遇到了一个奇怪的要求。我需要将唯一的错误 id 附加到 log4j 消息并将该消息 id 返回给 interface.So,我虽然让我们创建一个 spring 服务,像这样
public class LoggingService {
protected static Logger logger = LoggerFactory.getLogger(LoggingService.class);
public String debug(String debug_msg)
{
String uniqueMsgId = generateUniqueId();
logger.debug(concatIdWithMsg(uniqueMsgId, debug_msg));
return uniqueMsgId;
}
}
并将其自动连接到我需要的任何地方。
public class LoginLogoutController {
@Autowired
LoggingService logger;
@RequestMapping(value = "/login", method = RequestMethod.GET)
public String getLoginPage()
{
logger.debug("Login page requested");
}
}
虽然它运行良好,但 logger msg 中的源类是 LoggingService,这是显而易见的。我想要的是传递 Autowiring LoggingService 的类,以便记录器消息显示问题的原始来源。我试图以某种方式改变服务
但不知道如何通过源类
public class LoggingService<T> {
protected static Logger logger = null;
Class<T> sourceClass;
public void construct(Class<T> sourceClass)
{
this.sourceClass = sourceClass;
logger = LoggerFactory.getLogger(sourceClass);
}
public String debug(String debug_msg)
{
String uniqueMsgId = generateUniqueId();
logger.debug(concatIdWithMsg(uniqueMsgId, debug_msg));
return null;
}
}
最佳答案
我使用这种机制来注入(inject)记录器。
创建此注释..
/**
* Indicates InjectLogger of appropriate type to
* be supplied at runtime to the annotated field.
*
* The injected logger is an appropriate implementation
* of org.slf4j.Logger.
*/
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
@Retention(RUNTIME)
@Target(FIELD)
@Documented
public @interface InjectLogger {
}
现在让我们定义一个实际执行注入(inject)记录器实现工作的类。
/**
* Auto injects the underlying implementation of logger into the bean with field
* having annotation <code>InjectLogger</code>.
*
*/
import java.lang.reflect.Field;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.util.ReflectionUtils;
import static org.springframework.util.ReflectionUtils.FieldCallback;
public class LoggerInjector implements BeanPostProcessor {
public Object postProcessAfterInitialization(Object bean, String beanName)
throws BeansException {
return bean;
}
public Object postProcessBeforeInitialization(final Object bean,
String beanName) throws BeansException {
ReflectionUtils.doWithFields(bean.getClass(), new FieldCallback() {
public void doWith(Field field) throws IllegalArgumentException,
IllegalAccessException {
// make the field accessible if defined private
ReflectionUtils.makeAccessible(field);
if (field.getAnnotation(InjectLogger.class) != null) {
Logger log = LoggerFactory.getLogger(bean.getClass());
field.set(bean, log);
}
}
});
return bean;
}
}
使用它甚至更简单。只需将上面创建的 Logger 注释添加到所需类中的 Log 字段即可。
import org.slf4j.Logger;
public class Demo {
@InjectLogger
private Logger log;
public void doSomething() {
log.info("message");
log.error("Lets see how the error message looks...");
}
}
关于Spring Autowiring ...将源类传递给 Autowiring 类,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/25717778/