安卓day29网络编程 HttpClient AsyncHttpClient 断点续传多线程下载器 HttpUtils

转载 于 2019-03-01 20:50:00 发布 · 259 阅读 · 0 ·
CC 4.0 BY-SA版权
原文链接：http://www.cnblogs.com/index42/p/10458701.html
文章标签：

#移动开发 #java #ui

本文详细介绍在Android开发中如何使用HttpClient、AsyncHttpClient进行网络请求，包括GET和POST方法，并实现断点续传和多线程下载功能，同时提供具体代码实例。

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一、排坑

HttpClient、Header飘红

Android 6.0 已经移除了httpClient

module下的build.gradle中加入:

android{
      useLibrary 'org.apache.http.legacy'
}

 导入jar包

放入libs文件夹，右键选择add as library

退出整个程序

MainActivity内加入

public static List<Activity> activityList = new LinkedList();
    public void exit()  
       {  
      
           for(Activity act:activityList)  
           {  
               act.finish();  
           }  
      
           System.exit(0);  
      
       }

在每个activity的oncreat里面写上如下这么一句代码，记得要写在 setContentView 之后：

MainActivity.activityList.add(this)

退出

exit();

存储路径

sdcard：实际上只是一个快捷方式，指向了/storage/self/primary

下载速度

使用BufferedRandomAccessFile代替RandomAccessFile

真机比模拟器明显快很多

 

 

二、HttpClient

public class MainActivity extends Activity {

    Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            Toast.makeText(MainActivity.this, (String)msg.obj, 0).show();
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }


    public void get(View v){
        EditText et_name = (EditText) findViewById(R.id.et_name);
        EditText et_pass = (EditText) findViewById(R.id.et_pass);
        
        final String name = et_name.getText().toString();
        final String pass = et_pass.getText().toString();
        
        
        Thread t = new Thread(){
            @Override
            public void run() {
                String path = "http://10.32.189.73:8080/d0301/LoginServlet?username=" + URLEncoder.encode(name) + "&password=" + pass;
                //使用httpClient框架做get方式提交
                //1.创建HttpClient对象
                HttpClient hc = new DefaultHttpClient();
                
                //2.创建httpGet对象，构造方法的参数就是网址
                HttpGet hg = new HttpGet(path);
                
                //3.使用客户端对象，把get请求对象发送出去
                try {
                    HttpResponse hr = hc.execute(hg);
                    //拿到响应头中的状态行
                    StatusLine sl = hr.getStatusLine();
                    if(sl.getStatusCode() == 200){
                        //拿到响应头的实体
                        HttpEntity he = hr.getEntity();
                        //拿到实体中的内容，其实就是服务器返回的输入流
                        InputStream is = he.getContent();
                        String text = Utils.getTextFromStream(is);
                        
                        //发送消息，让主线程刷新ui显示text
                        Message msg = handler.obtainMessage();
                        msg.obj = text;
                        handler.sendMessage(msg);
                    }
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        };
        t.start();
        
    }
    
    public void post(View v){
        EditText et_name = (EditText) findViewById(R.id.et_name);
        EditText et_pass = (EditText) findViewById(R.id.et_pass);
        
        final String name = et_name.getText().toString();
        final String pass = et_pass.getText().toString();
        
        Thread t = new Thread(){
            @Override
            public void run() {
                String path = "http://10.32.189.73:8080/d0301/LoginServlet";
                //1.创建客户端对象
                HttpClient hc = new DefaultHttpClient();
                //2.创建post请求对象
                HttpPost hp = new HttpPost(path);
                
                //封装form表单提交的数据
                BasicNameValuePair bnvp = new BasicNameValuePair("username", name);
                BasicNameValuePair bnvp2 = new BasicNameValuePair("password", pass);
                List<BasicNameValuePair> parameters = new ArrayList<BasicNameValuePair>();
                //把BasicNameValuePair放入集合中
                parameters.add(bnvp);
                parameters.add(bnvp2);
                
                try {
                    //要提交的数据都已经在集合中了，把集合传给实体对象
                    UrlEncodedFormEntity entity = new UrlEncodedFormEntity(parameters, "utf-8");
                    //设置post请求对象的实体，其实就是把要提交的数据封装至post请求的输出流中
                    hp.setEntity(entity);
                    //3.使用客户端发送post请求
                    HttpResponse hr = hc.execute(hp);
                    if(hr.getStatusLine().getStatusCode() == 200){
                        InputStream is = hr.getEntity().getContent();
                        String text = Utils.getTextFromStream(is);
                        
                        //发送消息，让主线程刷新ui显示text
                        Message msg = handler.obtainMessage();
                        msg.obj = text;
                        handler.sendMessage(msg);
                    }
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        };
        t.start();
        
    }
}

 三、异步HttpClient框架

源码：https://github.com/loopj/android-async-http

public class MainActivity extends Activity {

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


    public void get(View v){
        EditText et_name = (EditText) findViewById(R.id.et_name);
        EditText et_pass = (EditText) findViewById(R.id.et_pass);
        
        final String name = et_name.getText().toString();
        final String pass = et_pass.getText().toString();
        String url = "http://10.32.189.73:8080/d0301/LoginServlet?username=" + URLEncoder.encode(name) + "&password=" + pass;
        //创建异步httpclient
        AsyncHttpClient ahc = new AsyncHttpClient();
        
        //发送get请求提交数据
        ahc.get(url, new MyResponseHandler());
    }
    
    public void post(View v){
        EditText et_name = (EditText) findViewById(R.id.et_name);
        EditText et_pass = (EditText) findViewById(R.id.et_pass);
        
        final String name = et_name.getText().toString();
        final String pass = et_pass.getText().toString();
        String url = "http://10.32.189.73:8080/d0301/LoginServlet";
        
        //创建异步httpclient
        AsyncHttpClient ahc = new AsyncHttpClient();
        
        //发送post请求提交数据
        //把要提交的数据封装至RequestParams对象
        RequestParams params = new RequestParams();
        params.add("username", name);
        params.add("password", pass);
        ahc.post(url, params, new MyResponseHandler());
    }
    
    class MyResponseHandler extends AsyncHttpResponseHandler {

        //请求服务器成功时，此方法调用
        @Override
        public void onSuccess(int statusCode, org.apache.http.Header[] headers,
                byte[] responseBody) {
            Toast.makeText(MainActivity.this, new String(responseBody), Toast.LENGTH_SHORT).show();
            
        }

        //请求失败此方法调用
        @Override
        public void onFailure(int statusCode, org.apache.http.Header[] headers,
                byte[] responseBody, Throwable error) {
            Toast.makeText(MainActivity.this, "请求失败", Toast.LENGTH_SHORT).show();
            
        }
    }
}

四、断点续传多线程下载器

添加BufferedRandomAccessFile

源码：https://files.cnblogs.com/files/index42/BufferedRandomAccessFile.zip

public class MainActivity extends AppCompatActivity {
    private static int ThreadCount = 3;
    private static int finishedThread = 0;
    public static List<Activity> activityList = new LinkedList();
    private String filepath= Environment.getExternalStorageDirectory()+"/ahmk/";
    private String downloadFilename=filepath+"test.zip";
    private static final String TAG = "MainActivity";
    int currentProgress;
    private int length;
    private String fileName = "test.zip";
    private static class Lock{};
    private static Object lock=new Lock();
    //确定下载地址
    private String path = "https://files.cnblogs.com/files/index42/" + fileName;
    private ProgressBar pb;
    TextView tv;

    Handler handler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            //把变量改成long，在long下运算
            tv.setText((long) pb.getProgress() * 100 / pb.getMax() + "%");
        }
    };
    Handler handler2 = new Handler() {
        public void handleMessage(android.os.Message msg) {
            //把变量改成long，在long下运算
            tv.setText("文件已存在");
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        MainActivity.activityList.add(this);
        Log.e(TAG, filepath);
        pb = (ProgressBar) findViewById(R.id.pb);
        tv = (TextView) findViewById(R.id.tv);
        if (ContextCompat.checkSelfPermission(MainActivity.this,
                Manifest.permission.READ_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED  ){
            //申请权限
            ActivityCompat.requestPermissions(MainActivity.this,
                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE},1);
        }else {
            //把动作告诉系统

        }
    }

    public void click(View v) {

        Thread t = new Thread() {
            @Override
            public void run() {
                //发送get请求，请求这个地址的资源
                try {
                    File file = new File(downloadFilename);
                    if(file.exists()) {
                        handler2.sendEmptyMessage(1);
                        Log.e(TAG, "已经存在文件");
                        return;
                    }
                    URL url = new URL(path);
                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                    conn.setRequestMethod("GET");
                    conn.setConnectTimeout(5000);
                    conn.setReadTimeout(5000);
                    Log.e(TAG, conn.getResponseCode()+"");
                    if (conn.getResponseCode() == 200) {
                        //拿到所请求资源文件的长度
                        length = conn.getContentLength();
                        Log.e(TAG, length+"");
                        //设置进度条的最大值就是原文件的总长度
                        pb.setMax(length);
                        Log.e(TAG, "run3: ");
                        File dir = new File(filepath);
                        if(!dir.exists()){
                            dir.mkdirs();
                        }
                        //生成临时文件
                        BufferedRandomAccessFile raf = new BufferedRandomAccessFile(file, "rwd");
                        //设置临时文件的大小
                        raf.setLength(length);
                        raf.close();
                        //计算出每个线程应该下载多少字节
                        int size = length / ThreadCount;

                        for (int i = 0; i < ThreadCount; i++) {
                            //计算线程下载的开始位置和结束位置
                            int startIndex = i * size;
                            int endIndex = (i + 1) * size - 1;
                            //如果是最后一个线程，那么结束位置写死
                            if (i == ThreadCount - 1) {
                                endIndex = length - 1;
                            }
//                            System.out.println("线程" + i + "的下载区间是：" + startIndex + "---" + endIndex);
                            new DownLoadThread(startIndex, endIndex, i).start();
                        }
                    }
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        };
        t.start();
    }
    class DownLoadThread extends Thread{
        int startIndex;
        int endIndex;
        int threadId;

        public DownLoadThread(int startIndex, int endIndex, int threadId) {
            super();
            this.startIndex = startIndex;
            this.endIndex = endIndex;
            this.threadId = threadId;
        }

        @Override
        public void run() {
            //再次发送http请求，下载原文件
            try {
                File progressFile = new File(filepath,threadId + ".txt");
                //判断进度临时文件是否存在
                if(progressFile.exists()){
                    FileInputStream fis = new FileInputStream(progressFile);
                    BufferedReader br = new BufferedReader(new InputStreamReader(fis));
                    //从进度临时文件中读取出上一次下载的总进度，然后与原本的开始位置相加，得到新的开始位置
                    int lastProgress = Integer.parseInt(br.readLine());
                    startIndex += lastProgress;

                    //把上次下载的进度显示至进度条
                    currentProgress += lastProgress;
                    pb.setProgress(currentProgress);

                    //发送消息，让主线程刷新文本进度
                    handler.sendEmptyMessage(1);
                    fis.close();
                }
                Log.e(TAG, "线程" + threadId + "的下载区间是：" + startIndex + "---" + endIndex);
                HttpURLConnection conn;
                URL url = new URL(path);
                conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod("GET");
                conn.setConnectTimeout(5000);
                conn.setReadTimeout(5000);
                //设置本次http请求所请求的数据的区间
                conn.setRequestProperty("Range", "bytes=" + startIndex + "-" + endIndex);

                //请求部分数据，相应码是206
                if(conn.getResponseCode() == 206){
                    //流里此时只有1/3原文件的数据
                    InputStream is = conn.getInputStream();
                    byte[] b = new byte[1024];
                    int len = 0;
                    int total = 0;
                    //拿到临时文件的输出流
                    File file = new File(downloadFilename);
                    BufferedRandomAccessFile raf = new BufferedRandomAccessFile(file, "rwd");
                    //把文件的写入位置移动至startIndex
                    raf.seek(startIndex);
                    while((len = is.read(b)) != -1){
                        //每次读取流里数据之后，同步把数据写入临时文件
                        raf.write(b, 0, len);
                        total += len;
                        //Log.e(TAG, "线程" + threadId + "下载了" + total);

                        //每次读取流里数据之后，把本次读取的数据的长度显示至进度条
                        currentProgress += len;
                        pb.setProgress(currentProgress);
                        //发送消息，让主线程刷新文本进度
                        handler.sendEmptyMessage(1);

                        //生成一个专门用来记录下载进度的临时文件
                        BufferedRandomAccessFile progressRaf = new BufferedRandomAccessFile(progressFile, "rwd");
                        //每次读取流里数据之后，同步把当前线程下载的总进度写入进度临时文件中
                        progressRaf.write((total + "").getBytes());
                        progressRaf.close();
                    }
                    Log.e(TAG, "线程" + threadId + "下载完毕-------------------小志参上！");
                    raf.close();

                    finishedThread++;
                    synchronized (lock) {
                        Log.e(TAG, "synchron");
                        if(finishedThread == ThreadCount){
                            for (int i = 0; i < ThreadCount; i++) {
                                File f = new File(filepath, i + ".txt");
                                f.delete();
                            }
                            Log.e(TAG, "over synchron");
                            finishedThread = 0;
                            pb.setProgress(length);
                            handler.sendEmptyMessage(1);
                        }
                    }

                }
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 1:
                //权限回调
                if (grantResults[0]==PackageManager.PERMISSION_GRANTED&&grantResults[1]==PackageManager.PERMISSION_GRANTED){

                }else {
                    //提示用户权限未被授予
                    Log.e("MainActivity","未授予权限");
                    exit();
                }
                break;
        }
    }
    public void exit()
    {

        for(Activity act:activityList)
        {
            act.finish();
        }

        System.exit(0);

    }
}
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    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:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开始下载" 
        android:onClick="click"
        />
    <ProgressBar 
        android:id="@+id/pb"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        style="@android:style/Widget.ProgressBar.Horizontal"
        />
    <TextView 
        android:id="@+id/tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
</LinearLayout>

 五、HttpUtils的使用

源码：https://github.com/wyouflf/xUtils

public class MainActivity extends Activity {

    private TextView tv_failure;
    private TextView tv_progress;
    private ProgressBar pb;
    public static List<Activity> activityList = new LinkedList();
    private static final String TAG = "MainActivity";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        MainActivity.activityList.add(this);
        tv_failure = (TextView) findViewById(R.id.tv_failure);
        tv_progress = (TextView) findViewById(R.id.tv_progress);
        pb = (ProgressBar) findViewById(R.id.pb);
        if (ContextCompat.checkSelfPermission(MainActivity.this,
                Manifest.permission.READ_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED  ){
            //申请权限
            ActivityCompat.requestPermissions(MainActivity.this,
                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE},1);
        }else {
            //把动作告诉系统

        }
    }

    public void click(View v){
        HttpUtils utils = new HttpUtils();
        String fileName = "test.zip";
        //确定下载地址
        String path = "https://files.cnblogs.com/files/index42/" + fileName;
        String filepath= Environment.getExternalStorageDirectory()+"/ahmk/";
        String downloadFilename=filepath+"test.zip";
        File file = new File(downloadFilename);
        if(file.exists()) {
            tv_progress.setText("已经存在文件");
            Log.e(TAG, "已经存在文件");
            return;
        }
        utils.download(path, //下载地址
                downloadFilename, //文件保存路径
                true,//是否支持断点续传
                true, new RequestCallBack<File>() {
                    
                    //下载成功后调用
                    @Override
                    public void onSuccess(ResponseInfo<File> arg0) {
                        Toast.makeText(MainActivity.this, arg0.result.getPath(), Toast.LENGTH_SHORT).show();
                        
                    }
                    
                    //下载失败调用
                    @Override
                    public void onFailure(HttpException arg0, String arg1) {
                        // TODO Auto-generated method stub
                        tv_failure.setText(arg1);
                    }
                    
                    @Override
                    public void onLoading(long total, long current,
                            boolean isUploading) {
                        // TODO Auto-generated method stub
                        super.onLoading(total, current, isUploading);
                        pb.setMax((int)total);
                        pb.setProgress((int)current);
                        tv_progress.setText(current * 100 / total + "%");
                    }
                });
    }
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 1:
                //权限回调
                if (grantResults[0]==PackageManager.PERMISSION_GRANTED&&grantResults[1]==PackageManager.PERMISSION_GRANTED){

                }else {
                    //提示用户权限未被授予
                    Log.e("MainActivity","未授予权限");
                    exit();
                }
                break;
        }

    }
    public void exit()
    {

        for(Activity act:activityList)
        {
            act.finish();
        }

        System.exit(0);

    }
}

 

转载于:https://www.cnblogs.com/index42/p/10458701.html

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