class 父类 { } class 子类 extends 父类 { } public class Penguin { private String name; private int id; public Penguin(String myName, int myid) { name = myName; id = myid; } public void eat(){ System.out.println(name+"正在吃"); } public void sleep(){ Syst…

public class Variable{ static int allClicks=0; // 类变量 String str="hello world"; // 实例变量 public void method(){ int i =0; // 局部变量 } } public class Test{ public void pupAge(){ int age = 0; age = age + 7; System.out.println("小狗的年龄是: " + ag…

try { // 程序代码 }catch(ExceptionName e1) { //Catch 块 } import java.io.*; public class ExcepTest{ public static void main(String args[]){ try{ int a[] = new int[2]; System.out.println("Access element three :" + a[3]); }catch(ArrayIndexOutOfBoundsEx…

1:jar可到Mysql官网下载:地址Mysql 连接jar包.:https://dev.mysql.com/downloads/connector/j/如图,在下拉列表框中选择Platform Independent public class Test{ // 定义MySQL的数据库驱动程序 public static final String DBDRIVER = "com.mysql.cj.jdbc.Driver" ; public static void main(String…

这个异常是时区的错误,因此只你需要设置为你当前系统时区即可,解决方案如下: import java.sql.Connection ; import java.sql.DriverManager ; import java.sql.SQLException ; public class Test{ // 定义MySQL的数据库驱动程序 public static final String DBDRIVER = "com.mysql.cj.jdbc.Driver" ; // 定义MySQL…

package test; public class temp { /* 第一个Java程序 * 它将打印字符串 Hello World */ public static void main(String []args) { System.out.println("Hello World"); // 打印 Hello World } } package test; public class temp { int puppyAge; public temp(String name) {…

import java.util.Scanner; public class ScannerDemo { public static void main(String[] args) { Scanner scan = new Scanner(System.in); // 从键盘接收数据 // next方式接收字符串 System.out.println("next方式接收:"); // 判断是否还有输入 if (scan.hasNext()) { String str1 = scan.…

BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); //使用 BufferedReader 在控制台读取字符 import java.io.*; public class BRRead { public static void main(String args[]) throws IOException { char c; // 使用 System.in 创建 BufferedReader Buffe…

/** 返回两个整型变量数据的较大值 */ public static int max(int num1, int num2) { int result; if (num1 > num2) result = num1; else result = num2; return result; } public class TestMax { /** 主方法 */ public static void main(String[] args) { int i = 5; int j = 2; int k…

import java.util.regex.*; class RegexExample1{ public static void main(String args[]){ String content = "I am noob " + "from runoob.com."; String pattern = ".*runoob.*"; boolean isMatch = Pattern.matches(pattern, content); Sy…