java - 使用 Spring 加载显示 NPE 的 java 属性文件

Question

这个问题已经有答案了:

Why is my Spring @Autowired field null? (21 个回答)

已关闭 7 年前。

我是 Spring 的新手，我正在尝试使用 Spring 框架加载属性文件，我能够成功地从 junit 测试加载所有属性，但是当我尝试将单元测试实现为函数时，它会抛出 NPE-

我的 junit 类(按预期工作)

@RunWith(SpringJUnit4ClassRunner.class)
@ActiveProfiles(profiles = "test")
@ContextConfiguration("classpath:spring/xml-config-context.xml")
public class GlueTestPropertiesTest2 extends TestCase {

    @Autowired
    GenericEnv env;

    @Autowired
    WebPropertiesLoader wpl;

    @Test
    public void testAppProperties() {

        System.out.println("Running MiniConfigSpringPropertiesTest ...");

        System.out.println("Environment        : " + env.toString());

        System.out.println("Database Properties: " + wpl.toString());
    }

}

我的实现类(正在展示 NPE):

@ActiveProfiles(profiles = "test")
@ContextConfiguration("classpath:spring/xml-config-context.xml")
public class GlueTestProperties {

    @Autowired
    GenericEnv env;

    @Autowired
    WebPropertiesLoader wpl;

    public static void main(String[] args) {
        GlueTestProperties gp = new GlueTestProperties();
        gp.callme();


    }


    private void callme(){

 System.out.println("Running ConfigSpringPropertiesTest ...");

        System.out.println("Environment        : " + env.toString());

        System.out.println("Database Properties: " + wpl.toString());
    }
}

WebPropertiesLoader bean:

@Component
public class WebPropertiesLoader {

    @Value("${bank.ease.login.url}")
    public String easeLoginUrl;

    @Value("${bank.browser.name}")
    public String browserName;

    @Value("${bank.browser.version}")
    public String browserVersion;

    @Value("${webdriver.chrome.driver}")
    public String chromeDriver;

    @Value("${webdriver.ie.driver}")
    public String ieDriver;

    @Value("${bank.web.feature.location}")
    public String webFeatureLocation;

    @Value("${bank.web.test.location}")
    public String webTestLocation;

    @Value("${bank.event.log}")
    public String eventLog;

    @Value("${bank.epoxy.backend}")
    public String epoxyBackend;

    @Value("${bank.epoxy.host}")
    public String epoxyHost;

    @Value("${bank.epoxy.port}")
    public String epoxyPort;

    @Value("${bank.epoxy.debug}")
    public String epoxyDebug;

    @Value("${bank.epoxy.implicitWait}")
    public String epoxyImplicitWait;

    @Value("${bank.epoxy.timeout}")
    public String epoxyTimeOut;

    @Value("${bank.epoxy.default.url}")
    public String epoxyDefaultURL;

    @Value("${bank.sassy.url}")
    public String sassyUrl;

    @Value("${bank.transite.url}")
    public String transiteUrl;

    @Value("${bank.transite.login.url}")
    public String transiteLoginUrl;


    public String getBrowserName() {
        return browserName;
    }

    public String getBrowserVersion() {
        return browserVersion;
    }

    public String getChromeDriver() {
        return chromeDriver;
    }

    public String getEpoxyDefaultURL() {
        return epoxyDefaultURL;
    }

    public String getSassyUrl() {
        return sassyUrl;
    }

    public String getTransiteUrl() {
        return transiteUrl;
    }

    public String getTransiteLoginUrl() {
        return transiteLoginUrl;
    }

    public String getIeDriver() {
        return ieDriver;
    }

    public String getWebFeatureLocation() {
        return webFeatureLocation;
    }

    public String getWebTestLocation() {
        return webTestLocation;
    }

    public String getEventLog() {
        return eventLog;
    }

    public String getEpoxyBackend() {
        return epoxyBackend;
    }

    public String getEpoxyHost() {
        return epoxyHost;
    }

    public String getEpoxyPort() {
        return epoxyPort;
    }

    public String getEpoxyDebug() {
        return epoxyDebug;
    }

    public String getEpoxyImplicitWait() {
        return epoxyImplicitWait;
    }

    public String getEpoxyTimeOut() {
        return epoxyTimeOut;
    }


    public String getEaseLoginUrl() {
        return easeLoginUrl;
    }

    @Override
    public String toString() {
        return "Ease application Default Properties [browserName=" + browserName + ", browserVersion=" + browserVersion
                + ", chromeDriver=" + chromeDriver + ", ieDriver=" + ieDriver + ", webFeatureLocation="
                + webFeatureLocation + ", webTestLocation=" + webTestLocation + ", eventLog=" + eventLog
                + ", epoxyBackend=" + epoxyBackend + ", epoxyHost=" + epoxyHost + ", epoxyPort=" + epoxyPort
                + ", epoxyDebug=" + epoxyDebug + ", epoxyImplicitWait=" + epoxyImplicitWait + ", epoxyTimeOut="
                + epoxyTimeOut + ", epoxyDefaultURL=" + epoxyDefaultURL + ", easeLoginUrl=" + easeLoginUrl + "]";
    }

}

测试环境bean:

@Component
public class TestEnv implements GenericEnv {

    private String envName = "test";

    @Value("${profile.name}")
    private String profileName;

    public String getEnvName() {
        return envName;
    }

    public void setEnvName(String envName) {
        this.envName = envName;
    }

    public String getProfileName() {
        return profileName;
    }

    public void setProfileName(String profileName) {
        this.profileName = profileName;
    }

    @Override
    public String toString() {
        return "TestEnv [envName=" + envName + ", profileName=" + profileName
                + "]";
    }

}

使用的上下文 xml:

?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://cxf.apache.org/core http://cxf.apache.org/schemas/core.xsd 
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- scans for annotated classes in the com.company package -->
    <context:component-scan base-package="com.glue.commons" />

    <!-- enables annotation based configuration -->
    <!-- <context:annotation-config /> -->

    <beans profile="dev">
        <!-- allows for ${} replacement in the spring xml configuration from the 
            application-default.properties, application-dev files on the classpath -->
        <context:property-placeholder
            location="classpath:properties/application-web-default.properties, classpath:properties/application-web-dev.properties"
            ignore-unresolvable="true" />

        <!-- scans for annotated classes in the com.env.dev package -->
        <context:component-scan base-package="com.glue.env.dev" />
    </beans>

    <beans profile="test">
        <!-- allows for ${} replacement in the spring xml configuration from the 
            application-default.properties, application-test files on the classpath -->
        <context:property-placeholder
            location="classpath:properties/application-web-default.properties, classpath:properties/application-web-qa2.properties"
            ignore-unresolvable="true" />

        <!-- scans for annotated classes in the com.env.test package -->
        <context:component-scan base-package="com.glue.env.test" />
    </beans>

    <beans profile="prod">
        <!-- allows for ${} replacement in the spring xml configuration from the 
            application-default.properties, application-prod files on the classpath -->
        <context:property-placeholder
            location="classpath:properties/application-web-default.properties, classpath:properties/application-web-prod.properties"
            ignore-unresolvable="true" />

        <!-- scans for annotated classes in the com.env.prod package -->
        <context:component-scan base-package="com.glue.env.prod" />
    </beans>
    <beans profile="dev">
        <!-- allows for ${} replacement in the spring xml configuration from the 
            application-default.properties, application-dev files on the classpath -->
        <context:property-placeholder
            location="classpath:properties/application-api-default.properties, classpath:properties/application-api-dev.properties"
            ignore-unresolvable="true" />

        <!-- scans for annotated classes in the com.env.dev package -->
        <context:component-scan base-package="com.glue.env.dev" />
    </beans>

    <beans profile="test">
        <!-- allows for ${} replacement in the spring xml configuration from the 
            application-default.properties, application-test files on the classpath -->
        <context:property-placeholder
            location="classpath:properties/application-api-default.properties, classpath:properties/application-api-qa2.properties"
            ignore-unresolvable="true" />

        <!-- scans for annotated classes in the com.env.test package -->
        <context:component-scan base-package="com.glue.env.test" />
    </beans>

    <beans profile="prod">
        <!-- allows for ${} replacement in the spring xml configuration from the 
            application-default.properties, application-prod files on the classpath -->
        <context:property-placeholder
            location="classpath:properties/application-api-default.properties, classpath:properties/application-api-prod.properties"
            ignore-unresolvable="true" />

        <!-- scans for annotated classes in the com.env.prod package -->
        <context:component-scan base-package="com.glue.env.prod" />
    </beans>

提前致谢，如果我犯了一些愚蠢的错误，请原谅我，但我需要你的帮助。

Answer 1

如果你使用main方法来创建它，那么spring将不知道这个类的任何信息，因此它不会 Autowiring 任何类 - 你会在所有用@注释的字段中得到空值自动连线。

您的 JUnit 工作正常，因为它是使用 spring 感知的 junit 运行程序实例化的。