Java版结果集行列倒置

从数据库里面取得的数据一般是以实体的方式返回。但是做报表的话，可能是从实体某个属性来显示，即所谓的行列倒置。所以有人写了行列倒置的SQL，这里也写个java实现的例子。属性是写死的。如果需要灵活点，换成用反射来遍历属性即可。

 

/** * 将List信息行列倒置 * */package jdk_1_4.test;import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import java.util.Iterator;import java.util.LinkedHashMap;import java.util.LinkedList;import java.util.List;import java.util.Map;public class V2HTest {/** * @param args */public static void main(String[] args) {List dataList = new ArrayList();setData(dataList,"1");setData(dataList,"2");//--按照日期和品牌排序Collections.sort(dataList, new Comparator() { public int compare(Object o1, Object o2) { DataModel dm1 = (DataModel)o1; DataModel dm2 = (DataModel)o2; int flag = dm1.getDate().compareTo(dm2.getDate()); if(flag == 0) { flag = dm1.getTobaccoName().compareTo(dm2.getTobaccoName()); } return flag; }}); /**/System.out.println("--------------------行列顺序转换前------------------");for(int i=0;i<dataList.size();i++){DataModel dm = (DataModel)dataList.get(i);System.out.println("日期："+dm.getDate());System.out.println("卷烟："+dm.getTobaccoName());System.out.println(dm.getDate()+"日生产计划："+dm.getProduceQty());System.out.println(dm.getDate()+"日销售计划："+dm.getSaleQty());System.out.println(dm.getDate()+"日最低库存线："+dm.getInvLineLow());System.out.println(dm.getDate()+"日最高库存线："+dm.getInvLineHigh());System.out.println(dm.getDate()+"日期末库存："+dm.getInventoryQty());System.out.println("----");}//--行列倒置Map v2hMap = new LinkedHashMap();v2hMap = v2h(dataList,6);Object[] tobaccoArr = (Object[])v2hMap.get("Tobacco");System.out.println("--------------------行列顺序转换后------------------/n");//System.out.println("-------卷烟品牌");System.out.print("");for(int i=0;i<tobaccoArr.length;i++){System.out.print(tobaccoArr[i]+"");}System.out.println();v2hMap.remove("Tobacco");/**/Iterator it = v2hMap.keySet().iterator();while(it.hasNext()){String key = it.next().toString();//System.out.println(key);/**/LinkedList hList = (LinkedList)v2hMap.get(key);for(int i=0;i<hList.size();i++){double[] objArr = (double[])hList.get(i);switch(i){case 0:{System.out.print(key+"日生产计划 ");break;}case 1:{System.out.print(key+"日销售计划 ");break;}case 2:{System.out.print(key+"日最低库存线 ");break;}case 3:{System.out.print(key+"日最高库存线 ");break;}case 4:{System.out.print(key+"日库存");break;}}for(int j=0;j<objArr.length;j++){System.out.print(""+objArr[j]+"");}System.out.println();}System.out.println("==================");}}//--行列倒置public static Map v2h(List dataList,int tobaccoCount){Map v2hMap = new LinkedHashMap();DataModel dm0 = (DataModel)dataList.get(0);String date = dm0.getDate();int index = 0;//--double[] produceQtyArr = new double[tobaccoCount];//当日各品牌生产计划double[] saleQtyArr = new double[tobaccoCount];//当日各品牌销售计划double[] invLineHighArr = new double[tobaccoCount];//当日各品牌最高库存double[] invLineLowArr = new double[tobaccoCount];//当日各品牌最低库存double[] inventoryQtyArr = new double[tobaccoCount];//当日各品牌最低库存LinkedList v2hList = new LinkedList();String[] tobaccoNameArr = new String[tobaccoCount];//--for(int i=0;i<dataList.size();i++){DataModel dm = (DataModel)dataList.get(i);if(!date.equals(dm.getDate())){v2hList.add(produceQtyArr);v2hList.add(saleQtyArr);v2hList.add(invLineLowArr);v2hList.add(invLineHighArr);v2hList.add(inventoryQtyArr);v2hMap.put(date, v2hList);produceQtyArr = new double[tobaccoCount];saleQtyArr = new double[tobaccoCount];invLineHighArr = new double[tobaccoCount];invLineLowArr = new double[tobaccoCount];inventoryQtyArr = new double[tobaccoCount];v2hList = new LinkedList();date = dm.getDate();index = 0;}inventoryQtyArr[index] = dm.getInventoryQty();produceQtyArr[index] = dm.getProduceQty();saleQtyArr[index] = dm.getSaleQty();invLineHighArr[index] = dm.getInvLineHigh();invLineLowArr[index] = dm.getInvLineLow();tobaccoNameArr[index] = dm.getTobaccoName();index++;if(i==dataList.size()-1){v2hList.add(produceQtyArr);v2hList.add(saleQtyArr);v2hList.add(invLineLowArr);v2hList.add(invLineHighArr);v2hList.add(inventoryQtyArr);v2hMap.put(date, v2hList);}}v2hMap.put("Tobacco", tobaccoNameArr);//--卷烟品牌return v2hMap;}//--计算public static void setData(List dataList,String date){DataModel dm1 = new DataModel();dm1.setDate(date);dm1.setTobaccoName("熊猫");dm1.setSaleQty(0.0);dm1.setProduceQty(0.0);dm1.setInvLineLow(1.0);dm1.setInvLineHigh(3.0);dm1.setInventoryQty(45.0);DataModel dm2 = new DataModel();dm2.setDate(date);dm2.setTobaccoName("84软盒中华");dm2.setSaleQty(0.0);dm2.setProduceQty(0.0);dm2.setInvLineLow(7.5);dm2.setInvLineHigh(20.0);dm2.setInventoryQty(52.0);DataModel dm3 = new DataModel();dm3.setDate(date);dm3.setTobaccoName("84硬盒中华");dm3.setSaleQty(0.0);dm3.setProduceQty(0.0);dm3.setInvLineLow(2100.0);dm3.setInvLineHigh(5000.0);dm3.setInventoryQty(1341.0);DataModel dm4 = new DataModel();dm4.setDate(date);dm4.setTobaccoName("软牡丹（8mg）");dm4.setSaleQty(0.0);dm4.setProduceQty(0.0);dm4.setInvLineLow(900.0);dm4.setInvLineHigh(2500.0);dm4.setInventoryQty(3565.0);DataModel dm5 = new DataModel();dm5.setDate(date);dm5.setTobaccoName("硬上海（8mg）");dm5.setSaleQty(4000.0);dm5.setProduceQty(0.0);dm5.setInvLineLow(3600.0);dm5.setInvLineHigh(8000.0);dm5.setInventoryQty(-1122.0);DataModel dm6 = new DataModel();dm6.setDate(date);dm6.setTobaccoName("外销牌号A");dm6.setSaleQty(0.0);dm6.setProduceQty(0.0);dm6.setInvLineLow(0.0);dm6.setInvLineHigh(0.0);dm6.setInventoryQty(10.0);//----------------------dataList.add(dm1);dataList.add(dm2);dataList.add(dm3);dataList.add(dm4);dataList.add(dm5);dataList.add(dm6);}}class DataModel{private String date;private String tobaccoName;private double inventoryQty;//当日期末库存private double saleQty;//当日销售计划private double produceQty;//当日生产数量private double invLineHigh;//当日最高库存线private double invLineLow;//当日最低库存线public String getDate() {return date;}public void setDate(String date) {this.date = date;}public String getTobaccoName() {return tobaccoName;}public void setTobaccoName(String tobaccoName) {this.tobaccoName = tobaccoName;}public double getInventoryQty() {return inventoryQty;}public void setInventoryQty(double inventoryQty) {this.inventoryQty = inventoryQty;}public double getSaleQty() {return saleQty;}public void setSaleQty(double saleQty) {this.saleQty = saleQty;}public double getProduceQty() {return produceQty;}public void setProduceQty(double produceQty) {this.produceQty = produceQty;}public double getInvLineHigh() {return invLineHigh;}public void setInvLineHigh(double invLineHigh) {this.invLineHigh = invLineHigh;}public double getInvLineLow() {return invLineLow;}public void setInvLineLow(double invLineLow) {this.invLineLow = invLineLow;}}