Java URL 验证：告别正则表达式局限，拥抱专业库的强大

"https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)"

<dependency>
    <groupId>org.hibernate.validator</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>6.1.7.Final</version> <!-- 或更高版本 -->
</dependency>
<dependency>
    <groupId>org.glassfish</groupId>
    <artifactId>jakarta.el</artifactId>
    <version>3.0.3</version> <!-- 运行时需要 -->
</dependency>

import org.hibernate.validator.constraints.URL;
import javax.validation.constraints.NotBlank;

public class MyData {

    @NotBlank(message = "URL不能为空")
    @URL(message = "必须是一个有效的URL")
    private String websiteUrl;

    // Getter and Setter
    public String getWebsiteUrl() {
        return websiteUrl;
    }

    public void setWebsiteUrl(String websiteUrl) {
        this.websiteUrl = websiteUrl;
    }
}

import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
import javax.validation.ConstraintViolation;
import java.util.Set;

public class UrlValidationExample {

    public static void main(String[] args) {
        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
        Validator validator = factory.getValidator();

        // 有效URL示例
        MyData validData1 = new MyData();
        validData1.setWebsiteUrl("https://www.test.com");
        validateAndPrint(validator, validData1); // 输出：URL https://www.test.com 是有效的.

        MyData validData2 = new MyData();
        validData2.setWebsiteUrl("https://api-apps.testapp.systems/test-service/v1/test");
        validateAndPrint(validator, validData2); // 输出：URL https://api-apps.testapp.systems/test-service/v1/test 是有效的.

        // 无效URL示例
        MyData invalidData1 = new MyData();
        invalidData1.setWebsiteUrl("invalid-url");
        validateAndPrint(validator, invalidData1); // 输出：URL invalid-url 是无效的. 错误信息: 必须是一个有效的URL

        MyData invalidData2 = new MyData();
        invalidData2.setWebsiteUrl("ftp://test.com"); // @URL默认只验证http(s)
        validateAndPrint(validator, invalidData2); // 输出：URL ftp://test.com 是无效的. 错误信息: 必须是一个有效的URL
    }

    private static void validateAndPrint(Validator validator, MyData data) {
        Set<ConstraintViolation<MyData>> violations = validator.validate(data);
        if (violations.isEmpty()) {
            System.out.println("URL " + data.getWebsiteUrl() + " 是有效的.");
        } else {
            System.out.println("URL " + data.getWebsiteUrl() + " 是无效的. 错误信息: ");
            for (ConstraintViolation<MyData> violation : violations) {
                System.out.println(violation.getMessage());
            }
        }
    }
}

<dependency>
    <groupId>commons-validator</groupId>
    <artifactId>commons-validator</artifactId>
    <version>1.7</version> <!-- 或更高版本 -->
</dependency>

import org.apache.commons.validator.routines.UrlValidator;

public class ApacheUrlValidatorExample {

    public static void main(String[] args) {
        // 默认配置：只允许 http, https, ftp 协议
        UrlValidator defaultValidator = new UrlValidator();
        testUrl(defaultValidator, "https://www.test.com");
        testUrl(defaultValidator, "https://api-apps.testapp.systems/test-service/v1/test");
        testUrl(defaultValidator, "http://localhost:8080/path"); // 默认允许本地地址
        testUrl(defaultValidator, "ftp://example.com/file.txt");
        testUrl(defaultValidator, "invalid-url");
        testUrl(defaultValidator, "file:///path/to/file.txt"); // 默认不支持file协议

        System.out.println("
--- 自定义协议 ---");
        // 允许自定义协议，例如：允许 http, https, file 协议
        String[] schemes = {"http", "https", "file"};
        UrlValidator customSchemeValidator = new UrlValidator(schemes);
        testUrl(customSchemeValidator, "https://www.test.com");
        testUrl(customSchemeValidator, "file:///C:/Users/test.txt");
        testUrl(customSchemeValidator, "ftp://example.com"); // 不在允许的协议列表中

        System.out.println("
--- 允许本地地址和查询参数 ---");
        // 结合选项：允许本地地址，允许查询参数，自定义协议
        long options = UrlValidator.ALLOW_LOCAL_URLS + UrlValidator.ALLOW_QUERY_FRAGMENT;
        UrlValidator advancedValidator = new UrlValidator(schemes, options);
        testUrl(advancedValidator, "http://localhost:8080/test?param=value#anchor");
        testUrl(advancedValidator, "https://example.com/path?query=param&id=123");
        testUrl(advancedValidator, "http://192.168.1.1/resource");
    }

    private static void testUrl(UrlValidator validator, String url) {
        if (validator.isValid(url)) {
            System.out.println("URL '" + url + "' 是有效的.");
        } else {
            System.out.println("URL '" + url + "' 是无效的.");
        }
    }
}