如何通过Java发送HTTP请求,通俗点讲,如何通过Java(模拟浏览器)发送HTTP请求。
Java有原生的API可用于发送HTTP请求,即java.net.URL, java.net.URLConnection,这些API很好用,很常用,但不够简便,
所以,也流行有许多Java HTTP请求的框架,如Apache的HttpClient。
目前项目主要用Java原到生的方式,所以,这里主要介绍此方式。
运用原生Java Api发送简单的就请求,帖子请求
HTTP请求粗分为两种,一种是得到请求,一种是后请求。使用Java发送这两种请求的代码大同小异,只是一些参数设置的不同。步骤如下:
1。通过统一资源定位器(java.net.URL)获取连接器(java.net.URLConnection)
2。设置请求的参数
3。发送请求
4。以输入流的形式获取返回内容
5。关闭输入流
<强>简单的得到请求示例如下:
包com.bjpowernode.httprequestdemo;
进口java.io.BufferedReader;
进口java.io.InputStream;
进口java.io.InputStreamReader;
进口java.net.HttpURLConnection;
进口java.net.URL;
进口java.net.URLConnection;
公开课HttpGetRequest {/* *
*主要
* @param arg游戏
* @throws例外
*/公共静态void main (String [] args){抛出异常
System.out.println (doGet ());
}/* *
* Get请求
* @return
* @throws例外
*/公共静态字符串doGet()抛出异常{
URL localURL=新的URL (http://localhost: 8080/OneHttpServer/);
URLConnection连接=localURL.openConnection ();
HttpURLConnection HttpURLConnection=(HttpURLConnection)连接;
httpURLConnection。setRequestProperty (“Accept-Charset”、“utf - 8”);
httpURLConnection。setRequestProperty(“内容类型”,“应用程序/x-www-form-urlencoded”);
InputStream InputStream=零;
InputStreamReader InputStreamReader=零;
BufferedReader读者=零;
StringBuffer resultBuffer=new StringBuffer ();
字符串tempLine=零;
如果(httpURLConnection.getResponseCode()在=300){
抛出新的异常(“HTTP请求不成功,响应代码”+ httpURLConnection.getResponseCode ());
}
尝试{
inputStream=httpURLConnection.getInputStream ();
inputStreamReader=new inputStreamReader (inputStream);
读者=new BufferedReader (inputStreamReader);
在((tempLine=reader.readLine ()) !=null) {
resultBuffer.append (tempLine);
}
最后}{
如果(读者!=null) {
reader.close ();
}
如果(inputStreamReader !=null) {
inputStreamReader.close ();
}
如果(inputStream !=null) {
inputStream.close ();
}
}
返回resultBuffer.toString ();
}
}
之前
<强>,简单的帖子请求示例如下:
包com.bjpowernode.httprequestdemo;
进口java.io.BufferedReader;
进口java.io.InputStream;
进口java.io.InputStreamReader;
进口java.io.OutputStream;
进口java.io.OutputStreamWriter;
进口java.net.HttpURLConnection;
进口java.net.URL;
进口java.net.URLConnection;
公开课HttpPostRequest {/* *
*主要
* @param arg游戏
* @throws例外
*/公共静态void main (String [] args){抛出异常
System.out.println (doPost ());
}/* *
* Post请求
* @return
* @throws例外
*/公共静态字符串doPost()抛出异常{
字符串parameterData=" https://www.yisu.com/zixun/username=nickhuang&blog=http://www.cnblogs.com/nick-huang/?
URL localURL=新的URL (http://localhost: 8080/OneHttpServer/);
URLConnection连接=localURL.openConnection ();
HttpURLConnection HttpURLConnection=(HttpURLConnection)连接;
httpURLConnection.setDoOutput(真正的);
httpURLConnection.setRequestMethod(“文章”);
httpURLConnection。setRequestProperty (“Accept-Charset”、“utf - 8”);
httpURLConnection。setRequestProperty(“内容类型”,“应用程序/x-www-form-urlencoded”);
httpURLConnection。内容长度setRequestProperty (“”, String.valueOf (parameterData.length ()));
OutputStream OutputStream=零;
OutputStreamWriter OutputStreamWriter=零;
InputStream InputStream=零;
InputStreamReader InputStreamReader=零;
BufferedReader读者=零;
StringBuffer resultBuffer=new StringBuffer ();
字符串tempLine=零;
尝试{
outputStream=httpURLConnection.getOutputStream ();
outputStreamWriter=new outputStreamWriter (outputStream);
outputStreamWriter.write (parameterData.toString ());
outputStreamWriter.flush ();
如果(httpURLConnection.getResponseCode()在=300){
抛出新的异常(“HTTP请求不成功,响应代码”+ httpURLConnection.getResponseCode ());
}
inputStream=httpURLConnection.getInputStream ();
inputStreamReader=new inputStreamReader (inputStream);
读者=new BufferedReader (inputStreamReader);
在((tempLine=reader.readLine ()) !=null) {
resultBuffer.append (tempLine);
}
最后}{
如果(outputStreamWriter !=null) {
outputStreamWriter.close ();
}
如果(outputStream !=null) {
outputStream.close ();
}
如果(读者!=null) {
reader.close ();
}
如果(inputStreamReader !=null) {
inputStreamReader.close ();
}
如果(inputStream !=null) {
inputStream.close ();
}
}
返回resultBuffer.toString ();
}
}
