找不到默认构造函数;嵌套的异常是java.lang.NoSuchMethodException bean配置

Question

我想在H2数据库上运行一些SQL，我相信我的SQL模式已经运行。尽管我不确定如何获取数据源的工作方式。我已经为我的数据源设置器添加了@Repository注释和一个@Autowired注释，希望有任何帮助。

package ping.repositories; 

import javax.sql.DataSource; 

import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.jdbc.core.JdbcTemplate; 
import org.springframework.stereotype.Repository; 
import ping.cascade.integration.CascadeInterface; 
import ping.cascade.integration.company.CascadeFactory; 
import ping.domain.Cascade; 
import ping.domain.PingRequestBody; 

import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 

import java.util.ArrayList; 

@Repository 
public class CascadeListRepository { 

    private static final Logger log = LoggerFactory.getLogger(CascadeListRepository.class); 

    private JdbcTemplate jdbcTemplate; 
    private DataSource dataSource; 

    private ArrayList<CascadeInterface> cascadeList; 
    private PingRequestBody pingRequestBody; 

    public CascadeListRepository(PingRequestBody pingRequestBody){ 
     this.cascadeList = new ArrayList<CascadeInterface>(); 
     this.pingRequestBody = pingRequestBody; 
    } 

    @Autowired 
    public void setDataSource(DataSource dataSource) { 
     this.jdbcTemplate = new JdbcTemplate(dataSource); 
    } 

    public ArrayList<CascadeInterface> getCascadeList(){ 

     CascadeFactory cascadeFactory = new CascadeFactory(); 



     jdbcTemplate.query(
       "SELECT cascade_id, cascade_name, cascade_object FROM cascade", 
       (rs, rowNum) -> new Cascade(rs.getInt("cascade_id"), rs.getString("cascade_name"), rs.getString("cascade_object")) 
     ).forEach(cascade -> log.info(cascade.toString())); 
     log.info("Finished sql"); 



     return cascadeList; 
    } 
} 

，异常是：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'cascadeListRepository' defined in URL [jar:file:/Users/charlesbryant/projects/java/spring/cb-ping-service/build/libs/cb-ping-service-0.1.0.jar!/ping/repositories/CascadeListRepository.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [ping.repositories.CascadeListRepository]: No default constructor found; nested exception is java.lang.NoSuchMethodException: ping.repositories.CascadeListRepository.<init>() 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1105) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1050) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) ~[spring-context-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.3.RELEASE.jar!/:1.3.3.RELEASE] 
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.3.RELEASE.jar!/:1.3.3.RELEASE] 
    at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.3.RELEASE.jar!/:1.3.3.RELEASE] 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.3.RELEASE.jar!/:1.3.3.RELEASE] 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.3.RELEASE.jar!/:1.3.3.RELEASE] 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.3.RELEASE.jar!/:1.3.3.RELEASE] 
    at ping.Application.main(Application.java:10) [cb-ping-service-0.1.0.jar!/:na] 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_31] 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_31] 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_31] 
    at java.lang.reflect.Method.invoke(Method.java:483) ~[na:1.8.0_31] 
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:54) [cb-ping-service-0.1.0.jar!/:na] 
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_31] 
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [ping.repositories.CascadeListRepository]: No default constructor found; nested exception is java.lang.NoSuchMethodException: ping.repositories.CascadeListRepository.<init>() 
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:85) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1098) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 
    ... 23 common frames omitted 
Caused by: java.lang.NoSuchMethodException: ping.repositories.CascadeListRepository.<init>() 
    at java.lang.Class.getConstructor0(Class.java:3074) ~[na:1.8.0_31] 
    at java.lang.Class.getDeclaredConstructor(Class.java:2170) ~[na:1.8.0_31] 
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:80) ~[spring-beans-4.2.5.RELEASE.jar!/:4.2.5.RELEASE] 

Answer 1

似乎是有道理的。您没有定义默认的构造函数。 IE：

public CascadeListRepository() //No parameters makes this the default 
{ 
} 

Answer 2

你不仅没有默认构造器，但你确实有构造函数需要一个PingRequestBody但你不自动装配这么春天将永远无法在瞬间自动实例化这个类。根据您的Spring应用程序上下文，您将要添加一个默认构造函数，即无参数或将@Autowired添加到您的现有构造函数中。

@Autowired 
public CascadeListRepository(PingRequestBody pingRequestBody){ 
    this.cascadeList = new ArrayList<CascadeInterface>(); 
    this.pingRequestBody = pingRequestBody; 
} 

@Charles Bryant，为了回应您的评论，您为什么要手动实例化控制器中的CascadeListRepository？你用@Repository注释它，所以它应该是你的spring应用程序上下文中的一个bean，你可以简单地在你的控制器中使用@Autowire。如果你手动实例化它，然后春天的上下文是不知道它，并没有控制它的生命周期...