Url网络下载 Post和Get请求
Post
//post请求
private void registerUser() {
String registerUrl = "http://169.254.230.253:8080/register";
try {
URL url = new URL(registerUrl);
HttpURLConnection postConnection = (HttpURLConnection) url.openConnection();
postConnection.setRequestMethod("POST");//post 请求
postConnection.setConnectTimeout(1000*5);
postConnection.setReadTimeout(1000*5);
postConnection.setDoInput(true);//允许从服务端读取数据
postConnection.setDoOutput(true);//允许写入
postConnection.setRequestProperty("Content-type", "application/x-www-form-urlencoded");//以表单形式传递参数
String postParms = "name=1702C2019&password=12345&verifyCode=8888";
OutputStream outputStream = postConnection.getOutputStream();
outputStream.write(postParms.getBytes());//把参数发送过去.
outputStream.flush();
final StringBuffer buffer = new StringBuffer();
int code = postConnection.getResponseCode();
if (code == 200) {//成功
InputStream inputStream = postConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String line = null;//一行一行的读取
while ((line = bufferedReader.readLine()) != null) {
buffer.append(line);//把一行数据拼接到buffer里
}
runOnUiThread(new Runnable() {
@Override
public void run() {
//把从服务端获取的数据提示出来
Toast.makeText(MainActivity.this, buffer.toString(), Toast.LENGTH_SHORT).show();
}
});
}
} catch (Exception e) {
e.printStackTrace();
}
}
Get
private void downloadFile() {
String downloadurl = "http://www.chinadaily.com.cn/hqzx/images/attachement/jpg/site385/20120924/00221918200911ca40e52b.jpg";
BufferedInputStream bfs = null;
FileOutputStream outputStream = null;
String savepath = "/sdcard/flowergirl.jpg";
File file = new File(savepath);
//如果文件存在就先删掉这个文件
if (file.exists()) {
file.delete();
}
try {
URL url = new URL(downloadurl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(1000 * 5);
connection.setReadTimeout(1000 * 5);
connection.setDoInput(true);
connection.connect();
//代表请求成功
if (connection.getResponseCode() == 200) {
InputStream inputStream = connection.getInputStream();
final Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
runOnUiThread(new Runnable() {
@Override
public void run() {
imageView.setImageBitmap(bitmap);
}
});
bfs = new BufferedInputStream(inputStream);
outputStream = new FileOutputStream(savepath);
byte[] bytes = new byte[1024];
int len = 0;
while ((len = bfs.read(bytes)) != -1) {
outputStream.write(bytes, 0, len);//写入文件
}
outputStream.flush();//强制把数据写入磁盘
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (bfs != null) {
bfs.close();
}
if (outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
package com.example.day14;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
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.io.PipedOutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private HandlerThread handlerThread;
private Handler handler;
private final static int DOWNLOAD = 1;
private final static int POSTDOWNLOAD = 2;
private ImageView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
handlerThread = new HandlerThread("Http");
handlerThread.start();
handler = new Httphandler(handlerThread.getLooper());
//让handler消息运行在子线程
imageView = findViewById(R.id.imagedown);
findViewById(R.id.btn1).setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn1:
handler.sendEmptyMessage(DOWNLOAD);
break;
case R.id.btn2:
handler.sendEmptyMessage(POSTDOWNLOAD);
break;
default:
break;
}
}
private class Httphandler extends Handler {
public Httphandler(Looper looper) {
super(looper);
}
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case DOWNLOAD:
downloadFile();
break;
case POSTDOWNLOAD:
PostdownloadFile();
default:
break;
}
}
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="vertical">
<Button
android:text="下载文件"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/btn1"
/>
<Button
android:text="POST下载文件"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/btn2"
/>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/imagedown"/>
</LinearLayout>