如何为构造函数创建实例？

Question

我无法为此编码创建对象。我如何访问此值，我想在此编码中返回 msg 值？

package com.my;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.VectorAppender;
import org.apache.log4j.spi.LoggingEvent;
import java.util.Vector;
public class LogCapture 
    {
    private final VectorAppender appender;
    private final Level level;
    public LogCapture(final Level level)
        {
        this.level = level;
        Logger root = Logger.getRootLogger();
        appender = new VectorAppender();
        root.addAppender(appender);
        }
public static void main(String args[])
{
    new LogCapture(Level.INFO);

    LogCapture.getMessage() ;
}
    public String getMessage()
        {
        Vector vector = appender.getVector();
        String msg = null;
        switch (vector.size())
            {
        case 0:
            break;
        case 1:
            LoggingEvent event = (LoggingEvent) vector.elementAt(0);
            msg = event.getRenderedMessage();
            break;
        }
        return msg;
    }
}

Answer 1

我不确定我是否理解这个问题，但这听起来很简单。您可以像这样创建一个实例：

new LogCapture(Level.INFO);

您可以在此处找到其他日志级别：
级别文档

编辑（因为OP有添加了更多代码）：
更改 main 方法中的代码，使其显示

LogCapture logCapture = new LogCapture(Level.INFO);
logCapture.getMessage();