029_Android Http的基本使用方法
http协议 ：超文本传输协议
| 请求协议 request | 响应协议 response |
|---|---|
| 请求首行 | 响应首行 |
| 请求头信息 | 响应头信息 |
| 空行 | 空行 |
| 请求体 | 响应体 |
Fiddler
Fiddler是一个http协议调试代理工具，它能够记录并检查所有你的电脑和互联网之间的http通讯，设置断点，查看所有的“进出”Fiddler的数据（指cookie,html,js,css等文件）。
GET请求抓包演示
GET.png
GET请求和POST请求的区别
get请求直接将请求参数暴露在url，不安全+一般用于向服务器请求数据，get请求没有请求体
post请求将请求参数放在请求体里面，安全的+一般用于向服务器提交数据
网络七层协议图.jpg
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应用层 ：应用程序，用户看得见的http协议
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表示层：将人看的懂的转成计算机看的懂
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会话层：发起一个连接
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传输层：规定传输协议和端口号 TCP协议，UDP协议
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网络层：规定网络ip ip协议
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数据链路层
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物理层：光缆、网线
文件下载（GET请求）
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
import android.media.MediaPlayer;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.SeekBar;
import android.widget.Toast;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
public class PracticeActivity extends AppCompatActivity {
private String TAG = "##";
private SeekBar seekBar;
private SurfaceView surfaceView;
private AsyncTask downloadAsyncTask, continueAsyncTask;
//存储文件的路径
private String filePath = "/sdcard/Video.mp4";
//要下载文件的url
private String url = "http://vodkgeyttp8.vod.126.net/cloudmusic/NjEyMTk1NjU=/dcec07fa4375312402fbd8e8ecb851e8/37dd00b0a2a6c4e788eeecdfef33d73d.mp4?wsSecret=6c21bd623bd80249c965220eba59f7f8&wsTime=1564728030";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_practice);
seekBar = findViewById(R.id.seekBar);
}
//三个按钮的监听
public void click(View view) {
switch (view.getId()) {
case R.id.downloadButton:
download();
break;
case R.id.pauseButton:
//关闭异步任务
if (downloadAsyncTask != null) {
downloadAsyncTask.cancel(true);
}
if (continueAsyncTask != null) {
continueAsyncTask.cancel(true);
}
break;
case R.id.continueButton:
continueDowbload();
break;
}
}
@SuppressLint("StaticFieldLeak")
private void continueDowbload() {
continueAsyncTask = new AsyncTask() {
@SuppressLint("WrongThread")
@Override
protected String doInBackground(String... strings) {
File file = new File(filePath);
//上一次下载的大小
int start = 0;
//总大小
int end = 0;
try {
HttpURLConnection connection = (HttpURLConnection) new URL(strings[0]).openConnection();
connection.connect();
if (connection.getResponseCode() == 200) {
start = (int) file.length();
end = connection.getContentLength();
Log.i(TAG, "doInBackground: 请求成功");
}
} catch (IOException e) {
e.printStackTrace();
}
if (start == end) {
Log.i(TAG, "doInBackground: GG");
return "下载完成";
}
InputStream is = null;
RandomAccessFile raf = null;
try {
HttpURLConnection connection = (HttpURLConnection) new URL(strings[0]).openConnection();
//设置请求体
connection.setRequestProperty("Range", "bytes=" + start + "-" + end);
connection.connect();
if (connection.getResponseCode() == 206) {
Log.i(TAG, "doInBackground: 开始第二次");
seekBar.setMax(end);
publishProgress(start);
is = connection.getInputStream();
//随机访问流
raf = new RandomAccessFile(filePath, "rw");
//设置写入位置
raf.seek(start);
int length = 0;
byte[] bytes = new byte[1024 * 8];
Log.i(TAG, "doInBackground: 再次写入");
while ((length = is.read(bytes)) != -1) {
raf.write(bytes, 0, length);
start += length;
publishProgress(start);
}
return "下载完成";
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (raf != null) {
try {
raf.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return "下载失败";
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
Toast.makeText(PracticeActivity.this, s, Toast.LENGTH_SHORT).show();
}
@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
seekBar.setProgress(values[0]);
}
}.execute(url);
}
@SuppressLint("StaticFieldLeak")
private void download() {
//异步任务
downloadAsyncTask = new AsyncTask() {
@SuppressLint("WrongThread")
@Override
protected String doInBackground(String... strings) {
InputStream is = null;
FileOutputStream os = null;
try {
//请求连接
URL url = new URL(strings[0]);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.connect();
//判断请求码
if (connection.getResponseCode() == 200) {
//获得请求数据的大小
int contentLength = connection.getContentLength();
//设置最大进度
seekBar.setMax(contentLength);
//获得输入 输出流
is = connection.getInputStream();
os = new FileOutputStream(filePath);
//每次读取的长度
int length = 0;
//当前下载的进度
int currentProgress = 0;
byte[] bytes = new byte[1024 * 8];
//开始下载
while ((length = is.read(bytes)) != -1) {
os.write(bytes, 0, length);
currentProgress += length;
//发布进度
publishProgress(currentProgress);
}
}
return "下载完成";
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
//关闭资源
if (is != null) {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (os != null) {
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return "下载失败";
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
Toast.makeText(PracticeActivity.this, s, Toast.LENGTH_SHORT).show();
}
@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
//更新进度
seekBar.setProgress(values[0]);
}
}.execute(url);
}
}
文件上传（POST请求）
private String upload(String uploadFileUrl, File uploadFile) {
OutputStream os = null;
FileInputStream is = null;
try {
HttpURLConnection connection = (HttpURLConnection) new URL(uploadFileUrl).openConnection();
//设置连接方式
connection.setRequestMethod("POST");
//设置可输出
connection.setDoOutput(true);
//拼接请求体
StringBuffer requestBody = new StringBuffer();
requestBody.append("-----------------------------7e324741816d4\r\n");
requestBody.append("Content-Disposition: form-data; name=\"file\"; filename=" + uploadFile.getName() + "\r\n");
requestBody.append("Content-Type: image/*" + "\r\n");
requestBody.append("\r\n");
byte[] requsetBodyByte = requestBody.toString().getBytes("UTF-8");
//设置请求头
connection.setRequestProperty("Content-Length", uploadFile.length() + requsetBodyByte.length + "");
connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=7e324741816d4");
//获得输出流
os = connection.getOutputStream();
//写入信息
os.write(requsetBodyByte);
//连接
connection.connect();
//读取本地文件并且写入服务器
is = new FileInputStream(uploadFile);
int length = 0;
byte[] bytes = new byte[1024 * 8];
while ((length = is.read(bytes)) != -1) {
os.write(bytes, 0, length);
}
if (connection.getResponseCode() == 200) {
return "上传成功";
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (os != null) {
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (is != null) {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return "上传失败";
}
}