Spring通过@Value注解注入系统属性

落日映苍穹つ 2022-05-09 17:50 338阅读 0赞

自己写了一个Spring注解方式注入系统属性的test，成功注入自定义的系统属性。

Model类定义

package cn.lin.luo.tian.profile;

import org.springframework.beans.factory.annotation.Value;  
import org.springframework.stereotype.Component;

@Component  
public class SystemProp \{  
    private String username;  
    private String password;

public SystemProp(@Value("\#\{systemProperties\['username'\]\}") String username,  
            @Value("\#\{systemProperties\['password'\]\}") String password) \{  
        super();  
        this.username = username;  
        this.password = password;  
    \}

public String getUsername() \{  
        return username;  
    \}

public void setUsername(String username) \{  
        this.username = username;  
    \}

public String getPassword() \{  
        return password;  
    \}

public void setPassword(String password) \{  
        this.password = password;  
    \}

配置类定义

package cn.lin.luo.tian.profile;

import org.springframework.context.annotation.Bean;  
import org.springframework.context.annotation.ComponentScan;  
import org.springframework.context.annotation.Configuration;  
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;

@Configuration  
@ComponentScan(basePackages = "cn.lin.luo.tian.profile")  
public class ProfileConfiguration \{

//如果是读取系统属性的话不需要注入这个bean  
    @Bean  
    public PropertySourcesPlaceholderConfigurer placeHolderConfigurer() \{  
        return new PropertySourcesPlaceholderConfigurer();  
    \}  
\}

测试类：

package cn.lin.luo.tian.profile;

import static org.junit.Assert.assertEquals;  
import static org.junit.Assert.assertNotNull;

import javax.annotation.Resource;

import org.junit.BeforeClass;  
import org.junit.Test;  
import org.junit.runner.RunWith;  
import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.test.context.ActiveProfiles;  
import org.springframework.test.context.ContextConfiguration;  
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)  
@ContextConfiguration(classes = ProfileConfiguration.class)  
@ActiveProfiles("pro")  
public class ProfileTest \{  
    @Resource(name = "getConfig")  
    public String config;  
    @Autowired  
    public SystemProp systemPro;  
    private static final String USERNAME = "Jack";  
    private static final String PASSWORD = "Rose";

@BeforeClass  
    public static void beforeClass() \{  
        System.setProperty("username", USERNAME);  
        System.setProperty("password", PASSWORD);  
    \}  
      
//    @Test  
//    public void configTest() \{  
//        assertNotNull(config);  
//        System.out.println(config);  
//    \}

@Test  
    public void spELTest() \{  
        assertNotNull(systemPro);  
        assertEquals(USERNAME, systemPro.getUsername());  
        assertEquals(PASSWORD, systemPro.getPassword());  
    \}

\}  
需要注意的是设置自定义系统属性username和password的时候需要在systemPro这个bean初始化前完成，所以在beforeClass方法中进行了属性值复制操作。