关于HttpURLConnection的用法

package com.example.fafa.mydemoaboutnet;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

private Button mBtn;
private TextView mViewText;
private Button mSend;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iniView();
}

private void iniView() {
mBtn = (Button) findViewById(R.id.my_btn);
mViewText = (TextView) findViewById(R.id.view_text);
mSend = (Button) findViewById(R.id.btn_send);
mSend.setOnClickListener(this);
mBtn.setOnClickListener(this);
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.my_btn:
getMessages();//服务器端获取数据
break;
case R.id.btn_send:
sendMessages();//客户端发送数据比如用户名密码之类的
break;
}

}

private void sendMessages() {
new Thread(new Runnable() {
HttpURLConnection connection=null;
BufferedReader mreader=null;//这一步写在外面不然finally无法处理
@Override
public void run() {
try {
URL url= new URL("http://192.168.191.1:8080/bigweb/tologin");
connection= ((HttpURLConnection) url.openConnection());
connection.setRequestMethod("POST");
DataOutputStream out =new DataOutputStream(connection.getOutputStream());
out.writeBytes("username=yang&password=123456");
//post请求  在这里我是用的朋友的阿帕奇上的一个登陆的模块 判断我传递过去的数据 然后返回给我一个字符串
//结果接受成功
connection.setRequestMethod("GET");
connection.setConnectTimeout(8000);
connection.setReadTimeout(8000);
InputStream in = connection.getInputStream();
String line;
mreader=new BufferedReader(new InputStreamReader(in));
StringBuilder response= new StringBuilder();
while((line=mreader.readLine())!=null){
response.append(line);
}
showView(response.toString());
} catch (Exception e) {
e.printStackTrace();
} finally {
if(mreader==null){
try {
mreader.close();//你请求的网址如果不正确 这里会报错
} catch (IOException e) {
e.printStackTrace();
}
}
if (connection!=null){
connection.disconnect();
}
}
}
}).start();
}

private void getMessages() {
new Thread(new Runnable() {
HttpURLConnection connection=null;
BufferedReader mreader=null;//这一步写在外面不然finally无法处理
@Override
public void run() {
try {
URL url= new URL("https://www.baidu.com");
connection= ((HttpURLConnection) url.openConnection());//获取实例传入目标地址
connection.setRequestMethod("GET");
connection.setConnectTimeout(8000);
connection.setReadTimeout(8000);
InputStream in = connection.getInputStream();
mreader=new BufferedReader(new InputStreamReader(in));
String line;
StringBuilder response= new StringBuilder();
while((line=mreader.readLine())!=null){
response.append(line);
}
showView(response.toString());
} catch (Exception e) {
e.printStackTrace();
} finally {
if(mreader==null){
try {
mreader.close();//你请求的网址如果不正确 这里会报错
} catch (IOException e) {
e.printStackTrace();
}
}
if (connection!=null){
connection.disconnect();
}
}
}
}).start();
}

private void showView(final String s) {
runOnUiThread(new Runnable() {
@Override
public void run() {
//这里进行了 UI操作子线程是不能更新UI的 需要用handler 但是这里的runOnUiRhread是可以的
//因为它本身就是进行了handler的 点进去你会发现他进行的是一个senddelaymessage操作
mViewText.setText(s);
}
});
}
}

以上是代码 XML就不贴出来了 XML就是二个按钮 一个是发送数据 一个是接受数据  还有一个ScrollView

里面存放一个TextView用来显示服务器端返回的数据