Java Android应用程序意外崩溃

我希望用户能够点击应用程序的按钮，从我的FactBook.java列表中获取一个随机事实（字符串）。当应用程序第一次打开时，我通过调用initFacts（）方法（静态）初始化列表，然后每次用户点击按钮时检查列表是否为空。如果是，我必须重新初始化列表，这样它就不会保持为空。然而，当我点击按钮时，应用程序崩溃了，但我找不到错误，我觉得一切都正常。有人能帮我吗？先谢谢你

package com.spdesigns.funfacts;

import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;

import java.util.Random;

public class FunFactsActivity extends AppCompatActivity {
    //private FactBook factBook = new FactBook();
    private ColorWheel colorWheel = new ColorWheel();
    // Declare our View vars
    private RelativeLayout relativeLayout;
    private TextView factTextView;
    private Button showFactButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fun_facts);

    // Assign the Views from the layout file to the corresponding variables
    relativeLayout = (RelativeLayout) findViewById(R.id.relativeLayout);
    factTextView = (TextView) findViewById(R.id.factTextView);
    showFactButton = (Button) findViewById(R.id.showFactButton);
    FactBook.initFacts();

    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // Update the screen with our new fact
            int color = colorWheel.getColor();
            relativeLayout.setBackgroundColor(color);
            showFactButton.setTextColor(color);
            factTextView.setText(FactBook.getFact());
        }
    };
    showFactButton.setOnClickListener(listener);
}
}

FactBook.java

package com.spdesigns.funfacts;

import java.util.Arrays;
import java.util.List;
import java.util.Random;

/**
 * FunFacts was
 * Created by Stelios Papamichail on 11/2/2017.
 * <p>
 * This file belongs to the com.spdesigns.funfacts package.
 */

class FactBook {
private static List<String> facts;



static void initFacts() {
    facts = Arrays.asList("If you somehow found a way to extract all of the gold from the bubbling core of our lovely little planet, you would be able to cover all of the land in a layer of gold up to your knees.",
            "McDonalds calls frequent buyers of their food “heavy users.",
            "The average person spends 6 months of their lifetime waiting on a red light to turn green.",
            "The largest recorded snowflake was in Keogh, MT during year 1887, and was 15 inches wide.",
            "You burn more calories sleeping than you do watching television.",
            "There are more lifeforms living on your skin than there are people on the planet.",
            "Southern sea otters have flaps of skin under their forelegs that act as pockets. When diving, they use these pouches to store rocks and food.",
            "In 1386 a pig in France was executed by public hanging for the murder of a child.",
            "One in every five adults believes that aliens are hiding in our planet disguised as humans.",
            "If you believe that you’re truly one in a million, there are still approximately 7,184 more people out there just like you.",
            "A single cloud can weight more than 1 million pounds.",
            "A human will eat on average 70 assorted insects and 10 spiders while sleeping.",
            "James Buchanan, the 15th U.S. president continuously bought slaves with his own money in order to free them.",
            "There are more possible iterations of a game of chess than there are atoms in the known universe.",
            "The average person walks the equivalent of three times around the world in a lifetime.",
            "Men are 6 times more likely to be struck by lightning than women.",
            "Coca-Cola would be green if coloring wasn’t added to it.",
            "You cannot snore and dream at the same time.",
            "The world’s oldest piece of chewing gum is over 9,000 years old!",
            "A coyote can hear a mouse moving underneath a foot of snow.",
            "Bolts of lightning can shoot out of an erupting volcano.",
            "New York drifts about one inch farther away from London each year.",
            "A U.S. dollar bill can be folded approximately 4,000 times in the same place before it will tear.",
            "A sneeze travels about 100 miles per hour.",
            "Earth has traveled more than 5,000 miles in the past 5 minutes.",
            "It would take a sloth one month to travel one mile.",
            "10% of the World’s population is left handed.",
            "A broken clock is right two times every day.",
            "According to Amazon, the most highlighted books on Kindle are the Bible, the Steve Jobs biography, and The Hunger Games.",
            "Bob Marley’s last words to his son before he died were “Money can’t buy life.",
            "A mole can dig a tunnel that is 300 feet long in only one night.",
            "A hippo’s wide open mouth is big enough to fit a 4-foot-tall child in.",
            "Chewing gum while you cut an onion will help keep you from crying.",
            "If you were to stretch a Slinky out until it’s flat, it would measure 87 feet long.",
            "Al Capone’s business card said he was a used furniture dealer",
            "There are more collect calls on Father’s Day than on any other day of the year.",
            "Banging your head against a wall burns 150 calories an hour.",
            "95% of people text things they could never say in person.",
            "A crocodile can’t poke its tongue out.",
            "It is physically impossible for pigs to look up into the sky.",
            "Guinness Book of Records holds the record for being the book most often stolen from Public Libraries.",
            "The word “gorilla” is derived from a Greek word meaning, “A tribe of hairy women.”" ,
            "Prisoners in Canadian war camps during WWII were treated so well, that a lot of them didn’t’ want to leave when the war was over." ,
            "Gorillas burp when they are happy " ,
            "In New York, it is illegal to sell a haunted house without telling the buyer." ,
            "In 2006 someone tried to sell New Zealand on eBay. The price got up to $3,000 before eBay shut it down." ,
            "It is considered good luck in Japan when a sumo wrestler makes your baby cry." ,
            "A man from Britain changed his name to Tim Pppppppppprice to make it harder for telemarketers to pronounce." ,
            "A woman from California once tried to sue the makers of Cap’n Crunch, because the Crunch Berries contained “no berries of any kind.”" ,
            "Apple launched a clothing line in 1986. It was described as a “train wreck” by others." ,
            "In Japan, crooked teeth are considered cute and attractive." ,
            "A Swedish woman lost her wedding ring, and found it 16 years later- growing on a carrot in her garden." ,
            "Donald duck comics were banned from Finland because he doesn’t wear pants." ,
            "The chance of you dying on the way to get lottery tickets is actually greater than your chance of winning." ,
            "Cherophobia is the fear of fun." ,
            "The toothpaste “Colgate” in Spanish translates to “go hang yourself”",
            "Pirates wore earrings because they believed it improved their eyesight.",
            "Human thigh bones are stronger than concrete." ,
            "Cockroaches can live for several weeks with their heads cut off, because their brains are located inside their body. They would eventually die from being unable to eat." ,
            "Scientists have tracked butterflies that travel over 3,000 miles." ,
            "To produce a single pound of honey, a single bee would have to visit 2 million flowers." ,
            "The population is expected to rise to 10.8 billion by the year 2080." ,
            "You breathe on average about 8,409,600 times a year" ,
            "More than 60,000 people are flying over the United States in an airplane right now." ,
            "Hamsters run up to 8 miles at night on a wheel." ,
            "A waterfall in Hawaii goes up sometimes instead of down." ,
            "A church in the Czech Republic has a chandelier made entirely of human bones." ,
            "Under the Code of Hammurabi, bartenders who watered down beer were punished by execution." ,
            "Our eyes are always the same size from birth, but our nose and ears never stop growing." ,
            "During your lifetime, you will produce enough saliva to fill two swimming pools." ,
            "You are 1% shorter in the evening than in the morning" ,
            "The elephant is the only mammal that can’t jump!" ,
            "Most dust particles in your house are made from dead skin!",
            "If 33 million people held hands, they could make it all the way around the equator." ,
            "Earth is the only planet that is not named after a god." ,
            "The bloodhound is the only animal whose evidence is admissible in court." ,
            "You are born with 300 bones, but by the time you are an adult you only have 206." ,
            "A ten-gallon hat will only hold ¾ of a gallon." ,
            "Just like fingerprints, everyone has different tongue prints." ,
            "ATM’s were originally thought to be failures, because the only users were prostitutes and gamblers who didn’t want to deal with tellers face to face." ,
            "Of all the words in the English language, the word “set” has the most definitions. The word “run” comes in close second." ,
            "A “jiffy” is the scientific name for 1/100th of a second." ,
            "One fourth of the bones in your body are located in your feet" ,
            "111,111,111 X 111,111,111 = 12,345,678,987,654,321" ,
            "Blue-eyed people tend to have the highest tolerance of alcohol." ,
            "A traffic jam lasted for more than 10 days, with cars only moving 0.6 miles a day." ,
            "The tongue is the strongest muscle in the body." ,
            "Every year more than 2500 left-handed people are killed from using right-handed products." ,
            "More than 50% of the people in the world have never made or received a telephone call." ,
            "The cigarette lighter was invented before the match.",
            "A flea can jump up to 200 times its own height. That is the equivalent of a human jumping the Empire State Building." ,
            "There are 5 temples in Kyoto, Japan that have blood stained ceilings. The ceilings are made from the floorboards of a castle where warriors killed themselves after a long hold-off against an army. To this day, you can still see the outlines and footprints." ,
            "There is a snake, called the boomslang, whose venom causes you to bleed out from every orifice on your body. You may even turn blue from internal bleeding, and it can take up to 5 days to die from the bleeding." ,
            "A ball of glass will bounce higher than a ball of rubber." ,
            "Saturn’s density is low enough that the planet would float in water." ,
            "68% of the universe is dark energy, and 27% is dark matter; both are invisible, even with our powerful telescopes. This means we have only seen 5% of the universe from earth." ,
            "The founders of Google were willing to sell Google for $1 million to Excite in 1999, but Excite turned them down. Google is now worth $527 Billion." ,
            "In the past 20 years, scientists have found over 1,000 planets outside of our solar system." ,
            "There are 60,000 miles of blood vessels in the human body." ,
            "If a pregnant woman has organ damage, the baby in her womb sends stem cells to help repair the organ." ,
            "If you started with $0.01 and doubled your money every day, it would take 27 days to become a millionaire." ,
            "Only one person in two billion will live to be 116 or older." ,
            "A person can live without food for about a month, but only about a week without water.",
            "If the amount of water in your body is reduced by just 1%, you’ll feel thirsty\n" +
                    "If it’s reduced by 10%, you’ll die." ,
            "On average, 12 newborns will be given to the wrong parents daily." ,
            "You can’t kill yourself by holding your breath."
);
}

static String getFact() {
    // Randomly select a fact
    if(facts.isEmpty()) {
        initFacts();
    }
    Random randomGenerator = new Random();
    int randomNumber= randomGenerator.nextInt(facts.size());
    String fact = facts.get(randomNumber);
    facts.remove(randomNumber);
    return fact;
}
}

package com.spdesigns.funfacts；
导入java.util.array；
导入java.util.List；
导入java.util.Random；
/**
*有趣的是
*由Stelios Papamichail于2017年11月2日创建。
*
*此文件属于com.spdesigns.funfacts包。
*/
班级概况{
私有静态列表事实；
静态void initFacts（）{
facts=ARRAYST.asList（“如果你不知何故找到了一种从我们可爱的小星球的冒泡核心提取所有黄金的方法，你将能够用一层黄金覆盖整个地球，直至膝盖。”，
麦当劳称经常购买他们食物的人为“重度使用者”，
“平均每个人一生中有6个月的时间等待红灯变绿。”，
“有记录以来最大的雪花出现在1887年的蒙大拿州基奥，宽15英寸。”，
“你睡觉比看电视消耗更多的卡路里。”，
“生活在你皮肤上的生命形式比地球上的人还多。”，
“南部海獭的前腿下有一层皮肤作为口袋。潜水时，它们用这些口袋来储存岩石和食物。”，
“1386年，法国一头猪因谋杀一名儿童而被公开绞死。”，
“五分之一的成年人认为外星人伪装成人类藏在我们的星球上。”，
“如果你真的相信自己是百万分之一，那么还有大约7184人和你一样。”，
“一朵云的重量可以超过100万磅。”，
“一个人睡觉时平均会吃70种昆虫和10只蜘蛛。”，
“美国第15任总统詹姆斯·布坎南（James Buchanan）不断用自己的钱购买奴隶以解放奴隶。”，
“国际象棋的可能迭代次数比已知宇宙中的原子数量还要多。”，
“一个人平均一生要环游世界三次。”，
“男性被闪电击中的可能性是女性的6倍。”，
“如果不加色素，可口可乐是绿色的。”，
“你不能同时打鼾和做梦。”，
“世界上最古老的口香糖已经有9000多年的历史了！”，
“土狼能听到一只老鼠在一英尺厚的雪下移动。”，
“闪电可以从喷发的火山中射出。”，
“纽约每年离伦敦大约有一英寸远。”，
“一张美元钞票在撕开之前，可以在同一个地方折叠大约4000次。”，
“打喷嚏的速度约为每小时100英里。”，
“在过去的5分钟里，地球已经行驶了5000多英里。”，
“懒惰一个月才能走一英里。”，
“世界上10%的人口是左撇子。”，
“一个坏了的钟每天对两次。”，
“据亚马逊称，Kindle上最引人注目的书籍是《圣经》、《史蒂夫·乔布斯传记》和《饥饿游戏》。”，
鲍勃·马利在他儿子去世前对他说的最后一句话是：“钱买不到生命。”，
“一只鼹鼠可以在一夜之间挖一条300英尺长的隧道。”，
“河马张开的大嘴足以容纳一个4英尺高的孩子。”，
“切洋葱时嚼口香糖有助于防止你哭泣。”，
“如果你要把一条紧身裤拉伸到它变平，它会有87英尺长。”，
“Al Capone的名片上写着他是一个二手家具经销商”，
“父亲节的对方付费电话比一年中任何一天都多。”，
“把头撞在墙上每小时能燃烧150卡路里。”，
“95%的人会发短信，说一些他们永远不会当面说的话。”，
“鳄鱼不会伸出舌头。”，
“猪在身体上是不可能仰望天空的。”，
《吉尼斯世界纪录大全》是公共图书馆被盗最多的一本书，
“gorilla”一词来源于希腊语，意思是“一群毛茸茸的女人。”，
“二战期间，加拿大战俘营中的战俘受到了很好的待遇，以至于很多战俘都不想在战争结束后离开。”，
“大猩猩高兴时打嗝”，
“在纽约，不告诉买家就出售闹鬼的房子是违法的。”，
“2006年，有人试图在eBay上出售新西兰。在eBay关闭新西兰之前，价格高达3000美元。”，
“在日本，相扑选手让宝宝哭被认为是好运。”，
“一名英国男子将自己的名字改为Tim PPPPlice，以使电话销售人员更难发音。”，
“一位来自加利福尼亚的妇女曾经试图起诉Cap'n Crunch的制造商，因为Crunch浆果“不含任何种类的浆果。”，
苹果在1986年推出了一条服装生产线。其他人把它描述为“火车失事”，
“在日本，弯曲的牙齿被认为是可爱和有吸引力的。”，
“一位瑞典妇女丢失了她的结婚戒指，16年后发现了它——在她的花园里靠胡萝卜生长。”，
唐老鸭漫画在芬兰被禁，因为他不穿裤子。
facts.remove(randomNumber);

Exception in thread "main" java.lang.UnsupportedOperationException
    at java.util.AbstractList.remove(AbstractList.java:161)
    at blah.FactBook.getFact(FactBook.java:131)
    ...

facts = new ArrayList<String>(Arrays.asList("If you somehow found a way to extract all..."));