图片转换工具类-ImageUtils

本是古典何须时尚 2022-05-21 08:00 188阅读 0赞

import java.awt.Image;  
import java.awt.image.BufferedImage;  
import java.awt.image.RenderedImage;  
import java.io.ByteArrayInputStream;  
import java.io.ByteArrayOutputStream;  
import java.io.File;  
import java.io.FileInputStream;  
import java.io.IOException;  
import java.io.InputStream;  
import java.util.Iterator;

import javax.imageio.ImageIO;  
import javax.imageio.ImageReader;  
import javax.imageio.stream.MemoryCacheImageInputStream;

/\*\*  
 \* 图片工具类  
 \*/  
public final class ImageUtils \{

public static void main(String\[\] args) \{  
  zoom("C:\\\\Users\\\\Administrator\\\\Pictures\\\\test.jpg",  
    "C:\\\\Users\\\\Administrator\\\\Pictures\\\\1.jpg", 100, "jpg");  
 \}

public static String zoom(String picFrom, String picTo, int width,  
   String formart) \{  
  formart = JPG;  
  try \{  
   byte\[\] k1 = readFromFile(picFrom);  
   BufferedImage img = getScaleImage(k1, formart.toUpperCase(), width);  
   RenderedImage rendImage = getScaleImage(k1, formart.toUpperCase(),  
     width);  
   // 以下是将图形保存为标准图片格式  
   ImageIO.write(rendImage, formart.toUpperCase(), new File(picTo));  
  \} catch (IOException e) \{

\}  
  return picTo;  
 \}

public static final String PNG = "png";  
 public static final String JPG = "jpg";  
 public static final String BMP = "bmp";  
 public static final String GIF = "gif";

public static byte\[\] readFromFile(String path) throws IOException \{  
  InputStream is = new FileInputStream(new File(path));  
  byte\[\] buf = new byte\[is.available()\];  
  is.read(buf);  
  is.close();  
  return buf;  
 \}

/\*\*  
  \* 构建一个image对象  
  \*   
  \* @param img  
  \* @return  
  \* @throws IOException  
  \*/  
 public static ImageInfo getImageInfo(byte\[\] img) throws IOException \{  
  ByteArrayInputStream bais = new ByteArrayInputStream(img);  
  MemoryCacheImageInputStream is = new MemoryCacheImageInputStream(bais);  
  Iterator<ImageReader> it = ImageIO.getImageReaders(is);  
  ImageReader r = null;  
  while (it.hasNext()) \{  
   r = it.next();  
   break;  
  \}  
  if (r == null) \{  
   return null;  
  \}  
  ImageInfo i = new ImageInfo();  
  i.setType(r.getFormatName().toLowerCase());  
  int index = r.getMinIndex();  
  /\*\*  
   \* 对于ImageReader的线程安全是不确定的  
   \*/  
  synchronized (r) \{  
   r.setInput(is);  
   i.setHeight(r.getHeight(index));  
   i.setWidth(r.getWidth(index));  
  \}  
  return i;  
 \}

public static BufferedImage getImage(byte\[\] img) throws IOException \{  
  ByteArrayInputStream bais = new ByteArrayInputStream(img);  
  BufferedImage src = ImageIO.read(bais);  
  return src;  
 \}

/\*\*  
  \* 等比例缩放  
  \*   
  \* @param img  
  \* @param width  
  \* @return  
  \* @throws IOException  
  \*/  
 public static BufferedImage getScaleImage(byte\[\] img, String type, int width)  
   throws IOException \{  
  ByteArrayInputStream bais = new ByteArrayInputStream(img);  
  BufferedImage src = ImageIO.read(bais);  
  int w = src.getWidth();  
  int h = src.getHeight();  
  int height = (int) (((float) width / w) \* h);  
  Image im = src.getScaledInstance(width, height, Image.SCALE\_SMOOTH);  
  BufferedImage bi = new BufferedImage(width, height, src.getType());  
  bi.getGraphics().drawImage(im, 0, 0, null);  
  return bi;  
 \}

public static byte\[\] getScaleImageBytes(byte\[\] img, String type, int width)  
   throws IOException \{  
  BufferedImage bi = getScaleImage(img, type, width);  
  ByteArrayOutputStream out = new ByteArrayOutputStream();  
  ImageIO.write(bi, type, out);  
  return out.toByteArray();  
 \}

/\*\*  
  \* 获取文件类型,没找到返回null,这方法太高效了,可能不准确, 这个是我看的网上的，有bug不准确  
  \*   
  \* @param byte1  
  \* @return  
  \*/  
 public static String fastParseFileType(byte\[\] byte1) \{  
  if ((byte1\[0\] == 71) && (byte1\[1\] == 73) && (byte1\[2\] == 70)  
    && (byte1\[3\] == 56) && ((byte1\[4\] == 55) || (byte1\[4\] == 57))  
    && (byte1\[5\] == 97)) \{  
   return GIF;  
  \}  
  if ((byte1\[6\] == 74) && (byte1\[7\] == 70) && (byte1\[8\] == 73)  
    && (byte1\[9\] == 70)) \{  
   return JPG;  
  \}  
  if ((byte1\[0\] == 66) && (byte1\[1\] == 77)) \{  
   return BMP;  
  \}  
  if ((byte1\[1\] == 80) && (byte1\[2\] == 78) && (byte1\[3\] == 71)) \{  
   return PNG;  
  \}  
  return null;  
 \}

public static class ImageInfo \{  
  private String type;  
  private int width;  
  private int height;

public String getType() \{  
   return type;  
  \}

public void setType(String type) \{  
   this.type = type;  
  \}

public int getWidth() \{  
   return width;  
  \}

public void setWidth(int width) \{  
   this.width = width;  
  \}

public int getHeight() \{  
   return height;  
  \}

public void setHeight(int height) \{  
   this.height = height;  
  \}  
 \}  
\}