java gets the image file stream from the remote network, compresses it and saves it locally

1. Get the image from the remote network

     /**
 * 根據(jù)地址獲得數(shù)據(jù)的字節(jié)流
 *
 * @param strUrl
 *            網(wǎng)絡(luò)連接地址
 * @return
 */
public static byte[] getImageFromNetByUrl(String strUrl) {
    try {
        URL url = new URL(strUrl);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setConnectTimeout(5 * 1000);
        InputStream inStream = conn.getInputStream();// 通過輸入流獲取圖片數(shù)據(jù)
        byte[] btImg = readInputStream(inStream);// 得到圖片的二進制數(shù)據(jù)
        return btImg;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

 /**
 * 根據(jù)地址獲得數(shù)據(jù)的字節(jié)流
 *
 * @param strUrl
 *            本地連接地址
 * @return
 */
public static byte[] getImageFromLocalByUrl(String strUrl) {
    try {
        File imageFile = new File(strUrl);
        InputStream inStream = new FileInputStream(imageFile);
        byte[] btImg = readInputStream(inStream);// 得到圖片的二進制數(shù)據(jù)
        return btImg;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

   /**
 * 從輸入流中獲取數(shù)據(jù)
 *
 * @param inStream
 *            輸入流
 * @return
 * @throws Exception
 */
public static byte[] readInputStream(InputStream inStream) throws Exception {
    ByteArrayOutputStream outStream = new ByteArrayOutputStream();
    byte[] buffer = new byte[10240];
    int len = 0;
    while ((len = inStream.read(buffer)) != -1) {
        outStream.write(buffer, 0, len);
    }
    inStream.close();
    return outStream.toByteArray();
}　　

2. Convert the file read from the network into a local file

       byte[] btImg1 = ImageUtil.getImageFromNetByUrl(fileUrl1);
if (null != btImg1 && btImg1.length > 0) {
    logger.debug("讀取到：" + btImg1.length + " 字節(jié)");
    ImageUtil.writeImageToDisk(btImg1, fileZipUrl1);
} else {
    logger.debug("沒有從該連接獲得內(nèi)容");
}
 
byte[] btImg2 = ImageUtil.getImageFromNetByUrl(fileUrl2);
if (null != btImg2 && btImg2.length > 0) {
    logger.debug("讀取到：" + btImg2.length + " 字節(jié)");
    ImageUtil.writeImageToDisk(btImg2, fileZipUrl2);
} else {
    logger.debug("沒有從該連接獲得內(nèi)容");
}

/**
 * 將圖片寫入到磁盤
 *
 * @param img
 *            圖片數(shù)據(jù)流
 * @param fileName
 *            文件保存時的名稱
 */
public static void writeImageToDisk(byte[] img, String zipImageUrl) {
    try {
        File file = new File(zipImageUrl);
        FileOutputStream fops = new FileOutputStream(file);
        fops.write(img);
        fops.flush();
        fops.close();
        System.out.println("圖片已經(jīng)寫入"+zipImageUrl);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

3. Compress the local image

import java.io.*; 
import java.util.Date; 
import java.awt.*; 
import java.awt.image.*; 
import javax.imageio.ImageIO; 
import com.sun.image.codec.jpeg.*; 
/**
 * 圖片壓縮處理
 */ 
public class ImgCompress { 
    private Image img; 
    private int width; 
    private int height;  
    /**
     * 構(gòu)造函數(shù)
     */ 
    public ImgCompress(String fileName) throws IOException { 
        File file = new File(fileName);// 讀入文件 
        img = ImageIO.read(file);      // 構(gòu)造Image對象 
        width = img.getWidth(null);    // 得到源圖寬 
        height = img.getHeight(null);  // 得到源圖長 
    } 
    /**
     * 按照寬度還是高度進行壓縮
     * @param w int 最大寬度
     * @param h int 最大高度
     */ 
    public void resizeFix(int w, int h) throws IOException { 
        if (width / height > w / h) { 
            resizeByWidth(w); 
        } else { 
            resizeByHeight(h); 
        } 
    } 
    /**
     * 以寬度為基準，等比例放縮圖片
     * @param w int 新寬度
     */ 
    public void resizeByWidth(int w) throws IOException { 
        int h = (int) (height * w / width); 
        resize(w, h); 
    } 
    /**
     * 以高度為基準，等比例縮放圖片
     * @param h int 新高度
     */ 
    public void resizeByHeight(int h) throws IOException { 
        int w = (int) (width * h / height); 
        resize(w, h); 
    } 
    /**
     * 強制壓縮/放大圖片到固定的大小
     * @param w int 新寬度
     * @param h int 新高度
     */ 
    public void resize(int w, int h) throws IOException { 
        // SCALE_SMOOTH 的縮略算法 生成縮略圖片的平滑度的 優(yōu)先級比速度高 生成的圖片質(zhì)量比較好 但速度慢 
        BufferedImage image = new BufferedImage(w, h,BufferedImage.TYPE_INT_RGB );  
        image.getGraphics().drawImage(img, 0, 0, w, h, null); // 繪制縮小后的圖 
        File destFile = new File("C:/Users/Administrator/Desktop/147.jpg"); 
        FileOutputStream out = new FileOutputStream(destFile); // 輸出到文件流 
        // 可以正常實現(xiàn)bmp、png、gif轉(zhuǎn)jpg 
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); 
        encoder.encode(image); // JPEG編碼 
        out.close(); 
    }

@SuppressWarnings("deprecation") 
public static void main(String[] args) throws Exception { 
    System.out.println("開始：" + new Date().toLocaleString()); 
    ImgCompress imgCom = new  ImgCompress("C:/Users/Administrator/Desktop/1479209533362.jpg"); 
    imgCom.resizeFix(285, 380); 
    System.out.println("結(jié)束：" + new Date().toLocaleString()); 
}

}

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