网络图片查看器HttpURLConnection+Bitmap

网络图片查看器

软件界面

MainActivity.java

package com.peng.image_show;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.EditText;import android.widget.ImageView;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;public class MainActivity extends AppCompatActivity {    private ImageView iv;    private EditText et_path;    /*private Handler handle = new Handler(){        @Override        public void handleMessage(Message msg) {            Bitmap bitmap = (Bitmap) msg.obj;            iv.setImageBitmap(bitmap);        }    };*/    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        et_path = (EditText) findViewById(R.id.et_path);        iv = (ImageView) findViewById(R.id.iv);    }    public void click(View view) {        new Thread() {            public void run() {                try {                    //获取图片路径                    String path = et_path.getText().toString().trim();                    //File file = new File(getCacheDir(), Base64.encodeToString(path.getBytes(),Base64.DEFAULT);                    File file = new File(getCacheDir(), "test.png");                    if (file.exists() && file.length() > 0) {                        //使用缓存图片                        System.out.println("---->>>>>>>>>>使用缓存的图片");                        final Bitmap cacheBitmap = BitmapFactory.decodeFile(file.getAbsolutePath());                 /*   Message msg = Message.obtain();                    msg.obj = cacheBitmap;                    handle.sendMessage(msg);*/                        runOnUiThread(new Runnable() {                            @Override                            public void run() {                                iv.setImageBitmap(cacheBitmap);                            }                        });                    } else {                        System.out.println("---->>>>>>>>>>使用网络的图片");                        //第一次访问连接网络                        //创建url对象                        URL url = new URL(path);                        //获取httpurlconnection                        HttpURLConnection conn = (HttpURLConnection) url.openConnection();                        //连接方式                        conn.setRequestMethod("GET");                        conn.setConnectTimeout(5000);                        //获取服务器的状态码                        int code = conn.getResponseCode();                        if (code == 200) {                            //获取图片的数据,不管什么数据,都是流的形式返回                            InputStream in = conn.getInputStream();                            file = new File(getCacheDir(), "test.png");                            FileOutputStream fos = new FileOutputStream(file);                            //fos文件输出流                            int len = -1;                            byte[] buffer = new byte[1024];                            while ((len = in.read(buffer)) != -1) {                                fos.write(buffer, 0, len);                            }                            fos.close();                            in.close();                            //获取位图工厂,获取bitmap                            final Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());                            runOnUiThread(new Runnable() {                                @Override                                public void run() {                                    //run方法一定执行在UI线里                                    iv.setImageBitmap(bitmap);                                }                            });                    /*Message msg =Message.obtain();//msg的静态方法,减少对象的创建                    msg.obj =bitmap;                    handle.sendMessage(msg);//发消息*/                        }                    }                } catch (Exception e) {                    e.printStackTrace();                }            }        }.start();    }}

activity_main.xml

<?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.image_show.MainActivity">    <EditText        android:id="@+id/et_path"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:hint="请输入查看的网址"        android:text="http://www.pptbz.com/pptpic/UploadFiles_6909/201204/2012041411433867.jpg" />    <Button        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:onClick="click"        android:text="查看" />    <ImageView        android:id="@+id/iv"        android:layout_width="wrap_content"        android:layout_height="wrap_content" /></LinearLayout>

需加权限

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