介绍：
MDC 中包含的可以被同一线程中执行的代码所访问内容。当前线程的子线程会继承其父线程中的 MDC 的内容。记录日志时，只需要从 MDC 中获取所需的信息即可。
作用：
使用MDC来记录日志，可以规范多开发下日志格式。
一：新建线程处理类 ThreadContext
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
/**
* 线程上下文
*
* @date 2017年3月1日
* @since 1.0.0
*/
public class ThreadContext {
/**
* 线程上下文变量的持有者
*/
private final static ThreadLocal<Map<String, Object>> CTX_HOLDER = new ThreadLocal<Map<String, Object>>();
static {
CTX_HOLDER.set(new HashMap<String, Object>());
}
/**
* traceID
*/
private final static String TRACE_ID_KEY = "traceId";
/**
* 会话ID
*/
private final static String SESSION_KEY = "token";
/**
* 操作用户ID
*/
private final static String VISITOR_ID_KEY = "userId";
/**
* 操作用户名
*/
private final static String VISITOR_NAME_KEY = "userName";
/**
* 客户端IP
*/
private static final String CLIENT_IP_KEY = "clientIp";
/**
* 添加内容到线程上下文中
*
* @param key
* @param value
*/
public final static void putContext(String key, Object value) {
Map<String, Object> ctx = CTX_HOLDER.get();
if (ctx == null) {
return;
}
ctx.put(key, value);
}
/**
* 从线程上下文中获取内容
*
* @param key
*/
@SuppressWarnings("unchecked")
public final static <T extends Object> T getContext(String key) {
Map<String, Object> ctx = CTX_HOLDER.get();
if (ctx == null) {
return null;
}
return (T) ctx.get(key);
}
/**
* 获取线程上下文
*/
public final static Map<String, Object> getContext() {
Map<String, Object> ctx = CTX_HOLDER.get();
if (ctx == null) {
return null;
}
return ctx;
}
/**
* 删除上下文中的key
*
* @param key
*/
public final static void remove(String key) {
Map<String, Object> ctx = CTX_HOLDER.get();
if (ctx != null) {
ctx.remove(key);
}
}
/**
* 上下文中是否包含此key
*
* @param key
* @return
*/
public final static boolean contains(String key) {
Map<String, Object> ctx = CTX_HOLDER.get();
if (ctx != null) {
return ctx.containsKey(key);
}
return false;
}
/**
* 清空线程上下文
*/
public final static void clean() {
CTX_HOLDER.remove();
}
/**
* 初始化线程上下文
*/
public final static void init() {
CTX_HOLDER.set(new HashMap<String, Object>());
}
/**
* 设置traceID数据
*/
public final static void putTraceId(String traceId) {
putContext(TRACE_ID_KEY, traceId);
}
/**
* 获取traceID数据
*/
public final static String getTraceId() {
return getContext(TRACE_ID_KEY);
}
/**
* 设置会话的用户ID
*/
public final static void putUserId(Integer userId) {
putContext(VISITOR_ID_KEY, userId);
}
/**
* 设置会话的用户ID
*/
public final static int getUserId() {
Integer val = getContext(VISITOR_ID_KEY);
return val == null ? 0 : val;
}
/**
* 设置会话的用户名
*/
public final static void putUserName(String userName) {
putContext(VISITOR_NAME_KEY, userName);
}
/**
* 获取会话的用户名称
*/
public final static String getUserName() {
return Optional.ofNullable(getContext(VISITOR_NAME_KEY))
.map(name -> String.valueOf(name))
.orElse("");
}
/**
* 取出IP
*
* @return
*/
public static final String getClientIp() {
return getContext(CLIENT_IP_KEY);
}
/**
* 设置IP
*
* @param ip
*/
public static final void putClientIp(String ip) {
putContext(CLIENT_IP_KEY, ip);
}
/**
* 设置会话ID
*
* @param token
*/
public static void putSessionId(String token) {
putContext(SESSION_KEY, token);
}
/**
* 获取会话ID
*
* @param token
*/
public static String getSessionId(String token) {
return getContext(SESSION_KEY);
}
/**
* 清空会话数据
*/
public final static void removeSessionId() {
remove(SESSION_KEY);
}
}
二：添加工具类TraceUtil
import java.util.UUID;
import org.slf4j.MDC;
import ThreadContext;
/**
* trace工具
*
* @date 2017年3月10日
* @since 1.0.0
*/
public class TraceUtil {
public static void traceStart() {
ThreadContext.init();
String traceId = generateTraceId();
MDC.put('traceId', traceId);
ThreadContext.putTraceId(traceId);
}
public static void traceEnd() {
MDC.clear();
ThreadContext.clean();
}
/**
* 生成跟踪ID
*
* @return
*/
private static String generateTraceId() {
return UUID.randomUUID().toString();
}
}三：添加ContextFilter，对于每个请求随机生成RequestID并放入MDC
import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.web.filter.OncePerRequestFilter;
import com.pingan.manpan.common.util.TraceUtil;
import com.pingan.manpan.user.dto.ThreadContext;
import com.pingan.manpan.web.common.surpport.IpUtils;
/**
* 上下文Filter
*
* @date 2017/3/10
* @since 1.0.0
*/
//@Order 标记组件的加载顺序
@Order(Ordered.HIGHEST_PRECEDENCE)
public class ContextFilter extends OncePerRequestFilter {
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
FilterChain filterChain) throws ServletException, IOException {
try {
ThreadContext.putClientIp(IpUtils.getClientIp(request));
TraceUtil.traceStart();
filterChain.doFilter(request, response);
} finally {
TraceUtil.traceEnd();
}
}
}四：在webConfiguriation注册filter
/**
* 请求上下文,应该在最外层
*
* @return
*/
@Bean
public FilterRegistrationBean requestContextRepositoryFilterRegistrationBean() {
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
filterRegistrationBean.setFilter(new ContextFilter());
filterRegistrationBean.addUrlPatterns("/*");
return filterRegistrationBean;
}五：修改log4j日志配置文件，设置日志traceId
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<jmxConfigurator/>
<property name="LOG_LEVEL_PATTERN" value="%X{traceId:-} %5p"/>
<property name="LOG_FILE" value="${LOG_PATH}/web.logx"/>
<property name="LOG_FILE_SUFFIX" value=".logx"/>
<include resource="org/springframework/boot/logging/logback/defaults.xml"/>
<include resource="org/springframework/boot/logging/logback/console-appender.xml"/>
<appender name="FILE"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<encoder>
<pattern>${FILE_LOG_PATTERN}</pattern>
</encoder>
<file>${LOG_FILE}${LOG_FILE_SUFFIX}</file>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<fileNamePattern>${LOG_FILE}.%d{yyyy-MM-dd}${LOG_FILE_SUFFIX}</fileNamePattern>
</rollingPolicy>
</appender>
<appender name="SYSLOG" class="ch.qos.logback.classic.net.SyslogAppender">
<syslogHost>127.0.0.1</syslogHost>
<facility>local6</facility>
<port>514</port>
<suffixPattern>${FILE_LOG_PATTERN}</suffixPattern>
</appender>
<logger name="druid.sql" level="DEBUG" />
<root level="INFO">
<appender-ref ref="CONSOLE"/>
<appender-ref ref="FILE"/>
<appender-ref ref="SYSLOG"/>
</root>
</configuration>
