在spring 3.0中，可以通过使用@value，对一些如xxx.properties文件中的文件，进行键值对的注入，例子如下：
1.首先在applicationContext.xml中加入：
1. <beans xmlns="http://www.springframework.org/schema/beans"
2. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
3. xsi:schemaLocation="http://www.springframework.org/schema/beans
4. >
1. <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
2. <property name="locations">
3. <list>
4. <value>classpath:test.properties</value>
5. </list>
6. </property>
7. </bean>
3.创建test.properties
abc=123
4.
1. import
2. import
3. import
4.
5. @RequestMapping("/admin/images")
6. @Controller
7. public class
8.
9. private
10.
11. @Value("${abc}")
12. public void
13. this.imageDir = val;
14. }
15. }
有时候需要从properties文件中加载配置，以前的方式是这样的：
<bean id="jdbcProperties" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath*:/spring/jdbc.properties</value>
</list>
</property>
</bean>最近发现这样也可以，代码更整洁：
<context:property-placeholder location="classpath:spring/jdbc.properties" />在bean定义中依然可以通过“${}”这种方式来去值：
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="initialSize" value="${jdbc.initialSize}" />
<property name="maxActive" value="${jdbc.maxActive}" />
<property name="maxIdle" value="${jdbc.maxIdle}" />
<property name="minIdle" value="${jdbc.minIdle}" />
</bean><context:property-placeholder ... /> is the XML equivalent to the PropertyPlaceholderConfigurer. So, prefer that. The <util:properties/>
In Spring 3.1 (not 3.0...) you can do something like this:
@Configuration
@PropertySource("/foo/bar/services.properties")
public class ServiceConfiguration {
@Autowired Environment environment;
@Bean public javax.sql.DataSource dataSource( ){
String user = this.environment.getProperty("ds.user");
...
}
}
@Configuration
@PropertySource("/foo/bar/services.properties")
public class ServiceConfiguration {
@Autowired Environment environment;
@Bean public javax.sql.DataSource dataSource( ){
String user = this.environment.getProperty("ds.user");
...
}
}In Spring 3.0, you can "access" properties defined using the PropertyPlaceHolderConfigurer mechanism using the SpEl annotations:
@Value("${ds.user}") private String user;
@Value("${ds.user}") private String user;If you want to remove the XML all together, simply register the PropertyPlaceholderConfigurer manually using Java configuration. I prefer the 3.1 approach. But, if youre using the Spring 3.0 approach (since 3.1's not GA yet...), you can now define the above XML like this:
@Configuration
public class MySpring3Configuration {
@Bean
public static PropertyPlaceholderConfigurer configurer() {
PropertyPlaceholderConfigurer ppc = ...
ppc.setLocations(...);
return ppc;
}
@Bean
public class DataSource dataSource(
@Value("${ds.user}") String user,
@Value("${ds.pw}") String pw,
...) {
DataSource ds = ...
ds.setUser(user);
ds.setPassword(pw);
...
return ds;
}
}
@Configuration
public class MySpring3Configuration {
@Bean
public static PropertyPlaceholderConfigurer configurer() {
PropertyPlaceholderConfigurer ppc = ...
ppc.setLocations(...);
return ppc;
}
@Bean
public class DataSource dataSource(
@Value("${ds.user}") String user,
@Value("${ds.pw}") String pw,
...) {
DataSource ds = ...
ds.setUser(user);
ds.setPassword(pw);
...
return ds;
}
}Note that the PPC is defined using a static bean definition method. This is required to make sure the bean is registered early, because the PPC is a BeanFactoryPostProcessor
