Apache生态圈是一个庞大的开源软件项目集合,它提供了丰富的Java库和框架,用于解决开发者在编程过程中遇到的各种问题。以下是Apache生态圈中30个必备的核心Jar包,它们将帮助你轻松构建高效的应用程序。
1. Apache Commons Lang
Apache Commons Lang提供了许多Java编程语言中常用但标准库中未包含的类,如StringUtils、ArrayUtils、CollectionUtils等。
import org.apache.commons.lang3.StringUtils;
public class LangExample {
public static void main(String[] args) {
String text = "Hello, World!";
System.out.println("Original: " + text);
System.out.println("Uppercase: " + StringUtils.upperCase(text));
}
}
2. Apache Commons BeanUtils
BeanUtils提供了对JavaBean进行操作的类,如属性复制、属性设置等。
import org.apache.commons.beanutils.BeanUtils;
public class BeanUtilsExample {
public static void main(String[] args) throws Exception {
Person person = new Person("John", "Doe");
Person clone = (Person) BeanUtils.cloneBean(person);
System.out.println("Original: " + person);
System.out.println("Clone: " + clone);
}
}
class Person {
private String name;
private String surname;
public Person(String name, String surname) {
this.name = name;
this.surname = surname;
}
@Override
public String toString() {
return "Person{" +
"name='" + name + '\'' +
", surname='" + surname + '\'' +
'}';
}
}
3. Apache Commons Collections
Collections提供了对Java集合框架的扩展,包括不可变集合、集合操作等。
import org.apache.commons.collections4.ListUtils;
import java.util.Arrays;
public class CollectionsExample {
public static void main(String[] args) {
List
List
System.out.println("Original: " + list);
System.out.println("Reversed: " + reversed);
}
}
4. Apache Commons IO
IO提供了文件读写、文件压缩等操作的工具类。
import org.apache.commons.io.FileUtils;
public class IOExample {
public static void main(String[] args) throws IOException {
File file = new File("example.txt");
FileUtils.write(file, "Hello, World!");
System.out.println("Content: " + FileUtils.readFileToString(file));
}
}
5. Apache Commons Math
Math提供了数学计算的工具类,如概率、统计等。
import org.apache.commons.math3.stat.descriptive.DescriptiveStatistics;
public class MathExample {
public static void main(String[] args) {
double[] values = {1, 2, 3, 4, 5};
DescriptiveStatistics stats = new DescriptiveStatistics(values);
System.out.println("Mean: " + stats.getMean());
System.out.println("Standard Deviation: " + stats.getStandardDeviation());
}
}
6. Apache Commons Validator
Validator提供了客户端和服务器端的数据验证框架。
import org.apache.commons.validator.routines.EmailValidator;
public class ValidatorExample {
public static void main(String[] args) {
String email = "user@example.com";
boolean isValid = EmailValidator.getInstance().isValid(email);
System.out.println("Is valid email? " + isValid);
}
}
7. Apache Commons DBCP
DBCP提供了数据库连接池服务,提高数据库连接的效率。
import org.apache.commons.dbcp2.BasicDataSource;
public class DBCPExample {
public static void main(String[] args) {
BasicDataSource dataSource = new BasicDataSource();
dataSource.setUrl("jdbc:mysql://localhost:3306/mydb");
dataSource.setUsername("user");
dataSource.setPassword("password");
// 使用连接池中的连接
try (Connection connection = dataSource.getConnection()) {
// 执行数据库操作
}
}
}
8. Apache Commons Email
Email提供了对Java Mail API的封装,简化邮件发送和接收操作。
import org.apache.commons.mail.Email;
import org.apache.commons.mail.EmailException;
import org.apache.commons.mail.SimpleEmail;
public class EmailExample {
public static void main(String[] args) {
Email email = new SimpleEmail();
email.setSubject("Test Email");
email.setFrom("user@example.com");
email.setTo("recipient@example.com");
email.setMsg("This is a test email.");
try {
email.send();
System.out.println("Email sent successfully!");
} catch (EmailException e) {
System.err.println("Failed to send email: " + e.getMessage());
}
}
}
9. Apache Commons FileUpload
FileUpload提供了文件上传功能,适用于Web应用程序。
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.List;
public class FileUploadExample extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
if (ServletFileUpload.isMultipartContent(request)) {
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
List
for (FileItem item : items) {
if (!item.isFormField()) {
String fileName = item.getName();
File storeFile = new File(getServletContext().getRealPath("/") + "uploads/" + fileName);
item.write(storeFile);
item.delete();
}
}
}
}
}
10. Apache Commons HTTPClient
HTTPClient提供了HTTP客户端与服务器的各种通讯操作。
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
public class HttpClientExample {
public static void main(String[] args) throws IOException {
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet("http://example.com");
CloseableHttpResponse response = httpClient.execute(httpGet);
String responseBody = EntityUtils.toString(response.getEntity());
System.out.println("Response: " + responseBody);
}
}
11. Apache Commons Lang
Lang提供了Java基本对象方法的工具类包,如StringUtils、ArrayUtils等。
import org.apache.commons.lang3.StringUtils;
public class LangExample {
public static void main(String[] args) {
String text = "Hello, World!";
System.out.println("Original: " + text);
System.out.println("Uppercase: " + StringUtils.upperCase(text));
}
}
12. Apache Commons Logging
Logging提供了Java的日志接口,支持多种日志实现。
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
public class LoggingExample {
private static final Logger logger = LogManager.getLogger(LoggingExample.class);
public static void main(String[] args) {
logger.info("This is an info message.");
logger.error("This is an error message.");
}
}
13. Apache Commons Validator
Validator提供了客户端和服务器端的数据验证框架。
import org.apache.commons.validator.routines.EmailValidator;
public class ValidatorExample {
public static void main(String[] args) {
String email = "user@example.com";
boolean isValid = EmailValidator.getInstance().isValid(email);
System.out.println("Is valid email? " + isValid);
}
}
14. Apache Commons Configuration
Configuration提供了Java应用程序的配置管理类库,支持properties和xml文件。
import org.apache.commons.configuration.PropertiesConfiguration;
public class ConfigurationExample {
public static void main(String[] args) {
PropertiesConfiguration config = new PropertiesConfiguration("config.properties");
String username = config.getString("username");
String password = config.getString("password");
System.out.println("Username: " + username);
System.out.println("Password: " + password);
}
}
15. Apache Commons Compress
Compress提供了文件打包、压缩类库,支持多种压缩格式。
import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
public class CompressExample {
public static void main(String[] args) throws IOException {
File tarFile = new File("example.tar.gz");
TarArchiveOutputStream tarOutputStream = new TarArchiveOutputStream(new GzipCompressorOutputStream(new FileOutputStream(tarFile)));
TarArchiveEntry entry = new TarArchiveEntry("example.txt");
entry.setSize(10);
tarOutputStream.putArchiveEntry(entry);
tarOutputStream.write("Hello, World!".getBytes());
tarOutputStream.closeArchiveEntry();
tarOutputStream.close();
}
}
16. Apache Commons Pool
Pool提供了对象池管理,提高资源利用率。
import org.apache.commons.pool2.impl.GenericObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
public class PoolExample {
public static void main(String[] args) {
GenericObjectPoolConfig config = new GenericObjectPoolConfig();
config.setMaxTotal(5);
GenericObjectPool
SomeClass instance = pool.borrowObject();
// 使用实例
pool.returnObject(instance);
}
}
class SomeClassFactory implements PoolableObjectFactory
public SomeClass create() throws Exception {
return new SomeClass();
}
public void destroy(SomeClass object) throws Exception {
// 销毁实例
}
public boolean validate(Object object) {
return true;
}
public void activate(Object object) throws Exception {
// 激活实例
}
public void passivate(Object object) throws Exception {
// 使实例处于待用状态
}
}
17. Apache Commons DBUtils
DBUtils提供了对JDBC的操作封装,简化数据查询和记录读取操作。
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
public class DBUtilsExample {
public static void main(String[] args) throws SQLException {
Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "user", "password");
QueryRunner runner = new QueryRunner();
String sql = "SELECT * FROM users";
ResultSetHandler> handler = new ResultSetHandler
>() {
public List
List
while (rs.next()) {
User user = new User();
user.setId(rs.getInt("id"));
user.setName(rs.getString("name"));
users.add(user);
}
return users;
}
};
List
System.out.println("Users: " + users);
}
}
class User {
private int id;
private String name;
// Getters and setters
}
18. Apache Commons CSV
CSV提供了读写CSV格式文件的Java类库。
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.CSVPrinter;
import org.apache.commons.csv.CSVRecord;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class CSVExample {
public static void main(String[] args) throws IOException {
// 读取CSV文件
CSVParser parser = new CSVParser(new FileReader("example.csv"), CSVFormat.DEFAULT);
for (CSVRecord record : parser) {
System.out.println(record.get(0) + ", " + record.get(1));
}
parser.close();
// 写入CSV文件
CSVPrinter printer = new CSVPrinter(new FileWriter("output.csv"), CSVFormat.DEFAULT);
printer.printRecord("Name", "Age");
printer.printRecord("John", "30");
printer.printRecord("Jane", "25");
printer.close();
}
}
19. Apache Commons HttpClient
HttpClient提供了HTTP客户端与服务器的各种通讯操作。
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
public class HttpClientExample {
public static void main(String[] args) throws IOException {
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet("http://example.com");
CloseableHttpResponse response = httpClient.execute(httpGet);
String responseBody = EntityUtils.toString(response.getEntity());
System.out.println("Response: " + responseBody);
}
}
20. Apache Commons IO
IO提供了文件读写、文件压缩等操作的工具类。
import org.apache.commons.io.FileUtils;
public class IOExample {
public static void main(String[] args) throws IOException {
File file = new File("example.txt");
FileUtils.write(file, "Hello, World!");
System.out.println("Content: " + FileUtils.readFileToString(file));
}
}
21. Apache Commons Math
Math提供了数学计算的工具类,如概率、统计等。
import org.apache.commons.math3.stat.descriptive.DescriptiveStatistics;
public class MathExample {
public static void main(String[] args) {
double[] values = {1, 2, 3, 4, 5};
DescriptiveStatistics stats = new DescriptiveStatistics(values);
System.out.println("Mean: " + stats.getMean());
System.out.println("Standard Deviation: " + stats.getStandardDeviation());
}
}
22. Apache Commons Validator
Validator提供了客户端和服务器端的数据验证框架。
import org.apache.commons.validator.routines.EmailValidator;
public class ValidatorExample {
public static void main(String[] args) {
String email = "user@example.com";
boolean isValid = EmailValidator.getInstance().isValid(email);
System.out.println("Is valid email? " + isValid);
}
}
23. Apache Commons DBCP
DBCP提供了数据库连接池服务,提高数据库连接的效率。
import org.apache.commons.dbcp2.BasicDataSource;
public class DBCPExample {
public static void main(String[] args) {
BasicDataSource dataSource = new BasicDataSource();
dataSource.setUrl("jdbc:mysql://localhost:3306/mydb");
dataSource.setUsername("user");
dataSource.setPassword("password");
// 使用连接池中的连接
try (Connection connection = dataSource.getConnection()) {
// 执行数据库操作
}
}
}
24. Apache Commons Email
Email提供了对Java Mail API的封装,简化邮件发送和接收操作。
import org.apache.commons.email.Email;
import org.apache.commons.email.EmailException;
import org.apache.commons.email.SimpleEmail;
public class EmailExample {
public static void main(String[] args) {
Email email = new SimpleEmail();
email.setSubject("Test Email");
email.setFrom("user@example.com");
email.setTo("recipient@example.com");
email.setMsg("This is a test email.");
try {
email.send();
System.out.println("Email sent successfully!");
} catch (EmailException e) {
System.err.println("Failed to send email: " + e.getMessage());
}
}
}
25. Apache Commons FileUpload
FileUpload提供了文件上传功能,适用于Web应用程序。
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.List;
public class FileUploadExample extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
if (ServletFileUpload.isMultipartContent(request)) {
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
List
for (FileItem item : items) {
if (!item.isFormField()) {
String fileName = item.getName();
File storeFile = new File(getServletContext().getRealPath("/") + "uploads/" + fileName);
item.write(storeFile);
item.delete();
}
}
}
}
}
26. Apache Commons HttpClient
HttpClient提供了HTTP客户端与服务器的各种通讯操作。
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
public class HttpClientExample {
public static void main(String[] args) throws IOException {
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet("http://example.com");
CloseableHttpResponse response = httpClient.execute(httpGet);
String responseBody = EntityUtils.toString(response.getEntity());
System.out.println("Response: " + responseBody);
}
}
27. Apache Commons IO
IO提供了文件读写、文件压缩等操作的工具类。
import org.apache.commons.io.FileUtils;
public class IOExample {
public static void main(String[] args) throws IOException {
File file = new File("example.txt");
FileUtils.write(file, "Hello, World!");
System.out.println("Content: " + FileUtils.readFileToString(file));
}
}
28. Apache Commons Math
Math提供了数学计算的工具类,如概率、统计等。
import org.apache.commons.math3.stat.descriptive.DescriptiveStatistics;
public class MathExample {
public static void main(String[] args) {
double[] values = {1, 2, 3, 4, 5};
DescriptiveStatistics stats = new DescriptiveStatistics(values);
System.out.println("Mean: " + stats.getMean());
System.out.println("Standard Deviation: " + stats.getStandardDeviation());
}
}
29. Apache Commons Validator
Validator提供了客户端和服务器端的数据验证框架。
import org.apache.commons.validator.routines.EmailValidator;
public class ValidatorExample {
public static void main(String[] args) {
String email = "user@example.com";
boolean isValid = EmailValidator.getInstance().isValid(email);
System.out.println("Is valid email? " + isValid);
}
}
30. Apache Commons DBCP
DB