http://metrics.dropwizard.io/metrics-healthchecks: An addition to Metrics which provides the ability to run application-specific health checks, allowing you to check your application's heath in production.
  • Coda Hale
  • Ryan Tenney
  • Artem Prigoda 
public class com.codahale.metrics.health.AsyncHealthCheckDecorator extends com.codahale.metrics.health.HealthCheck implements java.lang.Runnable
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: com.codahale.metrics.health.AsyncHealthCheckDecorator
  super_class: com.codahale.metrics.health.HealthCheck
{
  private static final java.lang.String NO_RESULT_YET_MESSAGE;
    descriptor: Ljava/lang/String;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: "Waiting for first asynchronous check result."

  private final com.codahale.metrics.health.HealthCheck healthCheck;
    descriptor: Lcom/codahale/metrics/health/HealthCheck;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final java.util.concurrent.ScheduledFuture<?> future;
    descriptor: Ljava/util/concurrent/ScheduledFuture;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/concurrent/ScheduledFuture<*>;

  private final long healthyTtl;
    descriptor: J
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final com.codahale.metrics.Clock clock;
    descriptor: Lcom/codahale/metrics/Clock;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private volatile com.codahale.metrics.health.HealthCheck$Result result;
    descriptor: Lcom/codahale/metrics/health/HealthCheck$Result;
    flags: (0x0042) ACC_PRIVATE, ACC_VOLATILE

  void <init>(com.codahale.metrics.health.HealthCheck, java.util.concurrent.ScheduledExecutorService, com.codahale.metrics.Clock);
    descriptor: (Lcom/codahale/metrics/health/HealthCheck;Ljava/util/concurrent/ScheduledExecutorService;Lcom/codahale/metrics/Clock;)V
    flags: (0x0000) 
    Code:
      stack=8, locals=5, args_size=4
        start local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
        start local 1 // com.codahale.metrics.health.HealthCheck healthCheck
        start local 2 // java.util.concurrent.ScheduledExecutorService executorService
        start local 3 // com.codahale.metrics.Clock clock
         0: .line 20
            aload 0 /* this */
            invokespecial com.codahale.metrics.health.HealthCheck.<init>:()V
         1: .line 21
            aload 1 /* healthCheck */
            ifnull 2
            iconst_1
            goto 3
      StackMap locals: com.codahale.metrics.health.AsyncHealthCheckDecorator com.codahale.metrics.health.HealthCheck java.util.concurrent.ScheduledExecutorService com.codahale.metrics.Clock
      StackMap stack:
         2: iconst_0
      StackMap locals:
      StackMap stack: int
         3: ldc "healthCheck cannot be null"
            invokestatic com.codahale.metrics.health.AsyncHealthCheckDecorator.check:(ZLjava/lang/String;)V
         4: .line 22
            aload 2 /* executorService */
            ifnull 5
            iconst_1
            goto 6
      StackMap locals:
      StackMap stack:
         5: iconst_0
      StackMap locals:
      StackMap stack: int
         6: ldc "executorService cannot be null"
            invokestatic com.codahale.metrics.health.AsyncHealthCheckDecorator.check:(ZLjava/lang/String;)V
         7: .line 23
            aload 1 /* healthCheck */
            invokevirtual java.lang.Object.getClass:()Ljava/lang/Class;
            ldc Lcom/codahale/metrics/health/annotation/Async;
            invokevirtual java.lang.Class.getAnnotation:(Ljava/lang/Class;)Ljava/lang/annotation/Annotation;
            checkcast com.codahale.metrics.health.annotation.Async
            astore 4 /* async */
        start local 4 // com.codahale.metrics.health.annotation.Async async
         8: .line 24
            aload 4 /* async */
            ifnull 9
            iconst_1
            goto 10
      StackMap locals: com.codahale.metrics.health.annotation.Async
      StackMap stack:
         9: iconst_0
      StackMap locals:
      StackMap stack: int
        10: ldc "healthCheck must contain Async annotation"
            invokestatic com.codahale.metrics.health.AsyncHealthCheckDecorator.check:(ZLjava/lang/String;)V
        11: .line 25
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.period:()J
            lconst_0
            lcmp
            ifle 12
            iconst_1
            goto 13
      StackMap locals:
      StackMap stack:
        12: iconst_0
      StackMap locals:
      StackMap stack: int
        13: ldc "period cannot be less than or equal to zero"
            invokestatic com.codahale.metrics.health.AsyncHealthCheckDecorator.check:(ZLjava/lang/String;)V
        14: .line 26
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.initialDelay:()J
            lconst_0
            lcmp
            iflt 15
            iconst_1
            goto 16
      StackMap locals:
      StackMap stack:
        15: iconst_0
      StackMap locals:
      StackMap stack: int
        16: ldc "initialDelay cannot be less than zero"
            invokestatic com.codahale.metrics.health.AsyncHealthCheckDecorator.check:(ZLjava/lang/String;)V
        17: .line 29
            aload 0 /* this */
            aload 3 /* clock */
            putfield com.codahale.metrics.health.AsyncHealthCheckDecorator.clock:Lcom/codahale/metrics/Clock;
        18: .line 30
            aload 0 /* this */
            aload 1 /* healthCheck */
            putfield com.codahale.metrics.health.AsyncHealthCheckDecorator.healthCheck:Lcom/codahale/metrics/health/HealthCheck;
        19: .line 31
            aload 0 /* this */
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.unit:()Ljava/util/concurrent/TimeUnit;
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.healthyTtl:()J
            lconst_0
            lcmp
            ifgt 20
            ldc 2
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.period:()J
            lmul
            goto 21
      StackMap locals: com.codahale.metrics.health.AsyncHealthCheckDecorator com.codahale.metrics.health.HealthCheck java.util.concurrent.ScheduledExecutorService com.codahale.metrics.Clock com.codahale.metrics.health.annotation.Async
      StackMap stack: com.codahale.metrics.health.AsyncHealthCheckDecorator java.util.concurrent.TimeUnit
        20: aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.healthyTtl:()J
      StackMap locals: com.codahale.metrics.health.AsyncHealthCheckDecorator com.codahale.metrics.health.HealthCheck java.util.concurrent.ScheduledExecutorService com.codahale.metrics.Clock com.codahale.metrics.health.annotation.Async
      StackMap stack: com.codahale.metrics.health.AsyncHealthCheckDecorator java.util.concurrent.TimeUnit long
        21: invokevirtual java.util.concurrent.TimeUnit.toMillis:(J)J
            putfield com.codahale.metrics.health.AsyncHealthCheckDecorator.healthyTtl:J
        22: .line 32
            aload 0 /* this */
            getstatic com.codahale.metrics.health.annotation.Async$InitialState.HEALTHY:Lcom/codahale/metrics/health/annotation/Async$InitialState;
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.initialState:()Lcom/codahale/metrics/health/annotation/Async$InitialState;
            invokevirtual com.codahale.metrics.health.annotation.Async$InitialState.equals:(Ljava/lang/Object;)Z
            ifeq 23
            ldc "Waiting for first asynchronous check result."
            invokestatic com.codahale.metrics.health.HealthCheck$Result.healthy:(Ljava/lang/String;)Lcom/codahale/metrics/health/HealthCheck$Result;
            goto 24
        23: .line 33
      StackMap locals:
      StackMap stack: com.codahale.metrics.health.AsyncHealthCheckDecorator
            ldc "Waiting for first asynchronous check result."
            invokestatic com.codahale.metrics.health.HealthCheck$Result.unhealthy:(Ljava/lang/String;)Lcom/codahale/metrics/health/HealthCheck$Result;
        24: .line 32
      StackMap locals: com.codahale.metrics.health.AsyncHealthCheckDecorator com.codahale.metrics.health.HealthCheck java.util.concurrent.ScheduledExecutorService com.codahale.metrics.Clock com.codahale.metrics.health.annotation.Async
      StackMap stack: com.codahale.metrics.health.AsyncHealthCheckDecorator com.codahale.metrics.health.HealthCheck$Result
            putfield com.codahale.metrics.health.AsyncHealthCheckDecorator.result:Lcom/codahale/metrics/health/HealthCheck$Result;
        25: .line 34
            getstatic com.codahale.metrics.health.annotation.Async$ScheduleType.FIXED_RATE:Lcom/codahale/metrics/health/annotation/Async$ScheduleType;
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.scheduleType:()Lcom/codahale/metrics/health/annotation/Async$ScheduleType;
            invokevirtual com.codahale.metrics.health.annotation.Async$ScheduleType.equals:(Ljava/lang/Object;)Z
            ifeq 28
        26: .line 35
            aload 0 /* this */
            aload 2 /* executorService */
            aload 0 /* this */
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.initialDelay:()J
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.period:()J
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.unit:()Ljava/util/concurrent/TimeUnit;
            invokeinterface java.util.concurrent.ScheduledExecutorService.scheduleAtFixedRate:(Ljava/lang/Runnable;JJLjava/util/concurrent/TimeUnit;)Ljava/util/concurrent/ScheduledFuture;
            putfield com.codahale.metrics.health.AsyncHealthCheckDecorator.future:Ljava/util/concurrent/ScheduledFuture;
        27: .line 36
            goto 29
        28: .line 37
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            aload 2 /* executorService */
            aload 0 /* this */
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.initialDelay:()J
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.period:()J
            aload 4 /* async */
            invokeinterface com.codahale.metrics.health.annotation.Async.unit:()Ljava/util/concurrent/TimeUnit;
            invokeinterface java.util.concurrent.ScheduledExecutorService.scheduleWithFixedDelay:(Ljava/lang/Runnable;JJLjava/util/concurrent/TimeUnit;)Ljava/util/concurrent/ScheduledFuture;
            putfield com.codahale.metrics.health.AsyncHealthCheckDecorator.future:Ljava/util/concurrent/ScheduledFuture;
        29: .line 40
      StackMap locals:
      StackMap stack:
            return
        end local 4 // com.codahale.metrics.health.annotation.Async async
        end local 3 // com.codahale.metrics.Clock clock
        end local 2 // java.util.concurrent.ScheduledExecutorService executorService
        end local 1 // com.codahale.metrics.health.HealthCheck healthCheck
        end local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
      LocalVariableTable:
        Start  End  Slot             Name  Signature
            0   30     0             this  Lcom/codahale/metrics/health/AsyncHealthCheckDecorator;
            0   30     1      healthCheck  Lcom/codahale/metrics/health/HealthCheck;
            0   30     2  executorService  Ljava/util/concurrent/ScheduledExecutorService;
            0   30     3            clock  Lcom/codahale/metrics/Clock;
            8   30     4            async  Lcom/codahale/metrics/health/annotation/Async;
    MethodParameters:
                 Name  Flags
      healthCheck      
      executorService  
      clock            

  void <init>(com.codahale.metrics.health.HealthCheck, java.util.concurrent.ScheduledExecutorService);
    descriptor: (Lcom/codahale/metrics/health/HealthCheck;Ljava/util/concurrent/ScheduledExecutorService;)V
    flags: (0x0000) 
    Code:
      stack=4, locals=3, args_size=3
        start local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
        start local 1 // com.codahale.metrics.health.HealthCheck healthCheck
        start local 2 // java.util.concurrent.ScheduledExecutorService executorService
         0: .line 43
            aload 0 /* this */
            aload 1 /* healthCheck */
            aload 2 /* executorService */
            invokestatic com.codahale.metrics.Clock.defaultClock:()Lcom/codahale/metrics/Clock;
            invokespecial com.codahale.metrics.health.AsyncHealthCheckDecorator.<init>:(Lcom/codahale/metrics/health/HealthCheck;Ljava/util/concurrent/ScheduledExecutorService;Lcom/codahale/metrics/Clock;)V
         1: .line 44
            return
        end local 2 // java.util.concurrent.ScheduledExecutorService executorService
        end local 1 // com.codahale.metrics.health.HealthCheck healthCheck
        end local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
      LocalVariableTable:
        Start  End  Slot             Name  Signature
            0    2     0             this  Lcom/codahale/metrics/health/AsyncHealthCheckDecorator;
            0    2     1      healthCheck  Lcom/codahale/metrics/health/HealthCheck;
            0    2     2  executorService  Ljava/util/concurrent/ScheduledExecutorService;
    MethodParameters:
                 Name  Flags
      healthCheck      
      executorService  

  public void run();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
         0: .line 48
            aload 0 /* this */
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.healthCheck:Lcom/codahale/metrics/health/HealthCheck;
            invokevirtual com.codahale.metrics.health.HealthCheck.execute:()Lcom/codahale/metrics/health/HealthCheck$Result;
            putfield com.codahale.metrics.health.AsyncHealthCheckDecorator.result:Lcom/codahale/metrics/health/HealthCheck$Result;
         1: .line 49
            return
        end local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/codahale/metrics/health/AsyncHealthCheckDecorator;

  protected com.codahale.metrics.health.HealthCheck$Result check();
    descriptor: ()Lcom/codahale/metrics/health/HealthCheck$Result;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=7, locals=3, args_size=1
        start local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
         0: .line 53
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.clock:Lcom/codahale/metrics/Clock;
            invokevirtual com.codahale.metrics.Clock.getTime:()J
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.result:Lcom/codahale/metrics/health/HealthCheck$Result;
            invokevirtual com.codahale.metrics.health.HealthCheck$Result.getTime:()J
            lsub
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.healthyTtl:J
            lsub
            lstore 1 /* expiration */
        start local 1 // long expiration
         1: .line 54
            lload 1 /* expiration */
            lconst_0
            lcmp
            ifle 13
         2: .line 55
            invokestatic com.codahale.metrics.health.HealthCheck$Result.builder:()Lcom/codahale/metrics/health/HealthCheck$ResultBuilder;
         3: .line 56
            invokevirtual com.codahale.metrics.health.HealthCheck$ResultBuilder.unhealthy:()Lcom/codahale/metrics/health/HealthCheck$ResultBuilder;
         4: .line 57
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.clock:Lcom/codahale/metrics/Clock;
            invokevirtual com.codahale.metrics.health.HealthCheck$ResultBuilder.usingClock:(Lcom/codahale/metrics/Clock;)Lcom/codahale/metrics/health/HealthCheck$ResultBuilder;
         5: .line 58
            ldc "Result was %s but it expired %d milliseconds ago"
            iconst_2
            anewarray java.lang.Object
            dup
            iconst_0
         6: .line 59
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.result:Lcom/codahale/metrics/health/HealthCheck$Result;
            invokevirtual com.codahale.metrics.health.HealthCheck$Result.isHealthy:()Z
            ifeq 7
            ldc "healthy"
            goto 8
      StackMap locals: com.codahale.metrics.health.AsyncHealthCheckDecorator long
      StackMap stack: com.codahale.metrics.health.HealthCheck$ResultBuilder java.lang.String java.lang.Object[] java.lang.Object[] int
         7: ldc "unhealthy"
      StackMap locals: com.codahale.metrics.health.AsyncHealthCheckDecorator long
      StackMap stack: com.codahale.metrics.health.HealthCheck$ResultBuilder java.lang.String java.lang.Object[] java.lang.Object[] int java.lang.String
         8: aastore
            dup
            iconst_1
         9: .line 60
            lload 1 /* expiration */
            invokestatic java.lang.Long.valueOf:(J)Ljava/lang/Long;
            aastore
        10: .line 58
            invokevirtual com.codahale.metrics.health.HealthCheck$ResultBuilder.withMessage:(Ljava/lang/String;[Ljava/lang/Object;)Lcom/codahale/metrics/health/HealthCheck$ResultBuilder;
        11: .line 61
            invokevirtual com.codahale.metrics.health.HealthCheck$ResultBuilder.build:()Lcom/codahale/metrics/health/HealthCheck$Result;
        12: .line 55
            areturn
        13: .line 64
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.result:Lcom/codahale/metrics/health/HealthCheck$Result;
            areturn
        end local 1 // long expiration
        end local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0   14     0        this  Lcom/codahale/metrics/health/AsyncHealthCheckDecorator;
            1   14     1  expiration  J
    Exceptions:
      throws java.lang.Exception

  boolean tearDown();
    descriptor: ()Z
    flags: (0x0000) 
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
         0: .line 68
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.future:Ljava/util/concurrent/ScheduledFuture;
            iconst_1
            invokeinterface java.util.concurrent.ScheduledFuture.cancel:(Z)Z
            ireturn
        end local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/codahale/metrics/health/AsyncHealthCheckDecorator;

  public com.codahale.metrics.health.HealthCheck getHealthCheck();
    descriptor: ()Lcom/codahale/metrics/health/HealthCheck;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
         0: .line 72
            aload 0 /* this */
            getfield com.codahale.metrics.health.AsyncHealthCheckDecorator.healthCheck:Lcom/codahale/metrics/health/HealthCheck;
            areturn
        end local 0 // com.codahale.metrics.health.AsyncHealthCheckDecorator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/codahale/metrics/health/AsyncHealthCheckDecorator;

  private static void check(boolean, java.lang.String);
    descriptor: (ZLjava/lang/String;)V
    flags: (0x000a) ACC_PRIVATE, ACC_STATIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // boolean expression
        start local 1 // java.lang.String message
         0: .line 76
            iload 0 /* expression */
            ifne 2
         1: .line 77
            new java.lang.IllegalArgumentException
            dup
            aload 1 /* message */
            invokespecial java.lang.IllegalArgumentException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 79
      StackMap locals:
      StackMap stack:
            return
        end local 1 // java.lang.String message
        end local 0 // boolean expression
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    3     0  expression  Z
            0    3     1     message  Ljava/lang/String;
    MethodParameters:
            Name  Flags
      expression  
      message     
}
SourceFile: "AsyncHealthCheckDecorator.java"
InnerClasses:
  public Result = com.codahale.metrics.health.HealthCheck$Result of com.codahale.metrics.health.HealthCheck
  public ResultBuilder = com.codahale.metrics.health.HealthCheck$ResultBuilder of com.codahale.metrics.health.HealthCheck
  public final InitialState = com.codahale.metrics.health.annotation.Async$InitialState of com.codahale.metrics.health.annotation.Async
  public final ScheduleType = com.codahale.metrics.health.annotation.Async$ScheduleType of com.codahale.metrics.health.annotation.Async