com.nominanuda.web.mvc.URLStreamer.java Source code

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Here is the source code for com.nominanuda.web.mvc.URLStreamer.java

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/*
 * Copyright 2008-2011 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 com.nominanuda.web.mvc;

import static org.apache.http.HttpStatus.SC_OK;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.entity.InputStreamEntity;
import org.apache.http.message.BasicHttpResponse;

import com.nominanuda.io.IOHelper;
import com.nominanuda.web.http.HttpCoreHelper;
import com.nominanuda.web.http.HttpProtocol;
import com.nominanuda.web.http.MimeHelper;

public abstract class URLStreamer implements WebService, HttpProtocol {
    private static final HttpCoreHelper httpCoreHelper = new HttpCoreHelper();
    private static final IOHelper ioHelper = new IOHelper();
    private static final MimeHelper mimeHelper = new MimeHelper();
    private String defaultContentType = CT_APPLICATION_OCTET_STREAM;

    public HttpResponse handle(HttpRequest request) throws IOException {
        URL url = getURL(request);
        URLConnection conn = url.openConnection();
        conn.connect();
        int len = conn.getContentLength();
        InputStream is = conn.getInputStream();
        String ce = conn.getContentEncoding();
        String ct = determineContentType(url, conn);
        if (len < 0) {
            byte[] content = ioHelper.readAndClose(is);
            is = new ByteArrayInputStream(content);
            len = content.length;
        }
        StatusLine statusline = httpCoreHelper.statusLine(SC_OK);
        HttpResponse resp = new BasicHttpResponse(statusline);
        resp.setEntity(new InputStreamEntity(is, len));
        httpCoreHelper.setContentType(resp, ct);
        httpCoreHelper.setContentLength(resp, len);//TODO not needed ??
        if (ce != null) {
            httpCoreHelper.setContentEncoding(resp, ce);
        }
        return resp;
    }

    private String determineContentType(URL url, URLConnection conn) {
        String ct = conn.getContentType();
        if (ct == null || "content/unknown".equals(ct)) {
            ct = mimeHelper.guessContentTypeFromPath(url.toString());
            //TODO add default charset if contenttype is textual
        }
        if (ct == null) {
            ct = defaultContentType;
        }
        return ct;
    }

    protected abstract URL getURL(HttpRequest request) throws IllegalArgumentException;

    public void setDefaultContentType(String defaultContentType) {
        this.defaultContentType = defaultContentType;
    }

}