java ImageIO.read（）中的内存泄漏

Question

我正在使用ImageIO.read（）。由原始App的main方法调用的类是：

import java.awt.*;
import javax.swing.*;
import java.io.File;
import java.awt.image.BufferedImage;
import java.awt.event.*;
import javax.swing.JPanel;

class ImageGenerator extends JPanel{

JpegReader jpeg;

public ImageGenerator(Aplicacion a){
    jpeg = new JpegReader();
    loadImage();

}


private void loadImage(){
    String path = "C:\\image.jpg";
    image = new BufferedImage(100,100, BufferedImage.TYPE_INT_RGB); //in case error
    try{
        image = jpeg.readImage(new File(path));
    }catch(Exception e){
        System.err.println(e.getMessage());
    }
}
public void paint(Graphics g){

    Graphics2D g2 = (Graphics2D) g;
    g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
            RenderingHints.VALUE_INTERPOLATION_BICUBIC);
    g2.drawImage(image, 0, 0, 1000, 800, null);
}

}

我正在使用上面的其他类JpegReader，我实际上在StackOverflow上找到了答案，但是我忘了引用他的作者的名字。

import java.awt.image.BufferedImage;
import javax.imageio.*;
import javax.imageio.stream.ImageInputStream;
import java.awt.color.*;
import java.awt.image.*;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.ArrayList;
import org.apache.sanselan.Sanselan;
import org.apache.sanselan.common.byteSources.ByteSource;
import org.apache.sanselan.common.byteSources.ByteSourceFile;
import org.apache.sanselan.ImageReadException;
import org.apache.sanselan.formats.jpeg.JpegImageParser;
import org.apache.sanselan.formats.jpeg.segments.UnknownSegment;
public class JpegReader {

public static final int COLOR_TYPE_RGB = 1;
public static final int COLOR_TYPE_CMYK = 2;
public static final int COLOR_TYPE_YCCK = 3;

private int colorType = COLOR_TYPE_RGB;
private boolean hasAdobeMarker = false;

public BufferedImage readImage(File file) throws IOException, ImageReadException {
    colorType = COLOR_TYPE_RGB;
    hasAdobeMarker = false;

    ImageInputStream stream = ImageIO.createImageInputStream(file);
    Iterator<ImageReader> iter = ImageIO.getImageReaders(stream);
    while (iter.hasNext()) {
        ImageReader reader = iter.next();
        reader.setInput(stream);

        BufferedImage image;
        ICC_Profile profile = null;
        try {
            image = reader.read(0);
        } catch (IIOException e) {
            System.out.println("Hello");
            colorType = COLOR_TYPE_CMYK;
            checkAdobeMarker(file);
            profile = Sanselan.getICCProfile(file);

            WritableRaster raster = (WritableRaster) reader.readRaster(0, null);
            if (colorType == COLOR_TYPE_YCCK)
                convertYcckToCmyk(raster);
            if (hasAdobeMarker)
                convertInvertedColors(raster);
            image = convertCmykToRgb(raster, profile);
            System.out.println("Hello");
        }finally {
            try {
                System.out.println("facebook");
                stream.close();
            } catch (IOException ioex) {
                //omitted.
            }
        }

        return image;
    }

    return null;
}

public void checkAdobeMarker(File file) throws IOException, ImageReadException {
    JpegImageParser parser = new JpegImageParser();
    ByteSource byteSource = new ByteSourceFile(file);
    @SuppressWarnings("rawtypes")
    ArrayList segments = parser.readSegments(byteSource, new int[] { 0xffee }, true);
    if (segments != null && segments.size() >= 1) {
        UnknownSegment app14Segment = (UnknownSegment) segments.get(0);
        byte[] data = app14Segment.bytes;
        if (data.length >= 12 && data[0] == 'A' && data[1] == 'd' && data[2] == 'o' && data[3] == 'b' && data[4] == 'e')
        {
            hasAdobeMarker = true;
            int transform = app14Segment.bytes[11] & 0xff;
            if (transform == 2)
                colorType = COLOR_TYPE_YCCK;
        }
    }
}

public static void convertYcckToCmyk(WritableRaster raster) {
    int height = raster.getHeight();
    int width = raster.getWidth();
    int stride = width * 4;
    int[] pixelRow = new int[stride];
    for (int h = 0; h < height; h++) {
        raster.getPixels(0, h, width, 1, pixelRow);

        for (int x = 0; x < stride; x += 4) {
            int y = pixelRow[x];
            int cb = pixelRow[x + 1];
            int cr = pixelRow[x + 2];

            int c = (int) (y + 1.402 * cr - 178.956);
            int m = (int) (y - 0.34414 * cb - 0.71414 * cr + 135.95984);
            y = (int) (y + 1.772 * cb - 226.316);

            if (c < 0) c = 0; else if (c > 255) c = 255;
            if (m < 0) m = 0; else if (m > 255) m = 255;
            if (y < 0) y = 0; else if (y > 255) y = 255;

            pixelRow[x] = 255 - c;
            pixelRow[x + 1] = 255 - m;
            pixelRow[x + 2] = 255 - y;
        }

        raster.setPixels(0, h, width, 1, pixelRow);
    }
}

public static void convertInvertedColors(WritableRaster raster) {
    int height = raster.getHeight();
    int width = raster.getWidth();
    int stride = width * 4;
    int[] pixelRow = new int[stride];
    for (int h = 0; h < height; h++) {
        raster.getPixels(0, h, width, 1, pixelRow);
        for (int x = 0; x < stride; x++)
            pixelRow[x] = 255 - pixelRow[x];
        raster.setPixels(0, h, width, 1, pixelRow);
    }
}

public static BufferedImage convertCmykToRgb(Raster cmykRaster, ICC_Profile cmykProfile) throws IOException {
    if (cmykProfile == null)
        cmykProfile = ICC_Profile.getInstance(JpegReader.class.getResourceAsStream("/ISOcoated_v2_300_eci.icc"));

    if (cmykProfile.getProfileClass() != ICC_Profile.CLASS_DISPLAY) {
        byte[] profileData = cmykProfile.getData();

        if (profileData[ICC_Profile.icHdrRenderingIntent] == ICC_Profile.icPerceptual) {
            intToBigEndian(ICC_Profile.icSigDisplayClass, profileData, ICC_Profile.icHdrDeviceClass); // Header is first

            cmykProfile = ICC_Profile.getInstance(profileData);
        }
    }

    ICC_ColorSpace cmykCS = new ICC_ColorSpace(cmykProfile);
    BufferedImage rgbImage = new BufferedImage(cmykRaster.getWidth(), cmykRaster.getHeight(), BufferedImage.TYPE_INT_RGB);
    WritableRaster rgbRaster = rgbImage.getRaster();
    ColorSpace rgbCS = rgbImage.getColorModel().getColorSpace();
    ColorConvertOp cmykToRgb = new ColorConvertOp(cmykCS, rgbCS, null);
    cmykToRgb.filter(cmykRaster, rgbRaster);
    return rgbImage;
}
static void intToBigEndian(int value, byte[] array, int index) {
    array[index]   = (byte) (value >> 24);
    array[index+1] = (byte) (value >> 16);
    array[index+2] = (byte) (value >>  8);
    array[index+3] = (byte) (value);
}
}

我正在使用sanselan-0.97-incubator.jar。

如果我大约运行这个程序31次，我会得到一个java堆空间错误，所以我怀疑我有内存泄漏。

请帮我查找内存泄漏或建议如何解决问题。

另请告诉我，我正在使用的jar文件是OKAY，还是已经过时了。我在查找sanselan jar文件时遇到了一些问题。

提前致谢。

Answer 1

此代码（JPEGReader）存在相同的内存问题。经过几次试验，我发现调用reader.dispose（）可以解决这个问题。

我给出了我修改过的方法。希望它对你有所帮助。

public BufferedImage readImage(File file) throws IOException, ImageReadException {
    colorType = COLOR_TYPE_RGB;
    hasAdobeMarker = false;

    ImageInputStream stream = ImageIO.createImageInputStream(file);
    try{
        Iterator<ImageReader> iter = ImageIO.getImageReaders(stream);
        while (iter.hasNext()) {
            ImageReader reader = iter.next();
            reader.setInput(stream);

            BufferedImage image;
            ICC_Profile profile = null;
            try {
                image = reader.read(0);
            } catch (IIOException e) {
                colorType = COLOR_TYPE_CMYK;
                checkAdobeMarker(file);
                profile = Sanselan.getICCProfile(file);
                WritableRaster raster = (WritableRaster) reader.readRaster(0, null);
                if (colorType == COLOR_TYPE_YCCK)
                    convertYcckToCmyk(raster);
                if (hasAdobeMarker)
                    convertInvertedColors(raster);
                image = convertCmykToRgb(raster, profile);
                return image;
            }
            finally {
                reader.dispose();
            }
        }
        return null;
    }
    finally {
        if (stream != null){
            stream.close();
        }
    }
}