使用JPA+querydsl如何实现多条件动态查询

<dependency>
			<groupId>com.querydsl</groupId>
			<artifactId>querydsl-jpa</artifactId>
			<version>4.2.1</version>
		</dependency>
		<dependency>
			<groupId>com.querydsl</groupId>
			<artifactId>querydsl-apt</artifactId>
			<version>4.2.1</version>
		</dependency>

<plugin>
				<groupId>com.querydsl</groupId>
				<artifactId>querydsl-Maven-plugin</artifactId>
				<executions>
					<execution>
						<phase>generate-sources</phase>
						<Goals>
							<goal>jpa-export</goal>
						</goals>
						<configuration>
						
							<targetFolder>target/generated-sources/java</targetFolder>
							<packages>com.jerry.gamemarket.entity</packages>
						</configuration>
					</execution>
				</executions>
			</plugin>

<targetFolder>target/generated-sources/java</targetFolder>

<packages>com.jerry.gamemarket.entity</packages>

@Bean
	public JPAQueryFactory queryFactory(EntityManager entityManager){
		return new JPAQueryFactory(entityManager);
	}

package com.jerry.gamemarket.dto;
import com.jerry.gamemarket.enums.OrderStatusEnums;
import com.jerry.gamemarket.enums.PayStatusEnums;
import lombok.Data;
import org.springframework.context.annotation.Bean;
import java.math.BigDecimal;

@Data
public class SearchOrderDTO {
    private  String orderId;
    //   private String id;
    private  String buyerName;
    private  String buyerPhone;
    private  String buyerAddress;
    private  String canteenName;
    private BigDecimal maxAmount;
    private BigDecimal minAmount;
    private Integer orderStatus;
    //    默认未支付
    private Integer payStatus;
    private Integer pageNum = 1;
    private Integer pageSize=10;
}

//
// Source code recreated from a .class file by IntelliJ idea
// (powered by Fernflower decompiler)
//
package com.querydsl.core;
import com.google.common.collect.ImmutableList;
import java.io.Serializable;
import java.util.List;
import javax.annotation.Nullable;
public final class QueryResults<T> implements Serializable {
    private static final long serialVersionUID = -4591506147471300909L;
    private static final QueryResults<Object> EMPTY = new QueryResults(ImmutableList.of(), 9223372036854775807L, 0L, 0L);
    private final long limit;
    private final long offset;
    private final long total;
    private final List<T> results;
    public static <T> QueryResults<T> emptyResults() {
        return EMPTY;
    }
    public QueryResults(List<T> results, @Nullable Long limit, @Nullable Long offset, long total) {
        this.limit = limit != null ? limit.longValue() : 9223372036854775807L;
        this.offset = offset != null ? offset.longValue() : 0L;
        this.total = total;
        this.results = results;
    }
    public QueryResults(List<T> results, QueryModifiers mod, long total) {
        this(results, mod.getLimit(), mod.getOffset(), total);
    }
    public List<T> getResults() {
        return this.results;
    }
    public long getTotal() {
        return this.total;
    }
    public boolean isEmpty() {
        return this.results.isEmpty();
    }
    public long getLimit() {
        return this.limit;
    }
    public long getOffset() {
        return this.offset;
    }
}

 @Override
    public QueryResults<OrderMaster> dymamicQuery(SearchOrderDTO searchOrderDTO) {
        QOrderMaster o = QOrderMaster.orderMaster;
        JPAQuery<OrderMaster> query = jpaQueryFactory.select(o).from(o);
        if (!StringUtils.isEmpty(searchOrderDTO.getOrderId())){
            query.where(o.orderId.like(searchOrderDTO.getOrderId()));
        }
        if (!StringUtils.isEmpty(searchOrderDTO.getBuyerName())){
            query.where(o.buyerName.like("%"+searchOrderDTO.getBuyerName()+"%"));
        }
        if (!StringUtils.isEmpty(searchOrderDTO.getBuyerPhone())){
            query.where(o.buyerPhone.eq(searchOrderDTO.getBuyerPhone()));
        }
        if (searchOrderDTO.getMaxAmount()!=null && searchOrderDTO.getMinAmount()!=null){
            query.where(o.orderAmount.goe(searchOrderDTO.getMinAmount()));
        }
        if (searchOrderDTO.getMaxAmount()!=null && searchOrderDTO.getMinAmount()!=null){
            query.where(o.orderAmount.loe(searchOrderDTO.getMaxAmount()));
        }
        if (searchOrderDTO.getOrderStatus()!=null){
            query.where(o.orderStatus.eq(searchOrderDTO.getOrderStatus()));
        }
        if (searchOrderDTO.getPayStatus()!=null){
            query.where(o.payStatus.eq(searchOrderDTO.getPayStatus()));
        }
        return query.orderBy(o.createTime.desc())
                .offset((searchOrderDTO.getPageNum()-1)*searchOrderDTO.getPageSize())
                .limit(searchOrderDTO.getPageSize())
                .fetchResults();
    }

@PostMapping("/searchorder")
    public QueryResults<OrderMaster> findByCase(@RequestBody SearchOrderDTO searchOrderDTO){
        QueryResults<OrderMaster> queryResults=orderService.dymamicQuery(searchOrderDTO);
        System.out.println(searchOrderDTO);
        System.out.println(queryResults.getResults());
        return queryResults;
    }

@Mappings({
@Mapping(source = "entity.name", target = "dto属性名")
})