12345website_tonghua/src/main/java/com/sooka/common/utils/Http.java

package com.sooka.common.utils;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Map;

/**
 * Created by yanhongliang on 16/6/14.
 */
public class Http {

    public interface SignParams {
        String signParams(String params);
    }

    static public void setOnSignParams(SignParams signParams) {
        onSignParams = signParams;
    }
    static private SignParams onSignParams;

    static public String stringFromParams(Map<String, Object> post) {

        StringBuilder buffer = new StringBuilder();

        if (post == null) return null;

        ArrayList<String> keys = new ArrayList<>(post.size());
        keys.addAll(post.keySet());
        Collections.sort(keys);

//        ArrayList<Map.Entry<String, Object>> params = new ArrayList<>(post.size());
//
//        for (Map.Entry<String, Object> entry: post.entrySet()) {
//            params.add(entry);
//        }
//
//        Collections.sort(params, new Comparator<Map.Entry<String, Object>>() {
//            @Override
//            public int compare(Map.Entry<String, Object> lhs, Map.Entry<String, Object> rhs) {
//
//                System.out.println("-----lhs-----:=>"+lhs.getKey().hashCode());
//                System.out.println("-----rhs-----:=>"+rhs.getKey().hashCode());
//
//                return lhs.getKey().hashCode() - rhs.getKey().hashCode();
//            }
//        });

        for (String key : keys) {
            Object value = post.get(key);
            if (buffer.length() > 0) buffer.append("&");
            buffer.append(key);
            buffer.append("=");
            try {
                buffer.append(URLEncoder.encode(String.valueOf(value), "UTF-8"));
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
        }

        String paramsString = new String(buffer);

        if (onSignParams != null) {
            paramsString = onSignParams.signParams(paramsString);
        }

        return paramsString;
    }

    public static String getMd5(String string) {

        byte[] hash;

        try {

            hash = MessageDigest.getInstance("MD5").digest(string.getBytes("UTF-8"));

        } catch (NoSuchAlgorithmException e) {

            throw new RuntimeException("Huh, MD5 should be supported?", e);

        } catch (UnsupportedEncodingException e) {

            throw new RuntimeException("Huh, UTF-8 should be supported?", e);

        }


        StringBuilder hex = new StringBuilder(hash.length * 2);

        for (byte b : hash) {

            if ((b & 0xFF) < 0x10) hex.append("0");

            hex.append(Integer.toHexString(b & 0xFF));

        }

        return hex.toString();

    }
}