OAuth2.0 授权模式，基于HttpClient 实现

功能代码如下：

package com.digipower.ucas.config;

import java.io.IOException;

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

/**
 * oauth2 客户端工具类
 * 
 * @author zzg
 *
 */
public class OAuthClientUtil {
	static String accessTokenURL = "http://cas.example.org:8099/cas/oauth2.0/accessToken";
	static String client_id = "key";
	static String client_secret = "secret";
	static String username = "admin";
	static String password = "123456";
	
	// 基于password 模式
	public static void main1(String[] args) {
		String grant_type = "password";
		CloseableHttpClient httpClient = HttpClients.createDefault();
		String url = "http://cas.example.org:8099/cas/oauth2.0/accessToken?client_id=" + client_id + "&grant_type="
				+ grant_type + "&username=" + username + "&password=" + password;
		HttpPost httpPost = new HttpPost(url);
		HttpResponse response = null;
		try {
			response = httpClient.execute(httpPost);
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		String result = "";
		if (response.getStatusLine().getStatusCode() == 200) {
			try {
				result = EntityUtils.toString(response.getEntity(), "UTF-8");
				// 解析token的json数据
				System.out.println("result:" + result);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	// 基于client_credentials
	public static void main2(String[] args) {
		String grant_type = "client_credentials";
		CloseableHttpClient httpClient = HttpClients.createDefault();
		String url = "http://cas.example.org:8099/cas/oauth2.0/accessToken?client_id=" + client_id + "&grant_type="
				+ grant_type + "&client_secret=" + client_secret;
		HttpPost httpPost = new HttpPost(url);
		HttpResponse response = null;
		try {
			response = httpClient.execute(httpPost);
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		String result = "";
		if (response.getStatusLine().getStatusCode() == 200) {
			try {
				result = EntityUtils.toString(response.getEntity(), "UTF-8");
				// 解析token的json数据
				System.out.println("result:" + result);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	
	// 基于refresh_token
	public static void main3(String[] args) {
		String grant_type = "refresh_token";
		String refresh_token = "RT-1-W7-9xisPcnQqLfyH2RIpAnnc7aWVPOtP";
		CloseableHttpClient httpClient = HttpClients.createDefault();
		String url = "http://cas.example.org:8099/cas/oauth2.0/accessToken?client_id=" + client_id + "&grant_type="
				+ grant_type + "&client_secret=" + client_secret + "&refresh_token=" + refresh_token;
		HttpPost httpPost = new HttpPost(url);
		HttpResponse response = null;
		try {
			response = httpClient.execute(httpPost);
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		String result = "";
		if (response.getStatusLine().getStatusCode() == 200) {
			try {
				result = EntityUtils.toString(response.getEntity(), "UTF-8");
				// 解析token的json数据
				System.out.println("result:" + result);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	// 基于/oauth2.0/profile, 获取用户信息
	public static void main(String[] args) {

		String access_token = "AT-2-ArvJnVOylh-qizLsOBv0UrqCzEEjyJuP";
		CloseableHttpClient httpClient = HttpClients.createDefault();
		String url = "http://cas.example.org:8099/cas/oauth2.0/profile?access_token=" + access_token;
		HttpGet httpGet = new HttpGet(url);
		
		HttpResponse response = null;
		try {
			response = httpClient.execute(httpGet);
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		String result = "";
		if (response.getStatusLine().getStatusCode() == 200) {
			try {
				result = EntityUtils.toString(response.getEntity(), "UTF-8");
				// 解析token的json数据
				System.out.println("result:" + result);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}