From 1ade0f345916cb3d6ca98cb6ccaa49c137914eee Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=90=B4=E6=86=B6=E8=B1=AA?= <1033474650@qq.com> Date: Thu, 23 May 2024 09:49:43 +0800 Subject: [PATCH 1/2] =?UTF-8?q?feat=EF=BC=9A=E6=96=B0=E5=A2=9E517=E7=9A=84?= =?UTF-8?q?=E4=BD=9C=E4=B8=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../SetAndMap/map1.java" | 80 +++++++++++++++++++ .../SetAndMap/map2.java" | 39 +++++++++ .../SetAndMap/set.java" | 78 ++++++++++++++++++ .../bigdecimal/bigdecimal1to2.java" | 32 ++++++++ .../bigdecimal/bigdecimal3.java" | 14 ++++ .../bigdecimal/bigdecimal4.java" | 23 ++++++ .../date/date1.java" | 10 +++ .../date/date2.java" | 31 +++++++ .../date/date3and4.java" | 21 +++++ .../date/date5.java" | 14 ++++ .../math/absolutevalue.java" | 21 +++++ .../math/avg.java" | 24 ++++++ .../math/minmax.java" | 28 +++++++ .../math/random.java" | 12 +++ .../math/round.java" | 21 +++++ .../person.java" | 60 ++++++++++++++ .../string/string13.java" | 21 +++++ .../string/string14.java" | 22 +++++ .../string/string15.java" | 24 ++++++ .../string/string1and2.java" | 15 ++++ .../string/string3.java" | 11 +++ .../string/string4.java" | 16 ++++ .../string/string5.java" | 23 ++++++ .../string/string6.java" | 12 +++ .../string/string7.java" | 29 +++++++ .../string/string8.java" | 15 ++++ .../string/string9to12.java" | 21 +++++ 27 files changed, 717 insertions(+) create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/map1.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/map2.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/set.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal1to2.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal3.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal4.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date1.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date2.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date3and4.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date5.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/absolutevalue.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/avg.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/minmax.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/random.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/round.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/person.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string13.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string14.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string15.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string1and2.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string3.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string4.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string5.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string6.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string7.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string8.java" create mode 100644 "work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string9to12.java" diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/map1.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/map1.java" new file mode 100644 index 0000000..541b282 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/map1.java" @@ -0,0 +1,80 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.SetAndMap; + +import java.util.Collection; +import java.util.HashMap; +import java.util.Map; +import java.util.Set; + + public class map1 {/*1. **创建和添加键值对** + 创建一个 `HashMap` 并添加至少3对键值对，键可以是字符串，值可以是整数。*/ + + public static void main(String[] args) { + Map map = new HashMap<>(); + map.put("狗", "1"); + map.put("猫", "2"); + map.put("鼠", "3"); + + /*2. **获取和打印值** + 使用键来获取对应的值，并打印出来。 */ + String keytofind = "鼠"; + String value = map.get(keytofind); + if (value != null) { + System.out.println(keytofind + "," + value); + } else { + System.out.println(keytofind + "not found"); + } + /* 3. **检查键是否存在** + 检查一个特定的键是否存在于 `HashMap` 中。*/ + String keytocheck = "猫"; + if (map.containsKey(keytocheck)) { + System.out.println(keytocheck + "exists in the hashmap"); + } else { + System.out.println(keytocheck + "dose not exist in the hashmap"); + } + + /* 4. **键集合遍历** + 遍历 `HashMap` 的键集合，并打印每个键。*/ + Set keys = map.keySet(); + + for (String mapkey : keys) { + System.out.println(keys); + } + + /* 5. **值集合遍历** + 遍历 `HashMap` 的值集合，并打印每个值。*/ + Collection values = map.values(); + + for (String mapvalue : values) { + System.out.println(value); + } + + /* 6. **键值对遍历** + 使用 `entrySet()` 遍历 `HashMap` 的所有键值对，并打印。*/ + for (Map.Entry entry : map.entrySet()) { + System.out.println("key:" + entry.getKey() + ",value:" + entry.getValue()); + } + + /* 7. **更新值** + 对一个已存在的键更新其对应的值。*/ + String keytoupdate = "鼠"; + int newValue = 0; + map.put(keytoupdate, String.valueOf(newValue)); + System.out.println(map); + + /*8. **移除键值对** + 移除一个特定的键值对，并确认它已被移除。*/ + String keytoremove = "鼠"; + String removedvalue = map.remove(keytoremove); + if (removedvalue != null) { + System.out.println("已移除:" + keytoremove ); + } else { + System.out.println("不存在:" + keytoremove); + } + System.out.println("剩余" + map); + /* 9. **Map 的大小** + 打印出 `HashMap` 的大小。*/ + System.out.println("size:" + map.size()); + } + } + + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/map2.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/map2.java" new file mode 100644 index 0000000..0e3fea1 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/map2.java" @@ -0,0 +1,39 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.SetAndMap; + +import java.util.HashMap; + + /*10. **使用泛型** + 创建一个泛型 `HashMap`，键为自定义对象，值为字符串，并添加键值对。*/ + + class CustomKey { + int id; + public CustomKey(int id) { + this.id = id; + } + @Override + public boolean equals(Object o) { + if (this == o) return true; + if (o == null || getClass() != o.getClass()) return false; + + CustomKey that = (CustomKey) o; + + return id == that.id; + } + @Override + public int hashCode() { + return id; + } + } + public class map2 { + public void main(String[] args) { + + HashMap customHashMap = new HashMap<>(); + + CustomKey customKey = new CustomKey(1); + + customHashMap.put(customKey, "Example Value"); + + System.out.println(customHashMap); + } + } + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/set.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/set.java" new file mode 100644 index 0000000..e797ae4 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/SetAndMap/set.java" @@ -0,0 +1,78 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.SetAndMap; + +import java.util.Arrays; +import java.util.HashSet; +import java.util.Iterator; +import java.util.Set; + + public class set {/*1. **创建和添加元素** + 创建一个 `HashSet` 并添加至少5个不同的字符串元素。*/ + + public static void main(String[] args) { + Set set = new HashSet<>(); + set.add("a"); + set.add("b"); + set.add("c"); + set.add("d"); + + /* 2. **元素检查** + 检查一个特定的字符串是否已经存在于你创建的 `HashSet` 中。*/ + System.out.println("是否存在某个元素" + set.contains("a")); + + /*3. **元素移除** + 从 `HashSet` 中移除一个已存在的元素，并确认它已被移除。*/ + set.remove("a"); + System.out.println("已移除" + set); + + /* 4. **集合大小** + 打印出 `HashSet` 的大小。*/ + System.out.println("大小" + set.size()); + + /* 5. **集合遍历** + 使用增强型 `for` 循环遍历 `HashSet` 并打印每个元素。*/ + for (String ele : set) { + System.out.println(ele); + } + + /*6. **集合转换为数组** + 将 `HashSet` 转换为数组，并打印数组中的每个元素。*/ + String[] array = set.toArray(new String[0]); + System.out.println(Arrays.toString(array)); + + /*7. **集合的并集** +创建两个 `HashSet` 对象，实现它们的并集操作。*/ + HashSet setA = new HashSet<>(); + setA.add("1"); + setA.add("2"); + setA.add("3"); + + HashSet setB = new HashSet<>(); + setB.add("2"); + setB.add("3"); + setB.add("4"); + + HashSet result = new HashSet<>(); + + result.addAll(setA); + result.addAll(setB); + System.out.println("并集:"+ result); + /* Iterator it = resset.iterator(); + while(it.hasNext()){ + object ele = (object) it.next(); + System.out.println(ele); + };*/ + /* 8. **集合的交集** +对上面创建的两个 `HashSet` 对象实现交集操作。*/ + result.clear(); + result.addAll(setA); + result.retainAll(setB); + System.out.println("交集"+ result); + /*9. **集合的差集** +对上面创建的两个 `HashSet` 对象实现差集操作。*/ + result.clear(); + result.addAll(setA); + result.removeAll(setB); + System.out.println("差集"+ result); + } + } + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal1to2.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal1to2.java" new file mode 100644 index 0000000..be6dea7 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal1to2.java" @@ -0,0 +1,32 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.bigdecimal; +import java.math.BigDecimal; + +public class bigdecimal1to2 { + + public static BigDecimal add(BigDecimal a, BigDecimal b) { + return a.add(b); + } + + public static BigDecimal subtract(BigDecimal a, BigDecimal b) { + return a.subtract(b); + } + + public static BigDecimal multiply(BigDecimal a, BigDecimal b) { + return a.multiply(b); + } + + public static BigDecimal divide(BigDecimal a, BigDecimal b) { + return a.divide(b); + } + + public static void main(String[] args) { + BigDecimal a = new BigDecimal("10.5"); + BigDecimal b = new BigDecimal("2.3"); + + System.out.println("加法: " + add(a, b)); + System.out.println("减法: " + subtract(a, b)); + System.out.println("乘法: " + multiply(a, b)); + System.out.println("除法: " + divide(a, b)); + } + } + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal3.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal3.java" new file mode 100644 index 0000000..9e2a4a4 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal3.java" @@ -0,0 +1,14 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.bigdecimal; +import java.math.BigDecimal; +import java.math.RoundingMode; +public class bigdecimal3 { + + public static void main(String[] args) { + BigDecimal originalValue = new BigDecimal("3.1415926535897932384"); + int scale = 5; + RoundingMode roundingMode = RoundingMode.HALF_UP; + + BigDecimal roundedValue = originalValue.setScale(scale, roundingMode); + System.out.println("Rounded Value: " + roundedValue); + } + } diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal4.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal4.java" new file mode 100644 index 0000000..8282a8f --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/bigdecimal/bigdecimal4.java" @@ -0,0 +1,23 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.bigdecimal; +import java.math.BigDecimal; +public class bigdecimal4 { + + public static int compareBigDecimals(BigDecimal bd1, BigDecimal bd2) { + return bd1.compareTo(bd2); + } + + public static void main(String[] args) { + BigDecimal bd1 = new BigDecimal("10.0"); + BigDecimal bd2 = new BigDecimal("10.000"); + + int comparisonResult = compareBigDecimals(bd1, bd2); + + if (comparisonResult == -1) { + System.out.println("bd1 is less than bd2"); + } else if (comparisonResult == 0) { + System.out.println("bd1 is equal to bd2"); + } else if (comparisonResult == 1) { + System.out.println("bd1 is greater than bd2"); + } + } + } diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date1.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date1.java" new file mode 100644 index 0000000..04a4eb6 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date1.java" @@ -0,0 +1,10 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.date; + +import java.util.Date; + +public class date1 { + public static void main(String[] args) { + Date now = new Date(); + System.out.println("time:"+now);} + +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date2.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date2.java" new file mode 100644 index 0000000..e93a4ce --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date2.java" @@ -0,0 +1,31 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.date; + +import java.util.Calendar; +import java.util.Date; + +public class date2 { + public static int getYear(Date date) { + Calendar calendar = Calendar.getInstance(); + calendar.setTime(date); + return calendar.get(Calendar.YEAR); + } + + public static int getMonth(Date date) { + Calendar calendar = Calendar.getInstance(); + calendar.setTime(date); + return calendar.get(Calendar.MONTH) + 1; + } + + public static int getDayOfMonth(Date date) { + Calendar calendar = Calendar.getInstance(); + calendar.setTime(date); + return calendar.get(Calendar.DAY_OF_MONTH); + } + + public static void main(String[] args) { + Date date = new Date(); + System.out.println("Year:" + getYear(date)); + System.out.println("Month:" + getMonth(date)); + System.out.println("Day of Month" + getDayOfMonth(date)); + } +} \ No newline at end of file diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date3and4.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date3and4.java" new file mode 100644 index 0000000..09815d4 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date3and4.java" @@ -0,0 +1,21 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.date; + +import java.text.ParseException; +import java.text.SimpleDateFormat; +import java.util.Date; + +public class date3and4 { + public static void main(String[] args) { + Date currentDate = new Date(); + SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); + String formattedDate = formatter.format(currentDate); + System.out.println("Formatted Date:"+formattedDate); + + try{ + Date newDate = formatter.parse(formattedDate); + System.out.println("Formatted String:"+newDate); + } catch (ParseException e){ + e.printStackTrace(); + } + } +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date5.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date5.java" new file mode 100644 index 0000000..fae56bb --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/date/date5.java" @@ -0,0 +1,14 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.date; + +import java.text.SimpleDateFormat; +import java.util.Date; + +public class date5 { + public static void main(String[] args) { + long timestamp = System.currentTimeMillis(); + Date date = new Date(timestamp); + System.out.println("timestamp:"+timestamp); + System.out.println("translatedDate"+date); + + } +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/absolutevalue.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/absolutevalue.java" new file mode 100644 index 0000000..47375eb --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/absolutevalue.java" @@ -0,0 +1,21 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.math;/*`Math` 类练习题： + + 1. 绝对值 + - 编写一个程序，接受一个用户输入的数字，然后输出该数字的绝对值。*/ + +import java.util.Scanner; + +public class absolutevalue { + public static void main(String[] args) { + Scanner scanner = new Scanner(System.in); + + System.out.println("please add a number"); + double number = scanner.nextDouble(); + + double absolutevalue = Math.abs(number); + System.out.println("math.absolutevalue:"+absolutevalue); + + scanner.close(); + } +} + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/avg.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/avg.java" new file mode 100644 index 0000000..8688fbc --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/avg.java" @@ -0,0 +1,24 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.math; + +/*5.计算平均值 + + - 创建一个方法，接受一个整数数组，并返回数组的平均值。*/ +public class avg { + public static double caculateAverage(int[] numbers) { + if (numbers == null || numbers.length == 0) { + throw new IllegalArgumentException("the numbers array is false"); + } + int sum = 0; + for (int number : numbers) { + sum += number; + } + return sum / (double) numbers.length; + } + + + public static void main(String[] args) { + int[] numbers = {1, 2, 3, 4, 5}; + double average = caculateAverage(numbers); + System.out.println("the average is:" + average); + } +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/minmax.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/minmax.java" new file mode 100644 index 0000000..d8e1037 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/minmax.java" @@ -0,0 +1,28 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.math; + + +/*2.最小值和最大值 + + - 创建一个方法，接受三个整数作为参数，返回这三个整数中的最小值和最大值。*/ +public class minmax { + public static void main(String[] args) { + int a = 5; + int b = 10; + int c = 15; + + int min = findMin(a,b,c); + int max = findMax(a,b,c); + + System.out.println("minimum:"+ min); + System.out.println("maximum:"+ max); + } + + public static int findMin(int num1,int num2,int num3){ + return Math.min(Math.min(num1,num2),num3); + } + + public static int findMax(int num1,int num2,int num3){ + return Math.max(Math.max(num1,num2),num3); + } + +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/random.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/random.java" new file mode 100644 index 0000000..47ece21 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/random.java" @@ -0,0 +1,12 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.math; + +/*4.随机数生成 + + - 使用 `Math.math.random()` 方法生成一个 0 到 1 之间的随机数，并将其乘以一个用户指定的最大值。*/ +public class random { + public static void main(String[] args) { + int upperBound = 2; + int randomNumber = (int)(Math.random() * upperBound); + System.out.println("randomNumber:"+randomNumber); + } +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/round.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/round.java" new file mode 100644 index 0000000..2d0c822 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/math/round.java" @@ -0,0 +1,21 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.math; + +import java.util.Scanner; + +/*3.四舍五入 + + - 编写一个程序，接受一个浮点数作为输入，并将其四舍五入到最近的整数。*/ +public class round { + public static void main(String[] args) { + Scanner scanner = new Scanner(System.in); + + System.out.println("please add a floatnumber"); + double floatnumber = scanner.nextDouble(); + + int roundedNumber = (int) Math.round(floatnumber); + System.out.println("math.round:"+ roundedNumber); + + scanner.close(); + } + +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/person.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/person.java" new file mode 100644 index 0000000..f3187b0 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/person.java" @@ -0,0 +1,60 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224; + +import java.util.Objects; + +/*`Object` 类练习题： + + 1. 重写 `toString` 方法 + - 创建一个 `Person` 类，包含 `name` 和 `age` 属性。重写 `toString` 方法，使其返回一个字符串，包含对象的 `name` 和 `age`。*/ +public class person { + private String name; + private int age; + + + + + public person(String name, int age){ + this.name = name; + this.age = age; + } + + public String getName () { + return name; + } + + public void setName (String name){ + this.name = name; + } + + public int getAge () { + return age; + } + + public void setAge ( int age){ + this.age = age; + } + + @Override + public String toString () { + return "name=" + name + ",age=" + age; + } + + +/*使用 `equals` 方法 + + - 在 `Person` 类中重写 `equals` 方法，使得可以通过 `name` 和 `age` 属性比较两个 `Person` 对象是否相等。*/ + @Override + public boolean equals (Object o){ + if (this == o) return true; + if (o == null || getClass() != o.getClass()) return false; + person person = (person) o; + return age == person.age && + Objects.equals(name, person.name); + } + + @Override + public int hashCode () { + return Objects.hash(name, age); + } + } + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string13.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string13.java" new file mode 100644 index 0000000..99a5128 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string13.java" @@ -0,0 +1,21 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string13 { + public static void main(String[] args) { + String str = "Hello, World!"; + char charToFind = 'o'; + int count = countChar(str, charToFind); + System.out.println("The character '" + charToFind + "' appears " + count + " times."); + } + + public static int countChar(String str, char charToFind) { + int count = 0; + for (int i = 0; i < str.length(); i++) { + if (str.charAt(i) == charToFind) { + count++; + } + } + return count; + } +} + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string14.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string14.java" new file mode 100644 index 0000000..c3200fa --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string14.java" @@ -0,0 +1,22 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string14 { + + public static void main(String[] args) { + String intString = "123"; + String floatString = "123.45"; + + int intValue = Integer.parseInt(intString); + float floatValue = Float.parseFloat(floatString); + + System.out.println("整数转换结果: " + intValue); + System.out.println("浮点数转换结果: " + floatValue); + + String intStringValue = String.valueOf(intValue); + String floatStringValue = String.valueOf(floatValue); + + System.out.println("整数转换为字符串: " + intStringValue); + System.out.println("浮点数转换为字符串: " + floatStringValue); + } +} + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string15.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string15.java" new file mode 100644 index 0000000..c0ab1ff --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string15.java" @@ -0,0 +1,24 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string15 { + public static void main(String[] args) { + String str1 = "Hello"; + String str2 = "World"; + String str3 = "Java"; + + StringBuilder sb = new StringBuilder(); + for (int i = 0; i < 3; i++) { + if (i > 0) { + sb.append("*"); + } + sb.append(str1); + sb.append("*"); + sb.append(str2); + sb.append("*"); + sb.append(str3); + } + + System.out.println(sb.toString()); + } +} + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string1and2.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string1and2.java" new file mode 100644 index 0000000..5bf276d --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string1and2.java" @@ -0,0 +1,15 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; +import static java.lang.reflect.Array.getLength; + +public class string1and2 { + public static void main(String[] args) { + String str1 = "Hello"; + String str2 = "World"; + String concatenatedString = str1 + "" + str2; + System.out.println(concatenatedString); + + int length = getLength(str1); + System.out.println("length:" + length); + } + +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string3.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string3.java" new file mode 100644 index 0000000..d7319ca --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string3.java" @@ -0,0 +1,11 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string3 { + public static void main(String[] args) { + String input = "Hello,World"; + String[] words = input.split(","); + for (String word : words){ + System.out.println(word); + } + } +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string4.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string4.java" new file mode 100644 index 0000000..bbf73d4 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string4.java" @@ -0,0 +1,16 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string4 { + public static String reverse(String original){ + if (original == null){ + return null; + } + return new StringBuilder(original).reverse().toString(); + } + + public static void main(String[] args) { + String original = "Hello World"; + String reversed =reverse(original); + System.out.println(reversed); + } +} diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string5.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string5.java" new file mode 100644 index 0000000..c248120 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string5.java" @@ -0,0 +1,23 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string5 { + + public static String toLowerCase(String input) { + return input.toLowerCase(); + } + + public static String toUpperCase(String input) { + return input.toUpperCase(); + } + + public static void main(String[] args) { + String original = "Java Programming"; + + String lowerCase = toLowerCase(original); + System.out.println("小写: " + lowerCase); + + String upperCase = toUpperCase(original); + System.out.println("大写: " + upperCase); + } +} + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string6.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string6.java" new file mode 100644 index 0000000..2b1532f --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string6.java" @@ -0,0 +1,12 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string6 { + public static void main(String[] args) { + String haystack = "Hello, this is a simple test!"; + String needle = "simple"; + + boolean contains = haystack.contains(needle); + System.out.println("字符串 '" + haystack + "' 是否包含子字符串 '" + needle + "': " + contains); + } +} + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string7.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string7.java" new file mode 100644 index 0000000..d11cc58 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string7.java" @@ -0,0 +1,29 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string7 { + public static String replaceAll(String str, char oldChar, char newChar) { + if (str == null) { + return null; + } + StringBuilder sb = new StringBuilder(); + for (int i = 0; i < str.length(); i++) { + char c = str.charAt(i); + if (c == oldChar) { + sb.append(newChar); + } else { + sb.append(c); + } + } + return sb.toString(); + } + + public static void main(String[] args) { + String original = "Hello World!"; + char oldChar = 'o'; + char newChar = '0'; + + String replaced = replaceAll(original, oldChar, newChar); + System.out.println(replaced); + } +} + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string8.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string8.java" new file mode 100644 index 0000000..ae40295 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string8.java" @@ -0,0 +1,15 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string8 { + public static void main(String[] args) { + String originalString = " Hello, World! "; + String trimmedString = trim(originalString); + System.out.println("Original String: " + originalString); + System.out.println("Trimmed String: " + trimmedString); + } + + public static String trim(String s) { + return s.trim(); + } +} + diff --git "a/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string9to12.java" "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string9to12.java" new file mode 100644 index 0000000..dece845 --- /dev/null +++ "b/work/com/java/minxi/java_20240517/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/string/string9to12.java" @@ -0,0 +1,21 @@ +package com.java.minxi.java_20240517.java_2302_吴憶豪_2244310224.string; + +public class string9to12 { + public static void main(String[] args) { + String str1 = "Hello"; + String str2 = "hello"; + + boolean areEqual = str1.equalsIgnoreCase(str2); + System.out.println("Strings are equal (ignoring case): " + areEqual); + + String substring = str1.substring(1,3); + System.out.println(substring); + + boolean result1 = str1.endsWith("o"); + System.out.println("结果:"+result1); + + boolean result2 = str2.startsWith("H"); + System.out.println("结果:"+result2); + } +} + -- Gitee From 1f2efd5883263700ce60ab71ef086358bb830684 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=90=B4=E6=86=B6=E8=B1=AA?= <1033474650@qq.com> Date: Wed, 29 May 2024 12:10:05 +0800 Subject: [PATCH 2/2] =?UTF-8?q?=E5=8F=98=E6=9B=B4?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../person.java" | 31 ++++++++++ .../rectangle.java" | 40 +++++++++++++ .../jdbc1.java" | 35 +++++++++++ .../jdbc2.java" | 38 ++++++++++++ .../jdbc3.java" | 60 +++++++++++++++++++ 5 files changed, 204 insertions(+) create mode 100644 "work/com/java/minxi/java_20240522/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/person.java" create mode 100644 "work/com/java/minxi/java_20240522/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/rectangle.java" create mode 100644 "work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc1.java" create mode 100644 "work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc2.java" create mode 100644 "work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc3.java" diff --git "a/work/com/java/minxi/java_20240522/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/person.java" "b/work/com/java/minxi/java_20240522/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/person.java" new file mode 100644 index 0000000..425488b --- /dev/null +++ "b/work/com/java/minxi/java_20240522/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/person.java" @@ -0,0 +1,31 @@ +package com.java.minxi.java_20240522.java_2302_吴憶豪_2244310224; + +public class person { + private String firstName; + private String lastName; + + public person(String firstName, String lastName) { + this.firstName = firstName; + this.lastName = lastName; + } + public void printFullName(){ + System.out.println(firstName+""+lastName); + } + + public String getFirstName() { + return firstName; + } + + public void setFirstName(String firstName) { + this.firstName = firstName; + } + + public String getLastName() { + return lastName; + } + + public void setLastName(String lastName) { + this.lastName = lastName; + } +} + diff --git "a/work/com/java/minxi/java_20240522/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/rectangle.java" "b/work/com/java/minxi/java_20240522/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/rectangle.java" new file mode 100644 index 0000000..17b3764 --- /dev/null +++ "b/work/com/java/minxi/java_20240522/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/rectangle.java" @@ -0,0 +1,40 @@ +package com.java.minxi.java_20240522.java_2302_吴憶豪_2244310224; + +import java.util.Scanner; + +class Rectangle { + private double width; + private double height; + + public Rectangle(double width, double height) { + this.width = width; + this.height = height; + } + + public double getArea(){ + return width * height; + } + public double getPerimeter(){ + return 2*(width+height); + } +} +public class rectangle { + public static void main(String[] args) { + Scanner scanner = new Scanner(System.in); + + System.out.println("please add width:"); + double width = scanner.nextDouble(); + + System.out.println("please add height"); + double height = scanner.nextDouble(); + + Rectangle rectangle = new Rectangle(width, height); + + double area = rectangle.getArea(); + double perimeter = rectangle.getPerimeter(); + + System.out.println("area:" + area); + System.out.println("perimeter:" + perimeter); + + } +} \ No newline at end of file diff --git "a/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc1.java" "b/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc1.java" new file mode 100644 index 0000000..4cb0325 --- /dev/null +++ "b/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc1.java" @@ -0,0 +1,35 @@ +package com.java.minxi.java_20240524.java_2302_吴憶豪_2244310224; + +import java.sql.*; + +public class jdbc1 { + public static void main(String[] args) { + String url = "jdbc:mysql://locallhost:3306/root"; + String user = "username"; + String password = "password"; + + try { + Class.forName("com.java.minxi.java_20240524.java_2302_吴憶豪_2244310224.jdbc1.Driver"); + + System.out.println("link start"); + Connection conn = DriverManager.getConnection(url, user, password); + + System.out.println("select infomaion"); + Statement stmt = conn.createStatement(); + ResultSet rs = stmt.executeQuery("select id,teacher_name,teacher_age from users"); + + while (rs.next()) { + int id = rs.getInt("id"); + String teacher_name = rs.getString("name"); + System.out.println("id:" + id); + System.out.println("name:" + teacher_name); + } + rs.close(); + stmt.close(); + conn.close(); + } + catch(Exception e){ + e.printStackTrace(); + } + } +} diff --git "a/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc2.java" "b/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc2.java" new file mode 100644 index 0000000..b935141 --- /dev/null +++ "b/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc2.java" @@ -0,0 +1,38 @@ +package com.java.minxi.java_20240524.java_2302_吴憶豪_2244310224; + +import java.sql.Connection; +import java.sql.DriverManager; +import java.sql.PreparedStatement; +import java.sql.ResultSet; + +public class jdbc2 { + public static void main(String[] args) { + String url = "jdbc:mysql://localhost:3306/root"; + String user = "username"; + String password = "password"; + + String sql = "select * from users where id = ? and age = ?"; + try { + Class.forName("com.mysql.cj.jdbc.Driver"); + Connection conn = DriverManager.getConnection(url, user, password); + PreparedStatement pstmt = conn.prepareStatement(sql); + pstmt.setInt(1, 1); + pstmt.setInt(2, 35); + ResultSet rs = pstmt.executeQuery(); + while (rs.next()) { + int id = rs.getInt("id"); + String name = rs.getString("teacher_name"); + int age = rs.getInt("teacher_age"); + System.out.println("id:" + id + ",name:" + name + ",age" + age); + } + rs.close(); + pstmt.close(); + conn.close(); + } + catch (Exception e){ + e.printStackTrace(); + + } + } + } + diff --git "a/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc3.java" "b/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc3.java" new file mode 100644 index 0000000..908971d --- /dev/null +++ "b/work/com/java/minxi/java_20240524/java_2302_\345\220\264\346\206\266\350\261\252_2244310224/jdbc3.java" @@ -0,0 +1,60 @@ +package com.java.minxi.java_20240524.java_2302_吴憶豪_2244310224; + +import java.io.File; +import java.io.InputStreamReader; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.sql.Connection; +import java.sql.PreparedStatement; +import java.util.HashMap; +import java.util.Map; +import java.util.Properties; + +public class jdbc3 { + public static void main(String[] args) { + Map druid = getConnectionData("druid"); + DruidDataSource dataSource = new DruidDataSource(); + dataSource.setUrl("jdbc:mysql://localhost:3306/root"); + dataSource.setUsername("username"); + dataSource.setPassword("password"); + dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver"); + + try { + Connection connection = dataSource.getConnection(); + String sql = "UPDATE users SET username = ? WHERE id = ?"; + PreparedStatement statement = connection.prepareStatement(sql); + statement.setString(1, "小严"); + statement.setInt(2, 3); + + int affectedRows = statement.executeUpdate(); + + statement.close(); + connection.close(); + + if (affectedRows > 0) { + System.out.println("true"); + } else { + System.out.println("false"); + } + }catch(Exception e){ + e.printStackTrace(); + } + } + public static Map getConnectionData(String fileName) { + Map map = new HashMap<>(); + try { + Properties properties = new Properties(); + String property = System.getProperty("user.dir"); + File file = new File(property + "\\" + fileName + ".properties"); + InputStreamReader inputStreamReader = new InputStreamReader(Files.newInputStream(file.toPath()), StandardCharsets.UTF_8); + properties.load(inputStreamReader); + for (Object o : properties.keySet()) { + String key = (String) o; + String value = properties.getProperty(key); + map.put(key, value); + } + } catch (Exception e) { + e.printStackTrace(); + } + return map; +} -- Gitee