使用HttpURLConnection查看图片

new Thread(){
@Override
public void run() {
super.run();
}
};

private android.os.Handler handler =new android.os.Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
//处理消息操作
};

/**
*Message msg=new Message;
*使用静态方法，减少new的次数，提高效率
*/
Message msg = Message.obtain();

package jacky.httpurlimage;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class MainActivity extends AppCompatActivity {

private static final int REQUESTSUCCESS = 0;
private static final int REQUESTNOTFIND = 1;
private EditText et_path;
//创建Handler对象
private android.os.Handler handler =new android.os.Handler(){
@Override
public void handleMessage(Message msg) {
//处理消息
super.handleMessage(msg);
switch (msg.what) {
case REQUESTSUCCESS:
Bitmap bitmap=(Bitmap)msg.obj;
iv_show.setImageBitmap(bitmap);
break;
case REQUESTNOTFIND:
Toast.makeText(getApplicationContext(),"网络连接失败！",Toast.LENGTH_LONG);
break;
}
}
};
private ImageView iv_show;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_path = (EditText) findViewById(R.id.et_path);
iv_show = (ImageView) findViewById(R.id.iv_show);
}
public void click(View v){
//开辟线程
new Thread(){
@Override
public void run() {
super.run();
try {
String path=et_path.getText().toString().trim();
URL url=new URL(path);
//获得连接
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setReadTimeout(5000);
int code = conn.getResponseCode();
if (code == 200) {
InputStream in = conn.getInputStream();
Bitmap bitmap = BitmapFactory.decodeStream(in);

/**
*Message msg=new Message;
*使用静态方法，减少new的次数，提高效率
*/
Message msg = Message.obtain();
//设置传出的数据
msg.obj = bitmap;
msg.what = REQUESTSUCCESS;
handler.sendMessage(msg);
} else {
Message msg = Message.obtain();
msg.what = REQUESTNOTFIND;
handler.sendMessage(msg);
}

} catch (Exception e) {
e.printStackTrace();
}
}
}.start();
}

}