Get a property as a boolean or null.

@param key the property name
540429
@Override
    public final Boolean optBool(final String key) {
        if (this.obj.optString(key, null) == null) {
            return null;
        } else {
            return this.obj.optBoolean(key);
        }
    }
1356647
public boolean getBoolean(String key, boolean def) {
        String value = getString(key);
        if (value == null) {
            return def;
        }
        else {
            return "true".equalsIgnoreCase(value);
        }
    }
60923
public boolean getBooleanUseEval(String key) {
        Object object = eval(key);
        return Checker.isNull(object) ? null : (boolean) object;
    }
975664
@SuppressWarnings("unchecked")
  @Nullable
  public <T> T get(Key<T> key) {
    return (T) data.get(key);
  }
836751
public @CheckForNull T get(String key) throws IOException {
        return get(key,false,null);
    }
1122463
@InterfaceAudience.Public
    public Object getProperty(String key) {
        if (getCurrentRevision() != null &&
                getCurrentRevision().getProperties().containsKey(key)) {
            return getCurrentRevision().getProperties().get(key);
        }
        return null;
    }
50553
public boolean getBoolean(String key, boolean defaultValue) {
		addToDefaults(key, Boolean.toString(defaultValue));
		String value = get(key);
		if (value == null) {
			return defaultValue;
		} else {
			return Boolean.valueOf(value);
		}
	}
515014
private String getPropertyValue( final String    key )
    {
        String    value = null;
        for ( Properties    source : _sources )
        {
            value = source.getProperty( key );

            if ( value != null )
            {
                break;
            }
        }

        return value;
    }
353398
public String get(String key) {
    if (properties.get(key) != null) {
      return properties.get(key);
    } else {
      return getConfigurationValue(key);
    }
  }
1105966
public boolean getBoolean(Enum<?> key, boolean defaultValue)
    {
        if (key == null)
        {
            return defaultValue;
        }

        return getBoolean(key.name(), defaultValue);
    }
394234
public Object getStateProperty(String key) {
		if (!StringUtils.isBlank(key)) {
			return getDeviceState().get(key);
		}
		return null;
	}
545820
@Override
    public boolean getBoolean(@NonNull String key) {
        if (key == null) { throw new IllegalArgumentException("key cannot be null."); }

        synchronized (lock) {
            final Object obj = getMValue(internalDict, key).asNative(internalDict);
            return CBLConverter.asBoolean(obj);
        }
    }
395107
public boolean getBoolean(String key) {
    String value = getString(key);
    return StringUtils.isNotEmpty(value) && Boolean.parseBoolean(value);
  }
722938
@SuppressWarnings("unused")
	private Boolean loadBooleanProperty(String propertyKey) {
		String booleanPropValue = prop.getProperty(propertyKey);
		if (booleanPropValue != null) {
			return Boolean.parseBoolean(booleanPropValue.trim());
		} else {
			return null;
		}
	}
8008
public boolean getBoolean(String key, boolean def) {
        Object tmp = objectMap.get(key);
        return tmp != null && tmp instanceof Boolean ? (Boolean) tmp : def;
    }
161712
public boolean getBooleanProperty( String key , boolean defaultValue )
    {
        String value = SystemTools.replaceSystemProperties(settings.getProperty(key));
        if (value == null)
            return defaultValue;
        return Boolean.valueOf(value.trim()).booleanValue();
    }
871575
public boolean isNull(String key){
		LazyNode token=getOptionalFieldToken(key);
		if(token==null)return true;
		if(token.type==LazyNode.VALUE_NULL)return true;
		return false;
	}