Interface TypeConverter

All Known Subinterfaces:
BulkTypeConverters
public interface TypeConverter
Pluggable strategy for converting objects to different types such as String, InputStream/OutputStream, Reader/Writer, Document, byte[], and ByteBuffer.

Type converters are a central part of Camel's integration infrastructure. Whenever Camel reads an Exchange body or header and needs it in a different Java type, it delegates to the TypeConverterRegistry to find an appropriate TypeConverter. Converters are discovered automatically at startup by scanning classpath resources for the Converter annotation, or they can be registered programmatically via TypeConverterRegistry.addTypeConverter(Class, Class, TypeConverter).

There are three conversion variants: convertTo(Class, Object) (returns null when the conversion is unavailable), mandatoryConvertTo(Class, Object) (throws NoTypeConversionAvailableException when no converter is found), and tryConvertTo(Class, Object) (silently returns null without propagating exceptions).

See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final Object
    MISS_VALUE
    Sentinel value indicating that no type converter was found, used internally for caching purposes.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    allowNull()
    Whether the type converter allows returning null as a valid response.
    <T> @Nullable T
    convertTo(Class<T> type, @Nullable Object value)
    Converts the value to the specified type
    <T> @Nullable T
    convertTo(Class<T> type, @Nullable Exchange exchange, @Nullable Object value)
    Converts the value to the specified type in the context of an exchange
    <T> T
    mandatoryConvertTo(Class<T> type, @Nullable Object value)
    Converts the value to the specified type
    <T> T
    mandatoryConvertTo(Class<T> type, @Nullable Exchange exchange, @Nullable Object value)
    Converts the value to the specified type in the context of an exchange
    <T> @Nullable T
    tryConvertTo(Class<T> type, @Nullable Object value)
    Tries to convert the value to the specified type, returning null if not possible to convert.
    <T> @Nullable T
    tryConvertTo(Class<T> type, @Nullable Exchange exchange, @Nullable Object value)
    Tries to convert the value to the specified type in the context of an exchange, returning null if not possible to convert.

  • Field Details

    • MISS_VALUE

      static final Object MISS_VALUE
      Sentinel value indicating that no type converter was found, used internally for caching purposes.

  • Method Details

    • allowNull

      boolean allowNull()
      Whether the type converter allows returning null as a valid response.

      By default null is not a valid response, returning false from this method.

    • convertTo

      <T> @Nullable T convertTo(Class<T> type, @Nullable Object value) throws TypeConversionException
      Converts the value to the specified type
      Parameters:
      type - the requested type
      value - the value to be converted
      Returns:
      the converted value, or null if not possible to convert
      Throws:
      TypeConversionException - is thrown if error during type conversion

    • convertTo

      <T> @Nullable T convertTo(Class<T> type, @Nullable Exchange exchange, @Nullable Object value) throws TypeConversionException
      Converts the value to the specified type in the context of an exchange

      Used when conversion requires extra information from the current exchange (such as encoding).

      Parameters:
      type - the requested type
      exchange - the current exchange
      value - the value to be converted
      Returns:
      the converted value, or null if not possible to convert
      Throws:
      TypeConversionException - is thrown if error during type conversion

    • mandatoryConvertTo

      <T> T mandatoryConvertTo(Class<T> type, @Nullable Object value) throws TypeConversionException, NoTypeConversionAvailableException
      Converts the value to the specified type
      Parameters:
      type - the requested type
      value - the value to be converted
      Returns:
      the converted value, is never null
      Throws:
      TypeConversionException - is thrown if error during type conversion
      NoTypeConversionAvailableException - if no type converters exists to convert to the given type

    • mandatoryConvertTo

      <T> T mandatoryConvertTo(Class<T> type, @Nullable Exchange exchange, @Nullable Object value) throws TypeConversionException, NoTypeConversionAvailableException
      Converts the value to the specified type in the context of an exchange

      Used when conversion requires extra information from the current exchange (such as encoding).

      Parameters:
      type - the requested type
      exchange - the current exchange
      value - the value to be converted
      Returns:
      the converted value, is never null
      Throws:
      TypeConversionException - is thrown if error during type conversion
      NoTypeConversionAvailableException - if no type converters exists to convert to the given type

    • tryConvertTo

      <T> @Nullable T tryConvertTo(Class<T> type, @Nullable Object value)
      Tries to convert the value to the specified type, returning null if not possible to convert.

      This method will not throw an exception if an exception occurred during conversion.

      Parameters:
      type - the requested type
      value - the value to be converted
      Returns:
      the converted value, or null if not possible to convert

    • tryConvertTo

      <T> @Nullable T tryConvertTo(Class<T> type, @Nullable Exchange exchange, @Nullable Object value)
      Tries to convert the value to the specified type in the context of an exchange, returning null if not possible to convert.

      This method will not throw an exception if an exception occurred during conversion. Converts the value to the specified type in the context of an exchange

      Used when conversion requires extra information from the current exchange (such as encoding).

      Parameters:
      type - the requested type
      exchange - the current exchange
      value - the value to be converted
      Returns:
      the converted value, or null if not possible to convert