public class HttpInvoker ... { public static final String GET_URL = " http://localhost:8080/welcome1 " ;
public static final String POST_URL = " http://localhost:8080/welcome1 " ;
public static void readContentFromGet() throws IOException ... {
// 拼凑get请求的URL字串,使用URLEncoder.encode对特殊和不可见字符进行编码
String getURL = GET_URL + " ?username= "
+ URLEncoder.encode( " fat man " , " utf-8 " );
URL getUrl = new URL(getURL);
// 根据拼凑的URL,打开连接,URL.openConnection函数会根据URL的类型,
// 返回不同的URLConnection子类的对象,这里URL是一个http,因此实际返回的是HttpURLConnection
HttpURLConnection connection = (HttpURLConnection) getUrl
.openConnection();
// 进行连接,但是实际上get request要在下一句的connection.getInputStream()函数中才会真正发到
// 服务器
connection.connect();
// 取得输入流,并使用Reader读取
BufferedReader reader = new BufferedReader( new InputStreamReader(
connection.getInputStream()));
System.out.println( " ============================= " );
System.out.println( " Contents of get request " );
System.out.println( " ============================= " );
String lines;
while ((lines = reader.readLine()) != null ) ... {
System.out.println(lines);
}
reader.close();
// 断开连接
connection.disconnect();
System.out.println( " ============================= " );
System.out.println( " Contents of get request ends " );
System.out.println( " ============================= " );
}
public static void readContentFromPost() throws IOException ... {
// Post请求的url,与get不同的是不需要带参数
URL postUrl = new URL(POST_URL);
// 打开连接
HttpURLConnection connection = (HttpURLConnection) postUrl
.openConnection();
// Output to the connection. Default is
// false, set to true because post
// method must write something to the
// connection
// 设置是否向connection输出,因为这个是post请求,参数要放在
// http正文内,因此需要设为true
connection.setDoOutput( true );
// Read from the connection. Default is true.
connection.setDoInput( true );
// Set the post method. Default is GET
connection.setRequestMethod( " POST " );
// Post cannot use caches
// Post 请求不能使用缓存
connection.setUseCaches( false );
// This method takes effects to
// every instances of this class.
// URLConnection.setFollowRedirects是static函数,作用于所有的URLConnection对象。
// connection.setFollowRedirects(true);
// This methods only
// takes effacts to this
// instance.
// URLConnection.setInstanceFollowRedirects是成员函数,仅作用于当前函数
connection.setInstanceFollowRedirects( true );
// Set the content type to urlencoded,
// because we will write
// some URL-encoded content to the
// connection. Settings above must be set before connect!
// 配置本次连接的Content-type,配置为application/x-www-form-urlencoded的
// 意思是正文是urlencoded编码过的form参数,下面我们可以看到我们对正文内容使用URLEncoder.encode
// 进行编码
connection.setRequestProperty( " Content-Type " ,
" application/x-www-form-urlencoded " );
// 连接,从postUrl.openConnection()至此的配置必须要在connect之前完成,
// 要注意的是connection.getOutputStream会隐含的进行connect。
connection.connect();
DataOutputStream out = new DataOutputStream(connection
.getOutputStream());
// The URL-encoded contend
// 正文,正文内容其实跟get的URL中'?'后的参数字符串一致
String content = " firstname= " + URLEncoder.encode( " 一个大肥人 " , " utf-8 " );
// DataOutputStream.writeBytes将字符串中的16位的unicode字符以8位的字符形式写道流里面
out.writeBytes(content);
out.flush();
out.close(); // flush and close
BufferedReader reader = new BufferedReader( new InputStreamReader(
connection.getInputStream()));
String line;
System.out.println( " ============================= " );
System.out.println( " Contents of post request " );
System.out.println( " ============================= " );
while ((line = reader.readLine()) != null ) ... {
System.out.println(line);
}
System.out.println( " ============================= " );
System.out.println( " Contents of post request ends " );
System.out.println( " ============================= " );
reader.close();
connection.disconnect();
}
/** */ /**
* @param args
*/
public static void main(String[] args) ... {
// TODO Auto-generated method stub
try ... {
readContentFromGet();
readContentFromPost();
} catch (IOException e) ... {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
HttpURLConnection
最新推荐文章于 2022-05-16 16:25:20 发布