Question

如何用java发送http报文

哪位能给出详细代码，（带注释的）
一楼给的挺好，应该是对于http输入流的获取很详细，但有一处不解，望指教，两个 conn.requestProperty("","")是干什么的，那里面的值又是什么意思？ 谢谢~

Answer 1

给你一个吧，这个能抓取任何程序

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class WebClient{
public static String getWebContent(String urlString,final String charset,int timeout) throws IOException {
if(urlString==null||urlString.length()==0) {
return null;
}
urlString = (urlString.startsWith("http://") || urlString
.startsWith("https://")) ? urlString : ("http://" + urlString)
.intern();
URL url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn
.setRequestProperty(
"User-Agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727)");//增加报头，模拟浏览器，防止屏蔽
conn.setRequestProperty("Accept", "text/html");//只接受text/html类型，当然也可以接受图片,pdf,*/*任意，就是tomcat/conf/web里面定义那些
conn.setConnectTimeout(timeout);
try {
if(conn.getResponseCode()!=HttpURLConnection.HTTP_OK) {
return null;
}
} catch (IOException e) {
e.printStackTrace();
return null;
}
InputStream input = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input,
charset));
String line = null;
StringBuffer sb = new StringBuffer();
while ((line = reader.readLine()) != null) {
sb.append(line).append("\r\n");
}
if(reader!=null) {
reader.close();
}
if(conn!=null) {
conn.disconnect();
}
return sb.toString();

}
public static String getWebContent(String urlString) throws IOException {
return getWebContent(urlString,"iso-8859-1",5000);
}

public static void main(String[]args) throws IOException {
String s = getWebContent("http://www.sina.com");
s = new String(s.getBytes("iso-8859-1"),"gb2312");
System.out.println(s);
}
}