Java tutorial
/* * ==================================================================== * 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.seo.support.http; import java.io.IOException; import java.io.InputStream; import org.apache.http.HeaderElement; import org.apache.http.HttpEntity; import org.apache.http.NameValuePair; import org.apache.http.ParseException; import org.apache.http.util.ByteArrayBuffer; /** * Static helpers for dealing with {@link HttpEntity}s. * * @since 4.0 */ public final class EntityUtils { private EntityUtils() { } /** * Ensures that the entity content is fully consumed and the content stream, if exists, * is closed. The process is done, <i>quietly</i> , without throwing any IOException. * * @param entity * * * @since 4.2 */ public static void consumeQuietly(final HttpEntity entity) { try { consume(entity); } catch (IOException ioex) { } } /** * Ensures that the entity content is fully consumed and the content stream, if exists, * is closed. * * @param entity * @throws IOException if an error occurs reading the input stream * * @since 4.1 */ public static void consume(final HttpEntity entity) throws IOException { if (entity == null) { return; } if (entity.isStreaming()) { InputStream instream = entity.getContent(); if (instream != null) { instream.close(); } } } /** * Read the contents of an entity and return it as a byte array. * * @param entity * @return byte array containing the entity content. May be null if * {@link HttpEntity#getContent()} is null. * @throws IOException if an error occurs reading the input stream * @throws IllegalArgumentException if entity is null or if content length > Integer.MAX_VALUE */ public static byte[] toByteArray(final HttpEntity entity) throws IOException { if (entity == null) { throw new IllegalArgumentException("HTTP entity may not be null"); } InputStream instream = entity.getContent(); if (instream == null) { return null; } try { if (entity.getContentLength() > Integer.MAX_VALUE) { throw new IllegalArgumentException("HTTP entity too large to be buffered in memory"); } int i = (int) entity.getContentLength(); if (i < 0) { i = 4096; } ByteArrayBuffer buffer = new ByteArrayBuffer(i); byte[] tmp = new byte[4096]; int l; while ((l = instream.read(tmp)) != -1) { buffer.append(tmp, 0, l); } return buffer.toByteArray(); } finally { instream.close(); } } /** * Obtains character set of the entity, if known. * * @param entity must not be null * @return the character set, or null if not found * @throws ParseException if header elements cannot be parsed * @throws IllegalArgumentException if entity is null * * @deprecated (4.1.3) use {@link ContentType#getOrDefault(HttpEntity)} */ @Deprecated public static String getContentCharSet(final HttpEntity entity) throws ParseException { if (entity == null) { throw new IllegalArgumentException("HTTP entity may not be null"); } String charset = null; if (entity.getContentType() != null) { HeaderElement values[] = entity.getContentType().getElements(); if (values.length > 0) { NameValuePair param = values[0].getParameterByName("charset"); if (param != null) { charset = param.getValue(); } } } return charset; } /** * Obtains mime type of the entity, if known. * * @param entity must not be null * @return the character set, or null if not found * @throws ParseException if header elements cannot be parsed * @throws IllegalArgumentException if entity is null * * @since 4.1 * * @deprecated (4.1.3) use {@link ContentType#getOrDefault(HttpEntity)} */ @Deprecated public static String getContentMimeType(final HttpEntity entity) throws ParseException { if (entity == null) { throw new IllegalArgumentException("HTTP entity may not be null"); } String mimeType = null; if (entity.getContentType() != null) { HeaderElement values[] = entity.getContentType().getElements(); if (values.length > 0) { mimeType = values[0].getName(); } } return mimeType; } /** * Get the entity content as a String, using the provided default character set * if none is found in the entity. * If defaultCharset is null, the default "ISO-8859-1" is used. * * @param entity must not be null * @param defaultCharset character set to be applied if none found in the entity * @return the entity content as a String. May be null if * {@link HttpEntity#getContent()} is null. * @throws ParseException if header elements cannot be parsed * @throws IllegalArgumentException if entity is null or if content length > Integer.MAX_VALUE * @throws IOException if an error occurs reading the input stream */ // public static String toString( // final HttpEntity entity, final Charset defaultCharset) throws IOException, ParseException { // if (entity == null) { // throw new IllegalArgumentException("HTTP entity may not be null"); // } // InputStream instream = entity.getContent(); // if (instream == null) { // return null; // } // try { // if (entity.getContentLength() > Integer.MAX_VALUE) { // throw new IllegalArgumentException("HTTP entity too large to be buffered in memory"); // } // int i = (int)entity.getContentLength(); // if (i < 0) { // i = 4096; // } // Charset charset = null; // try { // ContentType contentType = ContentType.getOrDefault(entity); // charset = contentType.getCharset(); // } catch (UnsupportedCharsetException ex) { // throw new UnsupportedEncodingException(ex.getMessage()); // } // if (charset == null) { // charset = defaultCharset; // } // if (charset == null) { // charset = HTTP.DEF_CONTENT_CHARSET; // } // Reader reader = new InputStreamReader(instream, charset); // CharArrayBuffer buffer = new CharArrayBuffer(i); // char[] tmp = new char[1024]; // int l; // while((l = reader.read(tmp)) != -1) { // buffer.append(tmp, 0, l); // } // return buffer.toString(); // } finally { // instream.close(); // } // } /** * Get the entity content as a String, using the provided default character set * if none is found in the entity. * If defaultCharset is null, the default "ISO-8859-1" is used. * * @param entity must not be null * @param defaultCharset character set to be applied if none found in the entity * @return the entity content as a String. May be null if * {@link HttpEntity#getContent()} is null. * @throws ParseException if header elements cannot be parsed * @throws IllegalArgumentException if entity is null or if content length > Integer.MAX_VALUE * @throws IOException if an error occurs reading the input stream */ // public static String toString( // final HttpEntity entity, final String defaultCharset) throws IOException, ParseException { // return toString(entity, Charset.forName(defaultCharset)); // } /** * Read the contents of an entity and return it as a String. * The content is converted using the character set from the entity (if any), * failing that, "ISO-8859-1" is used. * * @param entity * @return String containing the content. * @throws ParseException if header elements cannot be parsed * @throws IllegalArgumentException if entity is null or if content length > Integer.MAX_VALUE * @throws IOException if an error occurs reading the input stream */ // public static String toString(final HttpEntity entity) // throws IOException, ParseException { // return toString(entity, (Charset)null); // } }