Java tutorial
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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 org.apache.http.entity.mime; import java.io.File; import java.io.InputStream; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.Random; import org.apache.http.HttpEntity; import org.apache.http.entity.ContentType; import org.apache.http.entity.mime.content.ByteArrayBody; import org.apache.http.entity.mime.content.ContentBody; import org.apache.http.entity.mime.content.FileBody; import org.apache.http.entity.mime.content.InputStreamBody; import org.apache.http.entity.mime.content.StringBody; import org.apache.http.util.Args; /** * Builder for multipart {@link HttpEntity}s. * * @since 4.3 */ public class MultipartEntityBuilder { /** * The pool of ASCII chars to be used for generating a multipart boundary. */ private final static char[] MULTIPART_CHARS = "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" .toCharArray(); private final static String DEFAULT_SUBTYPE = "form-data"; private String subType = DEFAULT_SUBTYPE; private HttpMultipartMode mode = HttpMultipartMode.STRICT; private String boundary = null; private Charset charset = null; private List<FormBodyPart> bodyParts = null; public static MultipartEntityBuilder create() { return new MultipartEntityBuilder(); } MultipartEntityBuilder() { super(); } public MultipartEntityBuilder setMode(final HttpMultipartMode mode) { this.mode = mode; return this; } public MultipartEntityBuilder setLaxMode() { this.mode = HttpMultipartMode.BROWSER_COMPATIBLE; return this; } public MultipartEntityBuilder setStrictMode() { this.mode = HttpMultipartMode.STRICT; return this; } public MultipartEntityBuilder setBoundary(final String boundary) { this.boundary = boundary; return this; } public MultipartEntityBuilder setCharset(final Charset charset) { this.charset = charset; return this; } MultipartEntityBuilder addPart(final FormBodyPart bodyPart) { if (bodyPart == null) { return this; } if (this.bodyParts == null) { this.bodyParts = new ArrayList<FormBodyPart>(); } this.bodyParts.add(bodyPart); return this; } public MultipartEntityBuilder addPart(final String name, final ContentBody contentBody) { Args.notNull(name, "Name"); Args.notNull(contentBody, "Content body"); return addPart(new FormBodyPart(name, contentBody)); } public MultipartEntityBuilder addTextBody(final String name, final String text, final ContentType contentType) { return addPart(name, new StringBody(text, contentType)); } public MultipartEntityBuilder addTextBody(final String name, final String text) { return addTextBody(name, text, ContentType.DEFAULT_TEXT); } public MultipartEntityBuilder addBinaryBody(final String name, final byte[] b, final ContentType contentType, final String filename) { return addPart(name, new ByteArrayBody(b, contentType, filename)); } public MultipartEntityBuilder addBinaryBody(final String name, final byte[] b) { return addBinaryBody(name, b, ContentType.DEFAULT_BINARY, null); } public MultipartEntityBuilder addBinaryBody(final String name, final File file, final ContentType contentType, final String filename) { return addPart(name, new FileBody(file, contentType, filename)); } public MultipartEntityBuilder addBinaryBody(final String name, final File file) { return addBinaryBody(name, file, ContentType.DEFAULT_BINARY, file != null ? file.getName() : null); } public MultipartEntityBuilder addBinaryBody(final String name, final InputStream stream, final ContentType contentType, final String filename) { return addPart(name, new InputStreamBody(stream, contentType, filename)); } public MultipartEntityBuilder addBinaryBody(final String name, final InputStream stream) { return addBinaryBody(name, stream, ContentType.DEFAULT_BINARY, null); } private String generateContentType(final String boundary, final Charset charset) { final StringBuilder buffer = new StringBuilder(); buffer.append("multipart/form-data; boundary="); buffer.append(boundary); if (charset != null) { buffer.append("; charset="); buffer.append(charset.name()); } return buffer.toString(); } private String generateBoundary() { final StringBuilder buffer = new StringBuilder(); final Random rand = new Random(); final int count = rand.nextInt(11) + 30; // a random size from 30 to 40 for (int i = 0; i < count; i++) { buffer.append(MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]); } return buffer.toString(); } MultipartFormEntity buildEntity() { final String st = subType != null ? subType : DEFAULT_SUBTYPE; final Charset cs = charset; final String b = boundary != null ? boundary : generateBoundary(); final List<FormBodyPart> bps = bodyParts != null ? new ArrayList<FormBodyPart>(bodyParts) : Collections.<FormBodyPart>emptyList(); final HttpMultipartMode m = mode != null ? mode : HttpMultipartMode.STRICT; final AbstractMultipartForm form; switch (m) { case BROWSER_COMPATIBLE: form = new HttpBrowserCompatibleMultipart(st, cs, b, bps); break; case RFC6532: form = new HttpRFC6532Multipart(st, cs, b, bps); break; default: form = new HttpStrictMultipart(st, cs, b, bps); } return new MultipartFormEntity(form, generateContentType(b, cs), form.getTotalLength()); } public HttpEntity build() { return buildEntity(); } }