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名师互学网 > IT > 软件开发 > 后端开发 > Java

JAVA行转列工具类(参考水中加点糖的博客做了改进)

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JAVA行转列工具类(参考水中加点糖的博客做了改进)

目录

工具类代码测试类如何使用测试结果结尾
在工作中做统计时需要将sql查询结果行转列,因此上网查找方法,最终找到了大佬水中加点糖的博客,参考了他的工具类代码。

参考链接:https://blog.csdn.net/puhaiyang/article/details/105292195

由于自身业务需求是固定列有多个,因此在他的代码上做了改进,本文给出改进后的代码及使用方法。

工具类代码
package com.jxz.jxzmes.common.util;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.linkedHashSet;
import java.util.List;
import java.util.Set;
 

public class RowConvertColUtil {
    private static Set headerSet;
    private static Set fixedColumnSet;
 
    private RowConvertColUtil() {
    }
 
    public static class ConvertData {
        private Set headerSet;
        private Set fixedColumnSet;
        private List> dataList;
 
        public ConvertData(List> dataList, Set headerSet, Set fixedColumnSet) {
            this.headerSet = headerSet;
            this.fixedColumnSet = fixedColumnSet;
            this.dataList = dataList;
        }
 
        public Set getHeaderSet() {
            return headerSet;
        }
 
        public void setHeaderSet(Set headerSet) {
            this.headerSet = headerSet;
        }
 
        public Set getfixedColumnSet() {
            return fixedColumnSet;
        }
 
        public void setfixedColumnSet(Set fixedColumnSet) {
            this.fixedColumnSet = fixedColumnSet;
        }
 
        public List> getDataList() {
            return dataList;
        }
 
        public void setDataList(List> dataList) {
            this.dataList = dataList;
        }
    }
 
    
    public static synchronized ConvertData doConvertReturnObj(List orignalList, String headerName, String[] fixedColumn
    		, String valueFiedName, boolean needHeader,String[] fixedColumnName,String nullValue) throws Exception {
        List> lists = doConvert(orignalList, headerName, fixedColumn, valueFiedName, needHeader,fixedColumnName,nullValue);
        return new ConvertData(lists, headerSet, fixedColumnSet);
    }
 
    
    public static synchronized List> doConvert(List orignalList, String headerName, String[] fixedColumn
    		, String valueFiedName, boolean needHeader,String[] fixedColumnName,String nullValue) throws Exception {
        headerSet = new linkedHashSet<>();
        fixedColumnSet = new linkedHashSet<>();
        //resultList:首行名称list
        List> resultList = new ArrayList<>();
 
        getHeaderfixedColumnSet(orignalList, headerName, fixedColumn);
        if (needHeader) {
            List headerList = new ArrayList<>();
            //填充进header
            for(String value:fixedColumnName) {
            headerList.add(value);
            }
            headerList.addAll(headerSet);
            resultList.add(headerList);
        }
        for (Object fixedColumnItem : fixedColumnSet) {
        	//colList:数据list
            List colList = new ArrayList<>();
            //名称
            for(String ColNameItem:fixedColumnItem.toString().split("\|")) {
            	colList.add(ColNameItem);
        	}
            for (Object headerItem : headerSet) {
                boolean flag = true;
                for (Object orignalObjectItem : orignalList) {
                	Field fixedColumnField = null;
                	Field headerField = orignalObjectItem.getClass().getDeclaredField(headerName);
                    headerField.setAccessible(true);
                    fixedColumnField = orignalObjectItem.getClass().getDeclaredField(fixedColumn[0]);
                    fixedColumnField.setAccessible(true);
                    Field valueField = orignalObjectItem.getClass().getDeclaredField(valueFiedName);
                    valueField.setAccessible(true);
                    if (headerItem.equals(headerField.get(orignalObjectItem))) {
                        if (fixedColumnItem.toString().split("\|")[0].equals(fixedColumnField.get(orignalObjectItem))) {
                            colList.add(valueField.get(orignalObjectItem));
                            flag = false;
                            break;
                        }
                    }
                }
                if (flag) {
                    colList.add(nullValue);
                }
            }
            resultList.add(colList);
        }
        return resultList;
    }
 
    private static void getHeaderfixedColumnSet(List orignalList, String headerName, String[] fixedColumn) {
        try {
            for (Object item : orignalList) {
            	
                Field headerField = item.getClass().getDeclaredField(headerName);
                headerField.setAccessible(true);
                headerSet.add(headerField.get(item));
                StringBuffer sBuffer = new StringBuffer();
                int len = 1;
                for(String name:fixedColumn) {
                    Field fixedColumnField = item.getClass().getDeclaredField(name);
                    fixedColumnField.setAccessible(true);
                    sBuffer.append(fixedColumnField.get(item));
                    if(len 
测试类 
package com.jxz.jxzmes.common.util;

import java.util.*;

import org.springframework.stereotype.Controller;

import com.alibaba.fastjson.JSON;
import com.jxz.jxzmes.common.util.RowConvertColUtil.ConvertData;



@Controller
public class RowConvertCol {
    private static class ScoreInfo {
        private String stuName;
        private String sex;
        private Integer age;
        private String subjectName;
        private Integer value;
 
        public Integer getAge() {
			return age;
		}

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

		public String getSex() {
			return sex;
		}

		public void setSex(String sex) {
			this.sex = sex;
		}

		public String getStuName() {
            return stuName;
        }
 
        public String getSubjectName() {
            return subjectName;
        }
 
        public Integer getValue() {
            return value;
        }
 
        public ScoreInfo(String stuName, String sex, Integer age, String subjectName, Integer value) {
            this.stuName = stuName;
            this.sex = sex;
            this.age = age;
            this.subjectName = subjectName;
            this.value = value;
        }
 
        @Override
        public String toString() {
            return "ScoreInfo{" +
                    "stuName='" + stuName + ''' +
                    ", sex='" + sex + ''' +
                    ", age='" + age + ''' +
                    ", subjectName='" + subjectName + ''' +
                    ", value=" + value +
                    '}';
        }
    }
 
    public static void main(String[] args) throws Exception {
        func2();
    	//testDTO();
    }
    public static void testDTO(){


    }
 
    private static void func2() throws Exception {
        List scoreInfoList = new ArrayList<>();
        scoreInfoList.add(new ScoreInfo("张三", "男",15, "语文", 61));
        scoreInfoList.add(new ScoreInfo("张三", "男",15, "数学", 78));
        scoreInfoList.add(new ScoreInfo("张三", "男",15, "英语", 93));
        scoreInfoList.add(new ScoreInfo("李四", "男",14, "语文", 70));
        scoreInfoList.add(new ScoreInfo("李四", "男",14, "数学", 86));
        scoreInfoList.add(new ScoreInfo("李四", "男",14, "英语", 72));
        scoreInfoList.add(new ScoreInfo("王五", "男",15, "语文", 66));
        scoreInfoList.add(new ScoreInfo("赵六", "男",16, "语文", 91));
        scoreInfoList.add(new ScoreInfo("王五", "男",15, "数学", 88));
        scoreInfoList.add(new ScoreInfo("赵六", "男",16, "数学", 63));
        scoreInfoList.add(new ScoreInfo("王五", "男",15, "英语", 93));
        scoreInfoList.add(new ScoreInfo("赵六", "男",16, "英语", 58));
        scoreInfoList.add(new ScoreInfo("王七", "女",15, "英语", 65));
        scoreInfoList.add(new ScoreInfo("王七", "女",15, "数学", 91));
        for (ScoreInfo scoreInfo : scoreInfoList) {
            System.out.println(scoreInfo.toString());
        }
 
        System.out.println("-------------------");
        //doConvertReturnObj(要行转列的List,要行转列的字段,固定列字段数组,行转列对应值列的字段,是否返回表头,固定列字段名称数组,定义空值补数)
        String[] fixedColumn = {"stuName","sex","age"};
        String[] fixedColumnName = {"姓名","性别","年龄"};
        ConvertData lists = RowConvertColUtil.doConvertReturnObj(scoreInfoList, "subjectName", fixedColumn, "value", true,fixedColumnName,"0");
 
        for (List list : lists.getDataList()) {
            System.out.println(list.toString());
        }
    	List dtoList = new ArrayList<>();
    	TestDTO dto=null;
        System.out.println("lists.getDataList().size():"+lists.getDataList().size());
        System.out.println("-------------------");
        System.out.println(lists.getfixedColumnSet());
        System.out.println("lists.getFirstColSet().size():"+lists.getfixedColumnSet().size());
        System.out.println(lists.getHeaderSet());
        System.out.println("lists.getHeaderSet().size():"+lists.getHeaderSet().size());
        System.out.println("-------------------");
        
    }
}
 
如何使用 

根据自身需要,调用工具类中的doConvertReturnObj或doConvert方法。
方法传参如下:
(要行转列的List,要行转列的字段,固定列字段数组,行转列对应值列的字段,是否返回表头,固定列字段名称数组,定义空值补数)

测试结果

转换前:

转换后:

其中:
stuName,sex,age为固定列。
subjectName为需要行转列的字段。
value为行转列对应值列的字段。

结尾

欢迎私信或评论交流,一起进步。

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