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copied!<p>At the top of each country's processing thread, put the country code into Log4j's mapped diagnostic context (MDC). This uses a ThreadLocal variable so that you don't have to pass the country up and down the call stack explicitly. Then create a custom filter that looks at the MDC, and filters out any events that don't contain the current appender's country code.</p> <p>In your <code>Job</code>:</p> <pre><code>... public static final String MDC_COUNTRY = "com.y.foo.Country"; public void execute(JobExecutionContext context) /* Just guessing that you have the country in your JobContext. */ MDC.put(MDC_COUNTRY, context.get(MDC_COUNTRY)); try { /* Perform your job here. */ ... } finally { MDC.remove(MDC_COUNTRY); } } ... </code></pre> <p>Write a custom <a href="http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/spi/Filter.html" rel="nofollow noreferrer">Filter</a>:</p> <pre><code>package com.y.log4j; import org.apache.log4j.spi.LoggingEvent; /** * This is a general purpose filter. If its "value" property is null, * it requires only that the specified key be set in the MDC. If its * value is not null, it further requires that the value in the MDC * is equal. */ public final class ContextFilter extends org.apache.log4j.spi.Filter { public int decide(LoggingEvent event) { Object ctx = event.getMDC(key); if (value == null) return (ctx != null) ? NEUTRAL : DENY; else return value.equals(ctx) ? NEUTRAL : DENY; } private String key; private String value; public void setContextKey(String key) { this.key = key; } public String getContextKey() { return key; } public void setValue(String value) { this.value = value; } public String getValue() { return value; } } </code></pre> <p>In your log4j.xml:</p> <pre><code><appender name="fr" class="org.apache.log4j.FileAppender"> <param name="file" value="france.log"/> ... <filter class="com.y.log4j.ContextFilter"> <param name="key" value="com.y.foo.Country" /> <param name="value" value="fr" /> </filter> </appender> </code></pre>

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