JK时间训练营高级Java工程师体系课2023版2.0完结

//xia仔k：JK时间训练营高级Java工程师体系课2023版2.0完结

作为一个Java工程师，你可能会触及多种不同的编程任务，从后端开发到Android应用开发等。以下是一些简单的Java代码示例，展现了根本的功用和编程概念：

1. Hello World 程序

java复制代码
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}

2. 创立一个类并完成根本的属性和办法

java复制代码
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 "Person{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}

3. 运用汇合类存储和遍历数据

java复制代码
import java.util.ArrayList;
import java.util.List;
public class Main {
public static void main(String[] args) {
List fruits = new ArrayList<>();
fruits.add("Apple");
fruits.add("Banana");
fruits.add("Cherry");
for (String fruit : fruits) {
System.out.println(fruit);
}
}
}

4. 简单的异常处置

java复制代码
public class ExceptionExample {
public static void main(String[] args) {
try {
int result = 10 / 0;
} catch (ArithmeticException e) {
System.out.println("Division by zero is not allowed.");
e.printStackTrace();
} finally {
System.out.println("This block will always be executed.");
}
}
}

5. 运用多线程

java复制代码
public class ThreadExample implements Runnable {
@Override
public void run() {
for (int i = 0; i < 5; i++) {
System.out.println(Thread.currentThread().getName() + " - " + i);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) {
Thread t1 = new Thread(new ThreadExample(), "Thread 1");
Thread t2 = new Thread(new ThreadExample(), "Thread 2");
t1.start();
t2.start();
}
}

6. 运用Java 8的Stream API处置汇合

java复制代码
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
public class StreamExample {
public static void main(String[] args) {
List names = Arrays.asList("Alice", "Bob", "Charlie", "David");
List filteredNames = names.stream()
.filter(name -> name.startsWith("A") || name.startsWith("D"))
.collect(Collectors.toList());
System.out.println(filteredNames); // 输出: [Alice, David]
}
}
这些示例涵盖了Java编程的根底学问，包括类、办法、异常处置、汇合和多线程。在实践项目中，Java工程师可能会处置更复杂的逻辑和数据构造，并会运用框架（如Spring Boot）和工具（如Maven或Gradle）来简化和加速开发过程。