java8 多条件的filter过滤

java8 多条件的filter过滤

package com.example.core.mydemo.java;

import java.io.Serializable;
import java.time.LocalDateTime;

public class CostSettleDetailEntity implements Serializable {
    private static final long serialVersionUID = 1L;

    /**
     * id
     */
    private Integer id;
    /**
     * 主订单号
     */
    private String orderNo;
    /**
     * 会员号
     */
    private String memNo;
    /**
     * 金额
     */
    private Integer amt;
    /**
     * 费用编码
     */
    private String sourceCode;
    /**
     * 费用来源描述
     */
    private String sourceDetail;
    /**
     * 费用唯一凭证
     */
    private String uniqueNo;
    /**
     * 费用类型
     */
    private Integer costType;
    /**
     * 创建时间
     */
    private LocalDateTime createTime;
    /**
     * 创建人
     */
    private String createOp;
    /**
     * 修改时间
     */
    private LocalDateTime updateTime;
    /**
     *
     */
    private String updateOp;
    /**
     * 0-正常，1-已逻辑删除
     */
    private Integer isDelete;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getOrderNo() {
        return orderNo;
    }

    public void setOrderNo(String orderNo) {
        this.orderNo = orderNo;
    }

    public String getMemNo() {
        return memNo;
    }

    public void setMemNo(String memNo) {
        this.memNo = memNo;
    }

    public Integer getAmt() {
        return amt;
    }

    public void setAmt(Integer amt) {
        this.amt = amt;
    }

    public String getSourceCode() {
        return sourceCode;
    }

    public void setSourceCode(String sourceCode) {
        this.sourceCode = sourceCode;
    }

    public String getSourceDetail() {
        return sourceDetail;
    }

    public void setSourceDetail(String sourceDetail) {
        this.sourceDetail = sourceDetail;
    }

    public String getUniqueNo() {
        return uniqueNo;
    }

    public void setUniqueNo(String uniqueNo) {
        this.uniqueNo = uniqueNo;
    }

    public Integer getCostType() {
        return costType;
    }

    public void setCostType(Integer costType) {
        this.costType = costType;
    }

    public LocalDateTime getCreateTime() {
        return createTime;
    }

    public void setCreateTime(LocalDateTime createTime) {
        this.createTime = createTime;
    }

    public String getCreateOp() {
        return createOp;
    }

    public void setCreateOp(String createOp) {
        this.createOp = createOp;
    }

    public LocalDateTime getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(LocalDateTime updateTime) {
        this.updateTime = updateTime;
    }

    public String getUpdateOp() {
        return updateOp;
    }

    public void setUpdateOp(String updateOp) {
        this.updateOp = updateOp;
    }

    public Integer getIsDelete() {
        return isDelete;
    }

    public void setIsDelete(Integer isDelete) {
        this.isDelete = isDelete;
    }
}

package com.example.core.mydemo.java;

import java.util.ArrayList;
import java.util.List;

/**
 * filter过滤查询costType = 5 或者 costType=50的费用综合
 * output: fineAmt-1 = 399
 * fineAmt-2 = 0
 * fineAmt-3 = 199
 */
public class CostSettleFilterTest {
    public static void main(String[] args) {
        List<CostSettleDetailEntity> costSettleDetails = new ArrayList<CostSettleDetailEntity>();
        CostSettleDetailEntity entity = new CostSettleDetailEntity();
        entity.setOrderNo("3418639");
        entity.setMemNo("635206016");
        entity.setAmt(99);
        entity.setSourceCode("4");
        entity.setSourceDetail("取消订单违约金");
        entity.setCostType(5);
        costSettleDetails.add(entity);

        entity = new CostSettleDetailEntity();
        entity.setOrderNo("444186390");
        entity.setMemNo("635206016");
        entity.setAmt(100);
        entity.setSourceCode("5");
        entity.setSourceDetail("取消订单违约金");
        entity.setCostType(50);
        costSettleDetails.add(entity);

        entity = new CostSettleDetailEntity();
        entity.setOrderNo("5699556");
        entity.setMemNo("635206016");
        entity.setAmt(200);
        entity.setSourceCode("6");
        entity.setSourceDetail("取消订单违约金");
        entity.setCostType(6);
        costSettleDetails.add(entity);

        //求和
        int fineAmt11 =costSettleDetails.stream().mapToInt(CostSettleDetailEntity::getAmt).sum();
        System.out.println("fineAmt-1 = " + fineAmt11);

        //这样写不对，等于是双重过滤了。筛选不了结果
        int fineAmt22 =costSettleDetails.stream().filter(obj ->{
            return obj.getCostType() != null && 5 == obj.getCostType();  // 5
        }).filter(obj ->{
            return obj.getCostType() != null && 50 == obj.getCostType();  // 50
        }).mapToInt(CostSettleDetailEntity::getAmt).sum();
        System.out.println("fineAmt-2 = " + fineAmt22);

        //正确写法，在filter条件里面写 || 或的条件。
        int fineAmt33 =costSettleDetails.stream().filter(obj ->{
            return obj.getCostType() != null && ( 5 == obj.getCostType() ||  50 == obj.getCostType());  // 5  50
        }).mapToInt(CostSettleDetailEntity::getAmt).sum();
        System.out.println("fineAmt-3 = " + fineAmt33);

    }
}