背景
使用spring-ldap操作LDAP，完成LdapTemplate设置后，进行多条件查询，因为需求是能够多条件查询，所以在使用ldapTemplate.search系列方法时，着重考虑了下面的重载实现，第二个参数直接写过滤条件，只要按过滤语法书写即可，胜任各种复杂查询。
List users = ldapTemplate.search("ou=People", "(&(objectClass=person)(smart-type=E1))", new AttributesMapper() {
@Override
public LdapUser mapFromAttributes(Attributes attributes) throws NamingException {
return null;
}
});
但是这个查询的，不能使用spring-ldap的ODM，不能把LDAP返回的查询结果，直接转成POJO；也就是需要自己把Attributes attributes转成我需要的LdapUser实体对象。
LdapUser.java如下
import lombok.Getter;
import lombok.Setter;
import org.springframework.ldap.odm.annotations.Attribute;
import org.springframework.ldap.odm.annotations.Entry;
import org.springframework.ldap.odm.annotations.Id;
import javax.naming.Name;
@Setter
@Getter
@Entry(objectClasses = { "inetOrgPerson" ,"top","person" },base="ou=People") // ou=Internal, (只指定People，可按uid查询单个人员)
public class LdapUser extends BaseDTO {
@Id
protected Name dn;
@Attribute(name = "uid")
protected String uid;
@Attribute(name = "smart-type")
protected String userType;
@Attribute(name = "mail")
protected String mail;
@Attribute(name = "mobile")
protected String mobile;
@Attribute(name = "departmentNumber")
protected String deptId;
@Attribute(name = "departmentName")
protected String deptName;
// ...
}
}
这个POJO使用了spring-ldap 的ODM注解，类和属性分别使用了@Entry
和@Attribute(name = "uid")，其中@Attribute 中的name则标识LDAP查询返回的Attributes 中的一个属性的名称。
下面要做的反射任务
就是读取到POJO 这个LdapUser实体类中所有有带Attribute的属性，拿取到name后，从查询返回结果的Attributes 中遍历拿到对应name的 值，利用反射，给bean设置属性值。实现如下：
List users = ldapTemplate.search("ou=People", "(&(objectClass=person)(smart-type=E1))", new AttributesMapper() {
@Override
public LdapUser mapFromAttributes(Attributes attributes) throws NamingException {
LdapUser bean = null;
if (LdapUser.class.isAnnotationPresent(Entry.class)) {//是否加@Entry
try {
bean = LdapUser.class.newInstance();
} catch (Exception e) {
throw new RuntimeException("反射创建PIJO[]实例对象失败",e);
}
Field[] fields = LdapUser.class.getDeclaredFields();//拿到bean对应的属性
for (Field field : fields) {//遍历POJO 所有属性
boolean fieldHasAnno = field.isAnnotationPresent(Attribute.class);//类属性上是否加@Attribute(name = "smart-type")
if (fieldHasAnno) {
Attribute fieldAnno = field.getAnnotation(Attribute.class);
String name = fieldAnno.name();//注解的name值,如smart-type
for (NamingEnumeration attrEnumeration = attributes.getAll(); attrEnumeration.hasMore(); ) {
javax.naming.directory.Attribute attr = (javax.naming.directory.Attribute) attrEnumeration.next();
String ldapAttr = attr.getID();
if (ldapAttr.equals(name)) {
String ldapValue = attr.get().toString();
setProperty(bean, field.getName(), ldapValue);//反射：给bean设置属性值
} else {
continue;
}
}
}
}
} else {
throw new RuntimeException("PIJO[]需使用@Entry注解");
}
return bean;
}
});
/**
* 反射：给bean设置属性值
*
* @param bean
* @param name
* @param value
*/
private void setProperty(Object bean, String name, Object value) {
String setterName = "set" + StringUtils.capitalize(name);
Method setter;
try {
setter = bean.getClass().getMethod(setterName, value.getClass());
setter.invoke(bean, value);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
因为考虑到通用性，就把这一部分反射的工作抽象出来，用泛型替换具体类型，
实现了一个通用的转化ConvertAttributesMapper
import org.apache.commons.lang3.StringUtils;
import org.springframework.ldap.core.AttributesMapper;
import org.springframework.ldap.odm.annotations.Attribute;
import org.springframework.ldap.odm.annotations.Entry;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attributes;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
/**
* 实现Attributes 转成POJO
*/
public class ConvertAttributesMapper implements AttributesMapper {
Class clazz;
public ConvertAttributesMapper(Class clazz) {
this.clazz = clazz;
}
@Override
public T mapFromAttributes(Attributes attributes) throws NamingException {
T bean = null;
if (clazz.isAnnotationPresent(Entry.class)) {//是否加@Entry
try {
bean = clazz.newInstance();
} catch (Exception e) {
throw new RuntimeException("反射创建PIJO[]实例对象失败",e);
}
Field[] fields = clazz.getDeclaredFields();//拿到bean对应的属性
for (Field field : fields) {//遍历POJO 所有属性
boolean fieldHasAnno = field.isAnnotationPresent(Attribute.class);//类属性上是否加@Attribute(name = "smart-type")
if (fieldHasAnno) {
Attribute fieldAnno = field.getAnnotation(Attribute.class);
String name = fieldAnno.name();//注解的name值,如smart-type
for (NamingEnumeration attrEnumeration = attributes.getAll(); attrEnumeration.hasMore(); ) {
javax.naming.directory.Attribute attr = (javax.naming.directory.Attribute) attrEnumeration.next();
String ldapAttr = attr.getID();
if (ldapAttr.equals(name)) {
String ldapValue = attr.get().toString();
setProperty(bean, field.getName(), ldapValue);//反射：给bean设置属性值
} else {
continue;
}
}
}
}
} else {
throw new RuntimeException("PIJO[]需使用@Entry注解");
}
return bean;
}
/**
* 反射：给bean设置属性值
*
* @param bean
* @param name
* @param value
*/
private void setProperty(Object bean, String name, Object value) {
String setterName = "set" + StringUtils.capitalize(name);
Method setter;
try {
setter = bean.getClass().getMethod(setterName, value.getClass());
setter.invoke(bean, value);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}
//使用样例
AttributesMapper attributesMapper = new ConvertAttributesMapper(LdapUser.class);
List users = ldapTemplate.search("ou=People", "(&(objectClass=person)(smart-type=E1))", attributesMapper);
ps:BaseDTO是一个空的抽象类。