子类化java.util.logging.Formatter不起作用 [英] Subclassing java.util.logging.Formatter doesn't work

问题描述

我正在使用 java.util.logging 进行日志记录（我不想使用log4j或其他任何内容）。

I am using java.util.logging for logging (I don't want to use log4j or anything else).

这是我完整的私有logging.properties：

This is my complete private logging.properties:

handlers= java.util.logging.FileHandler
.level= INFO
java.util.logging.FileHandler.pattern = my.log
java.util.logging.FileHandler.limit = 500000
java.util.logging.FileHandler.count = 40
java.util.logging.FileHandler.formatter = java.util.logging.SimpleFormatter

这是我程序中的代码：

public static Logger log = Logger.getLogger(MyClass.class.getName());
// Is there anything else to be init'ed here? 
// I don't. I just start using log directly in the code.

log.severe("something");
log.info("something else");

因为这会给每行两条日志消息，所以我试过这个

Since this gives each log message on 2 lines, I tried this

如何让java日志输出显示在一行？

在第一个回复中复制LogFormatter类。

Copied the LogFormatter class in the first reply exactly.

在我的logging.properties中更改了一行

Changed one line in my logging.properties

java.util.logging.FileHandler.formatter = com.mycomp.myproj.LogFormatter;

现在我的日志已经开始以XML格式显示。我强烈认为 FileHandler 不喜欢我的 com.mycomp.myproj.LogFormatter ，因此默认为默认 XMLFormatter 。我怎么弄清楚为什么 FileHandler 没有使用我的LogFormatter类？

Now my log has started appearing in XML. I have a strong feeling that the FileHandler doesn't like my com.mycomp.myproj.LogFormatter and hence defaulting to the default XMLFormatter. How do I figure out why FileHandler isn't using my LogFormatter class?

推荐答案

您可以在FileHandler实例上的代码本身中设置格式化程序。

You can set the formatter in the code itself on the FileHandler instance.

import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.Logger;

// please change name of your own choice
Logger log = Logger.getLogger("CustomLogger"); 
log.setUseParentHandlers(false);
log.setLevel(Level.ALL);

FileHandler handler = new FileHandler("[log_file_location]");
handler.setFormatter(new CustomFormatter()); // set formatter
log.addHandler(handler);

log.info("test message");

handler.close(); // close the handler at some later point in your application.

CustomFormatter类定义如下。

The CustomFormatter class is defined as follows.

import java.util.logging.Formatter;
import java.util.logging.LogRecord;

public class CustomFormatter extends Formatter {

    @Override
    public String format(LogRecord record) {
        StringBuffer buffer = new StringBuffer();
        buffer.append(record.getMessage());
        return buffer.toString();
    }

}

您可以在CustomFormatter中编码输出您想要的任何格式的邮件。希望这会有所帮助。

You can code in CustomFormatter to output the messages in any format you want. Hope this helps.

这篇关于子类化java.util.logging.Formatter不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！