程序包 org.springframework.boot.json

接口 JsonWriter<T>

类型参数:

T - the type being written

函数接口:

这是一个函数接口, 因此可用作 lambda 表达式或方法引用的赋值目标。

@FunctionalInterface
public interface JsonWriter<T>

Interface that can be used to write JSON output. Typically used to generate JSON when a dependency on a fully marshalling library (such as Jackson or Gson) cannot be assumed.

For standard Java types, the standard() factory method may be used to obtain an instance of this interface. It supports String, Number and Boolean as well as Collection, Array, Map and WritableJson types. Typical usage would be:

 JsonWriter<Map<String,Object>> writer = JsonWriter.standard();
 writer.write(Map.of("Hello", "World!"), out);
 

More complex mappings can be created using the of(Consumer) method with a callback to configure the JSON members that should be written. Typical usage would be:

 JsonWriter<Person> writer = JsonWriter.of((members) -> {
     members.add("first", Person::firstName);
     members.add("last", Person::lastName);
     members.add("dob", Person::dateOfBirth)
         .whenNotNull()
         .as(DateTimeFormatter.ISO_DATE::format);
 });
 writer.write(person, out);
 

The writeToString(Object) method can be used if you want to write the JSON directly to a String. To write to other types of output, the write(Object) method may be used to obtain a WritableJson instance.

从以下版本开始:

3.4.0

作者:

Phillip Webb, Moritz Halbritter

嵌套类概要

嵌套类

修饰符和类型	接口	说明
static final class	JsonWriter.Member<T>	A member that contributes JSON.
static final record	JsonWriter.MemberPath	A path used to identify a specific JSON member.
static final class	JsonWriter.Members<T>	Callback used to configure JSON members.
static interface	JsonWriter.NameProcessor	Callback interface that can be applied to JsonWriter.Members to change names or filter members.
static interface	JsonWriter.PairExtractor<E>	Interface that can be used to extract name/value pairs from an element.
static interface	JsonWriter.ValueProcessor<T>	Callback interface that can be applied to JsonWriter.Members to process values before they are written.

方法概要

修饰符和类型	方法	说明
static <T> JsonWriter<T>	of(Consumer<JsonWriter.Members<T>> members)	Factory method to return a JsonWriter with specific member mapping.
static <T> JsonWriter<T>	standard()	Factory method to return a JsonWriter for standard Java types.
default JsonWriter<T>	withNewLineAtEnd()	Return a new JsonWriter instance that appends a new line after the JSON has been written.
default JsonWriter<T>	withSuffix(String suffix)	Return a new JsonWriter instance that appends the given suffix after the JSON has been written.
default WritableJson	write(T instance)	Provide a WritableJson implementation that may be used to write the given instance to various outputs.
void	write(T instance, Appendable out)	Write the given instance to the provided Appendable.
default String	writeToString(T instance)	Write the given instance to a JSON string.

方法详细资料

write

void write(T instance,
 Appendable out)
    throws IOException

Write the given instance to the provided Appendable.

参数:

instance - the instance to write (may be null

out - the output that should receive the JSON

抛出:

IOException - on IO error

writeToString

default String writeToString(T instance)

Write the given instance to a JSON string.

参数:

instance - the instance to write (may be null)

返回:

the JSON string

write

default WritableJson write(T instance)

Provide a WritableJson implementation that may be used to write the given instance to various outputs.

参数:

instance - the instance to write (may be null)

返回:

a WritableJson instance that may be used to write the JSON

withNewLineAtEnd

default JsonWriter<T> withNewLineAtEnd()

Return a new JsonWriter instance that appends a new line after the JSON has been written.

返回:

a new JsonWriter instance that appends a new line after the JSON

withSuffix

default JsonWriter<T> withSuffix(String suffix)

Return a new JsonWriter instance that appends the given suffix after the JSON has been written.

参数:

suffix - the suffix to write, if any

返回:

a new JsonWriter instance that appends a suffixafter the JSON

standard

static <T> JsonWriter<T> standard()

Factory method to return a JsonWriter for standard Java types. See class-level javadoc for details.

类型参数:

T - the type to write

返回:

a JsonWriter instance

of

static <T> JsonWriter<T> of(Consumer<JsonWriter.Members<T>> members)

Factory method to return a JsonWriter with specific member mapping. See class-level javadoc and JsonWriter.Members for details.

类型参数:

T - the type to write

参数:

members - a consumer, which should configure the members

返回:

a JsonWriter instance

另请参阅:

• JsonWriter.Members