图片上传的处理工具类

package com.tools;
//图片上传处理
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

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

public class CompressPic {
    public static String darwSmallImg(String url,int compressType, String fname, int new_w1,
            int new_h1, int new_w2, int new_h2) {
        String path = url + "\\" + fname;
        java.io.File file = new java.io.File(path); // 读入刚才上传的文件
        // 新的缩略图保存地址
        String newfname = "\\s" + fname;
        String newpath = url + newfname;
        
        int old_w=0,old_h=0;
        
        int width = 100;
        int height = 100;

        try {
            Image src = javax.imageio.ImageIO.read(file);
            old_w= src.getWidth(null); // 得到源图宽
            old_h = src.getHeight(null); // 得到源图高
            

            if ((old_w < new_w1 && old_h < new_h1) || (old_w < new_w2 && old_h < new_h2)) {
                // 这是不用压缩的情况
                FileInputStream input = new FileInputStream(path);
                FileOutputStream output = new FileOutputStream(newpath);

                int in = input.read();
                while (in != -1) {
                    output.write(in);
                    in = input.read();
                }
                input.close();output.close();

            } else {
                if(compressType==1){//135*90--90*135
                    if ((float) (old_w / old_h) < 0.75) {// 3:4此时为90:135
                        // 如果原图比要压缩的图小，则不压缩
                        if (old_w < new_w2) {
                            width = old_w;
                        } else {
                            width = new_w2;
                        }
                        if (old_h < new_h2) {
                            height = old_h;
                        } else {
                            height = new_h2;
                        }
                    } else if (0.75 <= (float) (old_w / old_h)) {
                        if (old_w < new_w1) {
                            width = old_w;
                        } else {
                            width = new_w1;
                        }
                        if (old_h < new_h1) {
                            height = old_h;
                        } else {
                            height = new_h1;
                        }
                    }
                }else if(compressType==2){//270*178
                    if(old_w<new_w1){
                        width=old_w;
                    }else{
                        width=new_w1;
                    }
                    if (old_h < new_h1) {
                        height = old_h;
                    } else {
                        height = new_h1;
                    }
                }

                BufferedImage tag = new BufferedImage(width, height,
                        BufferedImage.TYPE_INT_RGB);
                tag.getGraphics().drawImage(src, 0, 0, width, height, null); // 绘制缩小后的图

                FileOutputStream newimage = new FileOutputStream(newpath); // 输出到文件流

                JPEGImageEncoder encoder = JPEGCodec
                        .createJPEGEncoder(newimage);
                encoder.encode(tag); // 近JPEG编码
                newimage.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return old_w+"*"+old_h+"."+old_w/old_h;
    }
}