最近遇到自拍上传图片过大问题，很烦恼，所以自己写了一个压缩图片的工具类使用，自测效果很不错，可以压缩到KB以内，像素还可以分辨清晰
下面Java代码奉上：
1 import lombok.extern.slf4j.Slf4j;
2 import org.w3c.dom.Element;
3
4
5 import javax.imageio.IIOImage;
6 import javax.imageio.ImageIO;
7 import javax.imageio.ImageTypeSpecifier;
8 import javax.imageio.ImageWriter;
9 import javax.imageio.metadata.IIOMetadata;
10 import javax.imageio.plugins.jpeg.JPEGImageWriteParam;
11 import javax.imageio.stream.ImageOutputStream;
12 import java.awt.*;
13 import java.awt.image.BufferedImage;
14 import java.io.*;
15 import java.net.HttpURLConnection;
16 import java.net.URL;
17
18
19 /**
20 * @Author: Mr. Chang
21 */
22 @Slf4j
23 public class ImageZipUtils {
24
25 /**
26 * 采用指定宽度、高度或压缩比例 的方式对图片进行压缩
27 *
28 * @param imgsrc 源图片地址
29 * @param imgdist 目标图片地址
30 * @param widthdist 压缩后图片宽度（当rate==null时，必传）
31 * @param heightdist 压缩后图片高度（当rate==null时，必传）
32 * @param rate 压缩比例
33 */
34 public static void reduceImg(String imgsrc, String imgdist, int widthdist,
35 int heightdist, Float rate) {
36 try {
37 File srcfile = new File(imgsrc);
38 // 检查文件是否存在
39 if (!srcfile.exists()) {
40 return;
41 }
42 // 如果rate不为空说明是按比例压缩
43 if (rate != null && rate > 0) {
44 // 获取文件高度和宽度
45 int[] results = getImgWidth(srcfile);
46 if (results == null || results[0] == 0 || results[1] == 0) {
47 return;
48 } else {
49 widthdist = (int) (results[0] * rate);
50 heightdist = (int) (results[1] * rate);
51 }
52 }
53 // 开始读取文件并进行压缩
54 Image src = javax.imageio.ImageIO.read(srcfile);
55 BufferedImage tag = new BufferedImage((int) widthdist,
56 (int) heightdist, BufferedImage.TYPE_INT_RGB);
57
58 tag.getGraphics().drawImage(
59 src.getScaledInstance(widthdist, heightdist,
60 Image.SCALE_SMOOTH), 0, 0, null);
61
62 FileOutputStream out = new FileOutputStream(imgdist);
63 // JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
64 // encoder.encode(tag);
65 // out.close();
66 float per = (float) 0.85;
67 saveAsJPEG(100, tag, per, out);
68
69 } catch (IOException ex) {
70 ex.printStackTrace();
71 }
72 }
73
74 /**
75 * 以JPEG编码保存图片
76 *
77 * @param dpi 分辨率
78 * @param image_to_save 要处理的图像图片
79 * @param JPEGcompression 压缩比
80 * @param fos 文件输出流
81 * @throws IOException
82 */
83 public static void saveAsJPEG(Integer dpi, BufferedImage image_to_save, float JPEGcompression, FileOutputStream fos) throws IOException {
84 // Image writer
85 ImageWriter imageWriter = ImageIO.getImageWritersBySuffix("jpg").next();
86 ImageOutputStream ios = ImageIO.createImageOutputStream(fos);
87 imageWriter.setOutput(ios);
88 //and metadata
89 IIOMetadata imageMetaData = imageWriter.getDefaultImageMetadata(new ImageTypeSpecifier(image_to_save), null);
90
91
92 if (dpi != null && !dpi.equals("")) {
93
94 //new metadata
95 Element tree = (Element) imageMetaData.getAsTree("javax_imageio_jpeg_image_1.0");
96 Element jfif = (Element) tree.getElementsByTagName("app0JFIF").item(0);
97 jfif.setAttribute("Xdensity", Integer.toString(dpi));
98 jfif.setAttribute("Ydensity", Integer.toString(dpi));
99
100 }
101
102
103 if (JPEGcompression >= 0 && JPEGcompression <= 1f) {
104 // new Compression
105 JPEGImageWriteParam jpegParams = (JPEGImageWriteParam) imageWriter.getDefaultWriteParam();
106 jpegParams.setCompressionMode(JPEGImageWriteParam.MODE_EXPLICIT);
107 jpegParams.setCompressionQuality(JPEGcompression);
108
109 }
110
111 //new Write and clean up
112 imageWriter.write(imageMetaData, new IIOImage(image_to_save, null, null), null);
113 ios.close();
114 imageWriter.dispose();
115
116 }
117
118
119 /**
120 * 获取图片宽度
121 *
122 * @param file 图片文件
123 * @return 宽度
124 */
125 public static int[] getImgWidth(File file) {
126 InputStream is = null;
127 BufferedImage src = null;
128 int result[] = {0, 0};
129 try {
130 is = new FileInputStream(file);
131 src = javax.imageio.ImageIO.read(is);
132 result[0] = src.getWidth(null); // 得到源图宽
133 result[1] = src.getHeight(null); // 得到源图高
134 is.close();
135 } catch (Exception e) {
136 e.printStackTrace();
137 }
138 return result;
139 }
140
141 public static byte[] readInputStream(InputStream inStream) throws Exception {
142 ByteArrayOutputStream outStream = new ByteArrayOutputStream();
143 //创建一个Buffer字符串
144 byte[] buffer = new byte[1024];
145 //每次读取的字符串长度，如果为-1，代表全部读取完毕
146 int len = 0;
147 //使用一个输入流从buffer里把数据读取出来
148 while ((len = inStream.read(buffer)) != -1) {
149 //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
150 outStream.write(buffer, 0, len);
151 }
152 //关闭输入流
153 inStream.close();
154 //把outStream里的数据写入内存
155 return outStream.toByteArray();
156 }
157
158 /**
159 * 保存自拍照片
160 * @param userId
161 * @param photo_url
162 * @param suffixFromUrl
163 * @param path
164 * @throws Exception
165 */
166 public static void saveZipImage(Integer userId, String photo_url, String suffixFromUrl, String path) throws Exception {
167
168 //new一个URL对象
169 URL url = new URL(photo_url);
170 //打开链接
171 HttpURLConnection conn = (HttpURLConnection) url.openConnection();
172 //设置请求方式为"GET"
173 conn.setRequestMethod("GET");
174 //超时响应时间为5秒
175 conn.setConnectTimeout(5 * 1000);
176 //通过输入流获取图片数据
177 InputStream inStream = conn.getInputStream();
178 //得到图片的二进制数据，以二进制封装得到数据，具有通用性
179 byte[] data = readInputStream(inStream);
180 //new一个文件对象用来保存图片，默认保存当前工程根目录
181 File imageFile = new File(path + userId + suffixFromUrl);
182 //创建输出流
183 FileOutputStream outStream = new FileOutputStream(imageFile);
184 //写入数据
185 outStream.write(data);
186 //关闭输出流
187 outStream.close();
188
189 }
190
191 /**
192 * 开始压缩图片
193 * @param userId
194 * @param suffix
195 * @param path
196 * @return
197 */
198 public static String imageZipStart(Integer userId, String suffix, String path) {
199 /**
200 * d://3.jpg 源图片
201 * d://31.jpg 目标图片
202 * 压缩宽度和高度都是1000
203 *
204 */
205 String original = path + userId + suffix;
206 String target = path + userId + "target" + suffix;
207 File srcfile = new File(original);
208 log.info(userId + "用户自拍照压缩前自拍照大小:" + srcfile.length());
209 reduceImg(original, target, 888, 888, null);
210 File distfile = new File(target);
211 log.info("用户自拍照压缩后自拍照大小:" + distfile.length());
212 return target;
213 }
214
215 /**
216 * 删除文件
217 */
218 public static void delFile(String fileName) {
219 File deFile = new File(fileName);
220 if (deFile.exists()) {
221 deFile.delete();
222 }
223 }
224
225 }
如有更正，欢迎下方评论联系我，谢谢
原文地址：https://www.cnblogs.com/mzy520/p/11934565.html
时间： 2024-10-20 18:21:02