java - JUnit 依赖项未加载

Question

我有以下 JUnit 测试套件，当我尝试加载测试时，我在正在测试的类中 Autowiring 的依赖项似乎没有加载，并且收到以下错误消息:

package com.uk.jacob.service;

import static org.junit.Assert.*;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;

import com.uk.jacob.model.Ping;

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = PingerService.class)
@WebAppConfiguration
public class PingerServiceTests {

    @Test
    public void testPingerServiceReturnsOkWhenServiceIsUp(){
        PingerService pingerService = new PingerService();
        Ping ping = pingerService.ping("http://devnews.today");

        assertEquals(true, ping.ok);
    }

    @Test
    public void testPingerServiceReturnsOkWhenServiceIsDown(){
        PingerService pingerService = new PingerService();
        Ping ping = pingerService.ping("https://jacob.uk.comz");

        assertEquals(false, ping.ok);
    }

}

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void com.uk.jacob.service.PingerService.setHttpAdapter(com.uk.jacob.adapter.HttpAdapter); nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.uk.jacob.adapter.HttpAdapter] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}

Pinger服务:

package com.uk.jacob.service;

import java.io.IOException;
import java.net.HttpURLConnection;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.uk.jacob.adapter.HttpAdapter;
import com.uk.jacob.model.Ping;

@Component
public class PingerService {

    HttpAdapter httpAdapter;

    public Ping ping(String urlToPing) {
        Ping ping = new Ping();

        try {
            HttpURLConnection connection = httpAdapter.createHttpURLConnection(urlToPing);

            if(connectionIsOk(connection)){
                ping.ok = true;
            }
        } catch (Exception e) {
            ping.ok = false;
        }

        return ping;
    }

    private boolean connectionIsOk(HttpURLConnection connection) throws IOException {
        return connection.getResponseCode() == 200;
    }

    @Autowired
    public void setHttpAdapter(HttpAdapter httpAdapter){
        this.httpAdapter = httpAdapter;
    }

}

Http适配器:

package com.uk.jacob.adapter;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

import org.springframework.stereotype.Component;

@Component
public class HttpAdapter {
    public HttpURLConnection createHttpURLConnection(String urlToPing) throws IOException{
        URL url = new URL(urlToPing);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        connection.setRequestMethod("GET");
        connection.connect();

        return connection;
    }
}

Answer 1

你正在创建你的 pingerService 就像

PingerService pingerService = new PingerService();

在测试类中，所以它不是一个spring bean，所以spring不会在那里注入(inject)任何东西，它不会工作。相反，将 PingerService 添加到您的 spring 配置中:使用 @Component 注释它，并将其放在类路径中可以找到的位置，或者在 Spring 配置类中使用 @Bean 注释的方法创建它。

这导致了第二个问题:

@SpringApplicationConfiguration(classes = PingerService.class)

您必须在此处提供一个配置类，而不是单个服务。配置类必须实例化 spring bean，在您的情况下至少实例化 PingerService 和 HttpAdapter。

看看Spring java config (older version)

关于您的评论:对于配置类，带注释的 @SpringBootApplication 类就足够了吗？

是的，如果 PingerService 和 HttpAdapter 位于 SpringBootApplication 带注释的类的子包中，那么这就足够了，这样 ComponentScan 就可以找到它们。

如果您使用@SpringBootApplication，则会自动配置 ComponentScan