在 Spring 中，如何实现对 LDAP（Lightweight Directory Access Protocol）的支持？

在 Spring 里实现对 LDAP（Lightweight Directory Access Protocol）的支持，可借助 Spring LDAP 模块。以下是实现步骤与示例代码：

1. 添加依赖

若使用 Maven 项目，需在 pom.xml 里添加 Spring LDAP 的依赖：

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-ldap</artifactId>
    </dependency>
</dependencies>

2. 配置 LDAP 连接

在 application.properties 或者 application.yml 文件中配置 LDAP 连接信息。

application.properties 示例

spring.ldap.urls=ldap://localhost:389
spring.ldap.base=dc=example,dc=com
spring.ldap.username=cn=admin,dc=example,dc=com
spring.ldap.password=adminpassword

application.yml 示例

spring:
  ldap:
    urls: ldap://localhost:389
    base: dc=example,dc=com
    username: cn=admin,dc=example,dc=com
    password: adminpassword

3. 创建 LDAP 实体类

创建一个 Java 类来映射 LDAP 中的条目，使用 @Entry 注解标记该类，并使用 @Attribute 注解映射属性。

import org.springframework.ldap.odm.annotations.Attribute;
import org.springframework.ldap.odm.annotations.DnAttribute;
import org.springframework.ldap.odm.annotations.Entry;
import org.springframework.ldap.odm.annotations.Id;

import javax.naming.Name;

@Entry(objectClasses = {"inetOrgPerson", "organizationalPerson", "person", "top"})
public class Person {

    @Id
    private Name dn;

    @DnAttribute(value = "uid", index = 3)
    private String uid;

    @Attribute(name = "cn")
    private String commonName;

    @Attribute(name = "sn")
    private String surname;

    @Attribute(name = "userPassword")
    private String password;

    // Getters and Setters
    public Name getDn() {
        return dn;
    }

    public void setDn(Name dn) {
        this.dn = dn;
    }

    public String getUid() {
        return uid;
    }

    public void setUid(String uid) {
        this.uid = uid;
    }

    public String getCommonName() {
        return commonName;
    }

    public void setCommonName(String commonName) {
        this.commonName = commonName;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

4. 创建 LDAP 存储库接口

创建一个接口继承 LdapRepository，用于对 LDAP 进行增删改查操作。

import org.springframework.data.ldap.repository.LdapRepository;

public interface PersonRepository extends LdapRepository<Person> {
    Person findByUid(String uid);
}

5. 使用 LDAP 存储库

在服务类或者控制器中注入 PersonRepository 并使用它进行操作。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class PersonService {

    @Autowired
    private PersonRepository personRepository;

    public Person findByUid(String uid) {
        return personRepository.findByUid(uid);
    }

    public List<Person> findAll() {
        return personRepository.findAll();
    }

    public Person save(Person person) {
        return personRepository.save(person);
    }

    public void delete(Person person) {
        personRepository.delete(person);
    }
}

6. 完整示例代码展示

以下是一个完整的 Spring Boot 应用示例，包含上述所有代码部分：

DemoApplication.java

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}    

Person.java

import org.springframework.ldap.odm.annotations.Attribute;
import org.springframework.ldap.odm.annotations.DnAttribute;
import org.springframework.ldap.odm.annotations.Entry;
import org.springframework.ldap.odm.annotations.Id;

import javax.naming.Name;

@Entry(objectClasses = {"inetOrgPerson", "organizationalPerson", "person", "top"})
public class Person {

    @Id
    private Name dn;

    @DnAttribute(value = "uid", index = 3)
    private String uid;

    @Attribute(name = "cn")
    private String commonName;

    @Attribute(name = "sn")
    private String surname;

    @Attribute(name = "userPassword")
    private String password;

    // Getters and Setters
    public Name getDn() {
        return dn;
    }

    public void setDn(Name dn) {
        this.dn = dn;
    }

    public String getUid() {
        return uid;
    }

    public void setUid(String uid) {
        this.uid = uid;
    }

    public String getCommonName() {
        return commonName;
    }

    public void setCommonName(String commonName) {
        this.commonName = commonName;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}    

PersonRepository.java

import org.springframework.data.ldap.repository.LdapRepository;

public interface PersonRepository extends LdapRepository<Person> {
    Person findByUid(String uid);
}    

PersonService.java

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class PersonService {

    @Autowired
    private PersonRepository personRepository;

    public Person findByUid(String uid) {
        return personRepository.findByUid(uid);
    }

    public List<Person> findAll() {
        return personRepository.findAll();
    }

    public Person save(Person person) {
        return personRepository.save(person);
    }

    public void delete(Person person) {
        personRepository.delete(person);
    }
}    

通过以上步骤，你就能在 Spring 应用中实现对 LDAP 的支持，实现对 LDAP 目录的增删改查操作。