Http Post和Get请求

主类代码

package com.example.unit13;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    ImageView imageView;
    HandlerThread thread;
    private HttpHandler handler;
    private static final int DOWNLOAD=1;//GET  Handler发送码
    private static final int REGISTER=2;//POST Handler发送码
    InputStream is;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageView=findViewById(R.id.image1);
        findViewById(R.id.load).setOnClickListener(this);
        findViewById(R.id.post).setOnClickListener(this);
        thread=new HandlerThread("thread");
        thread.start();
        handler=new HttpHandler(thread.getLooper());//让hanlder消息运行子线程


    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.load:
                downLoadFile();
                handler.sendEmptyMessage(DOWNLOAD);
                break;
            case R.id.post:
                handler.sendEmptyMessage(REGISTER);
                break;
                default:break;
        }
    }
    private void registerUser(){
        String registerUrl="http://169.254.230.253:8080/register";
        try {
            URL url = new URL(registerUrl);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setReadTimeout(5000);
            connection.setConnectTimeout(5000);
            connection.setDoInput(true);//允许读取
            connection.setDoOutput(true);//允许写入
            connection.setRequestProperty("content-type","application/x-www-form-urlencoded");//以表单形式传递参数
            String postParms="name=1702c&password=12345&verifyCode=8888";
            OutputStream oos=connection.getOutputStream();
            oos.write(postParms.getBytes());//把参数发送过去
            oos.flush();
            final StringBuffer sb=new StringBuffer();
            int code=connection.getResponseCode();
            if(code==200){//成功
                InputStream is = connection.getInputStream();
                BufferedReader bis=new BufferedReader(new InputStreamReader(is));
                String line=null;//一行一行读
                while((line=bis.readLine())!=null){
                     sb.append(line);//拼接
                }
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        //把获取的数据提示出来
                        Toast.makeText(MainActivity.this,sb.toString(),Toast.LENGTH_SHORT).show();
                    }
                });
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private class HttpHandler extends Handler{
        public HttpHandler(Looper loopers){
            super(loopers);
        }
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what){
                case DOWNLOAD:
                     downLoadFile();
                    break;
                case REGISTER:
                    registerUser();
                    break;
            }
        }
    }
    //需要放到子线程中去 使用HandlerTjread
    private void downLoadFile() {
        String downloadURL="http://pic34.nipic.com/20131020/6704106_203943375000_2.jpg";
//      String downloadURL="https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1561115440688&di=ac408b4a82c7962ce3894450b0299ba8&imgtype=0&src=http%3A%2F%2Fp1.qhmsg.com%2Fdmsmty%2F898_709_%2Ft01a57725210bedecaf.jpg";
      String savePah="/sdcard/bigbig.jpg";
        BufferedInputStream bis=null;
        FileOutputStream fos=null;
        File file=new File(savePah);
        if(file.exists()){
            file.delete();//如果文件存在,删掉
        }
        try {
            URL url = new URL(downloadURL);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            connection.setReadTimeout(5000);
            connection.setConnectTimeout(5000);
            connection.setDoInput(true);
            connection.connect();
            //代表请求成功
            if(connection.getResponseCode()==200){
                is = connection.getInputStream();
                //文件输入流
                 bis=new BufferedInputStream(is);
                //文件输出流
                fos=new FileOutputStream(savePah);
                byte[] bytes=new byte[1024];
                int len=0;
                while ((len=bis.read(bytes))!=-1){
                    fos.write(bytes,0,len);//写入文件
                }
                fos.flush();//强制把数据写入磁盘

            }
            final Bitmap bitmap= BitmapFactory.decodeFile(savePah);
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    imageView.setImageBitmap(bitmap);
                }
            });
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try {
                if(bis!=null){
                    bis.close();
                }
                if(fos!=null){
                    fos.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

效果图