java爬取猫咪上的图片

首先是对知识点归纳

1.用到获取网页源代码，分析图片地址，发现图片的地址都是按编号排列的，所以想到用循环获取

2.保存图片要用到流操作和文件操作，对两部分知识进行了复习巩固

3.保存后的图片有一部分是广告文字，所以我又看了一下如何截取图片

下面上代码：

网页源代码不粘贴了

对网页源代码分析之后进行循环提取图片链接并下载：

package 文件操作;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class Pic696 {

    public static void main(String[] args) {
    for(int i =1;i<72;i++) {
        for (int j =1; j < 50; j++) {

            if(i<10&&j<10) {
                String strUrl ="https://mmslt1.com/tp/girl/FEILIN/A-00"+i+"/0"+j+".jpg";
//                System.out.println(i+" "+j);
                System.out.println(strUrl);
                URL url;
                try {
                    url = new URL(strUrl);
                    try {
                        Pig(url, i, j);
                    } catch (IOException e) {
                        System.out.println("404");
                    }
                } catch (MalformedURLException e) {
                    
                }
                
            }
            if(i<10&&j>=10) {
                String strUrl ="https://mmslt1.com/tp/girl/FEILIN/A-00"+i+"/"+j+".jpg";
//                System.out.println(i+" "+j);
                System.out.println(strUrl);
                URL url;
                try {
                    url = new URL(strUrl);
                    try {
                        Pig(url, i, j);
                    } catch (IOException e) {
                        System.out.println("404");
                    }
                } catch (MalformedURLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                
            }
            if(i>=10&&j<10) {
                String strUrl ="https://mmslt1.com/tp/girl/FEILIN/A-0"+i+"/0"+j+".jpg";
//                System.out.println(i+" "+j);
                System.out.println(strUrl);
                URL url;
                try {
                    url = new URL(strUrl);
                    try {
                    Pig(url, i, j);
                } catch (IOException e) {
                    System.out.println("404");
                }
                } catch (MalformedURLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                
            }
            if(i>=10&&j>=10) {
            String strUrl ="https://mmslt1.com/tp/girl/FEILIN/A-0"+i+"/"+j+".jpg";
//            System.out.println(i+" "+j);
            System.out.println(strUrl);
            URL url;
            try {
                url = new URL(strUrl);
                try {
                Pig(url, i, j);
            } catch (IOException e) {
                System.out.println("404");
            }
            } catch (MalformedURLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            
            }
        }
    }
            
}
    
    static void Pig(URL urlStr,int i,int j) throws IOException {
        //构造连接
        HttpURLConnection conn = (HttpURLConnection)urlStr.openConnection();
        conn.setRequestMethod("GET");
        //这个网站要模拟浏览器才行
        conn.setRequestProperty("User-Agent","Mozilla/5.0 (Windows NT 10.0; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0");
        //打开连接
        conn.connect();

        //打开这个网站的输入流
        InputStream inStream = conn.getInputStream();
        //用这个做中转站 ，把图片数据都放在了这里，再调用toByteArray()即可获得数据的byte数组
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        //用这个是很好的，不用一次就把图片读到了文件中
        //要是需要把图片用作其他用途呢？所以直接把图片的数据弄成一个变量，十分有用
        //相当于操作这个变量就能操作图片了

        byte [] buf = new byte[1024];
        //为什么是1024？
        //1024Byte=1KB，分配1KB的缓存
        
        int len = 0;

        //读取图片数据
        while((len=inStream.read(buf))!=-1){
//        System.out.println(len);
        outStream.write(buf,0,len);
        }
        inStream.close();
        outStream.close();

        //把图片数据填入文件中
//        File files = new File("E://Pic696");
//        files.mkdirs();
        File file = new File("E://Pic696/Pic"+i+"_"+j+".jpg");

        FileOutputStream op = new FileOutputStream(file);

        op.write(outStream.toByteArray());

        op.close();
     }    
}

对下载下来的图片进行截取（获取原来的尺寸，减掉一部分）

package 文件操作;

import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Iterator;

import javax.imageio.ImageIO;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import javax.swing.ImageIcon;



public class cityScore {
 
    public static void main(String[] args) {
        for (int i = 1; i < 10; i++) {
            for (int j = 1; j < 40; j++) {
                String OldPic ="E:/Pic696/Pic"+i+"_"+j+".jpg";
                String NewPic ="E:/Pic696/new/Pic"+i+"_"+j+".jpg";
                ImageIcon imageIcon = new ImageIcon(OldPic);
                int iconWidth = imageIcon.getIconWidth();
                int iconHeight =imageIcon.getIconHeight();
                cutImage(OldPic, NewPic,iconWidth, iconHeight-70);
            }
        }
        
    }
    
    /**
     * 图片裁剪
     * @param srcImageFile 图片裁剪地址
     * @param result 图片输出文件夹
     * @param destWidth 图片裁剪宽度
     * @param destHeight 图片裁剪高度
     */
    public final static void cutImage(String srcImageFile, String result,
            int destWidth, int destHeight) {
        try {
            Iterator iterator = ImageIO.getImageReadersByFormatName("JPEG");/*PNG,BMP*/  
            ImageReader reader = (ImageReader)iterator.next();/*获取图片尺寸*/
            InputStream inputStream = new FileInputStream(srcImageFile); 
            ImageInputStream iis = ImageIO.createImageInputStream(inputStream);  
            reader.setInput(iis, true);  
            ImageReadParam param = reader.getDefaultReadParam();  
            Rectangle rectangle = new Rectangle(0,0, destWidth, destHeight);/*指定截取范围*/   
            param.setSourceRegion(rectangle);  
            BufferedImage bi = reader.read(0,param);
            ImageIO.write(bi, "JPEG", new File(result));
        } catch (Exception e) {
            System.out.println(e);
        }
    }
}