网络图片查看器

package com.tang.netview;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.text.TextUtils;
import android.util.Base64;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;


/**
 * @描述： TODO
 * 
 * @作者：
 * @时间: 2015-9-7上午1:47:33
 */
public class MainActivity extends Activity
{
	private String				TAG			= "MainActivity";
	private static final int	YICHANG		= 3;
	private static final int	SUCCESSONE	= 1;
	private static final int	SUCCESSTWO	= 2;
	private static final int	FAILE		= 4;
	private EditText			et_path;
	private ImageView			iv;


	@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);
	}

	Handler			handler	= new Handler()
							{
								public void handleMessage(android.os.Message msg)
								{
									switch (msg.what)
									{
										case SUCCESSONE:
											Bitmap bitmap1 = (Bitmap) msg.obj;
											iv.setImageBitmap(bitmap1);
											break;
										case SUCCESSTWO:
											Bitmap bitmap2 = (Bitmap) msg.obj;
											iv.setImageBitmap(bitmap2);
											break;
										case FAILE:
											Toast.makeText(MainActivity.this,
													"请求失败", 0).show();
											break;

										case YICHANG:
											Toast.makeText(MainActivity.this,
													"发生异常", 0).show();
											break;

										default:
											break;
									}
								};
							};

	public void chakan(View view)
	{
		final String path = et_path.getText().toString().trim();// 图片网上的路径
		if (TextUtils.isEmpty(path))
		{
			Toast.makeText(MainActivity.this, "图片路径不能为空", 0).show();
			return;
		}

		new Thread()
		{
			public void run()
			{
				getImage(path);
			};
		}.start();
	}


	private void getImage(String path)
	{
		File file = new File(getCacheDir(), Base64.encodeToString(
				path.getBytes(), Base64.DEFAULT));// 保持的文件名

		if (file.exists() && file.length() > 0)
		{
			// 那缓存
			Toast.makeText(MainActivity.this, "那缓存", 0).show();
			Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());

			Message msg = new Message();
			msg.what = SUCCESSONE;
			msg.obj = bitmap;
			handler.sendMessage(msg);

			// iv.setImageBitmap(bitmap);
		} else
		{
			// 网上获取图片
			try
			{
				URL url = new URL(path);
				HttpURLConnection conn = (HttpURLConnection) url
						.openConnection();
				int code = conn.getResponseCode();

				Log.d(TAG, code + "'");

				if (code == 200)
				{
					InputStream is = conn.getInputStream();// 图片的流
					FileOutputStream fos = new FileOutputStream(file);
					byte[] buffer = new byte[1024];
					int len = -1;
					while ((len = is.read(buffer)) != -1)
					{
						fos.write(buffer, 0, len);
					}
					is.close();
					fos.close();
					Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
					Message msg = new Message();
					msg.what = SUCCESSTWO;
					msg.obj = bitmap;
					handler.sendMessage(msg);

					// iv.setImageBitmap(bitmap);
				} else
				{
					Message msg = Message.obtain();
					msg.what = FAILE;
					handler.sendMessage(msg);

					// Toast.makeText(MainActivity.this, "请求失败" , 0).show();
				}
			}
			catch (Exception e)
			{
				e.printStackTrace();
				Message msg = Message.obtain();
				msg.what = YICHANG;
				handler.sendMessage(msg);

				// Toast.makeText(MainActivity.this, "发生异常，请求失败" , 0).show();
			}
		}
	}

}