封装抓取网页信息的实例

package cn.mypic;


    import java.io.BufferedInputStream;
    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.net.MalformedURLException;
    import java.net.URL;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;


    public class GetContentPicture {
    //得到了图片地址并下载图片
    public void getHtmlPicture(String httpUrl) {
    URL url;
    BufferedInputStream in;
    FileOutputStream file;
    int count;                      //图片文件名序号
    FileNumber num=new FileNumber();//图片文件名序号类，num为对象
    count=num.NumberReadFromFile();//获取图片文件序号
    try {
    System.out.println("获取网络图片");
       String fileName = (String.valueOf(count)).concat(httpUrl.substring(httpUrl.lastIndexOf(".")));//图片文件序号加上图片的后缀名，后缀名用了String内的一个方法来获得
        //httpUrl.substring(httpUrl.lastIndexOf("/"));//这样获得的文件名即是图片链接里图片的名字
       String filePath = "d:/image/";//图片存储的位置
       url = new URL(httpUrl);

       in = new BufferedInputStream(url.openStream());

       file = new FileOutputStream(new File(filePath+fileName));
       int t;
       while ((t = in.read()) != -1) {
        file.write(t);
       }
       file.close();
       in.close();
       System.out.println("图片获取成功");
       count=count+1;//图片文件序号加1
       num.NumberWriteToFile(count);//将图片名序号保存
    } catch (MalformedURLException e) {
       e.printStackTrace();
    } catch (FileNotFoundException e) {
       e.printStackTrace();
    } catch (IOException e) {
       e.printStackTrace();
    }
    }

    //获取网页的代码保存在String格式的Content中
    public String getHtmlCode(String httpUrl) throws IOException {
    String content ="";
    URL uu = new URL(httpUrl); // 创建URL类对象
    BufferedReader ii = new BufferedReader(new InputStreamReader(uu
        .openStream())); // //使用openStream得到一输入流并由此构造一个BufferedReader对象
    String input;
    while ((input = ii.readLine()) != null) { // 建立读取循环，并判断是否有读取值
       content += input;
    }
    ii.close();
    return content;
    }
    //分析网页代码，找到匹配的网页图片地址
    public void get(String url) throws IOException {

    String searchImgReg = "(?x)(src|SRC|background|BACKGROUND)=('|\")/?(([\\w-]+/)*([\\w-]+\\.(jpg|JPG|png|PNG|gif|GIF)))('|\")";//用于在网页代码Content中查找匹配的图片链接。
    String searchImgReg2 = "(?x)(src|SRC|background|BACKGROUND)=('|\")(http://([\\w-]+\\.)+[\\w-]+(:[0-9]+)*(/[\\w-]+)*(/[\\w-]+\\.(jpg|JPG|png|PNG|gif|GIF)))('|\")";

    String content = this.getHtmlCode(url);//this指对象gcp，在此地调用获取网页代码，getHtmlCode方法
    //System.out.println(content); //输出的content将是一个连续的字符串。

    Pattern pattern = Pattern.compile(searchImgReg);//java.util.regex.Pattern
    Matcher matcher = pattern.matcher(content);     //java.util.regex.Matcher
    while (matcher.find()) {
       System.out.println(matcher.group(3));//输出图片链接地址到屏幕
    // System.out.println(url);
       this.getHtmlPicture(matcher.group(3));//对象调用getHtmlPicture从网上下载并输出图片文件到指定目录

    }

    pattern = Pattern.compile(searchImgReg2);
    matcher = pattern.matcher(content);
    while (matcher.find()) {
       System.out.println(matcher.group(3));
       this.getHtmlPicture(matcher.group(3));

    }
    // searchImgReg =
    // "(?x)(src|SRC|background|BACKGROUND)=('|\")/?(([\\w-]+/)*([\\w-]+\\.(jpg|JPG|png|PNG|gif|GIF)))('|\")";
    }
    //主函数url网页的地址
    public static void main(String[] args) throws IOException {

    String url = "http://www.baidu.com";
    GetContentPicture gcp = new GetContentPicture();
    gcp.get(url);


    }


}

 

 

package cn.mypic;

    import java.io.*;

    public class FileNumber{
    //文件写
    public void NumberWriteToFile(int x){
       int c=0;
       c=x;
       File filePath=new File("d:/image");//文件名序号TXT文件保存地址
       File f1=new File(filePath,"number.txt");
       try{
        FileOutputStream fout=new FileOutputStream(f1);
        DataOutputStream out=new DataOutputStream(fout);
        out.writeInt(c);

       }
       catch(FileNotFoundException e){
        System.err.println(e);
       }
       catch(IOException e){
        System.err.println(e);
       }

    }
    //文件读
    public int NumberReadFromFile(){
       int c1 = 0;
       File filePath=new File("d:/image");
       File f1=new File(filePath,"number.txt");
       try{
        FileInputStream fin=new FileInputStream(f1);
        DataInputStream in=new DataInputStream(fin);
        c1=in.readInt();
        System.out.println(c1);//输出文件内容至屏幕
       }
       catch(FileNotFoundException e){
        System.err.println(e);
       }
       catch(IOException e){
        System.err.println(e);
       }
       return c1;
    }
    public static void main(String args[]){

    }



}