实例：
DemoService ：文件：
package ch2.el; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Service; //注入：当前类是spring管理的一个bean //等效（可根据需要选择）:@[email protected][email protected][email protected] @Service public class DemoService { //注入普通字符串 @Value("其他类的属性") private String another; public String getAnother() { return another; } public void setAnother(String another) { this.another = another; } }
test.txt文件：
wwwweeebbfddfd
test.propeties文件：
book.author=wangyunfei book.name=spring boot
ResourceConfig文件：
package ch2.el;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
//声明当前类是一个配置类
@Configuration
//自动扫描ch2.el包下的所有@Service,@Component,@Repository和@Controller注册为Bean;
@ComponentScan("ch2.el")
public class ResourceConfig {
}
Eiconfig文件：
package ch2.el;
import org.apache.commons.io.IOUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.env.Environment;
import org.springframework.core.io.Resource;
//声明当前类是一个配置类
@Configuration
//自动扫描包下的所有@Service,@Component,@Repository和@Controller注册为Bean;
@ComponentScan("ch2.el")
//注入配置文件
@PropertySource("classpath:ch2/el/test.propeties")
public class ElConfig {
//将FunctionService类的实体Bean注入到UseFunctionService中,让UseFunctionService拥有FunctionService的功能
//等效注解: @[email protected][email protected]
//注入文字
@Value("I love you")
private String normal;
//注入操作系统属性
@Value("#{systemProperties[‘os.name‘]}")
private String osName;
//注入表达式结果
@Value("#{ T(java.lang.Math).random() * 100.0 }")
private double randomNumber;
//注入其他Bean属性
@Value("#{demoService.another}")
private String fromAnother;
//注入文件资源
@Value("classpath:ch2/el/test.txt")
private Resource testFile;
//注入网址资源
@Value("http://www.baidu.com")
private Resource testUrl;
//注入配置文件
@Value("${book.name}")
private String bookName;
//注入配置文件
@Autowired
private Environment environment;
//注入配置文件
@Bean
public static PropertySourcesPlaceholderConfigurer propertyConfigure()
{
return new PropertySourcesPlaceholderConfigurer();
}
public void outputResource()
{
try {
System.out.println(normal);
System.out.println(osName);
System.out.println(randomNumber);
System.out.println(fromAnother);
System.out.println(testFile);
System.out.println(testUrl);
System.out.println(IOUtils.toString(testUrl.getInputStream()));
System.out.println(bookName);
System.out.println(environment.getProperty("book.author"));
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Main文件：
package ch2.el;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class Main {
public static void main(String[] args)
{
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ResourceConfig.class);
ElConfig resourceElconfig = context.getBean(ElConfig.class);
resourceElconfig.outputResource();
context.close();
}
}