/*
* Copyright 2002-2017 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.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
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.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).
*
* <p>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>}.
*
* <p>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.
*
* <p>For example, the following snippet shows how to submit an HTML form:
* <pre class="code">
* RestTemplate template = new RestTemplate(); // FormHttpMessageConverter is configured by default
* MultiValueMap<String, String> form = new LinkedMultiValueMap<String, String>();
* form.add("field 1", "value 1");
* form.add("field 2", "value 2");
* form.add("field 2", "value 3");
* template.postForLocation("http://example.com/myForm", form);
* </pre>
*
* <p>The following snippet shows how to do a file upload:
* <pre class="code">
* MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();
* parts.add("field 1", "value 1");
* parts.add("file", new ClassPathResource("myFile.jpg"));
* template.postForLocation("http://example.com/myFileUpload", parts);
* </pre>
*
* <p>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 MultiValueMap
*/
public class FormHttpMessageConverter implements HttpMessageConverter<MultiValueMap<String, ?>> {
public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
private List<MediaType> supportedMediaTypes = new ArrayList<MediaType>();
private List<HttpMessageConverter<?>> partConverters = new ArrayList<HttpMessageConverter<?>>();
private Charset charset = DEFAULT_CHARSET;
private Charset multipartCharset;
public FormHttpMessageConverter() {
this.supportedMediaTypes.add(MediaType.APPLICATION_FORM_URLENCODED);
this.supportedMediaTypes.add(MediaType.MULTIPART_FORM_DATA);
this.partConverters.add(new ByteArrayHttpMessageConverter());
StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
stringHttpMessageConverter.setWriteAcceptCharset(false);
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<MediaType> supportedMediaTypes) {
this.supportedMediaTypes = supportedMediaTypes;
}
@Override
public List<MediaType> 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<HttpMessageConverter<?>> 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.
* <p>By default this is set to "UTF-8". As of 4.3, it will also be used as
* the default charset for the conversion of text bodies in a multipart request.
* In contrast to this, {@link #setMultipartCharset} only affects the encoding of
* <i>file names</i> in a multipart request according to the encoded-word syntax.
*/
public void setCharset(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".
* <p>If not set file names will be encoded as US-ASCII.
* @since 4.1.1
* @see <a href="http://en.wikipedia.org/wiki/MIME#Encoded-Word">Encoded-Word</a>
*/
public void setMultipartCharset(Charset charset) {
this.multipartCharset = charset;
}
@Override
public boolean canRead(Class<?> clazz, 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, 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<String, String> read(Class<? extends MultiValueMap<String, ?>> clazz,
HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
MediaType contentType = inputMessage.getHeaders().getContentType();
Charset charset = (contentType.getCharset() != null ? contentType.getCharset() : this.charset);
String body = StreamUtils.copyToString(inputMessage.getBody(), charset);
String[] pairs = StringUtils.tokenizeToStringArray(body, "&");
MultiValueMap<String, String> result = new LinkedMultiValueMap<String, String>(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<String, ?> map, MediaType contentType, HttpOutputMessage outputMessage)
throws IOException, HttpMessageNotWritableException {
if (!isMultipart(map, contentType)) {
writeForm((MultiValueMap<String, String>) map, contentType, outputMessage);
}
else {
writeMultipart((MultiValueMap<String, Object>) map, outputMessage);
}
}
private boolean isMultipart(MultiValueMap<String, ?> map, 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<String, String> form, MediaType contentType,
HttpOutputMessage outputMessage) throws IOException {
Charset charset;
if (contentType != null) {
outputMessage.getHeaders().setContentType(contentType);
charset = (contentType.getCharset() != null ? contentType.getCharset() : this.charset);
}
else {
outputMessage.getHeaders().setContentType(MediaType.APPLICATION_FORM_URLENCODED);
charset = this.charset;
}
StringBuilder builder = new StringBuilder();
for (Iterator<String> nameIterator = form.keySet().iterator(); nameIterator.hasNext();) {
String name = nameIterator.next();
for (Iterator<String> valueIterator = form.get(name).iterator(); valueIterator.hasNext();) {
String value = valueIterator.next();
builder.append(URLEncoder.encode(name, charset.name()));
if (value != null) {
builder.append('=');
builder.append(URLEncoder.encode(value, charset.name()));
if (valueIterator.hasNext()) {
builder.append('&');
}
}
}
if (nameIterator.hasNext()) {
builder.append('&');
}
}
final byte[] bytes = builder.toString().getBytes(charset.name());
outputMessage.getHeaders().setContentLength(bytes.length);
if (outputMessage instanceof StreamingHttpOutputMessage) {
StreamingHttpOutputMessage streamingOutputMessage = (StreamingHttpOutputMessage) outputMessage;
streamingOutputMessage.setBody(new StreamingHttpOutputMessage.Body() {
@Override
public void writeTo(OutputStream outputStream) throws IOException {
StreamUtils.copy(bytes, outputStream);
}
});
}
else {
StreamUtils.copy(bytes, outputMessage.getBody());
}
}
private void writeMultipart(final MultiValueMap<String, Object> parts, HttpOutputMessage outputMessage) throws IOException {
final byte[] boundary = generateMultipartBoundary();
Map<String, String> parameters = Collections.singletonMap("boundary", new String(boundary, "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(new StreamingHttpOutputMessage.Body() {
@Override
public void writeTo(OutputStream outputStream) throws IOException {
writeParts(outputStream, parts, boundary);
writeEnd(outputStream, boundary);
}
});
}
else {
writeParts(outputMessage.getBody(), parts, boundary);
writeEnd(outputMessage.getBody(), boundary);
}
}
private void writeParts(OutputStream os, MultiValueMap<String, Object> parts, byte[] boundary) throws IOException {
for (Map.Entry<String, List<Object>> 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();
Class<?> partType = partBody.getClass();
HttpHeaders partHeaders = partEntity.getHeaders();
MediaType partContentType = partHeaders.getContentType();
for (HttpMessageConverter<?> messageConverter : this.partConverters) {
if (messageConverter.canWrite(partType, partContentType)) {
HttpOutputMessage multipartMessage = new MultipartHttpOutputMessage(os);
multipartMessage.getHeaders().setContentDispositionFormData(name, getFilename(partBody));
if (!partHeaders.isEmpty()) {
multipartMessage.getHeaders().putAll(partHeaders);
}
((HttpMessageConverter<Object>) messageConverter).write(partBody, partContentType, multipartMessage);
return;
}
}
throw new HttpMessageNotWritableException("Could not write request: no suitable HttpMessageConverter " +
"found for request type [" + partType.getName() + "]");
}
/**
* Generate a multipart boundary.
* <p>This implementation delegates to
* {@link MimeTypeUtils#generateMultipartBoundary()}.
*/
protected byte[] generateMultipartBoundary() {
return MimeTypeUtils.generateMultipartBoundary();
}
/**
* Return an {@link HttpEntity} for the given part Object.
* @param part the part to return an {@link HttpEntity} for
* @return the part Object itself it is an {@link HttpEntity},
* or a newly built {@link HttpEntity} wrapper for that part
*/
protected HttpEntity<?> getHttpEntity(Object part) {
return (part instanceof HttpEntity ? (HttpEntity<?>) part : new HttpEntity<Object>(part));
}
/**
* Return the filename of the given multipart part. This value will be used for the
* {@code Content-Disposition} header.
* <p>The default implementation returns {@link Resource#getFilename()} if the part is a
* {@code Resource}, and {@code null} in other cases. Can be overridden in subclasses.
* @param part the part to determine the file name for
* @return the filename, or {@code null} if not known
*/
protected String getFilename(Object part) {
if (part instanceof Resource) {
Resource resource = (Resource) part;
String filename = resource.getFilename();
if (filename != null && this.multipartCharset != null) {
filename = MimeDelegate.encode(filename, this.multipartCharset.name());
}
return filename;
}
else {
return null;
}
}
private void writeBoundary(OutputStream os, byte[] boundary) throws IOException {
os.write('-');
os.write('-');
os.write(boundary);
writeNewLine(os);
}
private static void writeEnd(OutputStream os, byte[] boundary) throws IOException {
os.write('-');
os.write('-');
os.write(boundary);
os.write('-');
os.write('-');
writeNewLine(os);
}
private static void writeNewLine(OutputStream os) throws IOException {
os.write('\r');
os.write('\n');
}
/**
* Implementation of {@link org.springframework.http.HttpOutputMessage} used
* to write a MIME multipart.
*/
private static class MultipartHttpOutputMessage implements HttpOutputMessage {
private final OutputStream outputStream;
private final HttpHeaders headers = new HttpHeaders();
private boolean headersWritten = false;
public MultipartHttpOutputMessage(OutputStream outputStream) {
this.outputStream = outputStream;
}
@Override
public HttpHeaders getHeaders() {
return (this.headersWritten ? HttpHeaders.readOnlyHttpHeaders(this.headers) : this.headers);
}
@Override
public OutputStream getBody() throws IOException {
writeHeaders();
return this.outputStream;
}
private void writeHeaders() throws IOException {
if (!this.headersWritten) {
for (Map.Entry<String, List<String>> entry : this.headers.entrySet()) {
byte[] headerName = getAsciiBytes(entry.getKey());
for (String headerValueString : entry.getValue()) {
byte[] headerValue = getAsciiBytes(headerValueString);
this.outputStream.write(headerName);
this.outputStream.write(':');
this.outputStream.write(' ');
this.outputStream.write(headerValue);
writeNewLine(this.outputStream);
}
}
writeNewLine(this.outputStream);
this.headersWritten = true;
}
}
private byte[] getAsciiBytes(String name) {
try {
return name.getBytes("US-ASCII");
}
catch (UnsupportedEncodingException ex) {
// Should not happen - US-ASCII is always supported.
throw new IllegalStateException(ex);
}
}
}
/**
* Inner class to avoid a hard dependency on the JavaMail API.
*/
private static class MimeDelegate {
public static String encode(String value, String charset) {
try {
return MimeUtility.encodeText(value, charset, null);
}
catch (UnsupportedEncodingException ex) {
throw new IllegalStateException(ex);
}
}
}
}
