Java 读取 Properties 和 Yaml Properties

Java 可以使用 PropertiesConfiguration 来读取 properties 属性文件,Spring 4.3 后还支持了 Yaml 格式的属性文件

  • PropertiesConfiguration: 读取时可以自动进行类型转换,可以给定默认值
  • Yaml 格式的属性文件: 可以使用树形结构,方便分组,比 .properties 属性文件更灵活,但是以普通的 java.util.Properties 来读取

Gradle 依赖

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compile 'org.springframework:spring-context:4.3.0.RELEASE'
compile 'org.yaml:snakeyaml:1.17'
compile 'commons-configuration:commons-configuration:1.10'
testCompile 'org.springframework:spring-test:4.3.0.RELEASE'
testCompile 'junit:junit:4.12'

属性文件

config.properties

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username=Dr. Alice
age=22
# 存储试卷文件的目录
papersDirectory=/Users/Biao/Documents/套卷/papers

config.yml

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#mysql
mysql:
jdbc:
url: jdbc:mysql://localhost:3306
dirverClass: com.mysql.jdbc.Driver
username: root
password: root
username: Dr. Alice

Spring Bean 配置文件

spring-beans-config.xml

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="yamlProperties" class="org.springframework.beans.factory.config.YamlPropertiesFactoryBean">
<property name="resources">
<list>
<value>classpath:config.yml</value>
</list>
</property>
</bean>
<bean id="propertiesConfig" class="org.apache.commons.configuration.PropertiesConfiguration" init-method="load">
<property name="encoding" value="UTF-8"/>
<property name="URL" value="classpath:/config.properties"/>
</bean>
</beans>

propertiesConfig 的 encoding 设置为 UTF-8,则 properties 文件里就可以用中文了

测试案例

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import org.apache.commons.configuration.PropertiesConfiguration;
import org.junit.runner.RunWith;
import org.junit.Test;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringRunner;
import javax.annotation.Resource;
import java.util.Properties;
@RunWith(SpringRunner.class)
@ContextConfiguration({"classpath:spring-beans-config.xml"})
public class TestYamlPropertiesAndPropertiesConfig {
@Resource(name = "yamlProperties")
private Properties yamlProperties;
@Resource(name = "propertiesConfig")
private PropertiesConfiguration propertiesConfig;
@Test
public void testYamlProperties() {
System.out.println(yamlProperties.getProperty("mysql.jdbc.url"));
System.out.println(yamlProperties.getProperty("username"));
}
@Test
public void testPropertiesConfig() {
System.out.println(propertiesConfig.getString("username"));
System.out.println(propertiesConfig.getInteger("age", 0));
}
}

输出:

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Dr. Alice
22
jdbc:mysql://localhost:3306
Dr. Alice