JAVA“动态”为类添加属性

Posted 2020-09-28 每天一点

部分参考：http://www.cnblogs.com/zy2009/p/6725843.html

pom.xml中添加：

<dependency>
	<groupId>commons-beanutils</groupId>
	<artifactId>commons-beanutils</artifactId>
	<version>1.9.3</version>
</dependency>

<dependency>
	<groupId>cglib</groupId>
	<artifactId>cglib-nodep</artifactId>
	<version>3.2.4</version>
</dependency>

　　

使用cglib动态生成类与使用 commons-beanutils获取源对象属性-类型集合，封装成新对象并设置值代码：

package com.frinder.util;

import com.google.common.collect.Maps;
import com.kiktech.entity.LoggerEntity;
import net.sf.cglib.beans.BeanGenerator;
import net.sf.cglib.beans.BeanMap;
import org.apache.commons.beanutils.PropertyUtilsBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.beans.PropertyDescriptor;
import java.util.HashMap;
import java.util.Map;

/**
 * Created by frinder on 2017/7/18.
 */
public class ReflectUtil {

    static Logger logger = LoggerFactory.getLogger(ReflectUtil.class);

    public static Object getTarget(Object dest, Map<String, Object> addProperties) {
        // get property map
        PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean();
        PropertyDescriptor[] descriptors = propertyUtilsBean.getPropertyDescriptors(dest);
        Map<String, Class> propertyMap = Maps.newHashMap();
        for (PropertyDescriptor d : descriptors) {
            if (!"class".equalsIgnoreCase(d.getName())) {
                propertyMap.put(d.getName(), d.getPropertyType());
            }
        }
        // add extra properties
        addProperties.forEach((k, v) -> propertyMap.put(k, v.getClass()));
        // new dynamic bean
        DynamicBean dynamicBean = new DynamicBean(dest.getClass(), propertyMap);
        // add old value
        propertyMap.forEach((k, v) -> {
            try {
                // filter extra properties
                if (!addProperties.containsKey(k)) {
                    dynamicBean.setValue(k, propertyUtilsBean.getNestedProperty(dest, k));
                }
            } catch (Exception e) {
                logger.error(e.getMessage(), e);
            }
        });
        // add extra value
        addProperties.forEach((k, v) -> {
            try {
                dynamicBean.setValue(k, v);
            } catch (Exception e) {
                logger.error(e.getMessage(), e);
            }
        });
        Object target = dynamicBean.getTarget();
        return target;
    }


    public static void main(String[] args) {
        LoggerEntity entity = new LoggerEntity();
        entity.setAppName("appname");
        entity.setOperator("add");
        entity.setResult("result");
        entity.setUri("uri");
        entity.setMethod("method");
        Map<String, Object> addProperties = new HashMap() {{
            put("hello", "world");
            put("abc", "123");
        }};
        System.out.println(getTarget(entity, addProperties));
    }


    public static class DynamicBean {
        /**
         * 目标对象
         */
        private Object target;

        /**
         * 属性集合
         */
        private BeanMap beanMap;

        public DynamicBean(Class superclass, Map<String, Class> propertyMap) {
            this.target = generateBean(superclass, propertyMap);
            this.beanMap = BeanMap.create(this.target);
        }


        /**
         * bean 添加属性和值
         *
         * @param property
         * @param value
         */
        public void setValue(String property, Object value) {
            beanMap.put(property, value);
        }

        /**
         * 获取属性值
         *
         * @param property
         * @return
         */
        public Object getValue(String property) {
            return beanMap.get(property);
        }

        /**
         * 获取对象
         *
         * @return
         */
        public Object getTarget() {
            return this.target;
        }


        /**
         * 根据属性生成对象
         *
         * @param superclass
         * @param propertyMap
         * @return
         */
        private Object generateBean(Class superclass, Map<String, Class> propertyMap) {
            BeanGenerator generator = new BeanGenerator();
            if (null != superclass) {
                generator.setSuperclass(superclass);
            }
            BeanGenerator.addProperties(generator, propertyMap);
            return generator.create();
        }
    }

}

　　

 

 

 

 

 LoggerEntity代码：

package com.frinder.entity;

import net.logstash.logback.encoder.org.apache.commons.lang.builder.ReflectionToStringBuilder;

/**
 * Created by frinder on 2017/5/24.
 */
public class LoggerEntity {

    private String method;
    private String uri;
    private Object[] args;
    private Object result;
    private String operator;
    private String appName;

    /**
     * 获取当前对象
     *
     * @param method
     * @param uri
     * @param args
     * @param result
     * @return
     */
    public LoggerEntity get(String method, String uri, Object[] args, Object result, String operator, String appName) {
        setMethod(method);
        setUri(uri);
        setArgs(args);
        setResult(result);
        setOperator(operator);
        setAppName(appName);
        return this;
    }

    public String getMethod() {
        return method;
    }

    public void setMethod(String method) {
        this.method = method;
    }

    public String getUri() {
        return uri;
    }

    public void setUri(String uri) {
        this.uri = uri;
    }

    public Object[] getArgs() {
        return args;
    }

    public void setArgs(Object[] args) {
        this.args = args;
    }

    public Object getResult() {
        return result;
    }

    public void setResult(Object result) {
        this.result = result;
    }

    public String getOperator() {
        return operator;
    }

    public void setOperator(String operator) {
        this.operator = operator;
    }

    public String getAppName() {
        return appName;
    }

    public void setAppName(String appName) {
        this.appName = appName;
    }

    @Override
    public String toString() {
        return ReflectionToStringBuilder.toString(this);
    }
}

　　

 

测试结果，需要在调试模式下才能看到：