https://tomcat.apache.org/: Tomcat Core Logging Package 
public class org.apache.juli.OneLineFormatter extends java.util.logging.Formatter
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.apache.juli.OneLineFormatter
  super_class: java.util.logging.Formatter
{
  private static final java.lang.String UNKNOWN_THREAD_NAME;
    descriptor: Ljava/lang/String;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: "Unknown thread with ID "

  private static final java.lang.Object threadMxBeanLock;
    descriptor: Ljava/lang/Object;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL

  private static volatile java.lang.management.ThreadMXBean threadMxBean;
    descriptor: Ljava/lang/management/ThreadMXBean;
    flags: (0x004a) ACC_PRIVATE, ACC_STATIC, ACC_VOLATILE

  private static final int THREAD_NAME_CACHE_SIZE;
    descriptor: I
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: 10000

  private static java.lang.ThreadLocal<org.apache.juli.OneLineFormatter$ThreadNameCache> threadNameCache;
    descriptor: Ljava/lang/ThreadLocal;
    flags: (0x000a) ACC_PRIVATE, ACC_STATIC
    Signature: Ljava/lang/ThreadLocal<Lorg/apache/juli/OneLineFormatter$ThreadNameCache;>;

  private static final java.lang.String DEFAULT_TIME_FORMAT;
    descriptor: Ljava/lang/String;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: "dd-MMM-yyyy HH:mm:ss"

  private static final int globalCacheSize;
    descriptor: I
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: 30

  private static final int localCacheSize;
    descriptor: I
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: 5

  private java.lang.ThreadLocal<org.apache.juli.DateFormatCache> localDateCache;
    descriptor: Ljava/lang/ThreadLocal;
    flags: (0x0002) ACC_PRIVATE
    Signature: Ljava/lang/ThreadLocal<Lorg/apache/juli/DateFormatCache;>;

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=0, args_size=0
         0: .line 43
            new java.lang.Object
            dup
            invokespecial java.lang.Object.<init>:()V
            putstatic org.apache.juli.OneLineFormatter.threadMxBeanLock:Ljava/lang/Object;
         1: .line 44
            aconst_null
            putstatic org.apache.juli.OneLineFormatter.threadMxBean:Ljava/lang/management/ThreadMXBean;
         2: .line 46
            new org.apache.juli.OneLineFormatter$1
            dup
            invokespecial org.apache.juli.OneLineFormatter$1.<init>:()V
            putstatic org.apache.juli.OneLineFormatter.threadNameCache:Ljava/lang/ThreadLocal;
         3: .line 64
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=2, args_size=1
        start local 0 // org.apache.juli.OneLineFormatter this
         0: .line 72
            aload 0 /* this */
            invokespecial java.util.logging.Formatter.<init>:()V
         1: .line 73
            invokestatic java.util.logging.LogManager.getLogManager:()Ljava/util/logging/LogManager;
         2: .line 74
            new java.lang.StringBuilder
            dup
            ldc Lorg/apache/juli/OneLineFormatter;
            invokevirtual java.lang.Class.getName:()Ljava/lang/String;
            invokestatic java.lang.String.valueOf:(Ljava/lang/Object;)Ljava/lang/String;
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            ldc ".timeFormat"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
         3: .line 73
            invokevirtual java.util.logging.LogManager.getProperty:(Ljava/lang/String;)Ljava/lang/String;
            astore 1 /* timeFormat */
        start local 1 // java.lang.String timeFormat
         4: .line 75
            aload 1 /* timeFormat */
            ifnonnull 6
         5: .line 76
            ldc "dd-MMM-yyyy HH:mm:ss"
            astore 1 /* timeFormat */
         6: .line 78
      StackMap locals: org.apache.juli.OneLineFormatter java.lang.String
      StackMap stack:
            aload 0 /* this */
            aload 1 /* timeFormat */
            invokevirtual org.apache.juli.OneLineFormatter.setTimeFormat:(Ljava/lang/String;)V
         7: .line 79
            return
        end local 1 // java.lang.String timeFormat
        end local 0 // org.apache.juli.OneLineFormatter this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    8     0        this  Lorg/apache/juli/OneLineFormatter;
            4    8     1  timeFormat  Ljava/lang/String;

  public void setTimeFormat(java.lang.String);
    descriptor: (Ljava/lang/String;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=6, locals=3, args_size=2
        start local 0 // org.apache.juli.OneLineFormatter this
        start local 1 // java.lang.String timeFormat
         0: .line 90
            new org.apache.juli.DateFormatCache
            dup
            bipush 30
            aload 1 /* timeFormat */
            aconst_null
            invokespecial org.apache.juli.DateFormatCache.<init>:(ILjava/lang/String;Lorg/apache/juli/DateFormatCache;)V
         1: .line 89
            astore 2 /* globalDateCache */
        start local 2 // org.apache.juli.DateFormatCache globalDateCache
         2: .line 91
            aload 0 /* this */
            new org.apache.juli.OneLineFormatter$2
            dup
            aload 0 /* this */
            aload 1 /* timeFormat */
            aload 2 /* globalDateCache */
            invokespecial org.apache.juli.OneLineFormatter$2.<init>:(Lorg/apache/juli/OneLineFormatter;Ljava/lang/String;Lorg/apache/juli/DateFormatCache;)V
            putfield org.apache.juli.OneLineFormatter.localDateCache:Ljava/lang/ThreadLocal;
         3: .line 97
            return
        end local 2 // org.apache.juli.DateFormatCache globalDateCache
        end local 1 // java.lang.String timeFormat
        end local 0 // org.apache.juli.OneLineFormatter this
      LocalVariableTable:
        Start  End  Slot             Name  Signature
            0    4     0             this  Lorg/apache/juli/OneLineFormatter;
            0    4     1       timeFormat  Ljava/lang/String;
            2    4     2  globalDateCache  Lorg/apache/juli/DateFormatCache;
    MethodParameters:
            Name  Flags
      timeFormat  final

  public java.lang.String getTimeFormat();
    descriptor: ()Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.apache.juli.OneLineFormatter this
         0: .line 106
            aload 0 /* this */
            getfield org.apache.juli.OneLineFormatter.localDateCache:Ljava/lang/ThreadLocal;
            invokevirtual java.lang.ThreadLocal.get:()Ljava/lang/Object;
            checkcast org.apache.juli.DateFormatCache
            invokevirtual org.apache.juli.DateFormatCache.getTimeFormat:()Ljava/lang/String;
            areturn
        end local 0 // org.apache.juli.OneLineFormatter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/juli/OneLineFormatter;

  public java.lang.String format(java.util.logging.LogRecord);
    descriptor: (Ljava/util/logging/LogRecord;)Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=5, args_size=2
        start local 0 // org.apache.juli.OneLineFormatter this
        start local 1 // java.util.logging.LogRecord record
         0: .line 112
            new java.lang.StringBuilder
            dup
            invokespecial java.lang.StringBuilder.<init>:()V
            astore 2 /* sb */
        start local 2 // java.lang.StringBuilder sb
         1: .line 115
            aload 0 /* this */
            aload 2 /* sb */
            aload 1 /* record */
            invokevirtual java.util.logging.LogRecord.getMillis:()J
            invokevirtual org.apache.juli.OneLineFormatter.addTimestamp:(Ljava/lang/StringBuilder;J)V
         2: .line 118
            aload 2 /* sb */
            bipush 32
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
         3: .line 119
            aload 2 /* sb */
            aload 1 /* record */
            invokevirtual java.util.logging.LogRecord.getLevel:()Ljava/util/logging/Level;
            invokevirtual java.util.logging.Level.getLocalizedName:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         4: .line 122
            aload 2 /* sb */
            bipush 32
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
         5: .line 123
            aload 2 /* sb */
            bipush 91
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
         6: .line 124
            invokestatic java.lang.Thread.currentThread:()Ljava/lang/Thread;
            instanceof org.apache.juli.AsyncFileHandler$LoggerThread
            ifeq 9
         7: .line 127
            aload 2 /* sb */
            aload 1 /* record */
            invokevirtual java.util.logging.LogRecord.getThreadID:()I
            invokestatic org.apache.juli.OneLineFormatter.getThreadName:(I)Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         8: .line 128
            goto 10
         9: .line 129
      StackMap locals: java.lang.StringBuilder
      StackMap stack:
            aload 2 /* sb */
            invokestatic java.lang.Thread.currentThread:()Ljava/lang/Thread;
            invokevirtual java.lang.Thread.getName:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        10: .line 131
      StackMap locals:
      StackMap stack:
            aload 2 /* sb */
            bipush 93
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
        11: .line 134
            aload 2 /* sb */
            bipush 32
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
        12: .line 135
            aload 2 /* sb */
            aload 1 /* record */
            invokevirtual java.util.logging.LogRecord.getSourceClassName:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        13: .line 136
            aload 2 /* sb */
            bipush 46
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
        14: .line 137
            aload 2 /* sb */
            aload 1 /* record */
            invokevirtual java.util.logging.LogRecord.getSourceMethodName:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        15: .line 140
            aload 2 /* sb */
            bipush 32
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
        16: .line 141
            aload 2 /* sb */
            aload 0 /* this */
            aload 1 /* record */
            invokevirtual org.apache.juli.OneLineFormatter.formatMessage:(Ljava/util/logging/LogRecord;)Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        17: .line 144
            aload 2 /* sb */
            invokestatic java.lang.System.lineSeparator:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        18: .line 147
            aload 1 /* record */
            invokevirtual java.util.logging.LogRecord.getThrown:()Ljava/lang/Throwable;
            ifnull 24
        19: .line 148
            new java.io.StringWriter
            dup
            invokespecial java.io.StringWriter.<init>:()V
            astore 3 /* sw */
        start local 3 // java.io.StringWriter sw
        20: .line 149
            new org.apache.juli.OneLineFormatter$IndentingPrintWriter
            dup
            aload 3 /* sw */
            invokespecial org.apache.juli.OneLineFormatter$IndentingPrintWriter.<init>:(Ljava/io/Writer;)V
            astore 4 /* pw */
        start local 4 // java.io.PrintWriter pw
        21: .line 150
            aload 1 /* record */
            invokevirtual java.util.logging.LogRecord.getThrown:()Ljava/lang/Throwable;
            aload 4 /* pw */
            invokevirtual java.lang.Throwable.printStackTrace:(Ljava/io/PrintWriter;)V
        22: .line 151
            aload 4 /* pw */
            invokevirtual java.io.PrintWriter.close:()V
        23: .line 152
            aload 2 /* sb */
            aload 3 /* sw */
            invokevirtual java.io.StringWriter.getBuffer:()Ljava/lang/StringBuffer;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/StringBuffer;)Ljava/lang/StringBuilder;
            pop
        end local 4 // java.io.PrintWriter pw
        end local 3 // java.io.StringWriter sw
        24: .line 155
      StackMap locals:
      StackMap stack:
            aload 2 /* sb */
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            areturn
        end local 2 // java.lang.StringBuilder sb
        end local 1 // java.util.logging.LogRecord record
        end local 0 // org.apache.juli.OneLineFormatter this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0   25     0    this  Lorg/apache/juli/OneLineFormatter;
            0   25     1  record  Ljava/util/logging/LogRecord;
            1   25     2      sb  Ljava/lang/StringBuilder;
           20   24     3      sw  Ljava/io/StringWriter;
           21   24     4      pw  Ljava/io/PrintWriter;
    MethodParameters:
        Name  Flags
      record  

  protected void addTimestamp(java.lang.StringBuilder, long);
    descriptor: (Ljava/lang/StringBuilder;J)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=4, locals=6, args_size=3
        start local 0 // org.apache.juli.OneLineFormatter this
        start local 1 // java.lang.StringBuilder buf
        start local 2 // long timestamp
         0: .line 159
            aload 1 /* buf */
            aload 0 /* this */
            getfield org.apache.juli.OneLineFormatter.localDateCache:Ljava/lang/ThreadLocal;
            invokevirtual java.lang.ThreadLocal.get:()Ljava/lang/Object;
            checkcast org.apache.juli.DateFormatCache
            lload 2 /* timestamp */
            invokevirtual org.apache.juli.DateFormatCache.getFormat:(J)Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         1: .line 160
            lload 2 /* timestamp */
            ldc 1000
            lrem
            lstore 4 /* frac */
        start local 4 // long frac
         2: .line 161
            aload 1 /* buf */
            bipush 46
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
         3: .line 162
            lload 4 /* frac */
            ldc 100
            lcmp
            ifge 9
         4: .line 163
            lload 4 /* frac */
            ldc 10
            lcmp
            ifge 8
         5: .line 164
            aload 1 /* buf */
            bipush 48
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
         6: .line 165
            aload 1 /* buf */
            bipush 48
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
         7: .line 166
            goto 9
         8: .line 167
      StackMap locals: long
      StackMap stack:
            aload 1 /* buf */
            bipush 48
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            pop
         9: .line 170
      StackMap locals:
      StackMap stack:
            aload 1 /* buf */
            lload 4 /* frac */
            invokevirtual java.lang.StringBuilder.append:(J)Ljava/lang/StringBuilder;
            pop
        10: .line 171
            return
        end local 4 // long frac
        end local 2 // long timestamp
        end local 1 // java.lang.StringBuilder buf
        end local 0 // org.apache.juli.OneLineFormatter this
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0   11     0       this  Lorg/apache/juli/OneLineFormatter;
            0   11     1        buf  Ljava/lang/StringBuilder;
            0   11     2  timestamp  J
            2   11     4       frac  J
    MethodParameters:
           Name  Flags
      buf        
      timestamp  

  private static java.lang.String getThreadName(int);
    descriptor: (I)Ljava/lang/String;
    flags: (0x000a) ACC_PRIVATE, ACC_STATIC
    Code:
      stack=3, locals=4, args_size=1
        start local 0 // int logRecordThreadId
         0: .line 184
            getstatic org.apache.juli.OneLineFormatter.threadNameCache:Ljava/lang/ThreadLocal;
            invokevirtual java.lang.ThreadLocal.get:()Ljava/lang/Object;
            checkcast java.util.Map
            astore 1 /* cache */
        start local 1 // java.util.Map cache
         1: .line 185
            aconst_null
            astore 2 /* result */
        start local 2 // java.lang.String result
         2: .line 187
            iload 0 /* logRecordThreadId */
            ldc 1073741823
            if_icmple 4
         3: .line 188
            aload 1 /* cache */
            iload 0 /* logRecordThreadId */
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            invokeinterface java.util.Map.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.lang.String
            astore 2 /* result */
         4: .line 191
      StackMap locals: java.util.Map java.lang.String
      StackMap stack:
            aload 2 /* result */
            ifnull 6
         5: .line 192
            aload 2 /* result */
            areturn
         6: .line 195
      StackMap locals:
      StackMap stack:
            iload 0 /* logRecordThreadId */
            ldc 1073741823
            if_icmple 9
         7: .line 196
            new java.lang.StringBuilder
            dup
            ldc "Unknown thread with ID "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            iload 0 /* logRecordThreadId */
            invokevirtual java.lang.StringBuilder.append:(I)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            astore 2 /* result */
         8: .line 197
            goto 22
         9: .line 199
      StackMap locals:
      StackMap stack:
            getstatic org.apache.juli.OneLineFormatter.threadMxBean:Ljava/lang/management/ThreadMXBean;
            ifnonnull 17
        10: .line 200
            getstatic org.apache.juli.OneLineFormatter.threadMxBeanLock:Ljava/lang/Object;
            dup
            astore 3
            monitorenter
        11: .line 201
            getstatic org.apache.juli.OneLineFormatter.threadMxBean:Ljava/lang/management/ThreadMXBean;
            ifnonnull 13
        12: .line 202
            invokestatic java.lang.management.ManagementFactory.getThreadMXBean:()Ljava/lang/management/ThreadMXBean;
            putstatic org.apache.juli.OneLineFormatter.threadMxBean:Ljava/lang/management/ThreadMXBean;
        13: .line 200
      StackMap locals: java.lang.Object
      StackMap stack:
            aload 3
            monitorexit
        14: goto 17
      StackMap locals:
      StackMap stack: java.lang.Throwable
        15: aload 3
            monitorexit
        16: athrow
        17: .line 207
      StackMap locals:
      StackMap stack:
            getstatic org.apache.juli.OneLineFormatter.threadMxBean:Ljava/lang/management/ThreadMXBean;
            iload 0 /* logRecordThreadId */
            i2l
            invokeinterface java.lang.management.ThreadMXBean.getThreadInfo:(J)Ljava/lang/management/ThreadInfo;
        18: .line 206
            astore 3 /* threadInfo */
        start local 3 // java.lang.management.ThreadInfo threadInfo
        19: .line 208
            aload 3 /* threadInfo */
            ifnonnull 21
        20: .line 209
            iload 0 /* logRecordThreadId */
            i2l
            invokestatic java.lang.Long.toString:(J)Ljava/lang/String;
            areturn
        21: .line 211
      StackMap locals: java.lang.management.ThreadInfo
      StackMap stack:
            aload 3 /* threadInfo */
            invokevirtual java.lang.management.ThreadInfo.getThreadName:()Ljava/lang/String;
            astore 2 /* result */
        end local 3 // java.lang.management.ThreadInfo threadInfo
        22: .line 214
      StackMap locals:
      StackMap stack:
            aload 1 /* cache */
            iload 0 /* logRecordThreadId */
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            aload 2 /* result */
            invokeinterface java.util.Map.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
        23: .line 216
            aload 2 /* result */
            areturn
        end local 2 // java.lang.String result
        end local 1 // java.util.Map cache
        end local 0 // int logRecordThreadId
      LocalVariableTable:
        Start  End  Slot               Name  Signature
            0   24     0  logRecordThreadId  I
            1   24     1              cache  Ljava/util/Map<Ljava/lang/Integer;Ljava/lang/String;>;
            2   24     2             result  Ljava/lang/String;
           19   22     3         threadInfo  Ljava/lang/management/ThreadInfo;
      Exception table:
        from    to  target  type
          11    14      15  any
          15    16      15  any
    MethodParameters:
                   Name  Flags
      logRecordThreadId  
}
SourceFile: "OneLineFormatter.java"
NestMembers:
  org.apache.juli.OneLineFormatter$1  org.apache.juli.OneLineFormatter$2  org.apache.juli.OneLineFormatter$IndentingPrintWriter  org.apache.juli.OneLineFormatter$ThreadNameCache
InnerClasses:
  protected LoggerThread = org.apache.juli.AsyncFileHandler$LoggerThread of org.apache.juli.AsyncFileHandler
  org.apache.juli.OneLineFormatter$1
  org.apache.juli.OneLineFormatter$2
  private IndentingPrintWriter = org.apache.juli.OneLineFormatter$IndentingPrintWriter of org.apache.juli.OneLineFormatter
  private ThreadNameCache = org.apache.juli.OneLineFormatter$ThreadNameCache of org.apache.juli.OneLineFormatter