JAVA文件

public class MainActivity extends AppCompatActivity {

    private EditText readerName;
    private RadioGroup readerSex;
    private EditText borrowTime;
    private TextView returnTime;
    private CheckBox historyHobby;
    private CheckBox suspenseHobby;
    private CheckBox litAndArtHobby;
    private SeekBar ageSeekBar;
    private ImageView bookImage;
    private Button searchBook;
    private Button next;
    private ArrayList<Book> mBooks;
    private Person mperson;
    private ArrayList<Book> booksResult;
    private Date borrowDate;
    private SimpleDateFormat sdf;
    private Date returnDate;
    private boolean isLitAndArt;
    private boolean isSuspense;
    private boolean isHistory;
    private TextView starAge;
    private int bookIndex;
    private Book book;
    private int readerAge;


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

        //初始化控件
        findView();

        //初始化数据
        dataInit();

        //添加监听器
        addListener();

    }

    private void addListener() {
        //性别监听器
        readerSex.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch (checkedId){
                    case R.id.mealRadioButton:
                        mperson.setSex("男");
                        break;
                    case R.id.femealRadioButton:
                        mperson.setSex("女");
                        break;
                }
            }
        });

        //设置日期文本监听器
        borrowTime.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
//                sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                sdf = new SimpleDateFormat("yyyy-MM-dd");
                try {
                    //String转换为Date
                    borrowDate = sdf.parse(borrowTime.getText().toString());
                    returnDate = sdf.parse(returnTime.getText().toString());
                } catch (ParseException e) {
                    e.printStackTrace();
                }

            }
        });

        //爱好监听器
        historyHobby.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                isHistory = isChecked;
            }
        });
        suspenseHobby.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                isSuspense = isChecked;
            }
        });
        litAndArtHobby.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                isLitAndArt = isChecked;
            }
        });

        //设置年龄监听器
        ageSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                starAge = findViewById(R.id.starAgeTextView);
                starAge.setText(ageSeekBar.getProgress()+"");
            }
        });

        //查找按钮监听器
        searchBook.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //判断时间
                if (borrowDate.after(returnDate)){

                    Toast.makeText(MainActivity.this,"借书年份晚于还书年份，退出",Toast.LENGTH_SHORT);
//                    finish();
                }
                search();
            }
        });


    }

    private void search() {
        if (booksResult == null){
            booksResult = new ArrayList<>();
        }
        booksResult.clear();

        //第几本书
        bookIndex = 0;

        //遍历书
        for (int i = 0; i < mBooks.size(); i++) {
            book = mBooks.get(i);
            if (book != null){
                if (book.getSuitableAge()<readerAge&&
                        (book.isHistory() == isHistory ||
                                book.isSuspense() == isSuspense ||
                                book.isLitAndArt() == isLitAndArt)){
                    booksResult.add(book);
                }
            }
        }
        if (bookIndex<mBooks.size()){
            bookImage.setImageResource(booksResult.get(bookIndex).getPicture());
        }

    }

    private void dataInit() {
        mBooks = new ArrayList<>();

        mBooks.add(new Book("人生感悟",30,"哲理",R.drawable.aa,false,false,true));
        mBooks.add(new Book("边城",20,"回忆录",R.drawable.bb,true,false,true));
        mBooks.add(new Book("saplr",18,"技术",R.drawable.cc,false,false,true));
        mBooks.add(new Book("光辉岁月",40,"回忆录",R.drawable.dd,true,false,false));
        mBooks.add(new Book("唐诗三百首",18,"诗词",R.drawable.ee,true,false,true));
        mBooks.add(new Book("艺术画作",15,"艺术",R.drawable.f,false,false,true));
        mBooks.add(new Book("中国古代文学纲要",18,"教学",R.drawable.ff,true,false,false));
        mBooks.add(new Book("无花果",25,"叙述",R.drawable.gg,false,false,true));
        mBooks.add(new Book("古镇记忆",18,"回忆录",R.drawable.hh,false,false,true));

        mperson = new Person();

        booksResult = new ArrayList<>();

    }

    private void findView() {
        readerName = findViewById(R.id.nameEditText);
        readerSex = findViewById(R.id.sexRadioGroup);
        borrowTime = findViewById(R.id.borrowTimeEditText);
        returnTime = findViewById(R.id.returnTimeTextView);
        historyHobby = findViewById(R.id.historyCheckBox);
        suspenseHobby = findViewById(R.id.suspenseCheckBox);
        litAndArtHobby = findViewById(R.id.LitAndArtCheckBox);
        ageSeekBar = findViewById(R.id.ageSeekBar);
        bookImage = findViewById(R.id.image);
        searchBook = findViewById(R.id.searchButton);
        next = findViewById(R.id.nextButton);

    }
}

XML文件

<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"
    tools:context=".MainActivity"
    android:orientation="vertical"
    android:background="#FAFADA">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="借书"
        android:textSize="30sp"
        android:textStyle="bold"
        android:layout_marginLeft="20dp"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="2"
        android:orientation="vertical">

        <!-- 读者 -->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="读者："
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>

            <EditText
                android:id="@+id/nameEditText"
                android:layout_width="250dp"
                android:layout_height="match_parent"
                android:hint="输入姓名" />
        </LinearLayout>

        <!-- 性别 -->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="性别："
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>

            <RadioGroup
                android:id="@+id/sexRadioGroup"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:orientation="horizontal">

                <RadioButton
                    android:id="@+id/mealRadioButton"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:text="男"
                    android:textSize="20sp"
                    android:layout_marginRight="10dp"/>

                <RadioButton
                    android:id="@+id/femealRadioButton"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:text="女"
                    android:textSize="20sp"
                    android:layout_marginRight="10dp"/>

            </RadioGroup>

        </LinearLayout>

        <!-- 借出时间 -->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="借出时间："
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>

            <EditText
                android:id="@+id/borrowTimeEditText"
                android:layout_width="250dp"
                android:layout_height="match_parent"
                android:hint="输入格式为YYYY-MM-DD"/>
        </LinearLayout>

        <!-- 归还时间 -->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="归还时间："
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>

            <TextView
                android:id="@+id/returnTimeTextView"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="2016-06-30"
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>

        </LinearLayout>
        <!-- 爱好 -->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="爱好："
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>
            <CheckBox
                android:id="@+id/historyCheckBox"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="历史"
                android:textSize="20sp"
                android:layout_marginRight="10dp"/>
            <CheckBox
                android:id="@+id/suspenseCheckBox"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="悬疑"
                android:textSize="20sp"
                android:layout_marginRight="10dp"/>
            <CheckBox
                android:id="@+id/LitAndArtCheckBox"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="文艺"
                android:textSize="20sp"
                android:layout_marginRight="10dp"/>

        </LinearLayout>

        <!-- 年龄 -->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="年龄："
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>
            <TextView
                android:id="@+id/starAgeTextView"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="18"
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>
            <SeekBar
                android:id="@+id/ageSeekBar"
                android:layout_width="150dp"
                android:layout_height="match_parent"
                android:progress="18"
                android:min="0"
                android:max="100"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="100"
                android:gravity="center"
                android:textSize="20sp"
                android:textStyle="bold"
                android:layout_marginLeft="10dp"/>

        </LinearLayout>

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="2"
        android:orientation="vertical">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="2"
            android:orientation="horizontal"
            android:background="#FFFFFF">

            <ImageView
                android:id="@+id/image"
                android:layout_width="200dp"
                android:layout_height="200dp"
                android:layout_marginRight="5dp"
                android:layout_marginLeft="5dp"/>
            <LinearLayout
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:orientation="vertical">
                <TextView
                    android:id="@+id/bookeNameTextView"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:layout_weight="1"
                    android:text="书名"
                    android:gravity="center"
                    android:textSize="20sp"
                    android:textStyle="bold"
                    android:layout_marginLeft="10dp"/>
                <TextView
                    android:id="@+id/typeTextView"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:layout_weight="1"
                    android:text="类型"
                    android:gravity="center"
                    android:textSize="20sp"
                    android:textStyle="bold"
                    android:layout_marginLeft="10dp"/>
                <TextView
                    android:id="@+id/suitableAgeTextView"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:layout_weight="1"
                    android:text="适用年龄"
                    android:gravity="center"
                    android:textSize="20sp"
                    android:textStyle="bold"
                    android:layout_marginLeft="10dp"/>

            </LinearLayout>

        </LinearLayout>


        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:orientation="horizontal">

            <Button
                android:id="@+id/searchButton"
                android:layout_width="100dp"
                android:layout_height="50dp"
                android:layout_alignParentStart="true"
                android:layout_alignParentLeft="true"
                android:layout_alignParentTop="true"
                android:layout_alignParentBottom="true"
                android:layout_gravity="center"
                android:layout_marginLeft="20dp"
                android:layout_marginTop="20dp"
                android:layout_marginBottom="21dp"
                android:background="#0000ff"
                android:text="查找" />

            <Button
                android:id="@+id/nextButton"
                android:layout_width="100dp"
                android:layout_height="50dp"
                android:layout_alignParentTop="true"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:layout_alignParentBottom="true"
                android:layout_gravity="center"
                android:layout_marginTop="20dp"
                android:layout_marginRight="20dp"
                android:layout_marginBottom="20dp"
                android:background="#0000ff"
                android:text="下一个" />

        </RelativeLayout>
    </LinearLayout>
</LinearLayout>

麻烦解答一下，为啥输入信息（输入的格式正确）之后，点击查找按钮会闪退？
下面这个是闪退后的Logcat，但是看了一下，还是没看出来