123

        try {

            PostMethod postMethod = null;
            postMethod = new PostMethod(url) ;
            postMethod.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8") ;
//参数设置，需要注意的就是里边不能传NULL，要传空字符串
            NameValuePair[] data = {
                    new NameValuePair("username","111"),
                    new NameValuePair("password","222")
            };
            postMethod.setRequestBody(data);
            org.apache.commons.httpclient.HttpClient httpClient = new org.apache.commons.httpclient.HttpClient();

            int response = httpClient.executeMethod(postMethod); // 执行POST方法

            String result = postMethod.getResponseBodyAsString() ;
            System.out.println(result);
        } catch (Exception e) {
            System.out.println(1231);

            throw new RuntimeException(e.getMessage());
        }

<dependency>
    <groupId>commons-httpclient</groupId>
    <artifactId>commons-httpclient</artifactId>
    <version>3.1</version>
</dependency>