程序逻辑：
从文件config.txt读取url链接，根据url打开输入流，将接收到的网页内容保存到文件。
package com.changying.spider;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
public class Spider {
public static void main(String[] args) throws IOException {
System.out.println(args[0]);
System.out.println(args[1]);
File config = new File(args[0]);
//System.out.println("Hello World!");
BufferedReader fileReader = new BufferedReader(new FileReader(config));
String strUrl = fileReader.readLine();
System.out.println(strUrl);
URL url = new URL(strUrl);
InputStream in = url.openStream();
File resultFile = new File(args[1] + "\\url001.html");
if (!resultFile.exists()) {
resultFile.createNewFile();
}
//OutputStream result = new FileOutputStream(args[1] + "\\url001.html");
OutputStream result = new FileOutputStream(resultFile);
byte[] buffer = new byte[4096];
int bytes_read;
while ((bytes_read = in.read(buffer)) != -1) {
result.write(buffer, 0, bytes_read);
}
fileReader.close();
in.close();
result.close();
}
}