【Spring】 (3）注入方式读取各种配置

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package com.example.demo_2_2;import org.springframework.beans.factory.annotation.Value;import org.springframework.stereotype.Service;/** * Created by WangBin on 2017/4/10. * */@Servicepublic class DemoService {    @Value("注入的普通字符串")    private String another;    public String getAnother() {        return another;    }    public void setAnother(String another) {        this.another = another;    }}

package com.example.demo_2_2;import org.apache.commons.io.IOUtils;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Value;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;import java.io.IOException;import java.io.InputStream;/** * Created by WangBin on 2017/4/10. * */@Configuration@ComponentScan("com.example.demo_2_2")@PropertySource("classpath:test.properties")//注入配置文件  【classpath 指的是编译目录的文件  junit 测试类 不再包里生成编译的文件 放入 resource里】public class Elconfig {    @Value("我爱你")//注入普通字符串    private String normal;    @Value("#{systemProperties['os.name']}")//注入操作系统属性    private String osName;    @Value("#{T(java.lang.Math).random()*100.0}")//注入表达式结果    private double randomNumber;    @Value("#{demoService.another}")//注入其他bean的属性    private String fromAnother;    @Value("classpath:test.txt")//注入文件资源  (使用Value需要 注入下面的bean PropertySourcesPlaceholderConfigurer  PropertySource则不用)    private Resource testFile;    @Value("http://www.baidu.com/")//注入网址资源    private Resource testUrl;    @Value("${book.name}")//注入配置文件  需在类上 引入 配置文件【注意这里用的是$】    private String bookName;    @Autowired    private Environment environment; // 引入的是 类 上注解 @PropertySource getProperty 传入 key 去获取value    @Bean    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer(){        return new PropertySourcesPlaceholderConfigurer();    }        @Override    public String toString() {        String str = "";        String urlStr="";        try {            InputStream inputStream =testFile.getInputStream();            InputStream inputStream1 = testUrl.getInputStream();            str = IOUtils.toString(inputStream,"UTF-8");            urlStr = IOUtils.toString(inputStream1,"UTF-8");        } catch (IOException e) {            e.printStackTrace();        }        return "Elconfig{" +                "normal='" + normal + '\'' +                ", osName='" + osName + '\'' +                ", randomNumber=" + randomNumber +                ", fromAnother='" + fromAnother + '\'' +                ", testFile=" + str +                ", testUrl=" + urlStr +                ", bookName='" + bookName + '\'' +                ", environment='"+environment.getProperty("book.author")+                '}';    }}

package com.example.demo_2_2;import org.springframework.context.annotation.AnnotationConfigApplicationContext;/** * Created by WangBin on 2017/4/11. * */public class Main {    public static void main(String[] args) {        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Elconfig.class);        Elconfig elconfig = context.getBean(Elconfig.class);        System.err.println(""+elconfig.toString());        context.close();    }}

test.properties

book.author=wangbin
book.name=spring boot

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