logback StatusListener的定義方法源碼解讀

更新時(shí)間：2023年11月06日 09:49:17 作者：codecraft

這篇文章主要為大家介紹了logback StatusListener的定義方法源碼解讀,有需要的朋友可以借鑒參考下,希望能夠有所幫助,祝大家多多進(jìn)步,早日升職加薪

序

本文主要研究一下logback的StatusListener

StatusListener

ch/qos/logback/core/status/StatusListener.java

/**
 * A StatusListener registered with logback context's {@link StatusManager} will
 * receive notification of every incoming {@link Status status} message.
 * 
 * @author Ceki G&uuml;lc&uuml;
 */
public interface StatusListener {
    void addStatusEvent(Status status);
}

StatusListener定義了addStatusEvent方法，注冊(cè)到logback上下文的StatusManager的StatusListener將接收每個(gè)傳入狀態(tài)消息

NopStatusListener

ch/qos/logback/core/status/NopStatusListener.java

public class NopStatusListener implements StatusListener {
    public void addStatusEvent(Status status) {
        // nothing to do
    }
}

NopStatusListener實(shí)現(xiàn)了StatusListener，它的addStatusEvent是空操作

OnPrintStreamStatusListenerBase

abstract public class OnPrintStreamStatusListenerBase extends ContextAwareBase implements StatusListener, LifeCycle {
    boolean isStarted = false;
    static final long DEFAULT_RETROSPECTIVE = 300;
    long retrospectiveThresold = DEFAULT_RETROSPECTIVE;
    /**
     * The prefix to place before each status message
     * @since 1.1.10
     */
    String prefix;
    /**
     * The PrintStream used by derived classes
     * @return
     */
    abstract protected PrintStream getPrintStream();
    public void addStatusEvent(Status status) {
        if (!isStarted)
            return;
        print(status);
    }
    private void print(Status status) {
        StringBuilder sb = new StringBuilder();
        if(prefix != null)
            sb.append(prefix);
        StatusPrinter.buildStr(sb, "", status);
        getPrintStream().print(sb);
    }
    //......
}

OnPrintStreamStatusListenerBase聲明實(shí)現(xiàn)了StatusListener接口，它是一個(gè)抽象類，其addStatusEvent方法執(zhí)行print，而print則先添加prefix，再添加status，最后通過getPrintStream抽象方法獲取PrintStream，然后進(jìn)行print

OnConsoleStatusListener

ch/qos/logback/core/status/OnConsoleStatusListener.java

/**
 * Print all new incoming status messages on the console (System.out).
 *
 * @author Ceki G&uuml;lc&uuml;
 */
public class OnConsoleStatusListener extends OnPrintStreamStatusListenerBase {
    @Override
    protected PrintStream getPrintStream() {
        return System.out;
    }
}

OnConsoleStatusListener繼承了OnPrintStreamStatusListenerBase，其getPrintStream返回的是System.out

OnErrorConsoleStatusListener

ch/qos/logback/core/status/OnErrorConsoleStatusListener.java

/**
 * Print all new incoming status messages on the error console (System.err).
 *
 * @author Ceki G&uuml;lc&uuml;
 * @since 1.0.8
 */
public class OnErrorConsoleStatusListener extends OnPrintStreamStatusListenerBase {
    @Override
    protected PrintStream getPrintStream() {
        return System.err;
    }
}

OnErrorConsoleStatusListener繼承了OnPrintStreamStatusListenerBase，其getPrintStream返回的是System.err

StatusListenerAsList

ch/qos/logback/core/status/StatusListenerAsList.java

/**
 * Collect all incoming events in a list.
 * 
 * @author Ceki G&uuml;lc&uuml;
 * 
 */
public class StatusListenerAsList implements StatusListener {
    List<Status> statusList = new ArrayList<Status>();
    public void addStatusEvent(Status status) {
        statusList.add(status);
    }
    public List<Status> getStatusList() {
        return statusList;
    }
}

StatusListenerAsList實(shí)現(xiàn)了StatusListener接口，其addStatusEvent將status添加到statusList

小結(jié)

logback的StatusListener用于打印logback內(nèi)部的status信息，它有NopStatusListener實(shí)現(xiàn)及OnPrintStreamStatusListenerBase的實(shí)現(xiàn)(OnConsoleStatusListener及OnErrorConsoleStatusListener)，即往System.out或者err打印。

doc statusListener

以上就是logback StatusListener的定義方法源碼解讀的詳細(xì)內(nèi)容，更多關(guān)于logback StatusListener的資料請(qǐng)關(guān)注腳本之家其它相關(guān)文章！

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