Java 我试图使用rest控制器从h2数据库检索记录，但它说没有数据集
这是我的springboot应用程序代码，它显示错误无数据源集 应用程序属性Java 我试图使用rest控制器从h2数据库检索记录，但它说没有数据集,java,spring,spring-boot,hibernate,h2,Java,Spring,Spring Boot,Hibernate,H2,这是我的springboot应用程序代码，它显示错误无数据源集 应用程序属性 spring.datasource.url=jdbc:h2:mem:testdb spring.datasource.driverClassName=org.h2.Driver spring.datasource.username=sa spring.datasource.password= spring.jpa.database-platform=org.hibernate.dialect.H2Dialect ser
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
server.port=8081
# Enabling H2 Console
spring.h2.console.enabled=true
# Custom H2 Console URL
spring.h2.console.path=/h2
spring.jpa.hibernate.ddl-auto=create
package com.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import com.daoimpl.ProductDaoImpl;
import com.service.ProductService;
import pojo.Product;
@RestController
@RequestMapping("/product")
public class ProductController {
//ProductService productservice;
ProductDaoImpl pdi=new ProductDaoImpl();
@RequestMapping(value="/products", method= RequestMethod.GET)
public @ResponseBody List<Product>getAllProducts()
{
System.out.println("in controller");
//return pls.productListAllRecords();
return pdi.productListAllRecords();
}
}
您使用new关键字创建了JdbcTemplate实例，这类似于在Spring依赖项注入之外工作，因此不会注入数据源。请在代码中更新此项
@Autowired
JdbcTemplate jtemp=new JdbcTemplate();
首先，感谢您抽出时间回答这个问题，我按照您说的做了，但是遇到了新的错误java.lang.NullPointerException:nullpointer看起来您在应该注入DAO的线路上遇到了类似的问题。ProductDaoImpl pdi=新的ProductDaoImpl（）；还应设置为@Autowired private ProductDAO pdi；您的Spring应用程序主类应该具有类似于以下内容的内容@SpringBootApplication@ComponentScan（basePackages={“com.controller”，“com.service”}）@enableJParepositions（basePackages={“com.daoimpl”}）@EntityScan（basePackages={“pojo”}）此外，我建议遵循标准java包结构，因此可能类似这样。com.myapplication com.myapplication.controllers com.myapplication.services com.myapplication.daos com.myapplication.pojos这是因为默认情况下@SpringBootApplication将只扫描与应用程序定义相同的包下的包。因此，在您的情况下，您可以将RailwayBokking1应用程序保留在com.example.demo中，然后将控制器放在com.example.demo.controllers中，并在剩下的分离过程中执行以下操作，确保所有程序包都以com.example.demo开头。如果要使用不同的结构，则必须使用我在前面的注释中列出的其他注释。
<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.0-SNAPSHOT</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>dhooms-2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>dhooms-2</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web-services</artifactId>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<version>1.4.193</version>
<scope>runtime</scope>
</dependency>
<!-- <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency> -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</repository>
<repository>
<id>spring-snapshots</id>
<name>Spring Snapshots</name>
<url>https://repo.spring.io/snapshot</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</pluginRepository>
<pluginRepository>
<id>spring-snapshots</id>
<name>Spring Snapshots</name>
<url>https://repo.spring.io/snapshot</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</pluginRepository>
</pluginRepositories>
</project>
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.4.0-SNAPSHOT)
2020-07-21 10:34:34.754 INFO 4804 --- [ main] com.a.Dhooms2Application : Starting Dhooms2Application using Java 11.0.7 on DESKTOP-H9FM8Q7 with PID 4804 (C:\Users\siddhesh\Documents\workspace-spring-tool-suite-4-4.7.0.RELEASE\dhooms-2\target\classes started by siddhesh in C:\Users\siddhesh\Documents\workspace-spring-tool-suite-4-4.7.0.RELEASE\dhooms-2)
2020-07-21 10:34:34.758 INFO 4804 --- [ main] com.a.Dhooms2Application : No active profile set, falling back to default profiles: default
2020-07-21 10:34:35.935 INFO 4804 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFERRED mode.
2020-07-21 10:34:35.959 INFO 4804 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 11 ms. Found 0 JPA repository interfaces.
2020-07-21 10:34:36.355 INFO 4804 --- [ main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.ws.config.annotation.DelegatingWsConfiguration' of type [org.springframework.ws.config.annotation.DelegatingWsConfiguration$$EnhancerBySpringCGLIB$$84228bcc] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2020-07-21 10:34:36.440 INFO 4804 --- [ main] .w.s.a.s.AnnotationActionEndpointMapping : Supporting [WS-Addressing August 2004, WS-Addressing 1.0]
2020-07-21 10:34:37.011 INFO 4804 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8081 (http)
2020-07-21 10:34:37.024 INFO 4804 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2020-07-21 10:34:37.025 INFO 4804 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.36]
2020-07-21 10:34:37.235 INFO 4804 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2020-07-21 10:34:37.236 INFO 4804 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2396 ms
2020-07-21 10:34:37.345 INFO 4804 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2020-07-21 10:34:37.529 INFO 4804 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
2020-07-21 10:34:37.621 INFO 4804 --- [ main] o.s.b.a.h2.H2ConsoleAutoConfiguration : H2 console available at '/h2'. Database available at 'jdbc:h2:mem:testdb'
2020-07-21 10:34:37.993 INFO 4804 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2020-07-21 10:34:38.072 INFO 4804 --- [ task-1] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [name: default]
2020-07-21 10:34:38.157 INFO 4804 --- [ task-1] org.hibernate.Version : HHH000412: Hibernate ORM core version 5.4.18.Final
2020-07-21 10:34:38.160 WARN 4804 --- [ main] JpaBaseConfiguration$JpaWebConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning
2020-07-21 10:34:38.695 INFO 4804 --- [ task-1] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.1.0.Final}
2020-07-21 10:34:39.068 INFO 4804 --- [ task-1] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.H2Dialect
2020-07-21 10:34:39.662 INFO 4804 --- [ task-1] o.h.e.t.j.p.i.JtaPlatformInitiator : HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform]
2020-07-21 10:34:39.679 INFO 4804 --- [ task-1] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2020-07-21 10:34:40.048 INFO 4804 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8081 (http) with context path ''
2020-07-21 10:34:40.051 INFO 4804 --- [ main] DeferredRepositoryInitializationListener : Triggering deferred initialization of Spring Data repositories…
2020-07-21 10:34:40.052 INFO 4804 --- [ main] DeferredRepositoryInitializationListener : Spring Data repositories initialized!
2020-07-21 10:34:40.083 INFO 4804 --- [ main] com.a.Dhooms2Application : Started Dhooms2Application in 5.896 seconds (JVM running for 8.231)
2020-07-21 10:34:54.597 INFO 4804 --- [nio-8081-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2020-07-21 10:34:54.597 INFO 4804 --- [nio-8081-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2020-07-21 10:34:54.598 INFO 4804 --- [nio-8081-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 1 ms
in controller
hehehhe
2020-07-21 10:34:54.795 ERROR 4804 --- [nio-8081-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.IllegalStateException: No DataSource set] with root cause
java.lang.IllegalStateException: No DataSource set
at org.springframework.util.Assert.state(Assert.java:76) ~[spring-core-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.jdbc.support.JdbcAccessor.obtainDataSource(JdbcAccessor.java:77) ~[spring-jdbc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:375) ~[spring-jdbc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:464) ~[spring-jdbc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474) ~[spring-jdbc-5.3.0-M1.jar:5.3.0-M1]
at com.daoimpl.ProductDaoImpl.productListAllRecords(ProductDaoImpl.java:49) ~[classes/:na]
at com.controller.ProductController.getAllProducts(ProductController.java:29) ~[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:190) ~[spring-web-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:890) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:804) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1062) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:962) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.0-M1.jar:5.3.0-M1]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.0-M1.jar:5.3.0-M1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.0-M1.jar:5.3.0-M1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.0-M1.jar:5.3.0-M1]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.0-M1.jar:5.3.0-M1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]
@Autowired
JdbcTemplate jtemp=new JdbcTemplate();
@Autowired private JdbcTemplate jdbcTemplate;