本文实例讲述了JMagick实现基本图像处理的类。分享给大家供大家参考。具体分析如下：

　　JMagick是一个开源API，利用JNI(Java Native Interface)技术实现了对 ImageMagick API的Java访问接口,因此也将比纯Java实现的图片操作函数在速度上要快。

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 /** * JMagickHandler.java * * Author: Winter Lau * 2007-7-11 */ package com.eportal.img; import java.awt.Dimension; import java.io.File; import org.apache.commons.io.FileUtils; import com.gif4j.GifDecoder; import com.gif4j.GifEncoder; import com.gif4j.GifImage; import com.gif4j.GifTransformer; import dlog.common.util.StringUtils; import magick.ImageInfo; import magick.MagickException; import magick.MagickImage; /** * 使用JMagick进行图像处理 */ class JMagickHandler { private final static int DEFAULT_QUALITY = 90; protected JMagickHandler(){} private final static ThreadLocal<MyMagickImage> tLocal = new ThreadLocal<MyMagickImage>(); private String lastSrc = null; /** * 清除线程本地存储信息 */ private synchronized MyMagickImage getMagickImage(String src) throws Exception { MyMagickImage mi = tLocal.get(); if(mi != null && StringUtils.equals(src, lastSrc)) return mi; else if(mi != null) tLocal.remove(); this.lastSrc = src; ImageInfo info = new ImageInfo(src); mi = new MyMagickImage(info); tLocal.set(mi); return mi; } @Override public void cleanup() { MyMagickImage mi = tLocal.get(); if(mi != null) mi.destroyImages(); tLocal.remove(); } @Override public ImageExtInfo getImageInfo(String src) throws Exception { try{ MagickImage image = this.getMagickImage(src); ImageExtInfo ext = new ImageExtInfo(); Dimension dim = image.getDimension(); ext.setWidth((int)dim.getWidth()); ext.setHeight((int)dim.getHeight()); ext.setSize(image.sizeBlob()); ext.setAnimated(image.isAnimatedImage()); return ext; }catch(MagickException e){ return new PureJavaHandler().getImageInfo(src); } } private final static boolean hasUnicode(String str){ return str.getBytes().length != str.length(); } @Override public void resize(String src, String dest, int width, int height, int quality) throws Exception { boolean u_src = hasUnicode(src); MyMagickImage image; File srctmp = null; if(u_src){ srctmp = File.createTempFile("jmagick_s_" + src.hashCode(), null); FileUtils.copyFile(new File(src), srctmp); image = this.getMagickImage(srctmp.getAbsolutePath()); } else image = this.getMagickImage(src); image.getImageInfo().setQuality((quality>0)?quality:DEFAULT_QUALITY); MagickImage scaledimage = null; try{ if(image.isAnimatedImage()){ GifImage gifImage = GifDecoder.decode(new File(src)); GifImage newGif = GifTransformer.resize(gifImage, width, height, false); GifEncoder.encode(newGif, new File(dest)); } else{//others scaledimage = image.scaleImage(width, height); scaledimage.setImageFormat("JPEG"); scaledimage.profileImage("*", null); boolean u_dest = hasUnicode(dest); if(u_dest){ File tmp = File.createTempFile("jmagick_d_" + dest.hashCode(), null); scaledimage.setFileName(tmp.getAbsolutePath()); scaledimage.writeImage(image.getImageInfo()); FileUtils.copyFile(tmp, new File(dest)); FileUtils.forceDelete(tmp); } else{ scaledimage.setFileName(dest); scaledimage.writeImage(image.getImageInfo()); } } }finally{ if(srctmp != null) FileUtils.forceDelete(srctmp); if(scaledimage != null) scaledimage.destroyImages(); } } @Override public void rotate(String src, String dest, double degrees) throws Exception { boolean u_src = hasUnicode(src); MyMagickImage image; File srctmp = null; if(u_src){ srctmp = File.createTempFile("jmagick_s_" + src.hashCode(), null); FileUtils.copyFile(new File(src), srctmp); image = this.getMagickImage(srctmp.getAbsolutePath()); } else image = this.getMagickI