package com.lidaochen.test; import java.io.ByteArrayOutputStream; import java.io.InputStream; public class StreamTools { // 把InputStream转换成String public static String readStream(InputStream in) throws Exception { // 定义一个内存输出流 ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); int len = -1; byte[] buffer = new byte[1024]; // 1kb while ((len = in.read(buffer)) != -1) { byteArrayOutputStream.write(buffer, 0, len); } in.close(); String content = new String(byteArrayOutputStream.toByteArray()); return content; } }
package com.lidaochen.test; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; public class MainActivity extends AppCompatActivity { protected final int REQUESTSUCESS = 0; protected final int REQUESTNOTFOUND = 1; protected final int REQUESTEXCEPTION = 2; private EditText et_path; private TextView tv_result; // 在主线程中定义一个handler private Handler handler = new Handler() { // 这个方法是在主线程里面执行的 @Override public void handleMessage(android.os.Message msg) { // super.handleMessage(msg); // 区分一下是发送的哪条消息 switch (msg.what) { case REQUESTSUCESS: // 代表请求成功 String content = (String)msg.obj; tv_result.setText(content); break; case REQUESTNOTFOUND: Toast.makeText(getApplicationContext(), "请求的资源不存在!", Toast.LENGTH_SHORT).show(); break; case REQUESTEXCEPTION: Toast.makeText(getApplicationContext(), "服务器繁忙,请稍后......", Toast.LENGTH_SHORT).show(); break; default: break; } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 找到EditText控件 et_path = (EditText)findViewById(R.id.et_path); // 找到EditText控件 tv_result = (TextView)findViewById(R.id.tv_result); } // 避免anr 可以把耗时的操作放到子线程中 // 在4.0之后谷歌强制要求连接网络不能在主线程进行访问 // 只有主线程才可以更新UI public void click(View v) { // 创建一个子线程 new Thread() { public void run() { try { // 获取源码网址路径 String path = et_path.getText().toString().trim(); // 创建URL对象,指定我们要访问的网址 URL url = new URL(path); // 拿到HttpURLConnection对象,用于发送或者接收数据 HttpURLConnection connection = (HttpURLConnection) url.openConnection(); // 设置发送get请求 connection.setRequestMethod("GET"); // get要求大小,其实默认就是get请求 // 设置请求超时时间 connection.setReadTimeout(5000); // 获取服务器返回的状态码 int code = connection.getResponseCode(); // 如果code == 200说明请求成功 if (code == 200) { // 获取服务器返回的数据,是以流的形式返回的 InputStream is = connection.getInputStream(); // 使用我们定义的工具类,把is 转换成String String content = StreamTools.readStream(is); // 创建message对象 Message msg = new Message(); msg.what = REQUESTSUCESS; msg.obj = content; // 用我们创建的handler助手给系统发消息 handler.sendMessage(msg); } else { // 请求资源不存在 Toast是一个view 也不能在在线程更新ui Message msg = new Message(); msg.what = REQUESTNOTFOUND; handler.sendMessage(msg); } } catch (Exception e) { e.printStackTrace(); Message msg = new Message(); msg.what = REQUESTEXCEPTION; handler.sendMessage(msg); } } }.start(); } }
<?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" android:orientation="vertical" tools:context=".MainActivity"> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_path" android:hint="请输入网址..."/> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="查看" android:onClick="click"/> <ScrollView android:layout_width="match_parent" android:layout_height="wrap_content"> <TextView android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/tv_result"/> </ScrollView> </LinearLayout>