org.springframework.http.converter.FormHttpMessageConverter Maven / Gradle / Ivy
/*
* Copyright 2002-2019 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.http.converter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import javax.mail.internet.MimeUtility;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.StreamingHttpOutputMessage;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MimeTypeUtils;
import org.springframework.util.MultiValueMap;
import org.springframework.util.StreamUtils;
import org.springframework.util.StringUtils;
/**
* Implementation of {@link HttpMessageConverter} 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
* {@code "application/x-www-form-urlencoded"} media type as
* {@link MultiValueMap MultiValueMap<String, String>} and it can also
* write (but not read) the {@code "multipart/form-data"} media type as
* {@link MultiValueMap MultiValueMap<String, Object>}.
*
*
When writing multipart data, this converter uses other
* {@link HttpMessageConverter HttpMessageConverters} to write the respective
* MIME parts. By default, basic converters are registered (for {@code Strings}
* and {@code Resources}). These can be overridden through the
* {@link #setPartConverters partConverters} property.
*
*
For example, the following snippet shows how to submit an HTML form:
*
* RestTemplate template = 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
* template.postForLocation("http://example.com/myForm", form);
*
*
* The following snippet shows how to do a file upload:
*
* MultiValueMap<String, Object> parts = new LinkedMultiValueMap<>();
* parts.add("field 1", "value 1");
* parts.add("file", new ClassPathResource("myFile.jpg"));
* template.postForLocation("http://example.com/myFileUpload", parts);
*
*
* Some methods in this class were inspired by
* {@code org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity}.
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @since 3.0
* @see org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter
* @see org.springframework.util.MultiValueMap
*/
public class FormHttpMessageConverter implements HttpMessageConverter> {
/**
* The default charset used by the converter.
*/
public static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
private static final MediaType DEFAULT_FORM_DATA_MEDIA_TYPE =
new MediaType(MediaType.APPLICATION_FORM_URLENCODED, DEFAULT_CHARSET);
private List supportedMediaTypes = new ArrayList<>();
private List> partConverters = new ArrayList<>();
private Charset charset = DEFAULT_CHARSET;
@Nullable
private Charset multipartCharset;
public FormHttpMessageConverter() {
this.supportedMediaTypes.add(MediaType.APPLICATION_FORM_URLENCODED);
this.supportedMediaTypes.add(MediaType.MULTIPART_FORM_DATA);
StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
stringHttpMessageConverter.setWriteAcceptCharset(false); // see SPR-7316
this.partConverters.add(new ByteArrayHttpMessageConverter());
this.partConverters.add(stringHttpMessageConverter);
this.partConverters.add(new ResourceHttpMessageConverter());
applyDefaultCharset();
}
/**
* Set the list of {@link MediaType} objects supported by this converter.
*/
public void setSupportedMediaTypes(List supportedMediaTypes) {
this.supportedMediaTypes = supportedMediaTypes;
}
@Override
public List getSupportedMediaTypes() {
return Collections.unmodifiableList(this.supportedMediaTypes);
}
/**
* Set the message body converters to use. These converters are used to
* convert objects to MIME parts.
*/
public void setPartConverters(List> partConverters) {
Assert.notEmpty(partConverters, "'partConverters' must not be empty");
this.partConverters = partConverters;
}
/**
* Add a message body converter. Such a converter is used to convert objects
* to MIME parts.
*/
public void addPartConverter(HttpMessageConverter partConverter) {
Assert.notNull(partConverter, "'partConverter' must not be null");
this.partConverters.add(partConverter);
}
/**
* Set the default character set to use for reading and writing form data when
* the request or response Content-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) {@link #setMultipartCharset} is also set, in which case part
* headers are encoded as ASCII and filename is encoded with the
* "encoded-word" syntax from RFC 2047.
*
By default this is set to "UTF-8".
*/
public void setCharset(@Nullable Charset charset) {
if (charset != this.charset) {
this.charset = (charset != null ? charset : DEFAULT_CHARSET);
applyDefaultCharset();
}
}
/**
* Apply the configured charset as a default to registered part converters.
*/
private void applyDefaultCharset() {
for (HttpMessageConverter candidate : this.partConverters) {
if (candidate instanceof AbstractHttpMessageConverter) {
AbstractHttpMessageConverter converter = (AbstractHttpMessageConverter) candidate;
// Only override default charset if the converter operates with a charset to begin with...
if (converter.getDefaultCharset() != null) {
converter.setDefaultCharset(this.charset);
}
}
}
}
/**
* Set the character set to use when writing multipart data to encode file
* names. Encoding is based on the "encoded-word" syntax defined in RFC 2047
* and relies on {@code MimeUtility} from "javax.mail".
*
As of 5.0 by default part headers, including Content-Disposition (and
* its filename parameter) will be encoded based on the setting of
* {@link #setCharset(Charset)} or {@code UTF-8} by default.
* @since 4.1.1
* @see Encoded-Word
*/
public void setMultipartCharset(Charset charset) {
this.multipartCharset = charset;
}
@Override
public boolean canRead(Class clazz, @Nullable MediaType mediaType) {
if (!MultiValueMap.class.isAssignableFrom(clazz)) {
return false;
}
if (mediaType == null) {
return true;
}
for (MediaType supportedMediaType : getSupportedMediaTypes()) {
// We can't read multipart....
if (!supportedMediaType.equals(MediaType.MULTIPART_FORM_DATA) && supportedMediaType.includes(mediaType)) {
return true;
}
}
return false;
}
@Override
public boolean canWrite(Class clazz, @Nullable MediaType mediaType) {
if (!MultiValueMap.class.isAssignableFrom(clazz)) {
return false;
}
if (mediaType == null || MediaType.ALL.equals(mediaType)) {
return true;
}
for (MediaType supportedMediaType : getSupportedMediaTypes()) {
if (supportedMediaType.isCompatibleWith(mediaType)) {
return true;
}
}
return false;
}
@Override
public MultiValueMap read(@Nullable Class> clazz,
HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
MediaType contentType = inputMessage.getHeaders().getContentType();
Charset charset = (contentType != null && contentType.getCharset() != null ?
contentType.getCharset() : this.charset);
String body = StreamUtils.copyToString(inputMessage.getBody(), charset);
String[] pairs = StringUtils.tokenizeToStringArray(body, "&");
MultiValueMap result = new LinkedMultiValueMap<>(pairs.length);
for (String pair : pairs) {
int idx = pair.indexOf('=');
if (idx == -1) {
result.add(URLDecoder.decode(pair, charset.name()), null);
}
else {
String name = URLDecoder.decode(pair.substring(0, idx), charset.name());
String value = URLDecoder.decode(pair.substring(idx + 1), charset.name());
result.add(name, value);
}
}
return result;
}
@Override
@SuppressWarnings("unchecked")
public void write(MultiValueMap map, @Nullable MediaType contentType, HttpOutputMessage outputMessage)
throws IOException, HttpMessageNotWritableException {
if (!isMultipart(map, contentType)) {
writeForm((MultiValueMap) map, contentType, outputMessage);
}
else {
writeMultipart((MultiValueMap) map, outputMessage);
}
}
private boolean isMultipart(MultiValueMap map, @Nullable MediaType contentType) {
if (contentType != null) {
return MediaType.MULTIPART_FORM_DATA.includes(contentType);
}
for (String name : map.keySet()) {
for (Object value : map.get(name)) {
if (value != null && !(value instanceof String)) {
return true;
}
}
}
return false;
}
private void writeForm(MultiValueMap formData, @Nullable MediaType contentType,
HttpOutputMessage outputMessage) throws IOException {
contentType = getMediaType(contentType);
outputMessage.getHeaders().setContentType(contentType);
Charset charset = contentType.getCharset();
Assert.notNull(charset, "No charset"); // should never occur
final byte[] bytes = serializeForm(formData, charset).getBytes(charset);
outputMessage.getHeaders().setContentLength(bytes.length);
if (outputMessage instanceof StreamingHttpOutputMessage) {
StreamingHttpOutputMessage streamingOutputMessage = (StreamingHttpOutputMessage) outputMessage;
streamingOutputMessage.setBody(outputStream -> StreamUtils.copy(bytes, outputStream));
}
else {
StreamUtils.copy(bytes, outputMessage.getBody());
}
}
private MediaType getMediaType(@Nullable MediaType mediaType) {
if (mediaType == null) {
return DEFAULT_FORM_DATA_MEDIA_TYPE;
}
else if (mediaType.getCharset() == null) {
return new MediaType(mediaType, this.charset);
}
else {
return mediaType;
}
}
protected String serializeForm(MultiValueMap formData, Charset charset) {
StringBuilder builder = new StringBuilder();
formData.forEach((name, values) ->
values.forEach(value -> {
try {
if (builder.length() != 0) {
builder.append('&');
}
builder.append(URLEncoder.encode(name, charset.name()));
if (value != null) {
builder.append('=');
builder.append(URLEncoder.encode(String.valueOf(value), charset.name()));
}
}
catch (UnsupportedEncodingException ex) {
throw new IllegalStateException(ex);
}
}));
return builder.toString();
}
private void writeMultipart(final MultiValueMap parts, HttpOutputMessage outputMessage)
throws IOException {
final byte[] boundary = generateMultipartBoundary();
Map parameters = new LinkedHashMap<>(2);
if (!isFilenameCharsetSet()) {
parameters.put("charset", this.charset.name());
}
parameters.put("boundary", new String(boundary, StandardCharsets.US_ASCII));
MediaType contentType = new MediaType(MediaType.MULTIPART_FORM_DATA, parameters);
HttpHeaders headers = outputMessage.getHeaders();
headers.setContentType(contentType);
if (outputMessage instanceof StreamingHttpOutputMessage) {
StreamingHttpOutputMessage streamingOutputMessage = (StreamingHttpOutputMessage) outputMessage;
streamingOutputMessage.setBody(outputStream -> {
writeParts(outputStream, parts, boundary);
writeEnd(outputStream, boundary);
});
}
else {
writeParts(outputMessage.getBody(), parts, boundary);
writeEnd(outputMessage.getBody(), boundary);
}
}
/**
* When {@link #setMultipartCharset(Charset)} is configured (i.e. RFC 2047,
* "encoded-word" syntax) we need to use ASCII for part headers or otherwise
* we encode directly using the configured {@link #setCharset(Charset)}.
*/
private boolean isFilenameCharsetSet() {
return (this.multipartCharset != null);
}
private void writeParts(OutputStream os, MultiValueMap parts, byte[] boundary) throws IOException {
for (Map.Entry> entry : parts.entrySet()) {
String name = entry.getKey();
for (Object part : entry.getValue()) {
if (part != null) {
writeBoundary(os, boundary);
writePart(name, getHttpEntity(part), os);
writeNewLine(os);
}
}
}
}
@SuppressWarnings("unchecked")
private void writePart(String name, HttpEntity partEntity, OutputStream os) throws IOException {
Object partBody = partEntity.getBody();
if (partBody == null) {
throw new IllegalStateException("Empty body for part '" + name + "': " + partEntity);
}
Class partType = partBody.getClass();
HttpHeaders partHeaders = partEntity.getHeaders();
MediaType partContentType = partHeaders.getContentType();
for (HttpMessageConverter messageConverter : this.partConverters) {
if (messageConverter.canWrite(partType, partContentType)) {
Charset charset = isFilenameCharsetSet() ? StandardCharsets.US_ASCII : this.charset;
HttpOutputMessage multipartMessage = new MultipartHttpOutputMessage(os, charset);
multipartMessage.getHeaders().setContentDispositionFormData(name, getFilename(partBody));
if (!partHeaders.isEmpty()) {
multipartMessage.getHeaders().putAll(partHeaders);
}
((HttpMessageConverter