https://spring.io/projects/spring-boot: Spring Boot (Pivotal Software, Inc.) 
public abstract class org.springframework.boot.logging.Slf4JLoggingSystem extends org.springframework.boot.logging.AbstractLoggingSystem
  minor version: 0
  major version: 59
  flags: flags: (0x0421) ACC_PUBLIC, ACC_SUPER, ACC_ABSTRACT
  this_class: org.springframework.boot.logging.Slf4JLoggingSystem
  super_class: org.springframework.boot.logging.AbstractLoggingSystem
{
  private static final java.lang.String BRIDGE_HANDLER;
    descriptor: Ljava/lang/String;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: "org.slf4j.bridge.SLF4JBridgeHandler"

  public void <init>(java.lang.ClassLoader);
    descriptor: (Ljava/lang/ClassLoader;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
        start local 1 // java.lang.ClassLoader classLoader
         0: .line 40
            aload 0 /* this */
            aload 1 /* classLoader */
            invokespecial org.springframework.boot.logging.AbstractLoggingSystem.<init>:(Ljava/lang/ClassLoader;)V
         1: .line 41
            return
        end local 1 // java.lang.ClassLoader classLoader
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    2     0         this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;
            0    2     1  classLoader  Ljava/lang/ClassLoader;
    MethodParameters:
             Name  Flags
      classLoader  

  public void beforeInitialize();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
         0: .line 45
            aload 0 /* this */
            invokespecial org.springframework.boot.logging.AbstractLoggingSystem.beforeInitialize:()V
         1: .line 46
            aload 0 /* this */
            invokevirtual org.springframework.boot.logging.Slf4JLoggingSystem.configureJdkLoggingBridgeHandler:()V
         2: .line 47
            return
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;

  public void cleanUp();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
         0: .line 51
            aload 0 /* this */
            invokevirtual org.springframework.boot.logging.Slf4JLoggingSystem.isBridgeHandlerAvailable:()Z
            ifeq 2
         1: .line 52
            aload 0 /* this */
            invokevirtual org.springframework.boot.logging.Slf4JLoggingSystem.removeJdkLoggingBridgeHandler:()V
         2: .line 54
      StackMap locals:
      StackMap stack:
            return
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;

  protected void loadConfiguration(org.springframework.boot.logging.LoggingInitializationContext, java.lang.String, org.springframework.boot.logging.LogFile);
    descriptor: (Lorg/springframework/boot/logging/LoggingInitializationContext;Ljava/lang/String;Lorg/springframework/boot/logging/LogFile;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=3, locals=4, args_size=4
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
        start local 1 // org.springframework.boot.logging.LoggingInitializationContext initializationContext
        start local 2 // java.lang.String location
        start local 3 // org.springframework.boot.logging.LogFile logFile
         0: .line 59
            aload 2 /* location */
            ldc "Location must not be null"
            invokestatic org.springframework.util.Assert.notNull:(Ljava/lang/Object;Ljava/lang/String;)V
         1: .line 60
            aload 1 /* initializationContext */
            ifnull 3
         2: .line 61
            aload 0 /* this */
            aload 1 /* initializationContext */
            invokevirtual org.springframework.boot.logging.LoggingInitializationContext.getEnvironment:()Lorg/springframework/core/env/Environment;
            aload 3 /* logFile */
            invokevirtual org.springframework.boot.logging.Slf4JLoggingSystem.applySystemProperties:(Lorg/springframework/core/env/Environment;Lorg/springframework/boot/logging/LogFile;)V
         3: .line 63
      StackMap locals:
      StackMap stack:
            return
        end local 3 // org.springframework.boot.logging.LogFile logFile
        end local 2 // java.lang.String location
        end local 1 // org.springframework.boot.logging.LoggingInitializationContext initializationContext
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot                   Name  Signature
            0    4     0                   this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;
            0    4     1  initializationContext  Lorg/springframework/boot/logging/LoggingInitializationContext;
            0    4     2               location  Ljava/lang/String;
            0    4     3                logFile  Lorg/springframework/boot/logging/LogFile;
    MethodParameters:
                       Name  Flags
      initializationContext  
      location               
      logFile                

  private void configureJdkLoggingBridgeHandler();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
         0: .line 69
            new java.lang.Error
            dup
            ldc "Unresolved compilation problem: \n\tSLF4JBridgeHandler cannot be resolved\n"
            invokespecial java.lang.Error.<init>:(Ljava/lang/String;)V
            athrow
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;

  protected final boolean isBridgeJulIntoSlf4j();
    descriptor: ()Z
    flags: (0x0014) ACC_PROTECTED, ACC_FINAL
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
         0: .line 83
            aload 0 /* this */
            invokevirtual org.springframework.boot.logging.Slf4JLoggingSystem.isBridgeHandlerAvailable:()Z
            ifeq 1
            aload 0 /* this */
            invokevirtual org.springframework.boot.logging.Slf4JLoggingSystem.isJulUsingASingleConsoleHandlerAtMost:()Z
            ifeq 1
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         1: iconst_0
            ireturn
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;

  protected final boolean isBridgeHandlerAvailable();
    descriptor: ()Z
    flags: (0x0014) ACC_PROTECTED, ACC_FINAL
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
         0: .line 87
            ldc "org.slf4j.bridge.SLF4JBridgeHandler"
            aload 0 /* this */
            invokevirtual org.springframework.boot.logging.Slf4JLoggingSystem.getClassLoader:()Ljava/lang/ClassLoader;
            invokestatic org.springframework.util.ClassUtils.isPresent:(Ljava/lang/String;Ljava/lang/ClassLoader;)Z
            ireturn
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;

  private boolean isJulUsingASingleConsoleHandlerAtMost();
    descriptor: ()Z
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=3, args_size=1
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
         0: .line 91
            invokestatic java.util.logging.LogManager.getLogManager:()Ljava/util/logging/LogManager;
            ldc ""
            invokevirtual java.util.logging.LogManager.getLogger:(Ljava/lang/String;)Ljava/util/logging/Logger;
            astore 1 /* rootLogger */
        start local 1 // java.util.logging.Logger rootLogger
         1: .line 92
            aload 1 /* rootLogger */
            invokevirtual java.util.logging.Logger.getHandlers:()[Ljava/util/logging/Handler;
            astore 2 /* handlers */
        start local 2 // java.util.logging.Handler[] handlers
         2: .line 93
            aload 2 /* handlers */
            arraylength
            ifeq 4
            aload 2 /* handlers */
            arraylength
            iconst_1
            if_icmpne 3
            aload 2 /* handlers */
            iconst_0
            aaload
            instanceof java.util.logging.ConsoleHandler
            ifne 4
      StackMap locals: java.util.logging.Logger java.util.logging.Handler[]
      StackMap stack:
         3: iconst_0
            ireturn
      StackMap locals:
      StackMap stack:
         4: iconst_1
            ireturn
        end local 2 // java.util.logging.Handler[] handlers
        end local 1 // java.util.logging.Logger rootLogger
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    5     0        this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;
            1    5     1  rootLogger  Ljava/util/logging/Logger;
            2    5     2    handlers  [Ljava/util/logging/Handler;

  private void removeJdkLoggingBridgeHandler();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
         0: .line 99
            new java.lang.Error
            dup
            ldc "Unresolved compilation problem: \n\tSLF4JBridgeHandler cannot be resolved\n"
            invokespecial java.lang.Error.<init>:(Ljava/lang/String;)V
            athrow
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;

  private void removeDefaultRootHandler();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=3, args_size=1
        start local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
         0: .line 108
            invokestatic java.util.logging.LogManager.getLogManager:()Ljava/util/logging/LogManager;
            ldc ""
            invokevirtual java.util.logging.LogManager.getLogger:(Ljava/lang/String;)Ljava/util/logging/Logger;
            astore 1 /* rootLogger */
        start local 1 // java.util.logging.Logger rootLogger
         1: .line 109
            aload 1 /* rootLogger */
            invokevirtual java.util.logging.Logger.getHandlers:()[Ljava/util/logging/Handler;
            astore 2 /* handlers */
        start local 2 // java.util.logging.Handler[] handlers
         2: .line 110
            aload 2 /* handlers */
            arraylength
            iconst_1
            if_icmpne 6
            aload 2 /* handlers */
            iconst_0
            aaload
            instanceof java.util.logging.ConsoleHandler
            ifeq 6
         3: .line 111
            aload 1 /* rootLogger */
            aload 2 /* handlers */
            iconst_0
            aaload
            invokevirtual java.util.logging.Logger.removeHandler:(Ljava/util/logging/Handler;)V
        end local 2 // java.util.logging.Handler[] handlers
        end local 1 // java.util.logging.Logger rootLogger
         4: .line 113
            goto 6
         5: .line 114
      StackMap locals:
      StackMap stack: java.lang.Throwable
            pop
         6: .line 117
      StackMap locals:
      StackMap stack:
            return
        end local 0 // org.springframework.boot.logging.Slf4JLoggingSystem this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    7     0        this  Lorg/springframework/boot/logging/Slf4JLoggingSystem;
            1    4     1  rootLogger  Ljava/util/logging/Logger;
            2    4     2    handlers  [Ljava/util/logging/Handler;
      Exception table:
        from    to  target  type
           0     4       5  Class java.lang.Throwable
}
SourceFile: "Slf4JLoggingSystem.java"