import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;
import net.sf.json.JSONObject;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

public class APIVisit {

    // aesecb加密
    private static String AesEcbEncrypt(String plain, String key) {
            try {
                byte[] keyBytes = key.getBytes("utf-8");
                byte[] plainBytes = plain.getBytes("utf-8");
                SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
                Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
                cipher.init(Cipher.ENCRYPT_MODE, keySpec);
                byte[] encrypted = cipher.doFinal(plainBytes);
                return bytesToHex(encrypted);
            } catch (Exception e) {
                System.out.println(e.toString());
                return null;
            }

        }

        // aesecb解密
        private static String AesEcbDecrypt(String enc, String key) {

            try {
                byte[] keybytes = key.getBytes("utf-8");
                SecretKeySpec keySpec = new SecretKeySpec(keybytes, "AES");
                Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
                cipher.init(Cipher.DECRYPT_MODE, keySpec);
                byte[] hexbytes = hexToBytes(enc);
                byte[] plain = cipher.doFinal(hexbytes);
                return new String(plain, "utf-8");
            } catch (Exception ex) {
                System.out.println(ex.toString());
                return null;
            }
        }

        private static String bytesToHex(byte[] data) {
            String result="";
            for (int i = 0; i < data.length; i++) {
            	result+=Integer.toHexString((data[i] & 0xFF) | 0x100).toUpperCase().substring(1, 3);
            }
            return result;
        }

         public static byte[] hexToBytes(String hexStr) {
                 char [] data = hexStr.toCharArray();
                 int len = data.length;
                 byte[] out = new byte[len >> 1];
                 for (int i = 0, j = 0; j < len; i++) {
                     int f = Character.digit(data[j], 16) << 4;
                     j++;
                     f = f | Character.digit(data[j], 16);
                     j++;
                     out[i] = (byte) (f & 0xFF);
                 }
                 return out;
             }
    // 访问api
    public static void visit_by_token(String url, String token, String secret, Boolean enc, Map<String, String> param) {

        try {
           
            // http 设置和请求
            HttpClient client = HttpClientBuilder.create().build();
            URIBuilder uriBuilder = new URIBuilder(url);
            if (enc) {
                String data = "";
                JSONObject jobj = JSONObject.fromObject(param);
                data = jobj.toString();
                data = AesEcbEncrypt(data, secret);
                uriBuilder.setParameter("encrypt_data", data);
            } else {
                param.entrySet().forEach(item -> {
                        uriBuilder.setParameter(item.getKey(), item.getValue());
                        System.out.println("key:" + item.getKey() + ",vaule:" + item.getValue());
                    });
            }

            URI reqUrl = uriBuilder.build();
            HttpGet request = new HttpGet(reqUrl);
            request.setHeader("token", token);

            HttpResponse response = client.execute(request);

            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                String str = EntityUtils.toString(response.getEntity());
                System.out.println(str);
                JSONObject obj = JSONObject.fromObject(str);

                // 数据是否解密
                if (obj.containsKey("data")) {
                    String content = obj.get("data").toString();
                    if (enc) {
                        String plaintext = AesEcbDecrypt(content, secret);
                        System.out.printf("解密后:%s\n", plaintext);
                    } else {
                        System.out.printf("不需解密:%s\n", content);
                    }
                }
                return;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return;
    }

    public static String md5(String sSrc) {

        byte[] secretBytes = null;
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(sSrc.getBytes());
            secretBytes = md.digest();
        } catch (NoSuchAlgorithmException e) {
            System.out.println(e.toString());
            return null;
        }
        String md5code = new BigInteger(1, secretBytes).toString(16);// 16进制数字
        Integer l = md5code.length();
        for (int i = 0; i < 32 - l; i++) {
            md5code = "0" + md5code;
        }
        return md5code;
    }

    public static String getSign(String ts, String appKey, String appSecrect) {
	String s = appKey + appSecrect + ts;
	s = md5(s);
	return s;
    }

    public static void visit_by_sign(String url, String appkey, String secret, Boolean enc, Map<String, String> param) {

        try {
           
            // http 设置和请求
            HttpClient client = HttpClientBuilder.create().build();
            URIBuilder uriBuilder = new URIBuilder(url);
            if (enc) {
                String data = "";
                JSONObject jobj = JSONObject.fromObject(param);
                data = jobj.toString();
                data = AesEcbEncrypt(data, secret);
                uriBuilder.setParameter("encrypt_data", data);
            } else {
                param.entrySet().forEach(item -> {
                        uriBuilder.setParameter(item.getKey(), item.getValue());
                        System.out.println("key:" + item.getKey() + ",vaule:" + item.getValue());
                    });
            }
	    String ts = Long.toString(System.currentTimeMillis());
	    String sign = getSign(ts, appkey, secret);

            URI reqUrl = uriBuilder.build();
            HttpGet request = new HttpGet(reqUrl);
            request.setHeader("appkey", appkey);
            request.setHeader("timestamp", ts);
            request.setHeader("sign", sign);

            HttpResponse response = client.execute(request);

            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                String str = EntityUtils.toString(response.getEntity());
                System.out.println(str);
                JSONObject obj = JSONObject.fromObject(str);

                // 数据是否解密
                if (obj.containsKey("data")) {
                    String content = obj.get("data").toString();
                    if (enc) {
                        String plaintext = AesEcbDecrypt(content, secret);
                        System.out.printf("解密后:%s\n", plaintext);
                    } else {
                        System.out.printf("不需解密:%s\n", content);
                    }
                }
                return;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return;
    }

    public static String getToken(String tokenUrl, String user, String password) {
            try {

                        HttpClient client = HttpClientBuilder.create().build();
                        URIBuilder uriBuilder = new URIBuilder(tokenUrl);
                        uriBuilder.setParameter("user", user);
                        uriBuilder.setParameter("password", password);
                        URI reqUrl = uriBuilder.build();

                        HttpGet request = new HttpGet(reqUrl);


                        HttpResponse response = client.execute(request);
                        if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                            //读取返回
                            String str = EntityUtils.toString(response.getEntity());
                            System.out.printf("token result:%s\n", str);
                            JSONObject obj = JSONObject.fromObject(str);


                            //读取token
                            if (obj.containsKey("token")) {
                                return obj.get("token").toString();
                            }

                            return "";
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
	    return "";
    }



    public static void main(String[] args) throws Exception {
        // 配置请联系运营商获取
        // 实际接口url
       String apiUrl = "http://127.0.0.1:41002/api/v1/query/2001";
        // token url
        String tokenUrl = "http://127.0.0.1:41002/api/v1/token";
        // api 用户名和密码用于获取token
        String user = "529db83441acff61a054eba562185515";
        String password = "DMh7lbyv";
        // 密钥用于加密数据(非加密接口可不用)
        String secret = "1749f2a7019db090ca7c9cc69e64033c";
        // 是否加密
        Boolean is_enc = true;
	Boolean use_token = false;


	// 调用接口
        HashMap<String, String> param = new HashMap<>();
        // 接口参数根据实际api接口填写
	param.put("plate_no", "川Y01M21");
	param.put("plate_type", "02");
	param.put("owner", "吴军");

	if (use_token) {
		// 获取token
        	String token = getToken(tokenUrl, user, password);
        	if (token == "") {
            		System.out.println("token is empty");
            		return;
        	}
         	visit_by_token(apiUrl, token, secret, is_enc, param);
	} else {
	
         	visit_by_sign(apiUrl, user, secret, is_enc, param);
	}
    }
}