Spring properties to map

Spring属性注入详解

最新推荐文章于 2024-03-11 17:39:33 发布

转载最新推荐文章于 2024-03-11 17:39:33 发布 · 2.1k 阅读

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本文介绍如何使用Spring将properties文件以Map形式注入bean，并演示如何通过自定义PropertiesFactoryBean实现更复杂的转换逻辑。

Spring properties to map

一个key-value形式的properties文件以Map的形式注入到Spring的bean中

properties文件形式

RF09001=fooService#method1#name,phone

spring 配置

    <bean id="noMethodMap" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
        <property name="location" value="classpath:foo.properties"/>
    </bean>

注入到Bean中

    @Resource(name="noMethodMap")
    private Map<String, String> noMethodMap;

其他

如何定位注入源码

修改为一个不存在的资源名称

@Resource(name="nonexist")

此时启动会报错

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'nonexist' available
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:687)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1207)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:284)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
    at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:522)

可知是在哪里注入的了

在哪里将PropertiesFactoryBean转成Map

同样的处理方式将注入变量修改成一个错误的类型查看错误信息即可

private String noMethodMap; // map --> String

启动会报错

Caused by: org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'noMethodMap' is expected to be of type 'java.lang.String' but was actually of type 'java.util.Properties'
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:378)

就知道是在哪里进行类型转换的了

如果想对properties-->Map做一下自定义的处理呢

如RF09001-RF09010对应的都是同一个value

RF09001-RF09003=fooService#method1#name,phone

但是想Map中的实际形式为

RF09001=fooService#method1#name,phone
RF09002=fooService#method1#name,phone
RF09003=fooService#method1#name,phone

继承PropertiesFactoryBean 覆盖createProperties即可

public class MyPropertiesFactoryBean extends PropertiesFactoryBean{
    @Override
    protected Properties createProperties() throws IOException {
        Properties properties = super.createProperties();
        Enumeration<String> propertyNames = (Enumeration<String>) properties.propertyNames();
        while(propertyNames.hasMoreElements()){
            String name = propertyNames.nextElement();
            if(name.matches("\\w+-\\w+")){
                String rawName = name;
                String[] split = rawName.split("-");
                Integer start = Integer.valueOf(split[0].substring(2));
                Integer end = Integer.valueOf(split[1].substring(2));
                for (int i = start; i <= end; i++) {
                    properties.setProperty("RF" + i, properties.getProperty(rawName));
                }
            }
        }
        return properties;
    }

spring配置改成

<bean id="noMethodMap" class="com.foo.app.util.MyPropertiesFactoryBean">