Android中HttpURLConnection获取网址源码,子线程里更新UI

用ScrollVIE包裹TextVIEw显示源码

package com.peng.HTML_look;import androID.os.Bundle;import androID.os.Handler;import androID.support.v7.app.AppCompatActivity;import androID.vIEw.VIEw;import androID.Widget.EditText;import androID.Widget.TextVIEw;import java.io.inputStream;import java.net.httpURLConnection;import java.net.URL;public class MainActivity extends AppCompatActivity {    private TextVIEw tv_result;    private EditText et_path;    private Handler handler;    private String content;    @OverrIDe    protected voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentVIEw(R.layout.activity_main);        tv_result = (TextVIEw) findVIEwByID(R.ID.tv_result);        et_path = (EditText) findVIEwByID(R.ID.et_path);        handler = new Handler();    }    public voID click(VIEw vIEw) {        new Thread() {            public voID run() {                HTML();            }        }.start();    }    private voID HTML() {        //访问网络代码        try {            //获取源码路径            String path = et_path.getText().toString().trim();            //创建一个URL 对象指定我们要访问的网址(路径)            URL url = new URL(path);            //拿到httpurlconnection对象,用于发射或接收数据            httpURLConnection conn = (httpURLConnection) url.openConnection();            //设置发送get请求,get要求大写,默认get请求            conn.setRequestMethod("GET");            //设置请求超时时间            conn.setConnectTimeout(5000);            //获取服务器返回的状态码            int code = conn.getResponseCode();            //code 为200,则请求成功            if (code == 200) {                //从服务器返回数据,以流的形式返回,由于把流转换成字符很常见,封装成一个方法                inputStream inputStream = conn.getinputStream();                //使用工具类把inputstream 转换成string                content = StreamTools.readStream(inputStream);                handler.post(runnableui);               /* //把流的数据展示到textvIEw上,子线程不能更新UI                tv_result.setText(content);*/            }        } catch (Exception e) {            e.printstacktrace();        }    }    // 构建Runnable对象，在runnable中更新界面    Runnable runnableui = new Runnable() {        @OverrIDe        public voID run() {            //更新界面            tv_result.setText("the Content is:" + content);        }    };}

package com.peng.HTML_look;import java.io.inputStream;import java.io.ByteArrayOutputStream;/** * 读取流中的数据 * <p> * inputStream输入流转换成一个String * Created by Peng on 2016/7/28. */public class StreamTools {    //静态方法可以直接通过类名使用    public static String readStream(inputStream inputStream) throws Exception {        //定义内存输出流        ByteArrayOutputStream outStream = new ByteArrayOutputStream();        //定义缓存区        byte[] buffer = new byte[1024];        int len = -1;        while ((len = inputStream.read(buffer)) != -1) {            outStream.write(buffer, 0, len);            /**             * write (byte[] buffer, int offset, int len)             * 0缓冲 1初始位置 2缓冲区写的字节数             * 缓冲区被写入。             * 从0到len的长度,写入缓存buffer中             */        }        inputStream.close();        //把内存输入流读取到content中        String content = new String(outStream.toByteArray());        return content;    }}

<?xml version="1.0" enCoding="utf-8"?><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"    androID:orIEntation="vertical"    tools:context="com.peng.HTML_look.MainActivity">    <EditText        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content"        androID:ID="@+ID/et_path"        androID:hint="请输入查看的网址"/>    <button        androID:layout_wIDth="wrap_content"        androID:layout_height="wrap_content"        androID:onClick="click"        androID:text="查看"/>    <ScrollVIEw        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content">        <TextVIEw            androID:layout_wIDth="match_parent"            androID:layout_height="match_parent"            androID:textcolor="#000000"            androID:ID="@+ID/tv_result"/>    </ScrollVIEw></linearLayout>

<uses-permission androID:name="androID.permission.INTERNET"/>

 runOnUiThread(new Runnable() {                    @OverrIDe                    public voID run() {                        tv_result.setText("the Content is:" +content);                    }                });

   ...voID HTML(){   ....  //在子线程里 handler.post(runnableui); .... }----------// 在主线程中构建Runnable对象，在runnable中更新界面    Runnable runnableui = new Runnable() {        @OverrIDe        public voID run() {            //更新界面            tv_result.setText("the Content is:" + content);        }    };

private  static SHOW_CONTENT = 1;private Handler handler = new Handler() {        public voID handleMessage(Message msg) {            switch (msg.what) {                case SHOW_CONTENT:                    String content= (String) msg.obj;                    // 在这里进行UI *** 作，将结果显示到界面上                    tv_result.setText("the Content is:" + content);            }        }    };----------   ...voID HTML(){   ....  //在子线程里 Message message = new Message(); message.what = SHOW_CONTENT;    // 将服务器返回的结果存放到Message中    message.obj = content;    handler.sendMessage(message); }