//将地址转换为URL`
`URL url = new URL("http://localhost:8080/TestHttpURLConnectionPro/index.jsp"); 
// 此处的urlConnection对象实际上是根据URL的请求协议(此处是http)生成的URLConnection类的子类HttpURLConnection,故此处最好将其转化为HttpURLConnection类型的对象 
`URLConnection rulConnection = url.openConnection();
HttpURLConnection httpUrlConnection = (HttpURLConnection) rulConnection;`

`// 设置是否向httpUrlConnection输出，因为这个是post请求，参数要放在。http正文内，因此需要设为true, 默认情况下是false;
httpUrlConnection.setDoOutput(true);
//设置是否从httpUrlConnection读入，默认情况下是true;
httpUrlConnection.setDoInput(true);
// Post 请求不能使用缓存
httpUrlConnection.setUseCaches(false);
// 设定传送的内容类型是可序列化的java对象
// (如果不设此项,在传送序列化对象时,当WEB服务默认的不是这种类型时可能抛java.io.EOFException) httpUrlConnection.setRequestProperty("Content-type", "application/x-java-serialized-object");
// 设定请求的方法为"POST"，默认是GET
httpUrlConnection.setRequestMethod("POST");
// 连接，从上述第2条中url.openConnection()至此的配置必须要在connect之前完成， httpUrlConnection.connect();`

`private void doGet(){
	 try {
	 	url = url + "?name=" + URLEncoder.encode(name,"utf-8") + "&age=" + age; 
	} catch (UnsupportedEncodingException e) {
		 e.printStackTrace();
	 }
	 try {
		 URL httpUrl = new URL(url); //新建URL对象
		 HttpURLConnection conn = (HttpURLConnection) httpUrl.openConnection();//打开一个连接  
		 conn.setRequestMethod("GET");//设置请求方法为GET
		 conn.setReadTimeout(5000);//设置从服务器读取数据的超时限制为5秒
		 BufferedReader reader = new BufferedReader( new 	InputStreamReader(conn.getInputStream()));//获取服务器传递的数据输入流 String str;
		 StringBuffer sb = new StringBuffer(); //存储读取的数据
		 while((str = reader.readLine()) != null){
		//读取数据
		 sb.append(str);
	 }
	 	System.out.println("result:"+sb.toString());
	 } catch (MalformedURLException e) {
	 	e.printStackTrace(); 
	} catch (IOException e) {
	 	e.printStackTrace();
	 }
 }`

`private void doPost(){
	 try {
		 URL HttpUrl = new URL(url); 
		 HttpURLConnection conn = (HttpURLConnection) HttpUrl.openConnection();     		
		 conn.setRequestMethod("POST");   
		 conn.setReadTimeout(5000); 
		 OutputStream out = conn.getOutputStream(); //新建输出流对象 
		 String content = "name="+name+"&age="+age;//传递对象 
		 out.write(content.getBytes());//将传递对象转为字符流写入输出流中
		 //下面是对于服务器返回数据的处理
		 BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
		StringBuffer sb = new StringBuffer(); 
		String str; 
		while((str=reader.readLine())!=null){ 
		sb.append(str); 
	} 
		System.out.println(sb.toString()); 
	} catch (MalformedURLException e) {
	 	e.printStackTrace();
	 } catch (IOException e) {
	 	e.printStackTrace();
	 }
 }`

public class DownLoad {

	private Executor threadPool = Executors.newFixedThreadPool(3);
	
	private Handler handler;
	
	public DownLoad(Handler handler){
	    this.handler = handler;
	}
	static class DownLoadRunnable implements Runnable {
	
	    private String url;
	
	    private String fileName; 
	
	    private long start;
	
	    private long end;
	
	    private Handler handler;
	
	    public DownLoadRunnable(String url,String fileName,long start,long end,Handler handler){
	        this.url = url;
	        this.fileName = fileName;
	        this.start = start;
	        this.end = end;
	        this.handler = handler;
	    }
	    @Override
	    public void run() {
	        try {
	            URL httpUrl = new URL(url);
	            HttpURLConnection conn = (HttpURLConnection) httpUrl.openConnection();
	            conn.setRequestMethod("GET");
	            conn.setRequestProperty("Range","bytes="+start+"-"+end);
	            conn.setReadTimeout(5000);
	
	            RandomAccessFile access = new RandomAccessFile(new File(fileName),"rwd");
	            access.seek(start);
	            InputStream in = conn.getInputStream(); 
	            byte[] b = new byte[1024*4];
	            int len=0;
	            while((len=in.read(b))!=-1){
	                access.write(b,0,len);
	            }
	
	            if (access!=null){
	                access.close();
	            }
	            if (in!=null){
	                in.close();
	            }
	
	            Message msg = new Message();
	            msg.what = 1;
	            handler.sendMessage(msg);
	        } catch (IOException e) {
	            e.printStackTrace();
	        }
	    }
	}
	
	public void loadFile(String url) {
	    try {
	        URL httpUrl = new URL(url);
	        HttpURLConnection conn = (HttpURLConnection) httpUrl.openConnection();
	        conn.setRequestMethod("GET");
	        conn.setReadTimeout(5000);
	        int count = conn.getContentLength();
	        int block = count / 3; 
	        String fileName = getFileName(url);
	        File parent = Environment.getExternalStorageDirectory();
	        File download = new File(parent,fileName);
	
	        for (int i=0;i<3;i++){
	            long start = i*block;
	            long end = (i+1)*block-1;
	            if (i==2){
	                end = count;
	            }
	
	            DownLoadRunnable runnable = new DownLoadRunnable(url,download.getAbsolutePath(),start,end,handler);
	            threadPool.execute(runnable);
	        }
	    } catch (IOException e) {
	        e.printStackTrace();
	    }
	}
	public String getFileName(String url){
	    return url.substring(url.lastIndexOf("/")+1);
	}
}

// 01\. 定义okhttp
OkHttpClient okHttpClient_get = new OkHttpClient();
// 02.请求体
Request request = new Request.Builder()
.get()//get请求方式
.url("http://10.0.3.2:8080/WebServiceTest/servlet/ServcieTest?name=sy")//网址
.build();
Response response = okHttpClient_get.newCall(request).execute();
if (response.isSuccessful()) {
    // 打印数据
    System.out.println(response.body().string());
} else {       
     throw new IOException("Unexpected code " + response);
}

-  enqueue是异步方法

// 定义okhttp
OkHttpClient okHttpClient_post_kv = new OkHttpClient();
// 定义请求体
// 执行okhttp
RequestBody body = new FormBody.Builder()
                    .add("name", "sy")//添加参数体
                    .add("age", "18")
                    .build();
Request request = new Request.Builder()
    .post(body) //请求参数
    .url("http://10.0.3.2:8080/WebServiceTest/servlet/ServcieTest")
    .build();
Response response = okHttpClient_post_kv.newCall(request).execute();
System.out.println(response.body().string());

-  enqueue是异步方法

OkHttpClient okHttpClient_post_json = new OkHttpClient();
String json = "{\n" + " "age": "18",\n" + " "name": "sy"\n" + "}";
RequestBody body =
RequestBody.create(MediaType.parse("application/json;charset=utf-8"), json);
Request request = new Request.Builder()
.post(body)
.url("http://10.0.3.2:8080/WebServiceTest/servlet/ServcieTest")
.build();
Response response = okHttpClient_post_json.newCall(request).execute();
System.out.println(response.body().string());

OkHttpClient okHttpClient_upload = new OkHttpClient();
File file = new File(Environment.getExternalStorageDirectory() + "/download", "file.txt");
RequestBody body = RequestBody.create(MediaType.parse("application/octet-stream"), file);
Request request = new Request.Builder()
    .post(body)
    .url("http://10.0.3.2:8080/WebServiceTest/servlet/ServcieTest")
    .build();
Response response = okHttpClient_upload.newCall(request).execute();
System.out.println(response.body().string());

OkHttpClient okHttpClient_down = new OkHttpClient();
Request request =
new Request.Builder()
.get()
.url("http://10.0.3.2:8080/WebServiceTest/p22.jpg")
.build();
okHttpClient_down.newCall(request).enqueue(MainActivity.this);

 /**
 * 超时错误,服务器无响应
 * 
 * @param call
 * @param e
 */
@Override
public void onFailure(Call call, IOException e)
{

}

/**
 * 服务器响应
 * 
 * @param call
 * @param response
 * @throws IOException
 */
@Override
public void onResponse(Call call, Response response)
    throws IOException
{
    InputStream inputStream = response.body().byteStream();
    final BitmapDrawable bitmapDrawable = new BitmapDrawable(inputStream);

    runOnUiThread(new Runnable()
    {
        @Override
        public void run()
        {

            mIv_main_load_image.setImageDrawable(bitmapDrawable);
        }
    });

}

 OkHttpClient client=new OkHttpClient.Builder() 
 .connectTimeout(60, TimeUnit.SECONDS) //设置连接超时 
 .readTimeout(60, TimeUnit.SECONDS) //设置读超时 
 .writeTimeout(60,TimeUnit.SECONDS) //设置写超时 
 .retryOnConnectionFailure(true) //是否自动重连 
 .build(); //构建OkHttpClient对象 

 client.dispatcher().executorService().shutdown(); //清除并关闭线程池 
 client.connectionPool().evictAll(); //清除并关闭连接池 
 client.cache().close(); //清除cache

OkHttpClient eagerClient = client.newBuilder() 
.readTimeout(500, TimeUnit.MILLISECONDS)
.build();
Request request = new Request.Builder()
.url(“[https://api.github.com/repos/square/okhttpissues](https://api.github.com/repos/square/okhttpissues)“) 
//设置访问url 
.get() //类似的有post、delete、patch、head、put等方法，对应不同的网络请求方法 
.header(“User-Agent”, “OkHttpHeaders.java”) //设置header 
.addHeader(“Accept”, “application/json; q=0.5”) //添加header 
.removeHeader(“User-Agent”) //移除header 
.headers(new Headers.Builder().add(“User-Agent”, “OkHttp Headers.java”).build())//移除原有所有header，并设置新header 
.addHeader(“Accept”, “application/vnd.github.v3+json”) 
.build(); //构建request

 RequestBody formBody = new FormBody.Builder() //提交表单键值对 
 .add(“platform”, “android”) //添加键值对 
 .add(“name”, “XXX”) 
 .add(“subject”, “Hello”) 
 .addEncoded(URLEncoder.encode(“详细”,”GBK”), //添加已编码的键值对 
 URLEncoder.encode(“无”,”GBK”)) 
 .add(“描述”,”你好”) //其实会自动编码，但是无法控制编码格式 
 .build();

RequestBody requestBody = new MultipartBody.Builder()
.setType(MultipartBody.FORM)
.addPart(
        Headers.of("Content-Disposition", "form-data; name=\"title\""),
        RequestBody.create(null, "Logo"))
.addPart(
        Headers.of("Content-Disposition", "form-data; name=\"image\""),
        RequestBody.create(MediaType.parse("image/png"), new File("website/static/logo.png")))
.addFormDataPart("discription","beautiful")
.build();

Call call=client.newCall(request); //获取Call对象 
Response response=call.execute(); //同步执行网络请求，不要在主线程执行 
call.enqueue(new Callback()); //异步执行网络请求 
call.cancel(); //取消请求 
call.isCanceled(); //查询是否取消 
call.isExecuted(); //查询是否被执行过 
ResponseBody 
body.contentLength(); //body的长度 
String content=body.string(); //以字符串形式解码body 
byte[] byteContent=body.bytes(); //以字节数组形式解码body 
InputStreamReader reader=body.charStream(); //将body以字符流的形式解码 
InputStream inputStream=body.byteStream(); //将body以字节流的形式解码