/*
 * Copyright 2011 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.gradle.api.internal.artifacts.repositories.transport.http;

import org.apache.http.Header;
import org.apache.http.HttpResponse;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;

class HttpResponseResource extends AbstractHttpResource {
    private static final Logger LOGGER = LoggerFactory.getLogger(HttpResponseResource.class);

    private final String method;
    private final String source;
    private final HttpResponse response;

    public HttpResponseResource(String method, String source, HttpResponse response) {
        this.method = method;
        this.source = source;
        this.response = response;
    }

    public String getName() {
        return source;
    }

    @Override
    public String toString() {
        return String.format("Http %s Resource: %s", method, source);
    }

    public long getLastModified() {
        Header responseHeader = response.getFirstHeader("last-modified");
        if (responseHeader == null) {
            return 0;
        }
        try {
            return Date.parse(responseHeader.getValue());
        } catch (Exception e) {
            return 0;
        }
    }

    public long getContentLength() {
        return response.getEntity().getContentLength();
    }

    public boolean exists() {
        return true;
    }

    public boolean isLocal() {
        return false;
    }

    public InputStream openStream() throws IOException {
        LOGGER.debug("Attempting to download resource {}.", source);
        return response.getEntity().getContent();
    }

    @Override
    public void close() throws IOException {
        EntityUtils.consume(response.getEntity());
    }

}

/*
 * Copyright 2011 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.gradle.api.internal.artifacts.repositories.transport.http;

import org.apache.http.Header;
import org.apache.http.HttpResponse;
import org.apache.http.impl.cookie.DateUtils;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;

class HttpResponseResource extends AbstractHttpResource {
    private static final Logger LOGGER = LoggerFactory.getLogger(HttpResponseResource.class);

    private final String method;
    private final String source;
    private final HttpResponse response;

    public HttpResponseResource(String method, String source, HttpResponse response) {
        this.method = method;
        this.source = source;
        this.response = response;
    }

    public String getName() {
        return source;
    }

    @Override
    public String toString() {
        return String.format("Http %s Resource: %s", method, source);
    }

    public long getLastModified() {
        Header responseHeader = response.getFirstHeader("last-modified");
        if (responseHeader == null) {
            return 0;
        }
        try {
            return DateUtils.parseDate(responseHeader.getValue()).getTime();
        } catch (Exception e) {
            return 0;
        }
    }

    public long getContentLength() {
        return response.getEntity().getContentLength();
    }

    public boolean exists() {
        return true;
    }

    public boolean isLocal() {
        return false;
    }

    public InputStream openStream() throws IOException {
        LOGGER.debug("Attempting to download resource {}.", source);
        return response.getEntity().getContent();
    }

    @Override
    public void close() throws IOException {
        EntityUtils.consume(response.getEntity());
    }

}

Use org.apache.http.impl.cookie.DateUtils to parse last-modified headers.