final User mergedUser = this.entityManager.merge(user);
LOGGER.info(String.format("updated username with username %s", user.getUsername()));
return mergedUser;
}
/**
* Get all available Users as list
*
* @return List<User>
*/
public List<User> getAllUser() throws Exception {
LOGGER.info("Retrieving all User ...");
try {
final List<User> user = this.entityManager.createNamedQuery(User.FIND_ALL, User.class).getResultList();
return user;
} catch (Exception e) {
LOGGER.info(String.format("Getting all users failed %s", e.getMessage()));
return null;
}
}
/**
* Gets one user by username
*
* @param username
* @return
* @throws Exception
*/
public User getUser(final String userName) throws Exception {
// Retrieve contractOwner and check if owner exists.
LOGGER.info(String.format("try to get user with name %s", userName));
try {
// get user
return this.entityManager.createNamedQuery(User.FIND_BY_USERNAME, User.class)
.setParameter("username", userName).getSingleResult();
} catch (final NoResultException e) {
// user not found
LOGGER.info(String.format("No user %s found! Error Message: %s", userName, e.getMessage()));
throw new NotFoundException();
} catch (final Exception e) {
LOGGER.info(String.format("Sorry something went wrong - No user %s found! Error Message: %s", userName,
e.getMessage()));
throw new Exception(new InternalError("Something went wrong while retreiving an user"));
}
}
/**
* Deletes one user by username
*
* @param username
* @return
* @throws Exception
*/
public void deleteContract(final String userName) throws Exception {
LOGGER.info(String.format("Deleting user %s", userName));
final User user = getUser(userName);
try {
// delete from database
this.entityManager.remove(user);
} catch (final Exception e) {
LOGGER.info(String.format("Sorry something went wrong - user %s could not be deleted! Error Message: %s", userName,
e.getMessage()));
throw new Exception(new InternalError("Sorry something went wrong - user could not be deleted!"));
}
LOGGER.info(String.format("User successfully removed.", user.getUsername()));
}
}
我的用户
package entity;
import java.io.Serializable;
import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
/**
* The persistent class for the "USER" database table.
*
*/
@Entity
@Table(name = "USER")
@NamedQueries({@NamedQuery(name = "User.findAll", query = "SELECT u FROM User u"),
@NamedQuery(name = User.FIND_BY_USERNAME,
query = "SELECT u FROM User u WHERE u.username = :userName")})
public class User implements Serializable {
static final String PREFIX = "workflowManager.entity.User.";
public static final String FIND_ALL = PREFIX + "findAll";
public static final String FIND_BY_USERNAME = PREFIX + "findByUsername";
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
@Column(name = "PASSWORD")
@NotNull(message = "password is required")
@Size(max = 255, message = "password is too long")
private String password;
@Column(name = "ROLE")
@NotNull(message = "role is required")
@Size(max = 255, message = "role is too long")
private String role;
@Column(name = "USERNAME")
@NotNull(message = "username is required")
@Size(max = 255, message = "username is too long")
private String username;
// bi-directional many-to-one association to Coderepotarget
@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "CODEREPOTARGET")
private Coderepotarget coderepotargetBean;
// bi-directional many-to-one association to Workflowtooltarget
@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "WORKFLOWTOOLTARGET")
private Workflowtooltarget workflowtooltargetBean;
public User() {
}
public long getId() {
return this.id;
}
public void setId(long id) {
this.id = id;
}
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
public String getRole() {
return this.role;
}
public void setRole(String role) {
this.role = role;
}
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
public Coderepotarget getCoderepotargetBean() {
return this.coderepotargetBean;
}
public void setCoderepotargetBean(Coderepotarget coderepotargetBean) {
this.coderepotargetBean = coderepotargetBean;
}
public Workflowtooltarget getWorkflowtooltargetBean() {
return this.workflowtooltargetBean;
}
public void setWorkflowtooltargetBean(Workflowtooltarget workflowtooltargetBean) {
this.workflowtooltargetBean = workflowtooltargetBean;
}
}
更多信息： 在尝试让 userService 完成工作数小时后，我尝试在 UserApi 本身内完成所有逻辑。我将持久性上下文添加到 userApi 并实例化了 EntityManager。当我尝试使用 EntityManager 时，我得到了另一个 NPE。
我使用命令在 glassfish5 上部署应用程序mvn clean install
我还尝试了其他几个命令，例如 Maven->Update Project、mvn clean、project clean，并且我已经多次重新启动 Eclipse 等。
我使用 CDI 1.0 和 Dynamic Webmodule 3.0 但是当我启动服务器时它告诉我（没有更大的问题）：
BeforeBeanDiscovery.addAnnotatedType(AnnotatedType<?>) used for class org.glassfish.jersey.ext.cdi1x.servlet.internal.CdiExternalRequestScope is deprecated from CDI 1.1! [..]
我觉得那里也发生了一些很奇怪的事情？
现在我非常困惑和沮丧，也许你们知道缺少什么。
解决方案
好的，谢谢@Nikos 和@mtj！
事实证明，我的 Glassfish 服务器和最新版本的 Resteasy 和 Java 都面临着一些依赖性问题。
经过数小时调试依赖项后，我决定切换到 Jersey。
但是@Nikos 的建议是完全正确的！如果您想使用 ApplicationServlet，请确保使用classes.add(UserApi.class)ApplicationServlet 或将其留空，并希望您的系统能够自行找到它！
例如，Jersey 在控制台中告诉我它找到了哪些类作为 servlet，所以一定要检查日志！:-)
推荐阅读
- react-native - 在 react-navigation 中使用 react-redux 连接方法显示错误“路由'x'的组件必须是 React 组件
- php - Foreach 循环执行后返回数据
- sql - 尝试在 Spring Boot 中忽略具有 IN 条件的区分大小写时出现 HQL 语法异常
- java - 如何离线使用缓存，否则使用网络
- angularjs - 我们如何将数据推送到 laravel5 中的数组？
- ios - iOS版Flutter ImageCrop库相机权限错误
- dart - 在 Android 中使用 Flutter Firebase Auth Passwordless SignIn (SignInWithEmailAndLink) 找不到动态链接
- python - 使用 python 进行网页抓取
- c# - 如何将json拆分为空格分隔的字符串？
- angular - 如何在 Angular 7 项目中禁用自动填充