Java 利用HttpURLConnection发送http请求

写了一个简单的 Http 请求的Class，实现了 get, post ,postfile 

package com.asus.uts.util;


import org.json.JSONException;
import org.json.JSONObject;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * Created by jiezhou on 16/2/22.
 */
public class HttpHelper {
    public  static void main(String[] args) throws JSONException{
        JSONObject json = new JSONObject();
        json.put("un", "bruce");
        json.put("pwd", "123456");

        //get
        request r = get("http://127.0.0.1:5000/index/user/1/m", json);
        System.out.println(r.status_code);
        System.out.println(r.text);

        //post json data
        String s = "{'sex': 'm', 'name': '', 'id': 1}";
        JSONObject json2 = new JSONObject(s);
　　　　 request r2 = post("http://127.0.0.1:5000/index/user/1/m", json2);

        //post File
        String path = "/Users/jiezhou/Documents/test.py";
        postFile("http://127.0.0.1:5000/fileupload", "temp.txt", "/Users/jiezhou/Documents/temp.txt");

    }

    /**
     * 请求返回的对象
     * @author jiezhou
     *
     */
    public static class request{
        //状态码
        public int status_code;
        //返回数据
        public String text;
    }

    private HttpHelper(){

    }

    /**
     * 从服务器get 数据
     * @param getUrl     URL地址
     * @param params	 JSONObject类型的数据格式
     * @return request
     */
    public static request get(String getUrl, JSONObject params){
        request r = new request();
        HttpURLConnection conn = null;
        try {
            //拼接参数
            if (params != null) {
                String per = null;
                for (int i=0; i< params.names().length(); i++){
                    per = i == 0? "?" : "&";
                    getUrl += per + params.names().get(i).toString() + "=" + params.get(params.names().get(i).toString());
                }
            }

            URL url = new URL(getUrl);
            conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setReadTimeout(5000);
            conn.setConnectTimeout(10000);

            int status_code =  conn.getResponseCode();
            r.status_code = status_code;
            if (status_code == 200){
                InputStream is = conn.getInputStream();
                r.text = getStringFromInputStream(is);
            }
        } catch (Exception e) {

        }
        return r;
    }

    /**
     * post 数据
     * @param getUrl    URL地址
     * @param params	JSONObject类型的数据格式
     * @return request
     */
    public static request post(String getUrl, JSONObject params){
        request r = new request();
        HttpURLConnection conn = null;
        try {
            URL url = new URL(getUrl);
            conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("POST");
            conn.setReadTimeout(5000);
            conn.setConnectTimeout(10000);
            conn.setDoOutput(true);// 设置此方法,允许向服务器输出内容

            // post请求的参数
            String data = null;
            //拼接参数
            if (params != null) {
                data = params.toString();
            }

            // 获得一个输出流,向服务器写数据,默认情况下,系统不允许向服务器输出内容
            OutputStream out = conn.getOutputStream();// 获得一个输出流,向服务器写数据
            out.write(data.getBytes());
            out.flush();
            out.close();

            int status_code =  conn.getResponseCode();
            r.status_code = status_code;
            if (status_code == 200){
                InputStream is = conn.getInputStream();
                r.text = getStringFromInputStream(is);

            }
        } catch (Exception e) {
            System.out.println(e.getMessage().toString());
        }
        return r;
    }

    /**
     * post上传文件
     * @param getUrl        url 地址
     * @param fileName		文件名
     * @param filePath		文件路径
     * @return request
     */
    public static request postFile(String getUrl, String fileName, String filePath){
        request r = new request();
        HttpURLConnection conn = null;
        try {
            String end = "
";
            String twoHyphens = "--";
            String boundary = "******"; // 定义数据分隔线
            URL url = new URL(getUrl);
            conn = (HttpURLConnection) url.openConnection();
            conn.setDoOutput(true);// 设置此方法,允许向服务器输出内容
            conn.setDoInput(true);
            conn.setUseCaches(false);
            conn.setRequestMethod("POST");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setReadTimeout(5000);
            conn.setConnectTimeout(10000);
            conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
            // post请求的参数
            DataOutputStream ds = new DataOutputStream(conn.getOutputStream());
            ds.writeBytes(twoHyphens + boundary + end);
            ds.writeBytes("Content-Disposition: form-data; "
                    + "name="file";filename="" + fileName + """ + end);
            ds.writeBytes(end);
            /* 取得文件的FileInputStream */
            FileInputStream fStream = new FileInputStream(filePath);
            /* 设置每次写入1024bytes */
            int bufferSize = 1024;
            byte[] buffer = new byte[bufferSize];
            int length = -1;
            /* 从文件读取数据至缓冲区 */
            while ((length = fStream.read(buffer)) != -1) {
              /* 将资料写入DataOutputStream中 */
                ds.write(buffer, 0, length);
            }
            ds.writeBytes(end);
            ds.writeBytes(twoHyphens + boundary + twoHyphens + end);
            /* close streams */
            fStream.close();
            ds.flush();

            int status_code =  conn.getResponseCode();
            r.status_code = status_code;
            if (status_code == 200){
                InputStream is = conn.getInputStream();
                r.text = getStringFromInputStream(is);

            }
        } catch (Exception e) {
            System.out.println(e.getMessage().toString());
        }
        return r;
    }
    /**
     * 装换InputStream
     * @param is
     * @return
     * @throws IOException
     */
    private static String getStringFromInputStream(InputStream is) throws IOException {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        // 模板代码 必须熟练
        byte[] buffer = new byte[1024];
        int len = -1;
        // 一定要写len=is.read(buffer)
        // 如果while((is.read(buffer))!=-1)则无法将数据写入buffer中
        while ((len = is.read(buffer)) != -1) {
            os.write(buffer, 0, len);
        }
        is.close();
        String state = os.toString();// 把流中的数据转换成字符串,采用的编码是utf-8(模拟器默认编码)
        os.close();
        return state;
    }
}