用HttpClient模拟HTTP的GET和POST请求

一、HttpClient介绍

 

HttpClient是用来模拟HTTP请求的，其实实质就是把HTTP请求模拟后发给Web服务器

HTTP GET核心代码：

(1)DefaultHttpClient client = new DefaultHttpClient();

(2)HttpGet get = new HttpGet(String url);//此处的URL为http://..../path?arg1=value&....argn=value

(3)HttpResponse response = client.execute(get); //模拟请求

(4)int code = response.getStatusLine().getStatusCode();//返回响应码

(5)InputStream in = response.getEntity().getContent();//服务器返回的数据

 

HTTP POST核心代码：

(1)DefaultHttpClient client = new DefaultHttpClient();

(2)BasicNameValuePair pair = new BasicNameValuePair(String name,String value);//创建一个请求头的字段，比如content-type,text/plain

(3)UrlEncodedFormEntity entity = new UrlEncodedFormEntity(List<NameValuePair> list,String encoding);//对自定义请求头进行URL编码

(4)HttpPost post = new HttpPost(String url);//此处的URL为http://..../path

(5)post.setEntity(entity);

(6)HttpResponse response = client.execute(post);

(7)int code = response.getStatusLine().getStatusCode();

(8)InputStream in = response.getEntity().getContent();//服务器返回的数据

 

//测试代码：

public static void main(String[] args) throws Exception

    {

        DefaultHttpClient client = new DefaultHttpClient();

        List<NameValuePair> list = new ArrayList<NameValuePair>();

        

        String data = "aaa";

        NameValuePair pair1 = new BasicNameValuePair("data", data);

        list.add(pair1);

        UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, "UTF-8");

        HttpPost post = new HttpPost("http://192.168.0.10:80/Server/Servlet/");

        post.setEntity(entity);

        HttpResponse response = client.execute(post);

        if(response.getStatusLine().getStatusCode() == 200)

        {

            InputStream in = response.getEntity().getContent();// 接收服务器的数据

            String str = readString(in);

            System.out.println("str:" + str);

        }

        else

        {

            System.out.println("调用失败");

        }

    }

    

    private static String readString(InputStream in) throws Exception

    {

        byte[] data = new byte[1024];

        int length = 0;

        ByteArrayOutputStream bout = new ByteArrayOutputStream();

        while((length = in.read(data)) != -1)

        {

            bout.write(data, 0, length);

        }

        return new String(bout.toByteArray(), "UTF-8");

        

    }