com.feilong.taglib.display.barcode.BarcodeServlet.java Source code

Introduction

Here is the source code for com.feilong.taglib.display.barcode.BarcodeServlet.java

Source

/*
 * Copyright (C) 2008 feilong
 *
 * 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.feilong.taglib.display.barcode;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.feilong.accessor.KeyAccessor;
import com.feilong.accessor.session.SessionKeyAccessor;
import com.feilong.core.UncheckedIOException;
import com.feilong.tools.barcode.BarcodeEncodeUtil;
import com.feilong.tools.jsonlib.JsonUtil;
import com.feilong.tools.slf4j.Slf4jUtil;

/**
 * ??servlet.
 * 
 * <h3>:</h3>
 * 
 * <blockquote>
 * <p>
 * ??<a href="https://github.com/venusdrogon/feilong-taglib/wiki/feilongDisplay-barcode">feilongDisplay-barcode wiki</a>
 * </p>
 * </blockquote>
 * 
 * <h3>??:</h3>
 * 
 * <blockquote>
 * 
 * <pre class="code">
{@code
<!-- barcode -->
<servlet>
    <servlet-name>feilong-barcode</servlet-name>
    <servlet-class>com.feilong.taglib.display.barcode.BarcodeServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>feilong-barcode</servlet-name>
    <url-pattern>/feilongbarcode</url-pattern>
</servlet-mapping>
}
 * </pre>
 * 
 * </blockquote>
 * 
 * <h3>?:</h3>
 * 
 * <blockquote>
 * <p>
 * ??,?  {@link BarcodeTag} ??
 * </p>
 * </blockquote>
 *
 * @author <a href="http://feitianbenyue.iteye.com/">feilong</a>
 * @see <a href="https://github.com/venusdrogon/feilong-taglib/wiki/feilongDisplay-barcode">feilongDisplay-barcode wiki</a>
 * @since 1.5.4
 */
public class BarcodeServlet extends HttpServlet {

    /** The Constant log. */
    private static final Logger LOGGER = LoggerFactory.getLogger(BarcodeServlet.class);

    /** The Constant serialVersionUID. */
    private static final long serialVersionUID = 231074760785325078L;

    /*
     * (non-Javadoc)
     * 
     * @see javax.servlet.http.HttpServlet#service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
     */
    @Override
    public void service(ServletRequest request, ServletResponse response) throws ServletException {
        // ? ? ? barcodeId
        String barcodeId = request.getParameter(BarcodeRequestParams.BARCODE_ID);
        Validate.notEmpty(barcodeId, "barcodeId can't be null/empty!");

        //  barcodeId ?session?? BarcodeContentsAndConfig
        KeyAccessor keyAccessor = new SessionKeyAccessor();

        BarcodeContentsAndConfig barcodeContentsAndConfig = keyAccessor.get(barcodeId,
                (HttpServletRequest) request);
        Validate.notNull(barcodeContentsAndConfig, "barcodeContentsAndConfig can't be null!");

        // render
        render(barcodeContentsAndConfig, response);
    }

    /**
     * Encode.
     *
     * @param barcodeContentsAndConfig
     *            the barcode contents and config
     * @param response
     *            the response
     */
    private static void render(BarcodeContentsAndConfig barcodeContentsAndConfig, ServletResponse response) {
        try {
            ServletOutputStream outputStream = response.getOutputStream();
            BarcodeEncodeUtil.encode(barcodeContentsAndConfig.getContents(), outputStream,
                    barcodeContentsAndConfig.getBarcodeConfig());
        } catch (IOException e) {
            String message = Slf4jUtil.format("barcodeContentsAndConfig:{}",
                    JsonUtil.format(barcodeContentsAndConfig));
            LOGGER.error(message, e);
            throw new UncheckedIOException(message, e);
        }
    }
}