Java 利用HttpURLConnection发送http请求

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 = "\r\n";
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;
}
}