我在编译的时候,发现以下错误: "test.java": Error #: 353 : class java.net.URLConnection is abstract; cannot be instantiated at "test.java": Error #: 300 : constructor URLConnection(java.lang.String) not found in class java.net.URLConnection at "test.java": Error #: 300 : method open() not found in class java.net.URLConnection at "test.java": Error #: 300 : method setRequestMethod(java.lang.String) not found in class java.net.URLConnection at "test.java": Error #: 300 : method openDataInputStream() not found in class java.net.URLConnection at
sorry URL url = new URL("http://expert.csdn.net/member/logon.asp"); URLConnection conn= url.openConnection(); 应该是这样。
URLConnection conn =null;
DataInputStream in=null;
OutputStream out=null;conn =new URLConnection(url);//打开链接
conn.open();//确保链接
conn.setRequestMethod("POST"); //设置连接为Post方式
conn.setRequestProperty("username","josy");
conn.setRequestProperty("password","xxxx");
in=conn.openDataInputStream();//读返回得结果大概就是这样,忘了抓异常了,自己补上吧
就如同楼上的哪个兄台写的那样
"test.java": Error #: 353 : class java.net.URLConnection is abstract; cannot be instantiated at
"test.java": Error #: 300 : constructor URLConnection(java.lang.String) not found in class java.net.URLConnection at
"test.java": Error #: 300 : method open() not found in class java.net.URLConnection at
"test.java": Error #: 300 : method setRequestMethod(java.lang.String) not found in class java.net.URLConnection at
"test.java": Error #: 300 : method openDataInputStream() not found in class java.net.URLConnection at
URL url = new URL("http://expert.csdn.net/member/logon.asp");
URLConnection conn= url.openConnection();
应该是这样。
try{
String url="http://expert.csdn.net/member/logon.asp";
URL login = new URL(url);
HttpURLConnection conn =null;
DataInputStream in=null;
OutputStream out=null;
conn =(HttpURLConnection)login.openConnection();//openConnection();//打开链接
conn.setRequestMethod("POST"); //设置连接为Post方式
conn.setRequestProperty("username","username");
conn.setRequestProperty("password","userpwd");
conn.connect();//确保链接
in=new DataInputStream(conn.getInputStream());//读返回得结果
String ret="";
do{
ret=in.readLine();
System.out.println(ret);
}while(ret!=null);
conn.disconnect();
}
}catch(Exception e){}