Update doc

常用api以及算法.md

@@ -101,10 +101,144 @@ public static boolean equals(Object a, Object b) {
 ![image-20250404170313844](https://gitee.com/icecat2233/picture/raw/master/20250404170322675.png)
 
 1. 其中binarySearch()方法，给予的数组必须是排好序的。因为使用了二分法
+
 2. sort()方法中，对数组进行了默认升序排序，要进行其他顺序排序，需学习**红黑树**
 
    
 
+## JDK7时间类
+
+### Date类
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250410163120955.png" alt="image-20250410163119332" style="zoom:67%;" />
+
+
+
+### SimpleDateFormat类：用于日期格式化
+
+**将Date日期转化为易懂的形式**  我个人理解为可以将这个类作为修饰Date日期对象的类。
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250410163252914.png" alt="image-20250410163250157" style="zoom:67%;" />
+
+
+
+如何使用
+
+其中在创建日期格式化对象时，可以使用代参构造方法传入pattern,修改格式，代表元素如下图
+
+```java
+        //创建了一个日期格式化对象，使用默认模式
+        SimpleDateFormat format = new SimpleDateFormat(parttern"");
+        //创建日期对象，封装此刻时间
+        Date date = new Date();
+        //将日期对象转换为字符串
+        String resul = format.format(date);
+        System.out.println(resul);
+```
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250410161300015.png" alt="image-20250410161244449" style="zoom: 67%;" />
+
+### Calendar类：
+
+表示一个时间的日历对象
+
+#### 如何获取对象
+
+`Calendar c = Calendar.getInstance();`
+
+##### 常见方法
+
+set 修改
+
+get 获取  **注意获取月份时要进行+1操作**    
+
+​                **获取星期时**
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250410174127785.png" alt="image-20250410174126335" style="zoom:67%;" />
+
+add 在原有基础上添加或减少
+
+##### 细节点：
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250410173853270.png" alt="image-20250410173852190" style="zoom:50%;" />
+
+##### 案例：
+
+```java
+//键盘录入一个字符串，判断今天是今年的第几天
+public class CalendarTest {
+    public static void main(String[] args) throws ParseException {
+        System.out.println("请输入你想要求的日期 格式\"xxxx年xx月xx日\"");
+        Scanner sc =new Scanner(System.in);
+        String input = sc.nextLine();
+
+        //使用SimpleDateFormat 将日期字符串转化为日期对象
+        SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月dd日");
+        Date riqi = format.parse(input);
+        
+        //将日期对象转化为Calendar对象
+        Calendar c = Calendar.getInstance();
+        c.setTime(riqi);
+        
+        //使用get方法获取第几天
+        int day = c.get(Calendar.DAY_OF_YEAR);
+        System.out.println("今天是这一年的第"+day+"天");
+    }
+}
+```
+
+## JDK8版本后时间类（常用）
+
+### 日历类 LocalDateTime
+
+如何将字符串转化为日期对象：
+
+**注意：尽量将格式化中的MM月dd日等只写一个字符，要不然容易报错**
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411171745728.png" alt="image-20250411171744338" style="zoom:80%;" />
+
+```Java
+LocalDate date = LocalDate.parse(birthday, DateTimeFormatter.ofPattern("yyyy年M月d日"));
+```
+
+如何格式化日期对象
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411171614157.png" alt="image-20250411171612632" style="zoom: 80%;" />
+
+```java
+DateTimeFormatter.ofPattern("yyyy年M月d日")
+```
+
+#### 创建对象？
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411163642595.png" alt="image-20250411163640532" style="zoom:50%;" />
+
+**LocalDate time举例  LocalTime  LocalDateTime三者方法一致**
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411163543670.png" alt="image-20250411163541466" style="zoom:50%;" />
+
+#### 注意点：
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411163358361.png" alt="image-20250411163349987" style="zoom: 50%;" />
+
+
+
+### instant时间戳类
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411165138747.png" alt="image-20250411165137534" style="zoom:50%;" />
+
+### ZoneDateTime 带时区的时间对象
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411165733292.png" alt="image-20250411165732086" style="zoom:50%;" />
+
+### Zoneld类(时区类)
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411165031419.png" alt="image-20250411165030046" style="zoom:50%;" />
+
+### 时间中的工具类：ChronUnit
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250411171007818.png" alt="image-20250411171004330" style="zoom: 67%;" />
+
 ## 基本算法：
 
 ### 1:冒泡排序

异常.md

@@ -0,0 +1,44 @@
+# 异常
+
+分为Error 和 Exception
+
+其中Exception中 又分为两类，如图中所示
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250414182933522.png" alt="image-20250414182932233" style="zoom: 33%;" />
+
+其中两种错误的表现形式有下列
+
+
+
+![image-20250414183003770](imgh/image-20250414183003770.png)
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250414182755030.png" alt="image-20250414182746446" style="zoom: 67%;" />
+
+# 异常的两种处理方式
+
+1. **try...catch...捕获异常**
+
+   <img src="https://gitee.com/icecat2233/picture/raw/master/20250416155305609.png" alt="image-20250416155256665" style="zoom: 50%;" />
+
+2. **throws抛出异常**
+
+   <img src="https://gitee.com/icecat2233/picture/raw/master/20250416155817373.png" alt="image-20250416155816351" style="zoom:50%;" />
+
+## 两种方式怎么选择：
+
+思路：这个问题是否需要暴漏出来？
+需要暴漏，用throws
+
+不需要暴漏，用try catch
+
+## throws和throw的区别
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250416155752416.png" alt="image-20250416155750720" style="zoom:50%;" />
+
+# 自定义异常
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250416163826822.png" alt="image-20250416163824387" style="zoom:50%;" />
+
+# 异常中的细节
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250416164540545.png" alt="image-20250416164538085" style="zoom:50%;" />

集合-数据结构相关.md

@@ -0,0 +1,104 @@
+# 集合：
+
+**总结：**
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250417165937735.png" alt="image-20250417165922953" style="zoom:50%;" />
+
+其中Collection接口中又分为**set**接口和**list**接口
+
+## Collection:
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250417165721995.png" alt="image-20250417165713561" style="zoom:50%;" />
+
+**注意事项：**
+
+remove and contains方法依赖于底层equals方法
+
+## 集合通用遍历方法：
+
+### 1.迭代器  2.增强for循环  3.forEach
+
+首先获取迭代器：
+
+`Iterator<Student> it = c.iterator();`
+
+其次判断循环是否还有元素
+
+`hasNext()方法`    `next()方法`    
+
+注意：next()方法只调用一次，要不然会引起指针异常
+
+### 迭代器源码解析：
+
+![image-20250420172303418](https://gitee.com/icecat2233/picture/raw/master/20250420172317333.png)
+
+### **三种方法演示：**
+
+```java
+public class Test2 {
+    public static void main(String[] args) {
+        Collection<Student> c = new ArrayList<>();
+        c.add(new Student("小鸟游六花",15));
+        c.add(new Student("小鸟游七花",15));
+        c.add(new Student("小鸟游八花",15));
+
+        //迭代器循环
+        Iterator<Student> it = c.iterator();
+
+        while (it.hasNext()){
+            Student stu = it.next();
+            System.out.println(stu.getName()+"---"+stu.getAge());
+        }
+
+        //增强for循环
+        for (Student stu:c){
+            System.out.println(stu);
+        }
+
+        //forEach遍历
+        c.forEach(student -> System.out.println(student));
+    }
+}
+```
+
+# List集合
+
+## list集合特点以及方法
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250425155619805.png" alt="image-20250425155604336" style="zoom:67%;" />
+
+## 并发修改异常：
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250425154636875.png" alt="image-20250425154628294" style="zoom: 80%;" />
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250425155719001.png" alt="image-20250425155717100" style="zoom:80%;" />
+
+## List集合的5种遍历方式
+
+1. Iterator迭代器
+2. 增强for循环
+3. foreach
+4. 普通for循环
+5. ListIterator迭代器
+
+# 数据结构：栈 队列 链表 数组
+
+<img src="https://gitee.com/icecat2233/picture/raw/master/20250425163326284.png" alt="image-20250425163323615" style="zoom: 67%;" />
+
+## 其中Arraylist集合扩容机制为
+
+1. 在初始化时长度为0
+2. 调用添加方法add时长度为10
+3. 此后长度超过10时，会将数组长度增加原来的1/2
+
+#### **源码分析**：**此为长度还未超出10时的源码过程**
+
+![image-20250425165520793](https://gitee.com/icecat2233/picture/raw/master/20250425165535349.png)
+
+####          **此为超出10时源码过程**：
+
+![image-20250425165743512](imgh/image-20250425165743512.png)
+
+## LinkedList特有方法
+
+removeFirst()   removeLast()