HttpURLConnection使用总结

    url = new URL(MJConstant.SERVER_PATH + "api/meetings/"); //请求会议列表接口
    HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
    urlConn.setRequestMethod("GET");
    urlConn.setDoOutput(false);
    urlConn.setReadTimeout(5 * 1000);//设置超时时间
    urlConn.setRequestProperty("Authorization", "JWT " + HttpClientService.getToken());//请求头里加入签权信息
    urlConn.connect();
    //获得response数据
    InputStream is = urlConn.getInputStream();
    InputStreamReader isr = new InputStreamReader(is);
    //使用缓冲一行行的读入，加速InputStreamReader的速度
    BufferedReader buffer = new BufferedReader(isr);
    String inputLine = null;

    while ((inputLine = buffer.readLine()) != null) {
        resultData.append(inputLine);
        resultData.append("\n");
    }
    buffer.close();
    isr.close();
    urlConn.disconnect();
    String mStrContent = resultData.toString();
    //下面就是对数据的解析
  

    InputStream is = urlConn.getInputStream();
    if(urlConn.getResponseCode()>=400){
      InputStreamReader isr = new InputStreamReader(is);
    }else{
      InputStreamReader isr = new InputStreamReader(is);
  }
  

      HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
      urlConn.setRequestMethod("POST");
      urlConn.setDoOutput(true);
      urlConn.setDoInput(true);
      urlConn.setReadTimeout(5 * 1000);
      urlConn.setRequestProperty("Authorization", "JWT " + HttpClientService.getToken());
      urlConn.setUseCaches(false);
      urlConn.setInstanceFollowRedirects(true);
      urlConn.setRequestProperty("Content-Type",
              "application/json");
      urlConn.connect();
      //POST请求
      DataOutputStream out = new DataOutputStream(
              urlConn.getOutputStream());
      JSONObject obj = new JSONObject();
      obj.put("confirm_status", confirm_status);
      out.writeBytes(obj.toString());
      out.flush();
      out.close();

import java.io.*;
import java.net.*;
import java.util.*;

class Test {
    public static void main(String[] args) throws Exception {
        URL url = new URL("http://example.net/new-message.php");
        Map<String,Object> params = new LinkedHashMap<>();
        params.put("name", "Freddie the Fish");
        params.put("email", "fishie@seamail.example.com");
        params.put("reply_to_thread", 10394);
        params.put("message", "Shark attacks in Botany Bay have gotten out of control. We need more defensive dolphins to protect the schools here, but Mayor Porpoise is too busy stuffing his snout with lobsters. He's so shellfish.");

        StringBuilder postData = new StringBuilder();
        for (Map.Entry<String,Object> param : params.entrySet()) {
            if (postData.length() != 0) postData.append('&');
            postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
            postData.append('=');
            postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
        }
        byte[] postDataBytes = postData.toString().getBytes("UTF-8");

        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
        conn.setDoOutput(true);
        conn.getOutputStream().write(postDataBytes);

        Reader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
        for ( int c = in.read(); c != -1; c = in.read() )
            System.out.print((char)c);
    }
}

package cn.zhuangyan.test;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;

public class HttpPostUtil {
    URL url;
    HttpURLConnection conn;
    String boundary = "--------zypost";
    Map<String, String> textParams = new HashMap<String, String>();
    Map<String, File> fileparams = new HashMap<String, File>();
    DataOutputStream ds;

    public HttpPostUtil(String url) throws Exception {
        this.url = new URL(url);
    }
    //重新设置要请求的服务器地址，即上传文件的地址。
    public void setUrl(String url) throws Exception {
        this.url = new URL(url);
    }
    //增加一个普通字符串数据到form表单数据中
    public void addTextParameter(String name, String value) {
        textParams.put(name, value);
    }
    //增加一个文件到form表单数据中
    public void addFileParameter(String name, File value) {
        fileparams.put(name, value);
    }
    // 清空所有已添加的form表单数据
    public void clearAllParameters() {
        textParams.clear();
        fileparams.clear();
    }
    // 发送数据到服务器，返回一个字节包含服务器的返回结果的数组
    public byte[] send() throws Exception {
        initConnection();
        try {
            conn.connect();
        } catch (SocketTimeoutException e) {
            // something
            throw new RuntimeException();
        }
        ds = new DataOutputStream(conn.getOutputStream());
        writeFileParams();
        writeStringParams();
        paramsEnd();
        InputStream in;
        System.out.println(conn.getResponseMessage());
        if(conn.getResponseCode()>=400)
        {
            in = conn.getErrorStream();
        }else {
            in = conn.getInputStream();
        }

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int b;
        while ((b = in.read()) != -1) {
            out.write(b);
        }
        conn.disconnect();
        return out.toByteArray();
    }
    //文件上传的connection的一些必须设置
    private void initConnection() throws Exception {
        conn = (HttpURLConnection) this.url.openConnection();
        conn.setRequestMethod("POST");
        conn.setDoOutput(true);
        conn.setDoInput(true);
        conn.setUseCaches(false);
        conn.setInstanceFollowRedirects(true);
        conn.setConnectTimeout(10000); //连接超时为10秒
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Authorization","JWT eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VybmFtZSI6IjEiLCJ1c2VyX2lkIjoxLCJlbWFpbCI6IjFAMTM5LmNvbSIsImV4cCI6MTQ1Mzc2OTc2MH0.lbfFHcczHdWuYjnaqu7f9K0s6mafbq7_oWD7v-a3jcw");
        conn.setRequestProperty("Content-Type",
                "multipart/form-data; boundary=" + boundary);
    }
    //普通字符串数据
    private void writeStringParams() throws Exception {
        Set<String> keySet = textParams.keySet();
        for (Iterator<String> it = keySet.iterator(); it.hasNext();) {
            String name = it.next();
            String value = textParams.get(name);
            ds.writeBytes("--" + boundary + "\r\n");
            ds.writeBytes("Content-Disposition: form-data; name=\"" + name
                    + "\"\r\n");
            ds.writeBytes("\r\n");
            ds.writeBytes(encode(value) + "\r\n");
        }
    }
    //文件数据
    private void writeFileParams() throws Exception {
        Set<String> keySet = fileparams.keySet();
        for (Iterator<String> it = keySet.iterator(); it.hasNext();) {
            String name = it.next();
            File value = fileparams.get(name);
            ds.writeBytes("--" + boundary + "\r\n");
            ds.writeBytes("Content-Disposition: form-data; name=\"" + name
                    + "\"; filename=\"" + encode(value.getName()) + "\"\r\n");
            ds.writeBytes("Content-Type: " + getContentType(value) + "\r\n");
            ds.writeBytes("\r\n");
            ds.write(getBytes(value));
            ds.writeBytes("\r\n");
        }
    }
    //获取文件的上传类型，图片格式为image/png,image/jpg等。非图片为application/octet-stream
    private String getContentType(File f) throws Exception {

//    return "application/octet-stream";  // 此行不再细分是否为图片，全部作为application/octet-stream 类型
        ImageInputStream imagein = ImageIO.createImageInputStream(f);
        if (imagein == null) {
            return "application/octet-stream";
        }
        Iterator<ImageReader> it = ImageIO.getImageReaders(imagein);
        if (!it.hasNext()) {
            imagein.close();
            return "application/octet-stream";
        }
        imagein.close();
        return "image/" + it.next().getFormatName().toLowerCase();//将FormatName返回的值转换成小写，默认为大写

    }
    //把文件转换成字节数组
    private byte[] getBytes(File f) throws Exception {
        FileInputStream in = new FileInputStream(f);
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte[] b = new byte[1024];
        int n;
        while ((n = in.read(b)) != -1) {
            out.write(b, 0, n);
        }
        in.close();
        return out.toByteArray();
    }
    //添加结尾数据
    private void paramsEnd() throws Exception {
        ds.writeBytes("--" + boundary + "--" + "\r\n");
        ds.writeBytes("\r\n");
    }
    // 对包含中文的字符串进行转码，此为UTF-8。服务器那边要进行一次解码
    private String encode(String value) throws Exception{
        return URLEncoder.encode(value, "UTF-8");
    }
    public static void main(String[] args) throws Exception {
        HttpPostUtil u = new HttpPostUtil("http://192.168.4.34:8000/api/messages/");
        u.addTextParameter("media_type","2");
        u.addFileParameter("media", new File(
                "c:\\12014年2月桌面.jpg"));
        u.addTextParameter("group_id", "2");
        byte[] b = u.send();
        String result = new String(b);
        System.out.println(result);
    }
}