在spring中从属性文件中注入值数组（不使用spring boot）

Question

要求与此处发布的问题Injecting array of values from properties file in spring boot 相同，即使用 application.properties 文件中定义的相关属性列表。

问题是，我的代码使用 Core Spring。如何在不引入 Spring Boot 以使用 @ConfigurationProperties 的情况下实现相同的目标？从长远来看，使用逗号分隔的值列表将不起作用，因为我希望表达配置对象列表，而不仅仅是字符串列表

谢谢

Answer 1

您可以查看使用Apache Commons Configuration，它提供了丰富的方法来处理属性。

如果您想坚持使用属性文件，可以查看使用this page 处理列表和数组：-

List<Object> colorList = config.getList("colors.pie");

或者您可以使用基于 XML 的 hierarchical configurations 并使用以下内容：-

List<HierarchicalConfiguration<ImmutableNode>> fields = config.configurationsAt("tables.table(0).fields.field");

和

List<Object> fieldNames = config.getList("tables.table(0).fields.field.name");

阅读他们的user-guide，你应该会找到你要找的东西。

Answer 2

如果您可以将 spring-boot jar 添加为依赖项，则可以将 @ConfigurationProperties 与核心弹簧一起使用。

package com.stackoverflow.q54119803;

import static java.util.stream.Collectors.*;
import static org.junit.Assert.*;

import java.util.List;
import java.util.stream.Stream;

import org.junit.ClassRule;
import org.junit.Rule;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.io.ClassPathResource;
import org.springframework.test.context.junit4.rules.SpringClassRule;
import org.springframework.test.context.junit4.rules.SpringMethodRule;

@SuppressWarnings("javadoc")
public class So54119803 {

    /** The Constant SPRING_CLASS_RULE. */
    @ClassRule
    public static final SpringClassRule SPRING_CLASS_RULE = new SpringClassRule();

    final String anotherPropValue = "anotherPropValue";
    final List<String> expected = Stream.of("string1", this.anotherPropValue)
        .collect(toList());

    /** The spring method rule. */
    @Rule
    public final SpringMethodRule springMethodRule = new SpringMethodRule();

    @Autowired
    Props props;

    @Test
    public void test() {

        System.out.println(this.props);

        assertEquals(this.anotherPropValue, this.props.getAnotherProp());
        assertEquals(String.class, this.props.getClazz());
        assertEquals(this.expected, this.props.getStrings());

    }

    @Configuration
    @EnableConfigurationProperties
    static class Config {

        @Bean
        public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {

            final ClassPathResource location = new ClassPathResource("props.properties");
            final PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer = new PropertySourcesPlaceholderConfigurer();

            propertySourcesPlaceholderConfigurer.setLocation(location);
            return propertySourcesPlaceholderConfigurer;
        }

        @Bean
        @ConfigurationProperties("test")
        Props props() {
            return new Props();
        }

    }

    static class Props {

        String anotherProp;

        List<String> strings;

        Class<?> clazz;

        public String getAnotherProp() {
            return this.anotherProp;
        }

        public void setAnotherProp(String anotherProp) {
            this.anotherProp = anotherProp;
        }

        public List<String> getStrings() {
            return this.strings;
        }

        public void setStrings(List<String> strings) {
            this.strings = strings;
        }

        public Class<?> getClazz() {
            return this.clazz;
        }

        public void setClazz(Class<?> clazz) {
            this.clazz = clazz;
        }

        @Override
        public String toString() {
            return "Props [anotherProp=" + this.anotherProp + ", strings=" + this.strings + ", clazz=" + this.clazz
                    + "]";
        }

    }
}

示例道具文件：props.properties

#Conversions and references work fine
test.anotherProp=anotherPropValue
test.strings=string1,${test.anotherProp}
test.clazz=java.lang.String

示例中的依赖关系：

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-core</artifactId>
</dependency>

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-beans</artifactId>
</dependency>

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
</dependency>

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot</artifactId>
</dependency>

<dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
  <scope>test</scope>
</dependency>

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-test</artifactId>
  <scope>test</scope>
</dependency>