java压缩图片 生成缩略图_JAVA_编程开发_程序员俱乐部

class="title content-title">java压缩图片 生成缩略图

package?com.util;

import?java.awt.Image;
import?java.awt.image.BufferedImage;
import?java.io.File;
import?java.io.FileNotFoundException;
import?java.io.FileOutputStream;
import?java.io.IOException;

import?javax.imageio.ImageIO;

import?com.sun.image.codec.jpeg.JPEGCodec;
import?com.sun.image.codec.jpeg.JPEGEncodeParam;
import?com.sun.image.codec.jpeg.JPEGImageEncoder;

/**
*?压缩图片?创建图片缩略图
*?
*?@author?slzs
*/
public?class?PicCompression?{

/**
*?压缩图片方法
*?
*?@param?oldFile?将要压缩的图片
*?@param?width?压缩宽
*?@param?height?压缩高
*?@param?quality?压缩清晰度?<b>建议为1.0</b>
*?@param?smallIcon?压缩图片后,添加的扩展名（在图片后缀名前添加）
*?@param?percentage?是否等比压缩?若true宽高比率将将自动调整
*?@author?slzs
*?@return?如果处理正确返回压缩后的文件名?null则参数可能有误
*/
public?static?String?doCompress(String?oldFile,?int?width,?int?height,?float?quality,?String?smallIcon,?boolean?percentage)?{
???if?(oldFile?!=?null?&&?width?>?0?&&?height?>?0)?{
?????Image?srcFile=null;
????String?newImage?=?null;
????try?{
?????File?file?=?new?File(oldFile);
?????//?文件不存在
?????if?(!file.exists())?{
??????return?null;
?????}
?????/*读取图片信息*/
?????srcFile?=?ImageIO.read(file);
?????int?new_w?=?width;
?????int?new_h?=?height;
?????if?(percentage)?{
??????//?为等比缩放计算输出的图片宽度及高度
??????double?rate1?=?((double)?srcFile.getWidth(null))?/?(double)?width?+?0.1;
??????double?rate2?=?((double)?srcFile.getHeight(null))?/?(double)?height?+?0.1;
??????double?rate?=?rate1?>?rate2???rate1?:?rate2;
??????new_w?=?(int)?(((double)?srcFile.getWidth(null))?/?rate);
??????new_h?=?(int)?(((double)?srcFile.getHeight(null))?/?rate);
?????}
?????/*?宽高设定*/
?????BufferedImage?tag?=?new?BufferedImage(new_w,?new_h,?BufferedImage.TYPE_INT_RGB);
?????tag.getGraphics().drawImage(srcFile,?0,?0,?new_w,?new_h,?null);

?????/*压缩后的文件名?*/
?????String?filePrex?=?oldFile.substring(0,?oldFile.lastIndexOf('.'));
?????newImage?=?filePrex?+?smallIcon?+?oldFile.substring(filePrex.length());

?????/*压缩之后临时存放位置*/
?????FileOutputStream?out?=?new?FileOutputStream(newImage);

?????JPEGImageEncoder?encoder?=?JPEGCodec.createJPEGEncoder(out);
?????JPEGEncodeParam?jep?=?JPEGCodec.getDefaultJPEGEncodeParam(tag);

?????/*?压缩质量?*/
?????jep.setQuality(quality,?true);
?????encoder.encode(tag,?jep);

?????out.close();

????}?catch?(FileNotFoundException?e)?{
?????e.printStackTrace();
????}?catch?(IOException?e)?{
?????e.printStackTrace();
????}finally{
?????srcFile.flush();
????}
????return?newImage;
???}?else?{
????return?null;
???}
}

//测试
public?static?void?main(String?str[])?{
???System.out.println(PicCompression.doCompress("F:/big.jpg",?500,?500,?1,?"_small",?false));
???System.out.print("ok...");
}

//?效果图也列出来比较

}