# JSON Compatible Encoder { #json-compatible-encoder }

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }

which generates classes corresponding your tables,
for example, entities, condition-beans to specified
directories by DBFlute properties on "dfprop" directory.

Generated structures (directories and classes) are like this:
/- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
allcommon : classes bridging to DBFlute Runtime
bsbhv     : base behaviors
bsentity  : base entities
cbean     : condition-beans (both base and extended)

assignees: [ ]
body:
  - type: markdown
    attributes:
      value: |
        Please use our bug report template to report problems with something that has never worked.
        Regressions reports are greatly appreciated during our RC phase and before a final release.
  - type: textarea
    id: current-behavior
    attributes:
      label: Current Behavior
      description: Tell us what happens
    validations:

- The target JVM for the runtime. Each runtime has its own JVM compatibility constraints.
- Some base services that are available to code hosted by the runtime. This varies by runtime.
- Additional constraints. For example, the CLI client runtimes limit the libraries that are available to the code in that runtime, for performance reasons. 

Other modules and platforms define the services that they contribute to the runtime.

  // be an empty string if no device was explicitly requested, but will
  // otherwise be the name of this custom device. Ops are placed onto a custom
  // device if any of their inputs are on that custom device, but custom devices
  // are free to set a bad status in order to require explicit placement.
  void (*execute)(const TFE_Op* op, int* num_outputs,

 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *
 * <p>{@code containsKey(k)}, {@code put(k, v)} and {@code remove(k)} are all (expected and
 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash

     * @param <T> the target type
     * @param type the target class type
     * @param object the object to cast
     * @return object cast to type
     * @throws PACDecodingException if types are incompatible
     */
    public static <T> T as(final Class<T> type, final Object object) throws PACDecodingException {
        if (!type.isInstance(object)) {

     * Implementations must ensure that if two requests are equal according to
     * {@link #equals(Object)}, they have the same hashcode.
     *
     * @return a hash code value for this request
     */
    @Override
    int hashCode();

    /**
     * Returns {@code true} if the specified object is equal to this request.
     * Two requests are considered equal if they have the same type and all

import java.util.Objects;
import java.util.concurrent.Callable;
import org.jspecify.annotations.Nullable;

/**
 * Statistics about the performance of a {@link Cache}. Instances of this class are immutable.
 *
 * <p>Cache statistics are incremented according to the following rules:
 *
 * <ul>
 *   <li>When a cache lookup encounters an existing cache entry {@code hitCount} is incremented.

import java.util.Objects;
import java.util.concurrent.Callable;
import org.jspecify.annotations.Nullable;

/**
 * Statistics about the performance of a {@link Cache}. Instances of this class are immutable.
 *
 * <p>Cache statistics are incremented according to the following rules:
 *
 * <ul>
 *   <li>When a cache lookup encounters an existing cache entry {@code hitCount} is incremented.