我在试图获得多模块Spring启动应用程序的最新版本时遇到了麻烦,我设法将问题提炼到下面粘贴的简单测试应用程序(也可以在此要点:{{3 }}
当我尝试运行它时,它会启动,但会出现以下错误。请告诉我,我做错了什么显而易见的事情。 :(
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.4.2.RELEASE)
2016-12-10 16:41:04.035 INFO 25026 --- [ main] com.example.DemoApplication : Starting DemoApplication on den with PID 25026 (/Users/dre/src/demo/target/classes started by dre in /Users/dre/src/demo)
2016-12-10 16:41:04.039 INFO 25026 --- [ main] com.example.DemoApplication : No active profile set, falling back to default profiles: default
2016-12-10 16:41:04.108 INFO 25026 --- [ main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@21507a04: startup date [Sat Dec 10 16:41:04 EST 2016]; root of context hierarchy
2016-12-10 16:41:04.923 WARN 25026 --- [ main] s.c.a.AnnotationConfigApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demoApplication': Unsatisfied dependency expressed through field 'dc'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demoConfig' defined in file [/Users/dre/src/demo/target/classes/com/example/config/DemoConfig.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'java.lang.String' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}
2016-12-10 16:41:04.932 INFO 25026 --- [ main] utoConfigurationReportLoggingInitializer :
Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2016-12-10 16:41:05.035 ERROR 25026 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter :
***************************
APPLICATION FAILED TO START
***************************
Description:
Parameter 0 of constructor in com.example.config.DemoConfig required a bean of type 'java.lang.String' that could not be found.
Action:
Consider defining a bean of type 'java.lang.String' in your configuration.
Process finished with exit code 1
application.yml
demo:
foo:
str_val: Make it work!
objVal.objVal: This one too!
DemoApplication.java
package com.example;
import com.example.config.DemoConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class DemoApplication implements ApplicationRunner {
@Autowired
private DemoConfig dc;
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
@Override
public void run(ApplicationArguments args) throws Exception {
System.out.printf("String val: %s\nObject val: %s", dc.getStrVal(), dc.getObjVal());
}
}
DemoConfig.java
package com.example.config;
import lombok.Data;
import org.hibernate.validator.constraints.NotBlank;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
@Data
@Component
@ConfigurationProperties(prefix = "demo.foo")
public class DemoConfig {
@NotBlank private final String strVal;
private final ObjVal objVal;
@Data
public static class ObjVal {
@NotBlank private final String objVal;
}
}
的pom.xml
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-validation</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
答案 0 :(得分:1)
阅读文档应该有所帮助。
您的字段是最终字段,不会生成任何setter。然而,this is a requirement for @ConfigurationProperties
properties。绑定可以通过标准Java Beans属性描述符工作。绑定器从不支持构造函数注入。
但是这个错误是不同的。依赖注入与此处的任何其他组件没有区别。您基本上创建了Option Explicit
Sub CopyBetweenSheets()
Dim Outbook1 As Workbook
Dim OutBook As Workbook
Dim Lines As Long
Set OutBook = ThisWorkbook
Set Outbook1 = Workbooks.Add
With OutBook
With .Sheets("Sheet6")
' find last row in Column A in "Sheet6"
Lines = .Cells(.Rows.Count, "A").End(xlUp).Row
.Range("A1:N" & Lines).Copy
End With
End With
' paste to "A1" in "Sheet1" in the new workbook
Outbook1.Sheets("Sheet1").Range("A1").PasteSpecial xlPasteAll
End Sub
,其中@Component
和String
作为参数。因此,当应用程序上下文尝试创建bean时,它需要找到两个匹配这些类型的bean。这与ObjVal
无关。
长话短说,改变你的课程如下:
@ConfigurationProperties
我删除了Lombok,明确表示现在没有特定的构造函数。如果你有一个,参数必须是上下文中可用的spring bean。