Struts2學習：Action獲取properties文件的值

配置文件路徑：

配置內容：

方法一：不使用自動裝配，使用ClassLoader

Action內被調用的函數添加下段代碼：

Properties props = new Properties();
props.load(UploadFileAction.class.getClassLoader().getResourceAsStream("/struts/struts-config.properties"));
System.out.println(props.getProperty("destPath"));

執行效果：

爲了便於其餘Action重用，能夠將此部分寫成一個工具類：

import com.opensymphony.xwork2.Action;
import java.io.IOException;
import java.util.Properties;
public class StrutsConfig {
    public Properties GetProperties(Class actionClass) throws IOException {
        Properties props = new Properties();
        props.load(actionClass.getClassLoader().getResourceAsStream("/struts/struts-config.properties"));
        return props;
    }
}

而後Action裏如此調用便可：

Properties props = new StrutsConfig().GetProperties(UploadFileAction.class);
System.out.println(props.getProperty("destPath"));

方法二：@ConfigurationProperties + @PropertySource

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@ConfigurationProperties
@PropertySource("/struts/struts-config.properties")
public class Index {
    private String destPath;
    @RequestMapping("/")
    public String getProps() {
        return destPath;
    }
    public String getDestPath() {
        return destPath;
    }
    public void setDestPath(String destPath) {
        this.destPath = destPath;
    }
}

對於非application.properties的配置，需@PropertySource指明配置文件的路徑；不然默認是從application.properties中讀取配置，不須要寫該註解。

方法三：spring的xml配置中配置上properties，而後經過@Value注入（該方法在Spring MVC中驗證過，可是不知道集成struts2後是否受影響）

spring-context.xml

<util:properties id="APP_PROP" local-override="true" location="classpath:owlforest.properties" />

owlforest.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/linfu_test_db?useUnicode=true&characterEncoding=utf-8
jdbc.username=root
jdbc.password=root

代碼樣例：

import com.alibaba.druid.pool.DruidDataSource;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;

@Configuration
public class DataSourceConfiguration {
    @Value("#{APP_PROP['jdbc.driver']}")
    private String driver;

    @Value("#{APP_PROP['jdbc.url']}")
    private String url;

    @Value("#{APP_PROP['jdbc.username']}")
    private String username;

    @Value("#{APP_PROP['jdbc.password']}")
    private String password;

    public DruidDataSource createDataSource(){
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driver);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setDefaultAutoCommit(true);
        return dataSource;
    }
}

方法四：使用spring的PropertiesFactoryBean

@Bean
public PropertiesFactoryBean getProperties() {
    PropertiesFactoryBean propertiesFactoryBean = new PropertiesFactoryBean();
    propertiesFactoryBean.setLocations(new ClassPathResource("application.properties"));
    return propertiesFactoryBean;
}

調用：

@Autowired
private PropertiesFactoryBean propertiesFactoryBean;
public String getProperties(String key) throws IOException {
    Properties properties = propertiesFactoryBean.getObject();
    return properties.getProperty(key);  
}