构建JAVA简历项目实战,从基本语言到面向对象编程,集成集合框架与网络编程基础知识。通过实践项目——简历管理系统,集中展示JAVA技能,包括用户管理、职位发布、简历投递与管理功能,全面提升技术能力与就业竞争力。
JAVA语言是面向对象的编程语言,1995年由Sun Microsystems发布。以其跨平台性、面向对象、可移植性、健壮性等特性,成为广泛使用的编程语言之一。JAVA程序借助Java虚拟机(JVM)在不同平台运行,开发者在一台机器上编写代码,即可在任何支持JVM的平台上运行。JAVA的核心理念是“一次编写,处处运行”。
在JAVA中,变量用于存储数据,数据类型定义存储值的类型。基本数据类型包括整型(int
、long
)、浮点型(float
、double
)、字符型(char
)、布尔型(boolean
)等,每个类型拥有特定内存空间和操作符。
示例:
public class Main { public static void main(String[] args) { int age = 25; // 整型变量 double salary = 5000.5; // 浮点型变量 char grade = 'A'; // 字符变量 boolean isStudent = true; // 布尔型变量 System.out.println("Age: " + age); System.out.println("Salary: " + salary); System.out.println("Grade: " + grade); System.out.println("Is Student: " + isStudent); } }
JAVA提供多种控制结构实现流程控制,包括条件语句(if-else
)和循环语句(for
、while
、do-while
)。
示例:
public class ConditionalControl { public static void main(String[] args) { int score = 85; if (score >= 90) { System.out.println("Grade: A"); } else if (score >= 80) { System.out.println("Grade: B"); } else if (score >= 70) { System.out.println("Grade: C"); } else { System.out.println("Grade: D"); } } }
public class LoopControl { public static void main(String[] args) { for (int i = 1; i <= 5; i++) { System.out.println("Number: " + i); } int j = 1; while (j <= 5) { System.out.println("Number: " + j); j++; } } }
JAVA中的函数(方法)是可执行代码块,接收参数并返回结果。函数定义包含返回类型、函数名和参数列表。
示例:
public class FunctionExample { public static int addNumbers(int a, int b) { return a + b; } public static void main(String[] args) { int result = addNumbers(3, 4); System.out.println("Result: " + result); } }
JAVA的核心特性之一是面向对象编程。类作为对象模板,对象是类的实例。
public class Person { String name; int age; public Person(String name, int age) { this.name = name; this.age = age; } public void introduce() { System.out.println("Name: " + name + ", Age: " + age); } }
封装(Encapsulation)隐藏实现细节,继承允许创建共享特性的类层次结构,多态提供不同对象执行操作的灵活性。
示例:
public class Employee extends Person { int salary; public Employee(String name, int age, int salary) { super(name, age); this.salary = salary; } public void showInfo() { introduce(); System.out.println("Salary: " + salary); } }
JAVA集合框架提供高效数据存储与操作机制。如数组、ArrayList、LinkedList。
示例:
import java.util.ArrayList; public class CollectionExample { public static void main(String[] args) { ArrayList<String> fruits = new ArrayList<>(); fruits.add("Apple"); fruits.add("Banana"); fruits.add("Cherry"); for (String fruit : fruits) { System.out.println(fruit); } } }
Map存储键值对,Set存储无序、不重复元素。
示例:
import java.util.HashMap; import java.util.HashSet; public class MapAndSetExample { public static void main(String[] args) { HashMap<String, Integer> scores = new HashMap<>(); scores.put("Alice", 90); scores.put("Bob", 85); scores.put("Charlie", 95); for (String name : scores.keySet()) { System.out.println(name + ": " + scores.get(name)); } HashSet<Integer> numbers = new HashSet<>(); numbers.add(1); numbers.add(2); numbers.add(3); System.out.println(numbers); // 顺序不保证 } }
集合操作、添加、删除、查找、遍历等,迭代器用于遍历集合元素。
示例:
import java.util.ArrayList; import java.util.Iterator; public class CollectionIterationExample { public static void main(String[] args) { ArrayList<String> items = new ArrayList<>(); items.add("Book"); items.add("Pen"); items.add("Pencil"); Iterator<String> iterator = items.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next()); } } }
异常表示程序运行错误,JAVA中的异常体系包括检查异常和运行时异常。
示例:
public class ExceptionHandlingExample { public static void main(String[] args) { try { int result = divide(10, 0); System.out.println("Result: " + result); } catch (ArithmeticException e) { System.out.println("Error: Division by zero"); } } public static int divide(int a, int b) { return a / b; } }
try
块捕获可能异常,catch
块处理特定异常,finally
块执行无需异常处理的代码。
示例:
public class TryCatchFinallyExample { public static void main(String[] args) { try { readFile("nonexistent.txt"); } catch (FileNotFoundException e) { System.out.println("Error: File not found"); } finally { System.out.println("Cleanup complete"); } } public static void readFile(String fileName) throws FileNotFoundException { throw new FileNotFoundException(); } }
Socket编程是JAVA实现网络通信的基础。客户端与服务端通过Socket对象通信。
示例:
服务端:
import java.io.*; import java.net.*; public class ServerSocketExample { public static void main(String[] args) { try (ServerSocket serverSocket = new ServerSocket(8080)) { Socket clientSocket = serverSocket.accept(); PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true); out.println("Hello, client!"); } catch (IOException e) { e.printStackTrace(); } } }
客户端:
import java.io.*; import java.net.*; public class SocketClientExample { public static void main(String[] args) { try (Socket socket = new Socket("localhost", 8080)) { BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())); PrintWriter out = new PrintWriter(socket.getOutputStream(), true); out.println("Hello, server!"); String response = in.readLine(); System.out.println("Response: " + response); } catch (IOException e) { e.printStackTrace(); } } }
使用JAVA HttpURLConnection API发送HTTP请求。
示例:
import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; public class HttpGetExample { public static void main(String[] args) { try { URL url = new URL("https://www.example.com"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("GET"); BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream())); String output; StringBuffer response = new StringBuffer(); while ((output = in.readLine()) != null) { response.append(output); } in.close(); System.out.println("HTML Response: " + response.toString()); } catch (Exception e) { e.printStackTrace(); } } }
构建简单的HTTP服务器和客户端,实现文件传输或信息交换。
服务端:
import java.io.*; import java.net.*; import java.nio.charset.StandardCharsets; public class SimpleHttpServer { public static void main(String[] args) { try (ServerSocket serverSocket = new ServerSocket(8080)) { System.out.println("Server started on port 8080"); while (true) { Socket clientSocket = serverSocket.accept(); new Thread(new ClientHandler(clientSocket)).start(); } } catch (IOException e) { e.printStackTrace(); } } private static class ClientHandler implements Runnable { private Socket socket; public ClientHandler(Socket socket) { this.socket = socket; } @Override public void run() { try (BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())); PrintWriter out = new PrintWriter(socket.getOutputStream(), true)) { String request = in.readLine(); String response = "HTTP/1.1 200 OK\r\n\r\n"; out.println(response); File file = new File("index.html"); byte[] buffer = Files.readAllBytes(file.toPath()); out.write(buffer); out.flush(); } catch (IOException e) { e.printStackTrace(); } } } }
客户端:
import java.io.*; import java.net.*; public class SimpleHttpClient { public static void main(String[] args) { try { URL url = new URL("http://localhost:8080"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); int responseCode = connection.getResponseCode(); System.out.println("Response Code: " + responseCode); BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream())); String output; StringBuffer response = new StringBuffer(); while ((output = in.readLine()) != null) { response.append(output); } in.close(); System.out.println("Response: " + response.toString()); } catch (Exception e) { e.printStackTrace(); } } }
简历管理系统需包含用户管理、职位发布、简历投递和管理功能。设计时考虑用户界面、数据存储与检索、权限管理等。
用户注册与登录
职位发布
简历投递
简历管理
系统部署与发布
通过上述步骤,构建完整的简历管理系统,展示JAVA技能,提升技术能力与就业竞争力。