类 FormHttpMessageConverter
- java.lang.Object
- org.springframework.http.converter.FormHttpMessageConverter
- 所有已实现的接口:
HttpMessageConverter<MultiValueMap<String,?>>
public class FormHttpMessageConverter extends Object implements HttpMessageConverter<MultiValueMap<String,?>>
Implementation ofHttpMessageConverter
to read and write 'normal' HTML forms and also to write (but not read) multipart data (e.g. file uploads).In other words, this converter can read and write the
"application/x-www-form-urlencoded"
media type asMultiValueMap<String, String>
, and it can also write (but not read) the"multipart/form-data"
and"multipart/mixed"
media types asMultiValueMap<String, Object>
.Multipart Data
By default,
"multipart/form-data"
is used as the content type when writing multipart data. As of Spring Framework 5.2 it is also possible to write multipart data using other multipart subtypes such as"multipart/mixed"
and"multipart/related"
, as long as the multipart subtype is registered as a supported media typeand the desired multipart subtype is specified as the content type when writing the multipart data. Note that"multipart/mixed"
is registered as a supported media type by default.When writing multipart data, this converter uses other
HttpMessageConverters
to write the respective MIME parts. By default, basic converters are registered for byte array,String
, andResource
. These can be overridden viasetPartConverters(java.util.List<org.springframework.http.converter.HttpMessageConverter<?>>)
or augmented viaaddPartConverter(org.springframework.http.converter.HttpMessageConverter<?>)
.Examples
The following snippet shows how to submit an HTML form using the
"multipart/form-data"
content type.RestTemplate restTemplate = new RestTemplate(); // AllEncompassingFormHttpMessageConverter is configured by default MultiValueMap<String, Object> form = new LinkedMultiValueMap<>(); form.add("field 1", "value 1"); form.add("field 2", "value 2"); form.add("field 2", "value 3"); form.add("field 3", 4); // non-String form values supported as of 5.1.4 restTemplate.postForLocation("https://example.com/myForm", form);
The following snippet shows how to do a file upload using the
"multipart/form-data"
content type.MultiValueMap<String, Object> parts = new LinkedMultiValueMap<>(); parts.add("field 1", "value 1"); parts.add("file", new ClassPathResource("myFile.jpg")); restTemplate.postForLocation("https://example.com/myFileUpload", parts);
The following snippet shows how to do a file upload using the
"multipart/mixed"
content type.MultiValueMap<String, Object> parts = new LinkedMultiValueMap<>(); parts.add("field 1", "value 1"); parts.add("file", new ClassPathResource("myFile.jpg")); HttpHeaders requestHeaders = new HttpHeaders(); requestHeaders.setContentType(MediaType.MULTIPART_MIXED); restTemplate.postForLocation("https://example.com/myFileUpload", new HttpEntity<>(parts, requestHeaders));
The following snippet shows how to do a file upload using the
"multipart/related"
content type.MediaType multipartRelated = new MediaType("multipart", "related"); restTemplate.getMessageConverters().stream() .filter(FormHttpMessageConverter.class::isInstance) .map(FormHttpMessageConverter.class::cast) .findFirst() .orElseThrow(() -> new IllegalStateException("Failed to find FormHttpMessageConverter")) .addSupportedMediaTypes(multipartRelated); MultiValueMap<String, Object> parts = new LinkedMultiValueMap<>(); parts.add("field 1", "value 1"); parts.add("file", new ClassPathResource("myFile.jpg")); HttpHeaders requestHeaders = new HttpHeaders(); requestHeaders.setContentType(multipartRelated); restTemplate.postForLocation("https://example.com/myFileUpload", new HttpEntity<>(parts, requestHeaders));
Miscellaneous
Some methods in this class were inspired by
org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity
.- 从以下版本开始:
- 3.0
- 作者:
- Arjen Poutsma, Rossen Stoyanchev, Juergen Hoeller, Sam Brannen
- 另请参阅:
AllEncompassingFormHttpMessageConverter
,MultiValueMap
字段概要
字段 修饰符和类型 字段 说明 static Charset
DEFAULT_CHARSET
The default charset used by the converter.
构造器概要
构造器 构造器 说明 FormHttpMessageConverter()
方法概要
所有方法 实例方法 具体方法 修饰符和类型 方法 说明 void
addPartConverter(HttpMessageConverter<?> partConverter)
Add a message body converter.void
addSupportedMediaTypes(MediaType... supportedMediaTypes)
AddMediaType
objects to be supported by this converter.boolean
canRead(Class<?> clazz, MediaType mediaType)
Indicates whether the given class can be read by this converter.boolean
canWrite(Class<?> clazz, MediaType mediaType)
Indicates whether the given class can be written by this converter.protected byte[]
generateMultipartBoundary()
Generate a multipart boundary.protected String
getFilename(Object part)
Return the filename of the given multipart part.protected MediaType
getFormContentType(MediaType contentType)
Return the content type used to write forms, given the preferred content type.protected HttpEntity<?>
getHttpEntity(Object part)
Return anHttpEntity
for the given part Object.List<MediaType>
getSupportedMediaTypes()
Return the list ofMediaType
objects supported by this converter.MultiValueMap<String,String>
read(Class<? extends MultiValueMap<String,?>> clazz, HttpInputMessage inputMessage)
Read an object of the given type from the given input message, and returns it.protected String
serializeForm(MultiValueMap<String,Object> formData, Charset charset)
void
setCharset(Charset charset)
Set the default character set to use for reading and writing form data when the request or responseContent-Type
header does not explicitly specify it.void
setMultipartCharset(Charset charset)
Set the character set to use when writing multipart data to encode file names.void
setPartConverters(List<HttpMessageConverter<?>> partConverters)
Set the message body converters to use.void
setSupportedMediaTypes(List<MediaType> supportedMediaTypes)
Set the list ofMediaType
objects supported by this converter.void
write(MultiValueMap<String,?> map, MediaType contentType, HttpOutputMessage outputMessage)
Write an given object to the given output message.
字段详细资料
DEFAULT_CHARSET
public static final Charset DEFAULT_CHARSET
The default charset used by the converter.
构造器详细资料
FormHttpMessageConverter
public FormHttpMessageConverter()
方法详细资料
setSupportedMediaTypes
public void setSupportedMediaTypes(List<MediaType> supportedMediaTypes)
Set the list ofMediaType
objects supported by this converter.
addSupportedMediaTypes
public void addSupportedMediaTypes(MediaType... supportedMediaTypes)
AddMediaType
objects to be supported by this converter.The supplied
MediaType
objects will be appended to the list of supported MediaType objects.- 参数:
supportedMediaTypes
- a var-args list ofMediaType
objects to add- 从以下版本开始:
- 5.2
- 另请参阅:
setSupportedMediaTypes(List)
getSupportedMediaTypes
public List<MediaType> getSupportedMediaTypes()
Return the list ofMediaType
objects supported by this converter.- 指定者:
getSupportedMediaTypes
在接口中HttpMessageConverter<MultiValueMap<String,?>>
- 返回:
- the list of supported media types, potentially an immutable copy
- 另请参阅:
setSupportedMediaTypes(List)
,addSupportedMediaTypes(MediaType...)
setPartConverters
public void setPartConverters(List<HttpMessageConverter<?>> partConverters)
Set the message body converters to use. These converters are used to convert objects to MIME parts.
addPartConverter
public void addPartConverter(HttpMessageConverter<?> partConverter)
Add a message body converter. Such a converter is used to convert objects to MIME parts.
setCharset
public void setCharset(@Nullable Charset charset)
Set the default character set to use for reading and writing form data when the request or responseContent-Type
header does not explicitly specify it.As of 4.3, this is also used as the default charset for the conversion of text bodies in a multipart request.
As of 5.0, this is also used for part headers including
Content-Disposition
(and its filename parameter) unless (the mutually exclusive)multipartCharset
is also set, in which case part headers are encoded as ASCII and filename is encoded with theencoded-word
syntax from RFC 2047.By default this is set to "UTF-8".
setMultipartCharset
public void setMultipartCharset(Charset charset)
Set the character set to use when writing multipart data to encode file names. Encoding is based on theencoded-word
syntax defined in RFC 2047 and relies onMimeUtility
fromjavax.mail
.As of 5.0 by default part headers, including
Content-Disposition
(and its filename parameter) will be encoded based on the setting ofsetCharset(Charset)
orUTF-8
by default.- 从以下版本开始:
- 4.1.1
- 另请参阅:
- Encoded-Word
canRead
public boolean canRead(Class<?> clazz, @Nullable MediaType mediaType)
从接口复制的说明:HttpMessageConverter
Indicates whether the given class can be read by this converter.- 指定者:
canRead
在接口中HttpMessageConverter<MultiValueMap<String,?>>
- 参数:
clazz
- the class to test for readabilitymediaType
- the media type to read (can benull
if not specified); typically the value of aContent-Type
header.- 返回:
true
if readable;false
otherwise
canWrite
public boolean canWrite(Class<?> clazz, @Nullable MediaType mediaType)
从接口复制的说明:HttpMessageConverter
Indicates whether the given class can be written by this converter.- 指定者:
canWrite
在接口中HttpMessageConverter<MultiValueMap<String,?>>
- 参数:
clazz
- the class to test for writabilitymediaType
- the media type to write (can benull
if not specified); typically the value of anAccept
header.- 返回:
true
if writable;false
otherwise
read
public MultiValueMap<String,String> read(@Nullable Class<? extends MultiValueMap<String,?>> clazz, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException
从接口复制的说明:HttpMessageConverter
Read an object of the given type from the given input message, and returns it.- 指定者:
read
在接口中HttpMessageConverter<MultiValueMap<String,?>>
- 参数:
clazz
- the type of object to return. This type must have previously been passed to thecanRead
method of this interface, which must have returnedtrue
.inputMessage
- the HTTP input message to read from- 返回:
- the converted object
- 抛出:
IOException
- in case of I/O errorsHttpMessageNotReadableException
- in case of conversion errors
write
public void write(MultiValueMap<String,?> map, @Nullable MediaType contentType, HttpOutputMessage outputMessage) throws IOException, HttpMessageNotWritableException
从接口复制的说明:HttpMessageConverter
Write an given object to the given output message.- 指定者:
write
在接口中HttpMessageConverter<MultiValueMap<String,?>>
- 参数:
map
- the object to write to the output message. The type of this object must have previously been passed to thecanWrite
method of this interface, which must have returnedtrue
.contentType
- the content type to use when writing. May benull
to indicate that the default content type of the converter must be used. If notnull
, this media type must have previously been passed to thecanWrite
method of this interface, which must have returnedtrue
.outputMessage
- the message to write to- 抛出:
IOException
- in case of I/O errorsHttpMessageNotWritableException
- in case of conversion errors
getFormContentType
protected MediaType getFormContentType(@Nullable MediaType contentType)
Return the content type used to write forms, given the preferred content type. By default, this method returns the given content type, but adds the charset if it does not have one. IfcontentType
isnull
,application/x-www-form-urlencoded; charset=UTF-8
is returned.Subclasses can override this method to change this behavior.
- 参数:
contentType
- the preferred content type (can benull
)- 返回:
- the content type to be used
- 从以下版本开始:
- 5.2.2
serializeForm
protected String serializeForm(MultiValueMap<String,Object> formData, Charset charset)
generateMultipartBoundary
protected byte[] generateMultipartBoundary()
Generate a multipart boundary.This implementation delegates to
MimeTypeUtils.generateMultipartBoundary()
.
getHttpEntity
protected HttpEntity<?> getHttpEntity(Object part)
Return anHttpEntity
for the given part Object.- 参数:
part
- the part to return anHttpEntity
for- 返回:
- the part Object itself it is an
HttpEntity
, or a newly builtHttpEntity
wrapper for that part
getFilename
@Nullable protected String getFilename(Object part)
Return the filename of the given multipart part. This value will be used for theContent-Disposition
header.The default implementation returns
Resource.getFilename()
if the part is aResource
, andnull
in other cases. Can be overridden in subclasses.- 参数:
part
- the part to determine the file name for- 返回:
- the filename, or
null
if not known