如何配置的java.util.logging在Android？ [英] How to configure java.util.logging on Android?

问题描述

我想使用的java.util.logging在Android上。我想配置日志记录系统logging.properties。但是，我怎么能告诉机器人使用特定的配置文件？例如，我把logging.properties在应用程序的classpath根。如何安卓知道logging.properties的位置。

I want to use java.util.logging on Android. I want to configure the logging system with logging.properties. But how can I tell Android using the specific configure file? For example, I placed the logging.properties in the classpath root of the application. How Android knows the location of logging.properties.

感谢

推荐答案

这是现在的常见问题解答我的项目之一，希望更多的人会在这里找到这样的：java.util.logging的正常工作在Android上。请不要在你的code使用别的，日志框架就像在Java世界中害虫。

This is now an FAQ for one of my projects, hopefully more people will find this here: java.util.logging works fine on Android. Please don't use anything else in your code, logging frameworks are like a pest in the Java world.

什么是坏了是默认的日志处理程序附带的Andr​​oid，它忽略了与水平亦为信息任何日志消息。你看不到DEBUG等消息。

What is broken is the default logging handler shipped with Android, it ignores any log messages with level finer than INFO. You don't see DEBUG etc. messages.

原因是调用Log.isLoggable（）在AndroidHandler.java：

The reason is the call to Log.isLoggable() in AndroidHandler.java:

<一个href="https://github.com/android/platform_frameworks_base/blob/master/core/java/com/android/internal/logging/AndroidHandler.java">https://github.com/android/platform_frameworks_base/blob/master/core/java/com/android/internal/logging/AndroidHandler.java

下面是你如何解决它：

import android.util.Log;
import java.util.logging.*;

/**
 * Make JUL work on Android.
 */
public class AndroidLoggingHandler extends Handler {

    public static void reset(Handler rootHandler) {
        Logger rootLogger = LogManager.getLogManager().getLogger("");
        Handler[] handlers = rootLogger.getHandlers();
        for (Handler handler : handlers) {
            rootLogger.removeHandler(handler);
        }
        LogManager.getLogManager().getLogger("").addHandler(rootHandler);
    }

    @Override
    public void close() {
    }

    @Override
    public void flush() {
    }

    @Override
    public void publish(LogRecord record) {
        if (!super.isLoggable(record))
            return;

        String name = record.getLoggerName();
        int maxLength = 30;
        String tag = name.length() > maxLength ? name.substring(name.length() - maxLength) : name;

        try {
            int level = getAndroidLevel(record.getLevel());
            Log.println(level, tag, record.getMessage());
            if (record.getThrown() != null) {
                Log.println(level, tag, Log.getStackTraceString(record.getThrown()));
            }
        } catch (RuntimeException e) {
            Log.e("AndroidLoggingHandler", "Error logging message.", e);
        }
    }

    static int getAndroidLevel(Level level) {
        int value = level.intValue();
        if (value >= 1000) {
            return Log.ERROR;
        } else if (value >= 900) {
            return Log.WARN;
        } else if (value >= 800) {
            return Log.INFO;
        } else {
            return Log.DEBUG;
        }
    }
}

在应用程序中的主要活动/初始化code：

In the main activity/initialization code of your application:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    AndroidLoggingHandler.reset(new AndroidLoggingHandler());
    java.util.logging.Logger.getLogger("my.category").setLevel(Level.FINEST);
...

TL; DR：是，你可以使用一些魔法属性，或ADB shell命令，甚至学习如何愚蠢内置记录处理程序的 DalvikLogging.loggerNameToTag 类别名称来标记（你会做那些魔法属性和shell命令）转换，但何必呢？是不是登陆痛苦还不够吗？

TL;DR: Yes, you could use some magic properties, or adb shell command, or even learn how the stupid built-in logging handler's DalvikLogging.loggerNameToTag converts category names to tags (which you would have to do for those magic properties and shell commands), but why bother? Isn't logging painful enough?

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