一个处理SQL语句的Object对象

起因：

为了一个复杂的所谓的“万能查询”,允许用户自己选择各种条件进行查询。

根据查询条件和查询内容的不同，可能需要增加表，增加表时候还要显示这个表提供的可供选择的条件等等...

下面实现的内容是这个万能查询的SQL基础。



说明：

private final String SELECT = "SELECT";
	private final String FROM = "FROM";
	private final String WHERE = "WHERE";
	private final String GROUP_BY = "GROUP BY";
	private final String H***ING = "H***ING";
	private final String ORDER_BY = "ORDER BY";
	
	
	private List<String> selectList;
	private List<String> fromList; 
	private List<String> whereList;
	private List<String> groupList;
	private List<String> havingList; 
	private List<String> orderList;

程序根据查询语句创建了这六个list,分别存放对应的内容

针对这六个list提供了多种方式进行赋值和取值操作

1.其中getter和setter方法为默认的list赋值取值方式

2.提供了String类型的getter和setter(String)方法

3.提供了put(String)和remove(String)方法对List进行修改

重写toString()方法输出内容。

用途：在对SQL进行更复杂的拼接时可以用到。

package com.insigma.siis.local.comm.entity;

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

public class SqlStr {
	/**
	SELECT select_list
	   [ INTO new_table ]
	   FROM table_source
	   [ WHERE search_condition ]
	   [ GROUP BY group_by_expression ]
	   [ H***ING search_condition ]
	   [ ORDER BY order_expression [ ASC | DESC ] ]
	 */
private final String SELECT = "SELECT";
	private final String FROM = "FROM";
	private final String WHERE = "WHERE";
	private final String GROUP_BY = "GROUP BY";
	private final String H***ING = "H***ING";
	private final String ORDER_BY = "ORDER BY";
	
	
	private List<String> selectList;
	private List<String> fromList; 
	private List<String> whereList;
	private List<String> groupList;
	private List<String> havingList; 
	private List<String> orderList;
	
	public void Init(){
		selectList = new ArrayList<String>();
		fromList = new ArrayList<String>();
		whereList = new ArrayList<String>();
		groupList = new ArrayList<String>();
		havingList = new ArrayList<String>();
		orderList = new ArrayList<String>();
	}
	
	public SqlStr(){
		Init();
	}
	
	public SqlStr(String sql) throws Exception{
		Init();
		
		String SQL = sql.toUpperCase();
		int selectindex = SQL.indexOf(SELECT);
		int fromindex = SQL.indexOf(FROM);
		int whereindex = SQL.indexOf(WHERE);
		int groupindex = SQL.indexOf(GROUP_BY);
		int havingindex = SQL.indexOf(H***ING);
		int orderindex = SQL.indexOf(ORDER_BY);
		
		if(selectindex==-1||fromindex==-1){
			throw new Exception("sql不是一个符合要求的语句");
		}
		
		String selectString = sql.substring(SELECT.length(), fromindex);
		String fromString = sql.substring(FROM.length()+fromindex, whereindex!=-1?whereindex:(groupindex!=-1?groupindex:(havingindex!=-1?havingindex:(orderindex!=-1?orderindex:sql.length()))));
		String whereString = null;
		String groupString = null;
		String havingString = null;
		String orderString = null;
		
		putSelectStr(selectString);
		putFromStr(fromString);
		if(whereindex!=-1){
			whereString = sql.substring(WHERE.length()+whereindex, groupindex!=-1?groupindex:(havingindex!=-1?havingindex:(orderindex!=-1?orderindex:sql.length())));
			putWhereStr(whereString);
		}
		
		if(groupindex!=-1){
			groupString = sql.substring(GROUP_BY.length()+groupindex,havingindex!=-1?havingindex:(orderindex!=-1?orderindex:sql.length()));
			putGroupStr(groupString);
		}
		if(havingindex!=-1){
			havingString = sql.substring(H***ING.length()+havingindex,orderindex!=-1?orderindex:sql.length());
			putHavingStr(havingString);
		}
		if(orderindex!=-1){
			orderString = sql.substring(ORDER_BY.length()+orderindex);
			putOrderStr(orderString);
		}
	}
	
	@Override
	public String toString() {
		checkAll();
		if(selectList.size()==0||fromList.size()==0){
			return "";
		}
		StringBuffer sBuffer = new StringBuffer("select ");
		sBuffer.append(ListToString(selectList, ","));
		sBuffer.append(" from ");
		sBuffer.append(ListToString(fromList, ","));
		if(whereList.size()>0){
			sBuffer.append(" where ");
			sBuffer.append(ListToString(whereList, " and "));
		}
		if(groupList.size()>0){
			sBuffer.append(" group by ");
			sBuffer.append(ListToString(groupList, ","));
		}
		if(havingList.size()>0){
			sBuffer.append(" having ");
			sBuffer.append(ListToString(havingList, ","));
		}
		if(orderList.size()>0){
			sBuffer.append(" order by ");
			sBuffer.append(ListToString(orderList, ","));
		}
		return sBuffer.toString();
	}
	
	@SuppressWarnings({ "unchecked", "rawtypes" })
	public List checkList(List list){
		HashSet set = new HashSet(list); 
		if(set.size() != list.size()){
			return new ArrayList<String>(set);
		}
		return list;
	}
	
	@SuppressWarnings("unchecked")
	public void checkAll(){
		selectList = checkList(selectList);
		fromList = checkList(fromList);
		whereList = checkList(whereList);
		groupList = checkList(groupList);
		havingList = checkList(havingList);
		orderList = checkList(orderList);
	}
	
	/**
	 * *****************************String类型的put**********************************************
	 */
	@SuppressWarnings("unchecked")
	public void putSelectStr(String selectStr) {
		this.selectList.addAll(StringToList(selectStr, ","));
	}
	@SuppressWarnings("unchecked")
	public void putFromStr(String fromStr) {
		this.fromList.addAll(StringToList(fromStr, ","));
	}
	@SuppressWarnings("unchecked")
	public void putWhereStr(String whereStr) {
		this.whereList.addAll(StringToList(whereStr, "and"));
	}
	@SuppressWarnings("unchecked")
	public void putGroupStr(String groupStr) {
		this.groupList.addAll(StringToList(groupStr, ","));
	}
	@SuppressWarnings("unchecked")
	public void putHavingStr(String havingStr) {
		this.havingList.addAll(StringToList(havingStr, ","));
	}
	@SuppressWarnings("unchecked")
	public void putOrderStr(String orderStr) {
		this.orderList.addAll(StringToList(orderStr, ","));
	}
	
	/**
	 * *****************************String类型的remove**********************************************
	 */
	public void removeSelectStr(String selectStr) {
		this.selectList.removeAll(StringToList(selectStr, ","));
	}
	public void removeFromStr(String fromStr) {
		this.fromList.removeAll(StringToList(fromStr, ","));
	}
	public void removeWhereStr(String whereStr) {
		this.whereList.removeAll(StringToList(whereStr, " and "));
	}
	public void removeGroupStr(String groupStr) {
		this.groupList.removeAll(StringToList(groupStr, ","));
	}
	public void removeHavingStr(String havingStr) {
		this.havingList.removeAll(StringToList(havingStr, ","));
	}
	public void removeOrderStr(String orderStr) {
		this.orderList.removeAll(StringToList(orderStr, ","));
	}
	/**
	 * *****************************String类型的getter和setter**********************************************
	 */
	public String getSelectStr() {
		return ListToString(selectList,",");
	}
	@SuppressWarnings("unchecked")
	public void setSelectStr(String selectStr) {
		this.selectList = StringToList(selectStr, ",");
	}
	public String getFromStr() {
		return ListToString(fromList,",");
	}
	@SuppressWarnings("unchecked")
	public void setFromStr(String fromStr) {
		this.fromList = StringToList(fromStr, ",");
	}
	public String getWhereStr() {
		return ListToString(whereList," and ");
	}
	@SuppressWarnings("unchecked")
	public void setWhereStr(String whereStr) {
		this.whereList = StringToList(whereStr, ",");
	}
	public String getGroupStr() {
		return ListToString(groupList,",");
	}
	@SuppressWarnings("unchecked")
	public void setGroupStr(String groupStr) {
		this.groupList = StringToList(groupStr, ",");
	}
	public String getHavingStr() {
		return ListToString(havingList,",");
	}
	@SuppressWarnings("unchecked")
	public void setHavingStr(String havingStr) {
		this.havingList = StringToList(havingStr, ",");
	}
	public String getOrderStr() {
		return ListToString(orderList,",");
	}
	@SuppressWarnings("unchecked")
	public void setOrderStr(String orderStr) {
		this.orderList = StringToList(orderStr, ",");
	}
	
	
	
	
	/**
	 * *****************************默认的getter和setter**********************************************
	 */
	public List<String> getSelectList() {
		return selectList;
	}
	public void setSelectList(List<String> selectList) {
		this.selectList = selectList;
	}
	public List<String> getFromList() {
		return fromList;
	}
	public void setFromList(List<String> fromList) {
		this.fromList = fromList;
	}
	public List<String> getWhereList() {
		return whereList;
	}
	public void setWhereList(List<String> whereList) {
		this.whereList = whereList;
	}
	public List<String> getGroupList() {
		return groupList;
	}
	public void setGroupList(List<String> groupList) {
		this.groupList = groupList;
	}
	public List<String> getHavingList() {
		return havingList;
	}
	public void setHavingList(List<String> havingList) {
		this.havingList = havingList;
	}
	public List<String> getOrderList() {
		return orderList;
	}
	public void setOrderList(List<String> orderList) {
		this.orderList = orderList;
	}
	
	//list转为字符串
    @SuppressWarnings("rawtypes")
    public static String ListToString(List list,String spilt){
        StringBuffer sBuffer = new StringBuffer();
        for(int i=0;i<list.size();i++){
            if(!sBuffer.toString().equals("")){
                sBuffer.append(spilt);
            }
            sBuffer.append(list.get(i));
        }
        return sBuffer.toString();
    }
    //字符串转list
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public static List StringToList(String str,String spilt){
        String[] strs = str.split(spilt);
        if(strs.length>0){
            List list = new ArrayList();
            for(int i=0;i<strs.length;i++){
                list.add(strs[i].trim());
            }
            return list;
        }
        return null;
    }
    
    /**
     * 测试方法
     * @param args
     * @throws Exception
     */
	public static void main(String[] args) throws Exception {
		SqlStr sql4 = new SqlStr("select aac001,aac002,aac003 from ac17,ac01,ac02 where aac001=6864483 group by aac001,aac002 having count(aac001)>1 order by aac002");
		sql4.putFromStr("ac17,ac05");
		sql4.removeSelectStr("aac001,aac003");
		System.out.println(sql4);
		
		SqlStr sqlStr = new SqlStr("select * from ac01");
		System.out.println(sqlStr);
	}
	
}

测试方法的输出结果：

select aac002 from ac17,ac01,ac05,ac02 where aac001=6864483 group by aac001,aac002 having count(aac001)>1 order by aac002