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在spring中基于属性文件创建bean列表

spring properties

在spring中基于属性文件创建bean列表,spring,properties,Spring,Properties,我想在spring中创建基于属性文件的bean列表。为了说明这个问题，让我们假设我有一个教室 public class ClassRoom { private List<Student> students; public void setStudents(List<Student> students) { this.students = students; } } public class Student { private Strign

我想在spring中创建基于属性文件的bean列表。为了说明这个问题，让我们假设我有一个
教室

public class ClassRoom {

  private List<Student> students;

  public void setStudents(List<Student> students) {
      this.students = students;
  }
}

public class Student {
  private Strign firstName;
  private String lastName;

  /* cosntructor, setters, getters ... */
}
还有一些很好的实用程序，可以将这样的文件转换成我的
学生
类的
列表

到目前为止，我已经为我的spring配置中包含的学生列表创建了单独的.xml配置文件，但我并不特别喜欢向客户机提供部分xml配置的想法。我认为这应该分开

所以问题是：有没有冷泉实用程序可以为我做到这一点？还是由我来写

所以我决定证明我没有那么懒。该解决方案有一些明显的限制，如1级属性或只能对基本类型进行操作。但是满足了我的需要。因此，作为记录：

属性文件：

student.1.firstName=Jan
student.1.lastName=Zyka
student.1.age=30
student.2.firstName=David
student.2.lastName=Kalita
student.2.age=55
学生班级：

package com.jan.zyka.test.dao;

public class Student {

    private String firstName;
    private String lastName;
    private int age;
    private String common;

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getCommon() {
        return common;
    }

    public void setCommon(String common) {
        this.common = common;
    }

    @Override
    public String toString() {
        return "Student{" +
                "firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", age=" + age +
                ", common='" + common + '\'' +
                '}';
    }
}
弹簧定义：

<bean id="studentFactory" class="com.jan.zyka.test.BeanListFactory">
    <property name="propertyPrefix" value="student" />
    <property name="commonProperties">
        <map>
            <entry key="common" value="testCommonValue" />
        </map>
    </property>
    <property name="targetType">
        <value type="java.lang.Class">com.jan.zyka.test.dao.Student</value>
    </property>
    <property name="properties">
        <util:properties location="classpath:testListFactory.properties" />
    </property>
</bean>
工厂bean本身：

package com.jan.zyka.test;

import com.google.common.primitives.Primitives;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.FactoryBean;

import java.beans.PropertyDescriptor;
import java.util.*;

/**
 * <p>
 *    Creates list of beans based on property file.
 * </p>
 * <p>
 *    Each object should be defined in the property file as follows:
 *    <pre>
 *        &lt;prefix&gt;.&lt;index&gt;.&lt;property&gt;
 *    </pre>
 *
 *    So one example might be:
 *    <pre>
 *        student.1.firstName=Paul
 *        student.1.lastName=Verlaine
 *        student.2.firstName=Alex
 *        student.2.lastName=Hamburger
 *    </pre>
 *
 *    The target class must provide default constructor and setter for each property defined in the configuration file as per
 *    bean specification.
 * </p>
 *
 * @param <T> type of the target object
 */
public class BeanListFactory<T> implements FactoryBean<List<T>> {

    private String propertyPrefix;
    private Map<String, Object> commonProperties = Collections.emptyMap();
    private Class<T> targetType;
    private Properties properties;

    private List<T> loadedBeans;

    public String getPropertyPrefix() {
        return propertyPrefix;
    }

    public void setPropertyPrefix(String propertyPrefix) {
        this.propertyPrefix = propertyPrefix;
    }

    public Map<String, Object> getCommonProperties() {
        return commonProperties;
    }

    public void setCommonProperties(Map<String, Object> commonProperties) {
        this.commonProperties = commonProperties;
    }

    public Class<T> getTargetType() {
        return targetType;
    }

    public void setTargetType(Class<T> targetType) {
        this.targetType = targetType;
    }

    public Properties getProperties() {
        return properties;
    }

    public void setProperties(Properties properties) {
        this.properties = properties;
    }

    @Override
    public List<T> getObject() throws Exception {

        loadedBeans = new ArrayList<T>();
        int lastIndex = -1;

        T item = null;

        for (String property: prefixFilteredProperties()) {

            // The actual value
            final String propertyValue = properties.getProperty(property);

            // Remove Prefix
            property = property.substring(propertyPrefix.length() + 1);

            // Split by "."
            String tokens[] = property.split("\\.");

            if (tokens.length != 2) {
                throw new IllegalArgumentException("Each list property must be in form of: <prefix>.<index>.<property name>");
            }

            final int index = Integer.valueOf(tokens[0]);
            final String propertyName = tokens[1];

            // New index
            if (lastIndex != index) {
                if (lastIndex !=-1) {
                    loadedBeans.add(item);
                }
                lastIndex = index;

                item = targetType.newInstance();
                setCommonProperties(item, commonProperties);
            }

            // Set the property
            setProperty(item, propertyName, convertIfNecessary(propertyName, propertyValue));
        }

        // Add last item
        if (lastIndex != -1) {
            loadedBeans.add(item);
        }

        return loadedBeans;
    }

    @Override
    public Class<?> getObjectType() {
        return ArrayList.class;
    }

    @Override
    public boolean isSingleton() {
        return false;
    }

    private Object convertIfNecessary(String propertyName, String propertyValue) throws Exception {
        PropertyDescriptor descriptor = BeanUtils.getPropertyDescriptor(targetType, propertyName);
        Class<?> propertyType = Primitives.wrap(descriptor.getPropertyType());

        if (propertyType == String.class) {
            return propertyValue;
        }

        return propertyType.getDeclaredMethod("valueOf", String.class).invoke(propertyType, propertyValue);
    }

    private Set<String> prefixFilteredProperties() {
        Set<String> filteredProperties = new TreeSet<String>();

        for (String propertyName: properties.stringPropertyNames()) {
            if (propertyName.startsWith(this.propertyPrefix)) {
                filteredProperties.add(propertyName);
            }
        }

        return filteredProperties;
    }

    private void setCommonProperties(T item, Map<String, Object> commonProperties) throws Exception {
        for (Map.Entry<String, Object> commonProperty: commonProperties.entrySet()) {
            setProperty(item, commonProperty.getKey(), commonProperty.getValue());
        }
    }

    private static void setProperty(Object item, String propertyName, Object value) throws Exception {
        PropertyDescriptor descriptor = BeanUtils.getPropertyDescriptor(item.getClass(), propertyName);
        descriptor.getWriteMethod().invoke(item, value);
    }
}

package com.jan.zyka.test；
导入com.google.common.primitives.primitives；
导入org.springframework.beans.BeanUtils；
导入org.springframework.beans.factory.FactoryBean；
导入java.beans.PropertyDescriptor；
导入java.util.*；
/**
*
*基于属性文件创建bean列表。
*

*
*每个对象应在属性文件中定义如下：
*    
*prefix.index.property
*    
*
*因此，一个例子可能是：
*    
*学生1.名字=保罗
*学生1.姓氏=Verlaine
*学生2.名字=亚历克斯
*学生2.姓氏=汉堡包
*    
*
*根据，目标类必须为配置文件中定义的每个属性提供默认构造函数和setter
*bean规范。
*

*
*@param目标对象的类型
*/
公共类BeanListFactory实现FactoryBean{
私有字符串propertyPrefix；
私有映射commonProperties=Collections.emptyMap（）；
私有类targetType；
私人物业;；
私有列表加载bean；
公共字符串getPropertyPrefix（）{
返回propertyPrefix；
}
公共void setPropertyPrefix（字符串propertyPrefix）{
this.propertyPrefix=propertyPrefix；
}
公共映射getCommonProperties（）{
归还公共财产；
}
公共void setCommonProperties（映射commonProperties）{
this.commonProperties=commonProperties；
}
公共类getTargetType（）{
返回目标类型；
}
public void setTargetType（targetType类）{
this.targetType=targetType；
}
公共属性getProperties（）{
归还财产；
}
公共void集合属性（属性）{
这个。属性=属性；
}
@凌驾
公共列表getObject（）引发异常{
loadedBeans=newArrayList（）；
int lastIndex=-1；
T项=null；
for（字符串属性：prefixFilteredProperties（））{
//实际值
最后一个字符串propertyValue=properties.getProperty（property）；
//删除前缀
property=property.substring（propertyPrefix.length（）+1）；
//以“.”分割
字符串标记[]=property.split（“\\”）；
if（tokens.length！=2）{
抛出新的IllegalArgumentException（“每个列表属性的格式必须为：…）；
}
final int index=Integer.valueOf（令牌[0]）；
最终字符串propertyName=tokens[1]；
//新索引
if（lastIndex！=索引）{
如果（lastIndex！=-1）{
loadedBeans.add（项）；
}
lastIndex=指数；
item=targetType.newInstance（）；
setCommonProperties（项目，commonProperties）；
}
//设置属性
setProperty（item、propertyName、ConvertifEssential（propertyName、propertyValue））；
}
//添加最后一项
如果（lastIndex！=-1）{
loadedBeans.add（项）；
}
返回加载的bean；
}
@凌驾
公共类getObjectType（）{
返回ArrayList.class；
}
@凌驾
公共布尔isSingleton（）{
返回false；
}
私有对象ConvertifEssential（String propertyName、String propertyValue）引发异常{
PropertyDescriptor描述符=BeanUtils.getPropertyDescriptor（targetType，propertyName）；
类propertyType=Primitives.wrap（descriptor.getPropertyType（））；
if（propertyType==String.class）{
返回属性值；
}
返回propertyType.getDeclaredMethod（“valueOf”，String.class）.invoke（propertyType，propertyValue）；
}
专用集prefixFilteredProperties（）{
Set filteredProperties=new TreeSet（）；
对于（String propertyName:properties.stringPropertyNames（））{
if（propertyName.startsWith（this.propertyPrefix））{
filteredProperties.add（propertyName）；
}
}
返回过滤器属性；
}
私有void setCommonProperties（T项，映射commonProperties）引发异常{
对于（Map.Entry commonProperty:commonProperties.entrySet（））{
setProperty（item，commonProperty.getKey（），commonProperty.getValue（））；
}
}
私有静态void setProperty（对象项、字符串propertyName、对象值）引发异常{
PropertyDescriptor描述符=BeanUtils.getPropertyDescriptor（item.getClass（），propertyName）；
descriptor.getWriteMethod（）.invoke（项，值）；
}
}
发布这个针对Spring Boot的解决方案，希望能帮助其他仍在寻找答案的人。使用spring可以将属性文件映射到bean列表。您需要有一个包含bean集合的ConfigurationProperties bean，并使用适当的命名约定，如下所示

调查 
<bean id="studentFactory" class="com.jan.zyka.test.BeanListFactory">
    <property name="propertyPrefix" value="student" />
    <property name="commonProperties">
        <map>
            <entry key="common" value="testCommonValue" />
        </map>
    </property>
    <property name="targetType">
        <value type="java.lang.Class">com.jan.zyka.test.dao.Student</value>
    </property>
    <property name="properties">
        <util:properties location="classpath:testListFactory.properties" />
    </property>
</bean>

[
 Student{firstName='Jan', lastName='Zyka', age=30, common='testCommonValue'},  
 Student{firstName='David', lastName='Kalita', age=55, common='testCommonValue'}
]

package com.jan.zyka.test;

import com.google.common.primitives.Primitives;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.FactoryBean;

import java.beans.PropertyDescriptor;
import java.util.*;

/**
 * <p>
 *    Creates list of beans based on property file.
 * </p>
 * <p>
 *    Each object should be defined in the property file as follows:
 *    <pre>
 *        &lt;prefix&gt;.&lt;index&gt;.&lt;property&gt;
 *    </pre>
 *
 *    So one example might be:
 *    <pre>
 *        student.1.firstName=Paul
 *        student.1.lastName=Verlaine
 *        student.2.firstName=Alex
 *        student.2.lastName=Hamburger
 *    </pre>
 *
 *    The target class must provide default constructor and setter for each property defined in the configuration file as per
 *    bean specification.
 * </p>
 *
 * @param <T> type of the target object
 */
public class BeanListFactory<T> implements FactoryBean<List<T>> {

    private String propertyPrefix;
    private Map<String, Object> commonProperties = Collections.emptyMap();
    private Class<T> targetType;
    private Properties properties;

    private List<T> loadedBeans;

    public String getPropertyPrefix() {
        return propertyPrefix;
    }

    public void setPropertyPrefix(String propertyPrefix) {
        this.propertyPrefix = propertyPrefix;
    }

    public Map<String, Object> getCommonProperties() {
        return commonProperties;
    }

    public void setCommonProperties(Map<String, Object> commonProperties) {
        this.commonProperties = commonProperties;
    }

    public Class<T> getTargetType() {
        return targetType;
    }

    public void setTargetType(Class<T> targetType) {
        this.targetType = targetType;
    }

    public Properties getProperties() {
        return properties;
    }

    public void setProperties(Properties properties) {
        this.properties = properties;
    }

    @Override
    public List<T> getObject() throws Exception {

        loadedBeans = new ArrayList<T>();
        int lastIndex = -1;

        T item = null;

        for (String property: prefixFilteredProperties()) {

            // The actual value
            final String propertyValue = properties.getProperty(property);

            // Remove Prefix
            property = property.substring(propertyPrefix.length() + 1);

            // Split by "."
            String tokens[] = property.split("\\.");

            if (tokens.length != 2) {
                throw new IllegalArgumentException("Each list property must be in form of: <prefix>.<index>.<property name>");
            }

            final int index = Integer.valueOf(tokens[0]);
            final String propertyName = tokens[1];

            // New index
            if (lastIndex != index) {
                if (lastIndex !=-1) {
                    loadedBeans.add(item);
                }
                lastIndex = index;

                item = targetType.newInstance();
                setCommonProperties(item, commonProperties);
            }

            // Set the property
            setProperty(item, propertyName, convertIfNecessary(propertyName, propertyValue));
        }

        // Add last item
        if (lastIndex != -1) {
            loadedBeans.add(item);
        }

        return loadedBeans;
    }

    @Override
    public Class<?> getObjectType() {
        return ArrayList.class;
    }

    @Override
    public boolean isSingleton() {
        return false;
    }

    private Object convertIfNecessary(String propertyName, String propertyValue) throws Exception {
        PropertyDescriptor descriptor = BeanUtils.getPropertyDescriptor(targetType, propertyName);
        Class<?> propertyType = Primitives.wrap(descriptor.getPropertyType());

        if (propertyType == String.class) {
            return propertyValue;
        }

        return propertyType.getDeclaredMethod("valueOf", String.class).invoke(propertyType, propertyValue);
    }

    private Set<String> prefixFilteredProperties() {
        Set<String> filteredProperties = new TreeSet<String>();

        for (String propertyName: properties.stringPropertyNames()) {
            if (propertyName.startsWith(this.propertyPrefix)) {
                filteredProperties.add(propertyName);
            }
        }

        return filteredProperties;
    }

    private void setCommonProperties(T item, Map<String, Object> commonProperties) throws Exception {
        for (Map.Entry<String, Object> commonProperty: commonProperties.entrySet()) {
            setProperty(item, commonProperty.getKey(), commonProperty.getValue());
        }
    }

    private static void setProperty(Object item, String propertyName, Object value) throws Exception {
        PropertyDescriptor descriptor = BeanUtils.getPropertyDescriptor(item.getClass(), propertyName);
        descriptor.getWriteMethod().invoke(item, value);
    }
}

@Component
@ConfigurationProperties(prefix = "notification")
@Data
@Valid
public class NotificationProperties {
    @NotNull
    private Set<AlertThreshold> alertThresholds;
    @NotNull
    private Set<Subscriber> subscribers;
}

notification.alert-thresholds[0].step=PB
notification.alert-thresholds[0].status=RDY
notification.alert-thresholds[0].threshold=500

notification.alert-thresholds[1].step=LA
notification.alert-thresholds[1].status=RDY
notification.alert-thresholds[1].threshold=100

notification.subscribers[0].email=subscriber1@gmail.com
notification.subscribers[1].email=subscriber2@gmail.com

@Data
public class AlertThreshold {
    @NotNull
    private String step;
    @NotNull
    private String status;
    @NotNull
    private Integer threshold;
}

@Data
public class Subscriber {
    @Email
    private String email;
}