基于注解的DI容器配置元数据

小鱼儿 2022-08-06 13:21 162阅读 0赞

**一、定义POJO类**

package test; /\*\* \* IHelloStr接口 \* \* @author zxs \*/ public interface IHelloStr \{ public String getContent(); \}

package test; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.util.Properties; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /\*\* \* 基于文件形式，读取HelloWorld所需的字符串。 \* \* @author zxs \*/ public class FileHelloStrImpl implements IHelloStr \{ protected static final Log log = LogFactory.getLog(FileHelloStrImpl.class); private String propfilename; public FileHelloStrImpl(String propfilename) \{ this.propfilename = propfilename; \} public String getContent() \{ String helloworld = ""; try \{ Properties properties = new Properties(); //读入输入流 InputStream is = getClass().getClassLoader().getResourceAsStream( propfilename); properties.load(is); is.close(); //获得helloworld键对应的取值 helloworld = properties.getProperty("helloworld"); \} catch (FileNotFoundException ex) \{ log.error(ex); \} catch (IOException ex) \{ log.error(ex); \} return helloworld; \} \}

package test; /\*\* \* IHelloWorld接口 \* \* @author zxs \* \*/ public interface IHelloWorld \{ public abstract String getContent(); \}

package test; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class HelloWorld implements IHelloWorld \{ protected static final Log log = LogFactory.getLog(HelloWorld.class); private IHelloStr helloStr; public void setHelloStr(IHelloStr str) \{ this.helloStr = str; \} public String getContent() \{ return helloStr.getContent(); \} \}

**二、将上述两个POJO配置于类中,构造IoC容器**

package test; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.config.java.annotation.Bean; import org.springframework.config.java.annotation.Configuration; import org.springframework.config.java.context.JavaConfigApplicationContext; @Configuration public class JavaConfigDemo \{ protected static final Log log = LogFactory.getLog(JavaConfigDemo.class); @Bean public IHelloWorld helloWorld()\{ HelloWorld hw = new HelloWorld(); hw.setHelloStr(helloStr()); return hw; \} @Bean public IHelloStr helloStr()\{ return new FileHelloStrImpl("helloworld.properties"); \} public static void main(String\[\] args) \{ //从注解中装载DI容器配置元数据 JavaConfigApplicationContext context = new JavaConfigApplicationContext(JavaConfigDemo.class); //获得受管Bean IHelloWorld hw = context.getBean(IHelloWorld.class); //返回字符串 log.info(hw.getContent()); \} \}