标准化企业产品中的日志记录

解决该问题的最佳方法是重构代码并引入所需的日志记录。仅仅因为人们希望避免接触遗留代码而产生的怀疑点头是一种嗅觉，而不是争论。

现在，回答您的问题：即使不是为了弥补不良的设计或不良的日志记录习惯而发明AOP的，也可以将AspectJ用于您的目的。这里不适合使用像Spring AOP这样的“ AOP lite”框架，因为Spring AOP仅支持方法执行拦截，不支持方法调用拦截，这是您在这里需要的。

这是一个简单的AspectJ示例。请注意，每当我说“模块”时，我指的是软件包名称的最后一部分（在最后一个“。”之后），例如module1，如果软件包名称为，则为模块名称de.scrum_master.module1。

不同模块中的两个样本类：

package de.scrum_master.module1;

import java.util.logging.Logger;

public class Person {
    private String firstName;
    private String lastName;

    public Person(String firstName, String lastName) { this.firstName = firstName; this.lastName = lastName; }
    @Override public String toString() { return "Person[" + firstName + " " + lastName + "]"; }
    public void doSomething() { Logger.getLogger("GLOBAL").info("Doing something with " + this); }
    public void doSomethingElse() { Logger.getLogger("GLOBAL").info("Doing something else with " + this); }
}

package de.scrum_master.module2;

import java.util.logging.Logger;

public class Place {
    private String country;
    private String city;

    public Place(String country, String city) { this.country = country; this.city = city; }
    @Override public String toString() { return "Place[" + city + ", " + country + "]"; }
    public void doSomething() { Logger.getLogger("GLOBAL").info("Doing something with " + this); }
    public void doSomethingElse() { Logger.getLogger("GLOBAL").info("Doing something else with " + this); }
}

使用模块的驱动程序应用程序：

package de.scrum_master.app;

import java.util.logging.Logger;

import de.scrum_master.module1.Person;
import de.scrum_master.module2.Place;

public class Application {
    private static final Logger LOG = Logger.getLogger("GLOBAL");

    public static void main(String[] args) {
        doPersonStuff();
        doPlaceStuff();
    }

    private static void doPersonStuff() {
        LOG.info("Start doing person stuff...");
        Person person = new Person("Albert", "Einstein");
        person.doSomething();
        person.doSomethingElse();
        person = new Person("Werner", "Heisenberg");
        person.doSomething();
        person.doSomethingElse();
        LOG.info("Finished doing person stuff");
    }

    private static void doPlaceStuff() {
        LOG.info("Start doing place stuff...");
        Place place = new Place("Indonesia", "Jakarta");
        place.doSomething();
        place.doSomethingElse();
        place = new Place("Germany", "Berlin");
        place.doSomething();
        place.doSomethingElse();
        LOG.info("Finished doing place stuff");
    }
}

方面：

Aspect在[MODULE1]每个日志消息之前都添加了大写的模块名称前缀。使方面根据类或程序包名称登录到不同的日志文件中将非常简单。这只是一个示范。

package de.scrum_master.aspect;

import java.util.logging.Logger;

public aspect LogModulePrepender {
    void around(String message) :
        call(public void Logger.*(String)) && args(message)
    {
        String packageName = thisJoinPoint.getSourceLocation().getWithinType().getPackage().getName();
        String moduleName = packageName.replaceFirst(".*[.]", "").toUpperCase();
        proceed("[" + moduleName + "] " + message);
    }
}

日志输出：

请注意，为简单起见，在一起整理此小样本时，我使用Java日志记录而不是Log4j。它应该很容易适应。

Jul 25, 2014 11:11:48 AM de.scrum_master.app.Application info_aroundBody0
Information: [APP] Start doing person stuff...
Jul 25, 2014 11:11:48 AM de.scrum_master.module1.Person info_aroundBody0
Information: [MODULE1] Doing something with Person[Albert Einstein]
Jul 25, 2014 11:11:48 AM de.scrum_master.module1.Person info_aroundBody2
Information: [MODULE1] Doing something else with Person[Albert Einstein]
Jul 25, 2014 11:11:48 AM de.scrum_master.module1.Person info_aroundBody0
Information: [MODULE1] Doing something with Person[Werner Heisenberg]
Jul 25, 2014 11:11:48 AM de.scrum_master.module1.Person info_aroundBody2
Information: [MODULE1] Doing something else with Person[Werner Heisenberg]
Jul 25, 2014 11:11:48 AM de.scrum_master.app.Application info_aroundBody2
Information: [APP] Finished doing person stuff
Jul 25, 2014 11:11:48 AM de.scrum_master.app.Application info_aroundBody4
Information: [APP] Start doing place stuff...
Jul 25, 2014 11:11:48 AM de.scrum_master.module2.Place info_aroundBody0
Information: [MODULE2] Doing something with Place[Jakarta, Indonesia]
Jul 25, 2014 11:11:48 AM de.scrum_master.module2.Place info_aroundBody2
Information: [MODULE2] Doing something else with Place[Jakarta, Indonesia]
Jul 25, 2014 11:11:48 AM de.scrum_master.module2.Place info_aroundBody0
Information: [MODULE2] Doing something with Place[Berlin, Germany]
Jul 25, 2014 11:11:48 AM de.scrum_master.module2.Place info_aroundBody2
Information: [MODULE2] Doing something else with Place[Berlin, Germany]
Jul 25, 2014 11:11:48 AM de.scrum_master.app.Application info_aroundBody6
Information: [APP] Finished doing place stuff