队列特性：先进先出（FIFO)——先进队列的元素先出队列。
来源于我们生活中的队列（先排队的先办完事）。
下面以一个简单的例子实现循环队列的操作。
<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:id="@+id/start"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="开始"/>
<Button
android:id="@+id/pause"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="暂停"/>
<Button
android:id="@+id/clear"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="清除"/>
</LinearLayout>
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/MonitorData"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:singleLine="false"
android:textSize="18sp"
android:textStyle="normal"
android:textColor="#000"
android:text="@string/hello_world"/>
</ScrollView>
</LinearLayout>
package com.sl.queuedemo;
import java.util.Calendar;
import java.util.Timer;
import java.util.TimerTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.SystemClock;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
//线程发送数据入队，定时器定时处理数据
public class MainActivity extends Activity
{
private static final String TAG = "QueueDemo";
static final int REFRESH = 0;
private TextView mTextView;
public Button m_btnStart = null;
public Button m_btnPause = null;
public Button m_btnClear = null;
private boolean m_bIsReading = false;
//控制线程运行
private boolean m_bIsRunning = false;
//队列操作
public int m_nWt = 0;
public int m_nRd = 0;
public int m_nCnt=0;
private final byte MAX_QUEUE_SIZE = 20;
private final byte MAX_ELEMENT_SIZE = 6;
public byte m_ucMonitorData[][] = new byte[MAX_QUEUE_SIZE][MAX_ELEMENT_SIZE];
private int nLength = 6;
private byte TxBuffer[] = new byte[nLength];
private byte RxBuffer[] = new byte[nLength];
//时间操作
private int mYear;
private int mMonth;
private int mDay;
private int mHour;
private int mMinute;
private int mSecond;
public String m_sMonitorTime[] = new String[MAX_QUEUE_SIZE];
//同步设置
private Object Mutex = new Object();
//定时器设置
Timer timer = new Timer();
TimerTask task = new TimerTask()
{
@Override
public void run()
{
Message message = new Message();
message.what = REFRESH;
handler.sendMessage(message);
}
};
//线程处理
@SuppressLint("HandlerLeak")
Handler handler = new Handler()
{
public void handleMessage(Message msg)
{
switch (msg.what)
{
case REFRESH:
RefreshData();
break;
default:
break;
}
}
};
//线程
public Thread myThread = new Thread(new Runnable()
{
@Override
public void run()
{
while(m_bIsRunning)
{
TxBuffer[0]++;
TxBuffer[1]++;TxBuffer[1]++;
TxBuffer[2]++;
TxBuffer[3]++;
TxBuffer[4]++;TxBuffer[4]++;
TxBuffer[5]++;TxBuffer[5]++;TxBuffer[5]++;
InQueue(TxBuffer, nLength);
SystemClock.sleep(1000);
}
}
});
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextView = (TextView)findViewById(R.id.MonitorData);
m_btnStart = (Button)findViewById(R.id.start);
m_btnPause = (Button)findViewById(R.id.pause);
m_btnClear = (Button)findViewById(R.id.clear);
m_btnStart.setOnClickListener(listener);
m_btnPause.setOnClickListener(listener);
m_btnClear.setOnClickListener(listener);
m_bIsRunning = true;
myThread.start();
timer.schedule(task,1000,1000);
}
@Override
protected void onDestroy() {
super.onDestroy();
m_bIsRunning = false;
timer.cancel();
timer.purge();
}
public void RefreshData()
{
if(m_bIsReading)
{
String str = GetOutQueueString();
mTextView.setText(str);
}
}
OnClickListener listener = new View.OnClickListener()
{
@Override
public void onClick(View v)
{
switch(v.getId())
{
case R.id.start:
m_bIsReading = true;
RefreshData();
break;
case R.id.pause:
m_bIsReading = false;
break;
case R.id.clear:
ResetQueue();
RefreshData();
break;
default:
break;
}
}
};
public void InQueue(final byte TxBuffer[],final int nLength)
{
synchronized (Mutex)
{
if(nLength<=0)
{
return;
}
//入队时间
final Calendar c = Calendar.getInstance();
mYear = c.get(Calendar.YEAR);
mMonth = c.get(Calendar.MONTH) + 1;//获取的月份比实际月份小1，所以需要+1
mDay = c.get(Calendar.DAY_OF_MONTH);
mHour = c.get(Calendar.HOUR_OF_DAY);
mMinute = c.get(Calendar.MINUTE);
mSecond = c.get(Calendar.SECOND);
String year = "0" + mYear;
year = year.substring(year.length()-2, year.length());
String month = "0" + mMonth;
month = month.substring(month.length()-2, month.length());
String day = "0" + mDay;
day = day.substring(day.length()-2, day.length());
String hour = "0" + mHour;
hour = hour.substring(hour.length()-2, hour.length());
String minute = "0" + mMinute;
minute = minute.substring(minute.length()-2, minute.length());
String second = "0" + mSecond;
second = second.substring(second.length()-2, second.length());
String str = year + "." + month + "." + day + " " + hour + ":" + minute + ":" + second + " -- ";
m_sMonitorTime[m_nWt] = str;
//入队数据
for(int i =0;i<nLength;i++)
{
m_ucMonitorData[m_nWt][i] = TxBuffer[i];
}
m_nWt++;
if(m_nWt >= MAX_QUEUE_SIZE)
{
m_nWt = 0;
}
m_nCnt++;
if(m_nCnt > MAX_QUEUE_SIZE)
{
m_nCnt = MAX_QUEUE_SIZE;
m_nRd++;
if(m_nRd >= MAX_QUEUE_SIZE)
{
m_nRd = 0;
}
}
}
}
public boolean OutQueue(byte RxBuffer[])
{
synchronized (Mutex)
{
if(m_nCnt <= 0)
{
return false;
}
for(int i=0;i<MAX_ELEMENT_SIZE;i++)
{
RxBuffer[i] = m_ucMonitorData[m_nRd][i];
}
m_nRd++;
if(m_nRd >= MAX_QUEUE_SIZE)
{
m_nRd = 0;
}
m_nCnt--;
return true;
}
}
public String GetOutQueueString()
{
synchronized (Mutex)
{
String strline = "";
String str = "";
int index = m_nRd;
for(int i=0;i<m_nCnt;i++)
{
strline = strline + m_sMonitorTime[index];//时间
for(int j=0;j<MAX_ELEMENT_SIZE;j++)
{
strline = strline + str.format("%02X ",m_ucMonitorData[index][j]);//数据
}
strline = strline + "\n";//换行
index++;
if(index >= MAX_QUEUE_SIZE)
{
index = 0;
}
}
return strline;
}
}
public void ResetQueue()
{
synchronized (Mutex)
{
m_nCnt = 0;
m_nWt = 0;
m_nRd = 0;
Log.d(TAG, "重置队列");
}
}
}
开始运行
暂停运行
清除
重新开始
原文地址：http://blog.csdn.net/bingdianlanxin/article/details/43417607
