List对象集合通过对象属性进行查找

maven需要引入的JAR

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
        </dependency>
        <dependency>
            <groupId>commons-collections</groupId>
            <artifactId>commons-collections</artifactId>
            <version>3.2.2</version>
        </dependency>
        <dependency>
            <groupId>commons-beanutils</groupId>
            <artifactId>commons-beanutils</artifactId>
            <version>1.9.2</version>
        </dependency>

MyPredicate.java

import java.math.BigDecimal;

import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.collections.Predicate;

public class MyPredicate implements Predicate {
    private String property;
    private Object value;

    public MyPredicate(String property, Object value) {
        this.property = property;
        this.value = value;
    }

    public boolean evaluate(Object object) {

        try {
            Object beanValue;
            if (property.indexOf(".") > 0) {
                beanValue = PropertyUtils.getNestedProperty(object, property);
            } else {
                beanValue = PropertyUtils.getProperty(object, property);
            }
            if (beanValue == null) {
                return false;
            }
            if (!value.getClass().equals(beanValue.getClass())) {
                throw new RuntimeException("value.class!=beanValue.class");
            }
            return myCompare(beanValue, value);

        } catch (Exception e) {
            throw new RuntimeException(e.getMessage(), e.getCause());
        }

    }

    private boolean myCompare(Object value, Object beanValue) {
        if (beanValue.getClass().equals(Integer.class)) {
            if ((beanValue).equals(value)) {
                return true;
            }
        }
        if (beanValue.getClass().equals(BigDecimal.class)) {
            if (((BigDecimal) beanValue).compareTo((BigDecimal) value) == 0) {
                return true;
            }
        }
        if (beanValue.getClass().equals(String.class)) {
            if (beanValue.toString().equals(value.toString())) {
                return true;
            }
        }
        if (beanValue.getClass().equals(Double.class)) {
            if ((beanValue).equals(value)) {
                return true;
            }
        } else {
            if (beanValue == value) {
                return true;
            }
        }
        return false;
    }

}

测试方法

import org.andy.work.entity.UserEntity;
import org.andy.work.util.MyPredicate;
import org.apache.commons.collections.CollectionUtils;
import org.junit.Test;
import org.apache.commons.collections.Predicate;
import java.util.ArrayList;
import java.util.List;


    @Test
    public void test() {
        List<UserEntity> list = new ArrayList<UserEntity>();
        UserEntity userEntity1 = new UserEntity(1, "吕布", "111");
        UserEntity userEntity2 = new UserEntity(2, "孙权", "222");
        UserEntity userEntity3 = new UserEntity(3, "吕布", "333");
        UserEntity userEntity4 = new UserEntity(4, "刘备", "444");
        UserEntity userEntity5 = new UserEntity(5, "张飞", "555");
        list.add(userEntity1);
        list.add(userEntity2);
        list.add(userEntity3);
        list.add(userEntity4);
        list.add(userEntity5);

        UserEntity userEntity6 = new UserEntity(6, "吕布", "666");

        Predicate isProblem = new MyPredicate("name", userEntity6.getName());
        List<UserEntity> result = (List<UserEntity>) CollectionUtils.select(list, isProblem);
        System.out.println(result.toString());

    }

输出打印

    [UserEntity{id=1, name='吕布', password='111'}, UserEntity{id=3, name='吕布', password='333'}]