功能：

基于HttpURLConnection 实现的常用 Http 常用方法：

• post
• get
• put
• delete

源码：

package com.dotions.utils;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Map;

/**
 * @Description HTTP toolkit
 * 
 * @author Dotions 2016年7月26日 下午4:50:26
 */
public class HttpSimpleUtils {

    static {
        System.setProperty("sun.net.http.allowRestrictedHeaders", "true");
    }

    public static String post(String strUrl, final String json, Map<String, String> header) throws IOException {
        final HttpURLConnection connection = getHttpURLConnection(strUrl);

        return execute(connection, header, new HttpCallback() {
            public void doSomething() throws IOException {
                connection.setDoOutput(true);
                connection.setRequestMethod(Method.POST);
                IOUtil.copy(json.getBytes(), connection.getOutputStream());

            }
        });
    }

    public static String post(String strUrl, final String json) throws IOException {
        return post(strUrl, json, null);
    }

    public static String get(String strUrl, Map<String, String> header) throws IOException {
        final HttpURLConnection connection = getHttpURLConnection(strUrl);

        return execute(connection, header, new HttpCallback() {
            public void doSomething() throws IOException {
                connection.setRequestMethod(Method.GET);
            }
        });
    }

    public static String get(String strUrl) throws IOException {
        return get(strUrl, null);
    }

    public static String put(String strUrl, final String json, Map<String, String> header) throws IOException {
        final HttpURLConnection connection = getHttpURLConnection(strUrl);

        return execute(connection, header, new HttpCallback() {
            public void doSomething() throws IOException {
                connection.setDoOutput(true);
                connection.setRequestMethod(Method.PUT);
                IOUtil.copy(json.getBytes(), connection.getOutputStream());
            }
        });
    }

    public static String put(String strUrl, final String json) throws IOException {
        return put(strUrl, json, null);
    }

    public static String delete(String strUrl, Map<String, String> header) throws IOException {
        final HttpURLConnection connection = getHttpURLConnection(strUrl);

        return execute(connection, header, new HttpCallback() {
            public void doSomething() throws IOException {
                connection.setRequestMethod(Method.DELETE);
            }
        });
    }

    public static String delete(String strUrl) throws IOException {
        return delete(strUrl, null);
    }

    /*
     * Execute http request and return result
     */
    private static String execute(HttpURLConnection connection, Map<String, String> header, HttpCallback callback)
            throws IOException {
        if (connection == null) {
            return null;
        }

        // Set custom http header
        if (header != null && header.size() > 0) {
            for (String key : header.keySet()) {
                connection.setRequestProperty(key, header.get(key));
            }
        }

        // Set timeout
        connection.setReadTimeout(DefaultTimeOut.SOCKET);
        connection.setConnectTimeout(DefaultTimeOut.CONNECTION);

        if (callback != null) {
            callback.doSomething();
        }

        System.out.println("responseCode = " + connection.getResponseCode());

        if (connection.getResponseCode() == ResponseCode.SUCCESS) {
            return StringUtil.toString(connection.getInputStream());
        }

        return null;

    }

    /*
     * Get http URL connection
     */
    private static HttpURLConnection getHttpURLConnection(String strUrl) throws IOException {
        if (StringUtil.isBlank(strUrl)) {
            return null;
        }

        URL url = new URL(strUrl);
        return (HttpURLConnection) url.openConnection();
    }

    /**
     * Default timeout config
     */
    private static interface DefaultTimeOut {
        public int SOCKET = 20000;
        public int CONNECTION = 5000;
    }

    /**
     * Http method
     */
    private static interface Method {
        public String GET = "GET";
        public String POST = "POST";
        public String PUT = "PUT";
        public String DELETE = "DELETE";
    }

    /**
     * Http ResponseCode
     */
    @SuppressWarnings("unused")
    private static interface ResponseCode {
        public int SUCCESS = 200;
        public int NOT_FOUND = 404;
    }

    private interface HttpCallback {
        public void doSomething() throws IOException;
    }

}