ThreadLocal

  使用ThreadLocal可以使对象达到线程隔离的目的。为每一个使用该变量的线程都提供一个变量值的副本，是Java中一种较为特殊的线程绑定机制，是每一个线程都可以独立地改变自己的副本，而不会和其它线程的副本冲突。

ThreadLocal常用方法

• 构造方法：ThreadLocal()：创建一个线程本地变量

• protected T initialValue()：返回此线程局部变量的当前线程的初始值。最多在每次访问线程来获得每个线程局部变量时调用此方法一次，即线程第一次使用 get() 方法访问变量的时候。如果线程先于 get 方法调用 set(T) 方法，则不会在线程中再调用 initialValue 方法。

• T get()：

• void set(T value)：将此线程局部变量的当前线程副本中的值设置为指定值。许多应用程序不需要这项功能，它们只依赖于 initialValue() 方法来设置线程局部变量的值。

• void remove()：移除此线程局部变量的值。这可能有助于减少线程局部变量的存储需求。如果再次访问此线程局部变量，那么在默认情况下它将拥有其 initialValue。

• 在程序中一般都重写initialValue方法，以给定一个特定的初始值。

• 注意ThreadLocal对象在那里构造就属于那个线程。不可以跨越线程调用ThreadLocal对象

• 注意所有线程使用完毕ThreadLocal中包含的对象的时候，需要重置对象的属性。因为ThreadLocal实现的方法并不是克隆或者拷贝。

案例【未封装】

Boss.java

package com.hzj163.myhandler;

import java.util.ArrayList;

//副本BOSS
public class Boss {

    //boss名称
    String name;
    //boss掉落装备
    ArrayList<String> equipment;
    //是否死亡
    boolean dead;

    public boolean isDead() {
        return dead;
    }

    public void setDead(boolean dead) {
        this.dead = dead;
    }


    public Boss() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public ArrayList<String> getEquipment() {
        return equipment;
    }

    public void setEquipment(ArrayList<String> equipment) {
        this.equipment = equipment;
    }
}

WOWHFB.java

package com.hzj163.myhandler;


import java.util.ArrayList;

//魔兽世界英雄副本
public class WOWHFB {
    //副本名称
    String  name;
    //BOSS列表
    ArrayList<Boss> bosses;


    public WOWHFB(String name, ArrayList<Boss> bosses) {
        this.name = name;
        this.bosses = bosses;
    }

    public WOWHFB() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public ArrayList<Boss> getBosses() {
        return bosses;
    }

    public void setBosses(ArrayList<Boss> bosses) {
        this.bosses = bosses;
    }
}

OtherActivity.java

package com.hzj163.myhandler;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Random;

//这里为了演示ThreadLocal，所以不做任何封装
public class OtherActivity extends AppCompatActivity {

    //副本对象
    WOWHFB wowhfb;
    TextView textView1;
    TextView textView2;
    TextView textView3;
    Handler handlerMain = new Handler();
    Button button1;

    //管理线程
    HashSet hashSet;

    //同步锁
    Object object = new Object();


    //初始化副本
    public WOWHFB initWowhfb() {
        //实例化副本对象【准备让3个队伍同时进入副本砍BOSS】
        WOWHFB wowhfb = new WOWHFB();
        wowhfb.setName("黑石塔上层");

        //设置boss
        Boss boss1 = new Boss();
        //boss名称
        boss1.setName("督军扎伊拉");
        //掉落装备
        ArrayList<String> equipment1 = new ArrayList();
        equipment1.add("沙赫拉姆荒芜之剑");
        equipment1.add("魔能军刺");
        equipment1.add("烬鳞护符");
        equipment1.add("奥秘兜帽");
        equipment1.add("霜染兜帽");
        equipment1.add("流光兜帽");
        equipment1.add("缚光者面罩");
        //设置装备
        boss1.setEquipment(equipment1);
        //设置boss是否死亡
        boss1.setDead(false);

        Boss boss2 = new Boss();
        boss2.setName("狂野的怒翼");
        ArrayList<String> equipment2 = new ArrayList();
        equipment2.add("黑手的毁灭战戟");
        equipment2.add("怒翼的火焰之牙");
        equipment2.add("鼓风项圈");
        equipment2.add("火刃项圈");
        equipment2.add("颅齿项链");
        equipment2.add("风印项链");
        equipment2.add("魔导师之链");
        boss2.setEquipment(equipment2);
        boss2.setDead(false);

        Boss boss3 = new Boss();
        boss3.setName("指挥官萨贝克");
        ArrayList<String> equipment3 = new ArrayList();
        equipment3.add("萨贝克的邪恶长剑");
        equipment3.add("萨贝克的野蛮长剑");
        equipment3.add("萨贝克的幸运石");
        equipment3.add("奥秘手套");
        equipment3.add("霜染手套");
        equipment3.add("流光手套");
        equipment3.add("缚光者手套");
        boss3.setEquipment(equipment3);
        boss3.setDead(false);

        Boss boss4 = new Boss();
        boss4.setName("奇拉克");
        ArrayList<String> equipment4 = new ArrayList();
        equipment4.add("芬克的解剖刀");
        equipment4.add("奇拉克的邪血药水");
        equipment4.add("罗杰的棕色金刚石印戒");
        equipment4.add("赛德的协鸣指环");
        equipment4.add("血棘指环");
        boss4.setEquipment(equipment4);
        boss4.setDead(false);


        Boss boss5 = new Boss();
        boss5.setName("折铁者高尔山");
        ArrayList<String> equipment5 = new ArrayList();
        equipment5.add("石化重锤");
        equipment5.add("联刃斗篷");
        equipment5.add("神射大氅");
        equipment5.add("暴力和谐斗篷");
        equipment5.add("邪骨斗篷");
        equipment5.add("秘法斗篷");
        boss5.setEquipment(equipment5);
        boss5.setDead(false);


        //实例化BOSS集合
        ArrayList<Boss> bosses = new ArrayList();
        bosses.add(boss1);
        bosses.add(boss2);
        bosses.add(boss3);
        bosses.add(boss4);
        bosses.add(boss5);
        //设置Boss集合
        wowhfb.setBosses(bosses);

        return wowhfb;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_other);
        getSupportActionBar().setTitle("黑石塔上层");

        textView1 = (TextView) findViewById(R.id.textView1);
        textView2 = (TextView) findViewById(R.id.textView2);
        textView3 = (TextView) findViewById(R.id.textView3);
        button1 = (Button) findViewById(R.id.button1);
        //负责监听所有线程结束
        hashSet = new HashSet();
        //实例化副本对象
        wowhfb = initWowhfb();

    }

    //线程1
    Runnable runnable1 = new Runnable() {
        @Override
        public void run() {
            //添加集合管理线程【需要同步，以为是多个线程共享一个集合】
            synchronized (object) {
                hashSet.add(this);
            }
            //开始副本,使用ThreadLocal隔离WOWHFB对象
            ThreadLocal<WOWHFB> threadLocal = new ThreadLocal() {
                //初始化副本
                @Override
                protected Object initialValue() {
                    return wowhfb;
                }
            };

            //战斗中......
            handlerMain.post(new Runnable() {
                @Override
                public void run() {
                    textView1.setText("战队1开始战斗");
                }
            });
            try {
                Thread.sleep(10000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            //战斗结束【使用threadLocal.get()拿出副本对象】
            WOWHFB temp = threadLocal.get();
            //杀死了两个boss
            temp.getBosses().get(0).setDead(true);
            temp.getBosses().get(1).setDead(true);
            //战利品
            ArrayList<String> result = new ArrayList();
            //获取装备
            Random random = new Random();
            //随机获取装备
            int randomTemp1 = random.nextInt(temp.getBosses().get(0).getEquipment().size());
            int randomTemp2 = random.nextInt(temp.getBosses().get(1).getEquipment().size());
            result.add(temp.getBosses().get(0).getEquipment().get(randomTemp1));
            result.add(temp.getBosses().get(1).getEquipment().get(randomTemp2));
            //收集信息
            final StringBuffer stringBuffer = new StringBuffer();
            stringBuffer.append("***战队1杀死的BOSS***");
            stringBuffer.append("\r\n");
            for (int i = 0; i < temp.getBosses().size(); i++) {
                if (temp.getBosses().get(i).isDead()) {
                    stringBuffer.append(temp.getBosses().get(i).getName());
                    stringBuffer.append("\r\n");
                }
            }
            stringBuffer.append("***战利品***");
            stringBuffer.append("\r\n");
            for (int i = 0; i < result.size(); i++) {
                stringBuffer.append(result.get(i));
                stringBuffer.append("\r\n");
            }

            //添加集合管理线程【需要同步，以为是多个线程共享一个集合】
            synchronized (object) {
                hashSet.remove(this);
            }
            //显示战利品
            handlerMain.post(new Runnable() {
                @Override
                public void run() {
                    textView1.setText(stringBuffer.toString());

                    //判断是否所有线程结束
                    if (hashSet.isEmpty()) {
                        button1.setEnabled(true);

                        //这里要注意的是ThreadLocal对象并没有克隆方案克隆出多个副本对象
                        //副本对象其实依然是一个，所以所有线程结束后，需要重置副本对象
                        wowhfb = initWowhfb();


                    }
                }
            });
        }
    };
    //线程2
    Runnable runnable2 = new Runnable() {

        @Override
        public void run() {

            synchronized (object) {
                hashSet.add(this);
            }

            //开始副本,使用ThreadLocal隔离WOWHFB对象
            ThreadLocal<WOWHFB> threadLocal = new ThreadLocal() {
                //初始化副本
                @Override
                protected Object initialValue() {
                    return wowhfb;
                }
            };

            handlerMain.post(new Runnable() {
                @Override
                public void run() {
                    textView2.setText("战队2开始战斗");
                }
            });
            //战斗中......
            try {
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            //战斗结束
            WOWHFB temp = threadLocal.get();
            //杀死了两个boss
            temp.getBosses().get(0).setDead(true);
            //战利品
            ArrayList<String> result = new ArrayList();
            //获取装备
            Random random = new Random();
            //随机获取装备
            int randomTemp1 = random.nextInt(temp.getBosses().get(0).getEquipment().size());
            result.add(temp.getBosses().get(0).getEquipment().get(randomTemp1));


            //收集信息
            final StringBuffer stringBuffer = new StringBuffer();
            stringBuffer.append("***战队2杀死的BOSS***");
            stringBuffer.append("\r\n");
            for (int i = 0; i < temp.getBosses().size(); i++) {
                if (temp.getBosses().get(i).isDead()) {
                    stringBuffer.append(temp.getBosses().get(i).getName());
                    stringBuffer.append("\r\n");
                }
            }
            stringBuffer.append("***战利品***");
            stringBuffer.append("\r\n");
            for (int i = 0; i < result.size(); i++) {
                stringBuffer.append(result.get(i));
                stringBuffer.append("\r\n");
            }


            synchronized (object) {
                hashSet.remove(this);
            }

            //显示战利品
            handlerMain.post(new Runnable() {
                @Override
                public void run() {
                    textView2.setText(stringBuffer.toString());

                    //判断是否所有线程结束
                    if (hashSet.isEmpty()) {
                        button1.setEnabled(true);
                        wowhfb = initWowhfb();
                    }

                }
            });


        }
    };

    //线程3
    Runnable runnable3 = new Runnable() {

        @Override
        public void run() {

            synchronized (object) {
                hashSet.add(this);
            }


            //开始副本,使用ThreadLocal隔离WOWHFB对象
            ThreadLocal<WOWHFB> threadLocal = new ThreadLocal() {
                //初始化副本
                @Override
                protected Object initialValue() {
                    return wowhfb;
                }
            };

            handlerMain.post(new Runnable() {
                @Override
                public void run() {
                    textView3.setText("战队3开始战斗");
                }
            });

            //战斗中......
            try {
                Thread.sleep(20000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            //战斗结束
            WOWHFB temp = threadLocal.get();
            //杀死了两个boss
            temp.getBosses().get(0).setDead(true);
            temp.getBosses().get(1).setDead(true);
            temp.getBosses().get(2).setDead(true);
            temp.getBosses().get(3).setDead(true);
            temp.getBosses().get(4).setDead(true);

            //战利品
            ArrayList<String> result = new ArrayList();
            //获取装备
            Random random = new Random();
            //随机获取装备
            int randomTemp1 = random.nextInt(temp.getBosses().get(0).getEquipment().size());

            int randomTemp2 = random.nextInt(temp.getBosses().get(1).getEquipment().size());

            int randomTemp3 = random.nextInt(temp.getBosses().get(2).getEquipment().size());

            int randomTemp4 = random.nextInt(temp.getBosses().get(3).getEquipment().size());

            int randomTemp5 = random.nextInt(temp.getBosses().get(4).getEquipment().size());

            result.add(temp.getBosses().get(0).getEquipment().get(randomTemp1));
            result.add(temp.getBosses().get(1).getEquipment().get(randomTemp2));
            result.add(temp.getBosses().get(2).getEquipment().get(randomTemp3));
            result.add(temp.getBosses().get(3).getEquipment().get(randomTemp4));
            result.add(temp.getBosses().get(4).getEquipment().get(randomTemp5));


            //收集信息
            final StringBuffer stringBuffer = new StringBuffer();
            stringBuffer.append("***战队3杀死的BOSS***");
            stringBuffer.append("\r\n");
            for (int i = 0; i < temp.getBosses().size(); i++) {
                if (temp.getBosses().get(i).isDead()) {
                    stringBuffer.append(temp.getBosses().get(i).getName());
                    stringBuffer.append("\r\n");
                }
            }
            stringBuffer.append("***战利品***");
            stringBuffer.append("\r\n");
            for (int i = 0; i < result.size(); i++) {
                stringBuffer.append(result.get(i));
                stringBuffer.append("\r\n");
            }


            synchronized (object) {
                hashSet.remove(this);
            }


            //显示战利品
            handlerMain.post(new Runnable() {
                @Override
                public void run() {
                    textView3.setText(stringBuffer.toString());
                    //判断是否所有线程结束
                    if (hashSet.isEmpty()) {
                        button1.setEnabled(true);
                        wowhfb = initWowhfb();

                    }
                }
            });
        }
    };


    public void btn1(View view) {

        new Thread(runnable1).start();
        new Thread(runnable2).start();
        new Thread(runnable3).start();
        button1.setEnabled(false);
    }

}

【封装版本，beans不变】

package com.hzj163.myhandler;

import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Switch;
import android.widget.TextView;

import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Random;


//封装版本
public class OtherActivity1 extends AppCompatActivity {
    //1战队开始
    public static final int START_1 = 1;
    //2战队开始
    public static final int START_2 = 2;
    //3战队开始
    public static final int START_3 = 3;
    //1战队结束
    public static final int END_1 = 4;
    //2战队结束
    public static final int END_2 = 5;
    //3战队结束
    public static final int END_3 = 6;


    //副本对象
    WOWHFB wowhfb;
    TextView textView1;
    TextView textView2;
    TextView textView3;


    Button button1;
    //管理线程
    HashSet hashSet;
    //同步锁
    Object object = new Object();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_other);
        getSupportActionBar().setTitle("黑石塔上层");
        textView1 = (TextView) findViewById(R.id.textView1);
        textView2 = (TextView) findViewById(R.id.textView2);
        textView3 = (TextView) findViewById(R.id.textView3);
        button1 = (Button) findViewById(R.id.button1);
        //负责监听所有线程结束
        hashSet = new HashSet();
        wowhfb = initWowhfb();

    }


    //主线程handler
    MyHandler handlerMain = new MyHandler(new WeakReference<OtherActivity1>(OtherActivity1.this));

    static class MyHandler extends Handler {
        WeakReference<OtherActivity1> weakReference;

        public MyHandler(WeakReference<OtherActivity1> weakReference) {
            this.weakReference = weakReference;
        }

        @Override
        public void handleMessage(Message msg) {
            OtherActivity1 temp = weakReference.get();
            switch (msg.what) {
                case START_1:
                    temp.textView1.setText("战队1开始战斗");
                    break;
                case START_2:
                    temp.textView2.setText("战队2开始战斗");
                    break;
                case START_3:
                    temp.textView3.setText("战队3开始战斗");
                    break;
                case END_1:
                    temp.textView1.setText(msg.obj.toString());
                    temp.reFB();
                    break;
                case END_2:
                    temp.textView2.setText(msg.obj.toString());
                    temp.reFB();
                    break;
                case END_3:
                    temp.textView3.setText(msg.obj.toString());
                    temp.reFB();
                    break;
            }
        }
    }


    //初始化副本
    public WOWHFB initWowhfb() {
        //实例化副本对象【准备让3个队伍同时进入副本砍BOSS】
        WOWHFB wowhfb = new WOWHFB();
        wowhfb.setName("黑石塔上层");

        //设置boss
        Boss boss1 = new Boss();
        //boss名称
        boss1.setName("督军扎伊拉");
        //掉落装备
        ArrayList<String> equipment1 = new ArrayList();
        equipment1.add("沙赫拉姆荒芜之剑");
        equipment1.add("魔能军刺");
        equipment1.add("烬鳞护符");
        equipment1.add("奥秘兜帽");
        equipment1.add("霜染兜帽");
        equipment1.add("流光兜帽");
        equipment1.add("缚光者面罩");
        //设置装备
        boss1.setEquipment(equipment1);
        //设置boss是否死亡
        boss1.setDead(false);

        Boss boss2 = new Boss();
        boss2.setName("狂野的怒翼");
        ArrayList<String> equipment2 = new ArrayList();
        equipment2.add("黑手的毁灭战戟");
        equipment2.add("怒翼的火焰之牙");
        equipment2.add("鼓风项圈");
        equipment2.add("火刃项圈");
        equipment2.add("颅齿项链");
        equipment2.add("风印项链");
        equipment2.add("魔导师之链");
        boss2.setEquipment(equipment2);
        boss2.setDead(false);

        Boss boss3 = new Boss();
        boss3.setName("指挥官萨贝克");
        ArrayList<String> equipment3 = new ArrayList();
        equipment3.add("萨贝克的邪恶长剑");
        equipment3.add("萨贝克的野蛮长剑");
        equipment3.add("萨贝克的幸运石");
        equipment3.add("奥秘手套");
        equipment3.add("霜染手套");
        equipment3.add("流光手套");
        equipment3.add("缚光者手套");
        boss3.setEquipment(equipment3);
        boss3.setDead(false);

        Boss boss4 = new Boss();
        boss4.setName("奇拉克");
        ArrayList<String> equipment4 = new ArrayList();
        equipment4.add("芬克的解剖刀");
        equipment4.add("奇拉克的邪血药水");
        equipment4.add("罗杰的棕色金刚石印戒");
        equipment4.add("赛德的协鸣指环");
        equipment4.add("血棘指环");
        boss4.setEquipment(equipment4);
        boss4.setDead(false);


        Boss boss5 = new Boss();
        boss5.setName("折铁者高尔山");
        ArrayList<String> equipment5 = new ArrayList();
        equipment5.add("石化重锤");
        equipment5.add("联刃斗篷");
        equipment5.add("神射大氅");
        equipment5.add("暴力和谐斗篷");
        equipment5.add("邪骨斗篷");
        equipment5.add("秘法斗篷");
        boss5.setEquipment(equipment5);
        boss5.setDead(false);


        //实例化BOSS集合
        ArrayList<Boss> bosses = new ArrayList();
        bosses.add(boss1);
        bosses.add(boss2);
        bosses.add(boss3);
        bosses.add(boss4);
        bosses.add(boss5);
        //设置Boss集合
        wowhfb.setBosses(bosses);

        return wowhfb;
    }


    //战斗流程
    public void startFB(int massageStartWhat, int massageEndWhat, int sleep) {
        //随机数准备
        Random random = new Random();
        //添加集合管理线程【需要同步，以为是多个线程共享一个集合】
        synchronized (object) {
            hashSet.add(this);
        }
        //开始副本,使用ThreadLocal隔离WOWHFB对象
        ThreadLocal<WOWHFB> threadLocal = new ThreadLocal() {
            //初始化副本
            @Override
            protected Object initialValue() {
                return wowhfb;
            }
        };
        //发送战斗中......消息
        Message messageStart = handlerMain.obtainMessage();
        messageStart.what = massageStartWhat;
        messageStart.sendToTarget();
        try {
            Thread.sleep(sleep);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //战斗结束【使用threadLocal.get()拿出副本对象】
        WOWHFB temp = threadLocal.get();
        //杀死了N个boss【随机】
        int bossDead = random.nextInt(temp.getBosses().size() - 1);
        bossDead++;
        //战利品
        ArrayList<String> result = new ArrayList();
        for (int i = 0; i < bossDead; i++) {
            temp.getBosses().get(i).setDead(true);
            //随机获取装备
            int randomTempIndex = random.nextInt(temp.getBosses().get(i).getEquipment().size());
            result.add(temp.getBosses().get(i).getEquipment().get(randomTempIndex));
        }
        //收集信息
        final StringBuffer stringBuffer = new StringBuffer();
        //判断战队
        switch (massageStartWhat) {
            case START_1:
                stringBuffer.append("***战队1杀死的BOSS***");
                break;
            case START_2:
                stringBuffer.append("***战队2杀死的BOSS***");
                break;
            case START_3:
                stringBuffer.append("***战队3杀死的BOSS***");
                break;
        }
        stringBuffer.append("\r\n");

        //收集杀死的Boss名称
        for (int i = 0; i < temp.getBosses().size(); i++) {
            if (temp.getBosses().get(i).isDead()) {
                stringBuffer.append(temp.getBosses().get(i).getName());
                stringBuffer.append("\r\n");
            }
        }
        //收集杀死的Boss的装备
        stringBuffer.append("***战利品***");
        stringBuffer.append("\r\n");
        for (int i = 0; i < result.size(); i++) {
            stringBuffer.append(result.get(i));
            stringBuffer.append("\r\n");
        }
        //添加集合管理线程【需要同步，以为是多个线程共享一个集合】
        synchronized (object) {
            hashSet.remove(this);
        }
        //发送战斗结束消息
        Message messageEnd = handlerMain.obtainMessage();
        messageEnd.what = massageEndWhat;
        messageEnd.obj = stringBuffer;
        messageEnd.sendToTarget();
    }
    //重置副本
    public void reFB() {
        //判断是否所有线程结束
        if (hashSet.isEmpty()) {
            button1.setEnabled(true);
            //这里要注意的是ThreadLocal对象并没有克隆方案克隆出多个副本对象
            //副本对象其实依然是一个，所以所有线程结束后，需要重置副本对象
            wowhfb = initWowhfb();
        }
    }


    //战队1
    Runnable runnable1 = new Runnable() {
        @Override
        public void run() {

            startFB(START_1, END_1, new Random().nextInt(5000) + 8000);
        }
    };

    //战队2
    Runnable runnable2 = new Runnable() {
        @Override
        public void run() {
            startFB(START_2, END_2, new Random().nextInt(5000) + 8000);

        }
    };

    //战队3
    Runnable runnable3 = new Runnable() {
        @Override
        public void run() {
            startFB(START_3, END_3, new Random().nextInt(5000) + 8000);
        }
    };

    public void btn1(View view) {

        //开始
        new Thread(runnable1).start();
        new Thread(runnable2).start();
        new Thread(runnable3).start();
        button1.setEnabled(false);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_other_activity1, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}