初学spring-boot遇到的自定义属性获取问题

Dear 丶 2022-05-20 08:10 161阅读 0赞

### 遇到如下一些问题：（springboot-1.5.14） ###

> 1.自己建立的包一定要在启动入口类`***Application.java`包下，这样`@EnableAutoConfiguration`注解才会自动扫描package，创建Beans

--------------------

> 2.当我们需要自定义配置时，`@EnableConfigurationProperties`功能是自动映射一个`POJO`到`SpringBoot`配置文件（默认是`application.properties`文件）的属性集。

##### 下面我们看下我自己做的一个小demo #####

1.首先在`resources/application.properties`文件中写下如下配置：

gt.name=cronous
    gt.describe=cool boy

2.首先看一下需要映射的实体类

package edu.hohai.myfirstspringboot.gt.entity;
    
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.stereotype.Component;
    
    @Component //代表这是一个bean组件
    @ConfigurationProperties(prefix = "gt") //application.properties文件中的自定义配置前缀prefix
    public class Blog { 
    
    
        private String name;
    
        private String describe;
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public String getDescribe() {
            return describe;
        }
    
        public void setDescribe(String describe) {
            this.describe = describe;
        }
    }

3.看下最原始的入口类

package edu.hohai.myfirstspringboot;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    @EnableAutoConfiguration
    public class MyfirstSpringBootApplication { 
    
        public static void main(String[] args) {
            SpringApplication.run(MyfirstSpringBootApplication.class, args);
        }
    }

4.再看一下我的`pom.xml`配置文件

<?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>edu.hohai</groupId>
        <artifactId>myfirst-spring-boot</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>myfirst-spring-boot</name>
        <description>Demo project for Spring Boot</description>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.14.RELEASE</version>
            <relativePath/> 
        </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</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
    
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
                <optional>true</optional>
                <scope>true</scope>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-configuration-processor</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>
                    <configuration>
                        <fork>true</fork>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    
    
    </project>

5.我的测试类

package edu.hohai.myfirstspringboot;
    
    import edu.hohai.myfirstspringboot.gt.entity.Blog;
    import edu.hohai.myfirstspringboot.gt.web.HelloController;
    import org.junit.Before;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    
    import org.springframework.boot.context.properties.EnableConfigurationProperties;
    import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
    
    import org.springframework.http.MediaType;
    import org.springframework.test.context.junit4.SpringRunner;
    import org.springframework.test.web.servlet.MockMvc;
    import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
    import org.springframework.test.web.servlet.setup.MockMvcBuilders;
    
    import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
    import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
    
    //基于1.5.14的mock测试用例
    @RunWith(SpringRunner.class)
    @WebMvcTest(HelloController.class)
    @EnableConfigurationProperties(Blog.class) //记得一定要绑定配置文件到POJO类，不然会无法创建bean
    public class MyfirstSpringBootApplicationTests{
    
        @Autowired
        private MockMvc mvc;
    
        @Autowired
        private Blog blog;
    
        @Before
        public void setUp() throws Exception {
            mvc = MockMvcBuilders.standaloneSetup(new HelloController()).build();
        }
    
        @Test //用于测试自己写的/hello路由请求，这里我们不关心这个，看下面的自定义属性测试
        public void getHello() throws Exception {
            mvc.perform(MockMvcRequestBuilders.get("/hello").accept(MediaType.APPLICATION_JSON))
                    .andExpect(status().isOk())
                    .andExpect(content().string("cronous"));
    
        }
        @Test //自定义属性配置的测试
        public void getProperty() throws Exception {
    
            System.out.println(blog.getName());
            System.out.println(blog.getDescribe());
        }
    
    }

如果少了绑定汇报如下错误：

2018-07-15 17:50:55.781 ERROR 4444 --- [           main] o.s.test.context.TestContextManager : Caught exception while allowing TestExecutionListener [org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener@6166e06f] to prepare test instance [edu.hohai.myfirstspringboot.MyfirstSpringBootApplicationTests@7bb58ca3] org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'edu.hohai.myfirstspringboot.MyfirstSpringBootApplicationTests': Unsatisfied dependency expressed through field 'blog'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'edu.hohai.myfirstspringboot.gt.entity.Blog' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {
       @org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1272) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:386) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118) ~[spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83) ~[spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener.prepareTestInstance(SpringBootDependencyInjectionTestExecutionListener.java:44) ~[spring-boot-test-autoconfigure-1.5.14.RELEASE.jar:1.5.14.RELEASE]
        at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230) ~[spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228) [spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287) [spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) [junit-4.12.jar:4.12]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289) [spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247) [spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94) [spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) [junit-4.12.jar:4.12]
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) [junit-4.12.jar:4.12]
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) [junit-4.12.jar:4.12]
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) [junit-4.12.jar:4.12]
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) [junit-4.12.jar:4.12]
        at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) [spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) [spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.junit.runners.ParentRunner.run(ParentRunner.java:363) [junit-4.12.jar:4.12]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191) [spring-test-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.junit.runner.JUnitCore.run(JUnitCore.java:137) [junit-4.12.jar:4.12]
        at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) [junit-rt.jar:na]
        at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47) [junit-rt.jar:na]
        at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) [junit-rt.jar:na]
        at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70) [junit-rt.jar:na]
    Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'edu.hohai.myfirstspringboot.gt.entity.Blog' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {
       @org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1493) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585) ~[spring-beans-4.3.18.RELEASE.jar:4.3.18.RELEASE]
        ... 28 common frames omitted
    
    
    org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'edu.hohai.myfirstspringboot.MyfirstSpringBootApplicationTests': Unsatisfied dependency expressed through field 'blog'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'edu.hohai.myfirstspringboot.gt.entity.Blog' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {
       @org.springframework.beans.factory.annotation.Autowired(required=true)}
    
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1272)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:386)
        at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118)
        at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
        at org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener.prepareTestInstance(SpringBootDependencyInjectionTestExecutionListener.java:44)
        at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230)
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228)
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287)
        at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289)
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247)
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
        at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
        at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
        at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
        at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
        at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
        at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
        at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
        at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
    Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'edu.hohai.myfirstspringboot.gt.entity.Blog' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {
       @org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1493)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
        ... 28 more
    
    2018-07-15 17:50:55.810  INFO 4444 --- [       Thread-3] o.s.w.c.s.GenericWebApplicationContext   : Closing org.springframework.web.context.support.GenericWebApplicationContext@1cbb87f3: startup date [Sun Jul 15 17:50:50 CST 2018]; root of context hierarchy
    
    Process finished with exit code -1

我也把controller类贴出来吧，不然不完整

package edu.hohai.myfirstspringboot.gt.web;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class HelloController {
    
        @RequestMapping("/hello")
        public String index(){
            return "cronous";
        }
    }

6.打印如下所示，说明我们成功获取

2018-07-15 18:29:24.897  INFO 4336 --- [           main] o.s.t.web.servlet.TestDispatcherServlet  : FrameworkServlet '': initialization completed in 7 ms
    cronous
    cool boy
    2018-07-15 18:29:24.931  INFO 4336 --- [       Thread-3] o.s.w.c.s.GenericWebApplicationContext   : Closing org.springframework.web.context.support.GenericWebApplicationContext@15bbf42f: startup date [Sun Jul 15 18:29:18 CST 2018]; root of context hierarchy
    
    Process finished with exit code 0