多个WAR共享同一个logback.xml

Question

<appender name="SIFT" class="ch.qos.logback.classic.sift.SiftingAppender">
    <discriminator class="ch.qos.logback.classic.sift.JNDIBasedContextDiscriminator">
        <defaultValue>unknown</defaultValue>
    </discriminator>
    <sift>
        <appender name="FILE-${contextName}" class="ch.qos.logback.core.FileAppender">
            <file>/var/log/${contextName}.log</file>
            <encoder>
                <pattern>%-50(%level %logger{35}) cn=%contextName - %msg%n</pattern>
            </encoder>
        </appender>
    </sift>
</appender>

<env-entry>
  <description>JNDI logging context for this app</description>
  <env-entry-name>logback/context-name</env-entry-name>
  <env-entry-type>java.lang.String</env-entry-type>
  <env-entry-value>ContextNameWebAppA</env-entry-value>
</env-entry>

Answer 1

我不知道使用Jndi鉴别器是安全的还是好的做法，但它似乎是日志返回解决此问题的方法:http://Logback.qos.ch/manual/loggingseparation.html
它们表明将其添加到配置中可以获得更好的性能：

<filter>
  <filter-name>LoggerContextFilter</filter-name>
  <filter-class>ch.qos.logback.classic.selector.servlet.LoggerContextFilter</filter-class>
</filter>
<filter-mapping>
  <filter-name>LoggerContextFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

另一方面，我可以分享如何避免设置系统属性logback.contextSelector=jndi。

相反，我使用MDCBasedDiscriminator，它将获得用MDC.put（key,value)定义的判别值。
MDC映射作为线程局部变量可用，因此必须为web服务器发起的每个线程设置它。
对于这个初始化，我使用了放在其他筛选器之前的javax.servlet.filter，这个筛选器将正确的值放入MDC。

我不认为这比您所做的更好，但它是JNDI属性的一种替代方法，问题是关闭日志位于unknown.log中。

下面是一些代码：

public class WarLoggingFilter implements Filter {
    private static final String WAR_NAME_ATTRIBUTE = "WAR_NAME";
    private String warName;

    @Override
    public void init(final FilterConfig filterConfig) throws ServletException {
        warName = filterConfig.getInitParameter(WAR_NAME_ATTRIBUTE);
    }

    @Override
    public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain)
            throws IOException, ServletException {
        insertIntoMDC(warName);
        chain.doFilter(request, response);
    }

    private void clearMDC() {
        MDC.remove(WAR_NAME_ATTRIBUTE);
    }

    private static void insertIntoMDC(final String warName) {
        MDC.put(WAR_NAME_ATTRIBUTE, warName);
    }

    @Override
    public void destroy() {
        clearMDC();
    }


    /**
     * Register this filter in the servlet context. Adds the necessary init
     * parameter.
     *
     * @param warName
     * @param servletContext
     */
    public static void registerMe(final String warName, final ServletContext servletContext) {
        // MDC for the startup thread
        insertIntoMDC(warName);
        // MCD for next threads
        final Dynamic addFilter = servletContext.addFilter(warName, WarLoggingFilter.class);
        addFilter.setInitParameter(WarLoggingFilter.WAR_NAME_ATTRIBUTE, warName);
        addFilter.addMappingForUrlPatterns(null, false, "/*");

    }

}

和日志文件：

<appender name="SIFT" class="ch.qos.logback.classic.sift.SiftingAppender">
        <discriminator class="ch.qos.logback.classic.sift.MDCBasedDiscriminator">
            <key>WAR_NAME</key>
            <defaultValue>unknown</defaultValue>
        </discriminator>
        <sift>
            <appender name="FILE-${WAR_NAME}" class="ch.qos.logback.core.FileAppender">
                <file>/tmp/${WAR_NAME}.log</file>
                <encoder>
                    <pattern>%date{ISO8601} %-5level %logger{30}\(%line\) - %message%n</pattern>
                </encoder>
            </appender>
        </sift>
    </appender>

public class MySecurityWebApplicationInitializer extends AbstractSecurityWebApplicationInitializer {

    /**
     * Invoked before the springSecurityFilterChain is added.
     *
     * @param servletContext
     *            the {@link ServletContext}
     */
    @Override
    protected void beforeSpringSecurityFilterChain(final ServletContext servletContext) {
        // Tell logback to log this web app events in a separate file
        WarLoggingFilter.registerMe("my_webapp", servletContext);
    }