HttpClient示例-优快云博客

//HttpClient httpClient = new DefaultHttpClient();

private void httpGetData() {
    new Thread() {
        @Override
        public void run() {
            // 创建一个HttpGet对象
            HttpGet httpGet = new HttpGet("http://192.168.1.88:8888/foo/secret.jsp");

            try {
                // 发送GET请求
                HttpResponse httpResponse = httpClient.execute(httpGet);

                // handler.sendMessage(msg);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }.start();
}

private void httpPostDate(final String name, final String pass) {
    new Thread() {
        @Override
        public void run() {
            try {
                HttpPost httPost = new HttpPost("http://192.168.1.88:8888/foo/login.jsp");

                // 如果传递参数个数比较多的话可以对传递的参数进行封装
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("name", name));
                params.add(new BasicNameValuePair("pass", pass));
                // 设置请求参数 // 实现将请求的参数封装到表单中,请求体重
                httPost.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));

                // 发送POST请求
                HttpResponse response = httpClient.execute(httPost);

                // 如果服务器成功地返回响应
                if (response.getStatusLine().getStatusCode() == 200) {
                    String msg = EntityUtils.toString(response.getEntity());
                    Looper.prepare();
                    // 提示登录成功
                    Toast.makeText(HttpClientTest.this, msg, Toast.LENGTH_SHORT).show();
                    Looper.loop();

                    // InputStream inputStream = response.getEntity().getContent();
                    // changeInputStream(inputStream, HTTP.UTF_8);
                }
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }.start();
}

// 将一个输入流转换成指定编码的字符串
public static String changeInputStream(InputStream inputStream, String encode) {
    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

    byte[] data = new byte[1024];
    int len = 0;
    String result = "";
    if (inputStream != null) {
        try {
            while ((len = inputStream.read(data)) != -1) {
                outputStream.write(data, 0, len);
            }
            result = new String(outputStream.toByteArray(), encode);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return result;
}

如果一开始就使用HttpClient发送get请求，会返回错误，通过HttpClient发送post请求（带有正确的用户名、密码），再次发送get请求即可正常访问被保护的资源，这是因为前面使用了HttpClient登录了系统，而且HttpClient可以维护与服务器之间的Session连接.

// secret.jsp
<%
Object user = session.getAttribute("user");
if(user != null && user.toString().trim().equals("admin"))
{
	// 正常页面内容
}
else
{
	out.println("您没有被授权访问该页面");	
}
%>

// login.jsp
<%
String name = request.getParameter("name");
String pass = request.getParameter("pass");
if (name.equals("admin")&& pass.equals("123"))
{
	session.setAttribute("user" , name);
	out.println("恭喜您，登录成功！");
}
else
{
	out.println("对不起，用户名、密码不符合！");
}
%>