代理模式处理海量高频数据

代码一：

package com.night.proxymodehandlemasshighfrequencydataupdate;
/**
*@author night
*/
public interface CommonDefn {
public static int HIGHLIGHT_BACKGROUND_COLOR_INDEX=0xff0033ff;
public class DoThingsReturn{
public Object cmd;
public Object data;
public int errCode;
public DoThingsReturn(Object cmd,Object data,int errorCode){
super();
this.cmd=cmd;
this.data=data;
this.errCode=errorCode;
}
}
}

代码二：

package com.night.proxymodehandlemasshighfrequencydataupdate;

import android.os.Handler;

/**
* used for updating the background of the view while the data changed
*@author night
*/
public interface RefreshHandlerInterface {
//the proxy updating method
public void updateBackground(Object handlerId,int color);
//the proxy handler
public Handler getHandler();
}

代码三：

package com.night.proxymodehandlemasshighfrequencydataupdate;

import java.util.TimerTask;

import android.util.Log;

/**
* decrease alpha channel value from 255 to 0.
*@author night
*/
public class ColorRefreshTask extends TimerTask{
private RefreshHandlerInterface refreshHandler;
private final static int DELAY_ONCE=200;
private final static int TOTAL_RUNTIME=1500;
private final static int POWER_16_16=16*16*16*16*16*16;
private final static int INCREASE_ONCE=0xff / (TOTAL_RUNTIME/DELAY_ONCE);
private int color;
private Object id;
private int startTime;
private int alphaChannel;
/**
* @param color(current background color)
* @param id id of the updated view
*/
public ColorRefreshTask(RefreshHandlerInterface refreshHandler,int color,Object id){
super();
Log.d("color", "ready to set color");
this.color=color;
this.id=id;
this.startTime=0;
this.alphaChannel=0;
this.refreshHandler=refreshHandler;
}
public void run(){
int colorComm=color-0xff000000;//RGB color value;
int currColor=0;
if(startTime<TOTAL_RUNTIME){
startTime+=DELAY_ONCE;
alphaChannel+=INCREASE_ONCE;
currColor=POWER_16_16*alphaChannel+colorComm;
// Log.d("color", Integer.toHexString(currColor));
sendMsg(currColor);
refreshHandler.getHandler().postDelayed(this, DELAY_ONCE);
}else{
sendMsg(currColor<=color?color:0);
cancel();
}
}
public void startTimer(){
refreshHandler.getHandler().postDelayed(this, DELAY_ONCE);
}
private void sendMsg(final int currColor){
final Runnable myUpdateResults=new Runnable() {

@Override
public void run() {
refreshHandler.updateBackground(id, currColor);
}
};
new Thread(){
public void run(){
refreshHandler.getHandler().post(myUpdateResults);
}
}.start();
}
public void stopTimer(){
this.cancel();
}
}

代码四：

package com.night.proxymodehandlemasshighfrequencydataupdate;

import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends Activity implements RefreshHandlerInterface{
private Handler _messageHandler=new Handler();
public Handler getHandler(){
return _messageHandler;
}
public void updateBackground(Object handlerId,int color){
if(!(handlerId instanceof CommonDefn.DoThingsReturn)){
return;//invalid parameter
}
else{
TextView current=(TextView)(((CommonDefn.DoThingsReturn)handlerId).data);
if(current.getVisibility()!=View.VISIBLE){
return;//no need to update for the view
}
if(color<=0){
current.setBackgroundDrawable(null);
current.setText(((CommonDefn.DoThingsReturn)handlerId).cmd.toString());
}else{
current.setBackgroundColor(color);
}
current.postInvalidate();
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView tv=(TextView)findViewById(R.id.txtview);
new Thread(){
java.util.Random rand=new java.util.Random();
long lastUpdate=System.currentTimeMillis();
public void run(){
while(!Thread.interrupted()||!MainActivity.this.isFinishing()){
//模拟高频更新数据
if(System.currentTimeMillis()-lastUpdate<2000l){//设置两次动画的最少间隔时间
continue;
}else{
lastUpdate=System.currentTimeMillis();
}
CommonDefn.DoThingsReturn updateWrapper=new CommonDefn.DoThingsReturn(String.valueOf(rand.nextInt()), tv, 0);
ColorRefreshTask refresh=new ColorRefreshTask(MainActivity.this, CommonDefn.HIGHLIGHT_BACKGROUND_COLOR_INDEX, updateWrapper);
_messageHandler.postDelayed(refresh, 200);//ready to for the current updating
}
}
}.start();
}
}