com.ajah.http.Http.java Source code

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Here is the source code for com.ajah.http.Http.java

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/*
 *  Copyright 2012 Eric F. Savage, code@efsavage.com
 *
 *   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 com.ajah.http;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.logging.Level;

import lombok.extern.java.Log;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

import com.ajah.http.err.BadRequestException;
import com.ajah.http.err.HttpException;
import com.ajah.http.err.NotFoundException;
import com.ajah.http.err.UnexpectedResponseCode;

/**
 * Offers a simple interface to HTTP client operations with sensible default
 * behaviors.
 * 
 * @author <a href="http://efsavage.com">Eric F. Savage</a>, <a
 *         href="mailto:code@efsavage.com">code@efsavage.com</a>.
 * 
 */
@Log
public class Http {

    private static String get(final String url) throws IOException, HttpException {
        URI uri;
        try {
            uri = URI.create(url);
        } catch (final IllegalArgumentException e) {
            log.warning("Illegal URI [" + url + "] - " + e.getMessage());
            throw new BadRequestException(e);
        }
        return get(uri);
    }

    /**
     * Fetch a URI and return it's response as a String.
     * 
     * @param uri
     *            The URI to fetch.
     * @return The response body as a String.
     * @throws IOException
     *             If the response could not be completed.
     * @throws UnexpectedResponseCode
     *             If an unexpected/illegal response status is issued.
     * @throws NotFoundException
     *             If the resource could not be found at the URI (404).
     */
    public static String get(final URI uri) throws IOException, UnexpectedResponseCode, NotFoundException {
        return EntityUtils.toString(internalGet(uri));
    }

    /**
     * Return the body of the response as a byte array (such as an image).
     * 
     * @see #getBytes(URI)
     * @param uri
     *            The URI to fetch.
     * @return The response body as a String.
     * @throws IOException
     *             If the response could not be completed.
     * @throws UnexpectedResponseCode
     *             If an unexpected/illegal response status is issued.
     * @throws NotFoundException
     *             If the resource could not be found at the URI (404).
     * @throws URISyntaxException
     */
    public static byte[] getBytes(final String uri)
            throws IOException, NotFoundException, UnexpectedResponseCode, URISyntaxException {
        return EntityUtils.toByteArray(internalGet(new URI(uri)));
    }

    /**
     * Return the body of the response as a byte array (such as an image).
     * 
     * @param uri
     *            The URI to fetch.
     * @return The response body as a String.
     * @throws IOException
     *             If the response could not be completed.
     * @throws UnexpectedResponseCode
     *             If an unexpected/illegal response status is issued.
     * @throws NotFoundException
     *             If the resource could not be found at the URI (404).
     */
    public static byte[] getBytes(final URI uri) throws IOException, NotFoundException, UnexpectedResponseCode {
        return EntityUtils.toByteArray(internalGet(uri));
    }

    /**
     * Calls {@link #get(URI)} but returns null instead of throwing exceptions.
     * 
     * @param uri
     *            The URL to fetch.
     * @return The response as a String, or null.
     */
    public static String getSafe(final String uri) {
        try {
            return get(uri);
        } catch (final IOException e) {
            log.log(Level.WARNING, e.getMessage(), e);
            return null;
        } catch (final HttpException e) {
            log.log(Level.WARNING, e.getMessage(), e);
            return null;
        }
    }

    private static HttpEntity internalGet(final URI uri)
            throws IOException, ClientProtocolException, NotFoundException, UnexpectedResponseCode {
        final HttpClient httpclient = new DefaultHttpClient();
        final HttpGet httpget = new HttpGet(uri);
        final HttpResponse response = httpclient.execute(httpget);
        if (response.getStatusLine().getStatusCode() == 200) {
            final HttpEntity entity = response.getEntity();
            return entity;
        } else if (response.getStatusLine().getStatusCode() == 404) {
            throw new NotFoundException(
                    response.getStatusLine().getStatusCode() + " - " + response.getStatusLine().getReasonPhrase());
        } else {
            throw new UnexpectedResponseCode(
                    response.getStatusLine().getStatusCode() + " - " + response.getStatusLine().getReasonPhrase());
        }
    }

}