AbstractMultipartForm.java
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package com.foxinmy.weixin4j.http.apache.mime;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.util.List;
import com.foxinmy.weixin4j.http.apache.content.ContentBody;
import com.foxinmy.weixin4j.util.ByteArrayBuffer;
/**
* HttpMultipart represents a collection of MIME multipart encoded content bodies. This class is
* capable of operating either in the strict (RFC 822, RFC 2045, RFC 2046 compliant) or
* the browser compatible modes.
*
* @since 4.3
*/
abstract class AbstractMultipartForm {
private static ByteArrayBuffer encode(
final Charset charset, final String string) {
final ByteBuffer encoded = charset.encode(CharBuffer.wrap(string));
final ByteArrayBuffer bab = new ByteArrayBuffer(encoded.remaining());
bab.append(encoded.array(), encoded.position(), encoded.remaining());
return bab;
}
private static void writeBytes(
final ByteArrayBuffer b, final OutputStream out) throws IOException {
out.write(b.buffer(), 0, b.length());
}
private static void writeBytes(
final String s, final Charset charset, final OutputStream out) throws IOException {
final ByteArrayBuffer b = encode(charset, s);
writeBytes(b, out);
}
private static void writeBytes(
final String s, final OutputStream out) throws IOException {
final ByteArrayBuffer b = encode(MIME.DEFAULT_CHARSET, s);
writeBytes(b, out);
}
protected static void writeField(
final MinimalField field, final OutputStream out) throws IOException {
writeBytes(field.getName(), out);
writeBytes(FIELD_SEP, out);
writeBytes(field.getBody(), out);
writeBytes(CR_LF, out);
}
protected static void writeField(
final MinimalField field, final Charset charset, final OutputStream out) throws IOException {
writeBytes(field.getName(), charset, out);
writeBytes(FIELD_SEP, out);
writeBytes(field.getBody(), charset, out);
writeBytes(CR_LF, out);
}
private static final ByteArrayBuffer FIELD_SEP = encode(MIME.DEFAULT_CHARSET, ": ");
private static final ByteArrayBuffer CR_LF = encode(MIME.DEFAULT_CHARSET, "\r\n");
private static final ByteArrayBuffer TWO_DASHES = encode(MIME.DEFAULT_CHARSET, "--");
final Charset charset;
final String boundary;
/**
* Creates an instance with the specified settings.
*
* @param charset the character set to use. May be {@code null}, in which case {@link MIME#DEFAULT_CHARSET} - i.e. US-ASCII - is used.
* @param boundary to use - must not be {@code null}
* @throws IllegalArgumentException if charset is null or boundary is null
*/
public AbstractMultipartForm(final Charset charset, final String boundary) {
super();
this.charset = charset != null ? charset : MIME.DEFAULT_CHARSET;
this.boundary = boundary;
}
public AbstractMultipartForm(final String boundary) {
this(null, boundary);
}
public abstract List<FormBodyPart> getBodyParts();
void doWriteTo(
final OutputStream out,
final boolean writeContent) throws IOException {
final ByteArrayBuffer boundaryEncoded = encode(this.charset, this.boundary);
for (final FormBodyPart part: getBodyParts()) {
writeBytes(TWO_DASHES, out);
writeBytes(boundaryEncoded, out);
writeBytes(CR_LF, out);
formatMultipartHeader(part, out);
writeBytes(CR_LF, out);
if (writeContent) {
part.getBody().writeTo(out);
}
writeBytes(CR_LF, out);
}
writeBytes(TWO_DASHES, out);
writeBytes(boundaryEncoded, out);
writeBytes(TWO_DASHES, out);
writeBytes(CR_LF, out);
}
/**
* Write the multipart header fields; depends on the style.
*/
protected abstract void formatMultipartHeader(
final FormBodyPart part,
final OutputStream out) throws IOException;
/**
* Writes out the content in the multipart/form encoding. This method
* produces slightly different formatting depending on its compatibility
* mode.
*/
public void writeTo(final OutputStream out) throws IOException {
doWriteTo(out, true);
}
/**
* Determines the total length of the multipart content (content length of
* individual parts plus that of extra elements required to delimit the parts
* from one another). If any of the @{link BodyPart}s contained in this object
* is of a streaming entity of unknown length the total length is also unknown.
* <p>
* This method buffers only a small amount of data in order to determine the
* total length of the entire entity. The content of individual parts is not
* buffered.
* </p>
*
* @return total length of the multipart entity if known, {@code -1}
* otherwise.
*/
public long getTotalLength() {
long contentLen = 0;
for (final FormBodyPart part: getBodyParts()) {
final ContentBody body = part.getBody();
final long len = body.getContentLength();
if (len >= 0) {
contentLen += len;
} else {
return -1;
}
}
final ByteArrayOutputStream out = new ByteArrayOutputStream();
try {
doWriteTo(out, false);
final byte[] extra = out.toByteArray();
return contentLen + extra.length;
} catch (final IOException ex) {
// Should never happen
return -1;
}
}
}