BaseDBTable.java

package com.jqmobile.core.android.db.orm;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.jqmobile.core.orm.DBTable;
import com.jqmobile.core.orm.exception.ORMNotDBTableException;
import com.jqmobile.core.orm.exception.ORMTableParmaryRepeatException;
import com.jqmobile.core.utils.plain.BeanUtils;
import com.jqmobile.core.utils.plain.StringUtils;

public class BaseDBTable {
	private final Class<?> tableClass;
	private final DBTable dbLable;
	private BaseDBColumn parmaryId;
	private List<BaseDBColumn> mappingFields = new ArrayList<BaseDBColumn>();
	private String createTableSql,insertSql,updateSql,dropTableSql,deleteSql,findSql;
	private final static Map<Class<?>, BaseDBTable> map = new HashMap<Class<?>, BaseDBTable>();
	public static BaseDBTable getInstance(Class<?> c) throws ORMNotDBTableException{
		synchronized (map) {
			if(!map.containsKey(c)){
				map.put(c, new BaseDBTable(c));
			}
		}
		return map.get(c);
	}
	private BaseDBTable(Class<?> c) throws ORMNotDBTableException{
		this.tableClass = c;
		this.dbLable = c.getAnnotation(DBTable.class);
		if(null == dbLable){
			throw new ORMNotDBTableException();
		}
		initSql();
	}
	public DBTable getDBTable() {
		return dbLable;
	}
	public List<BaseDBColumn> getMappingFields() {
		return mappingFields;
	}
	public String getTableName(){
		if(DBTable.DefaultValue.equals(dbLable.name())) return tableClass.getName().substring(tableClass.getName().lastIndexOf(".")+1);
		return dbLable.name();
	}
	public Class<?> getTableClass() {
		return tableClass;
	}
	private void initSql(){
		clear();
		Field[] fields = BeanUtils.getAllFields_Cache(tableClass);
		StringBuilder creatTableSql=new StringBuilder("create table "),
				dropTableSql=new StringBuilder(" DROP TABLE "),
				insertDataSql=new StringBuilder("insert into "),
				iValues = new StringBuilder(" ( "),
				updateDataSql=new StringBuilder("update "),
				deleteDataSql=new StringBuilder(" delete from "),
				findDataSql=new StringBuilder(" select * from ");
		String tableName = getTableName();
		creatTableSql.append(tableName);
		creatTableSql.append(" ( ");
		dropTableSql.append(tableName);
		insertDataSql.append(tableName);
		insertDataSql.append("(");
		updateDataSql.append(tableName);
		updateDataSql.append(" set \n");
		deleteDataSql.append(tableName);
		deleteDataSql.append(" where ");
		findDataSql.append(tableName);
		findDataSql.append(" where ");
		boolean isFirst = true;
		//临时变量，用于储存主键列名
		String tempId="";
		for(Field f : fields){
			if(f.getName().contains("$")) continue;
			BaseDBColumn column = BaseDBColumn.getInstance(f);
			if(!column.isMapping()) continue;
			//paimary id
			if(column.isPaimaryId()){
				//将主键列名赋值给临时变量
				tempId=column.getColumnName();
				
				if(null == parmaryId){
					this.parmaryId = column;
					deleteDataSql.append(column.getColumnName());
					deleteDataSql.append("=?");
					findDataSql.append(column.getColumnName());
					findDataSql.append("=?");
				}else{
					throw new ORMTableParmaryRepeatException(" old:"+parmaryId.getColumnName()+",now:"+f.getName());
				}
			}
			String columnType = column.getColumnType();
			String columnName = column.getColumnName();
			if(!isFirst) creatTableSql.append(" , \n ");
			creatTableSql.append(" ");
			creatTableSql.append(columnName);
			creatTableSql.append(" ");
			creatTableSql.append(columnType);
			if(!isFirst) insertDataSql.append(" , ");
			insertDataSql.append(columnName);
			if(!isFirst) iValues.append(" , ");
			iValues.append(" ? ");
			if(!columnName.equals(tempId)){
				updateDataSql.append(columnName);
			}
			if(!isFirst) updateDataSql.append("=?, ");
			//
			f.setAccessible(true);    
			mappingFields .add(column);
			isFirst = false;
		}
		creatTableSql.append(" ,PRIMARY KEY ("+tempId+") \n)");
		iValues.append(" ) ");
		insertDataSql.append(" ) ");
		insertDataSql.append(" values ");
		insertDataSql.append(iValues);
		updateDataSql.delete(updateDataSql.length()-2, updateDataSql.length()-1);
		updateDataSql.append(" where "+tempId+" = ?");
		this.createTableSql = creatTableSql.toString();
		this.insertSql = insertDataSql.toString();
		this.updateSql = updateDataSql.toString();
		this.dropTableSql = dropTableSql.toString();
		this.deleteSql = deleteDataSql.toString();
		this.findSql = findDataSql.toString();
	}
	private void clear() {
		parmaryId = null;
	}
	
	public BaseDBColumn getParmaryId() {
		return parmaryId;
	}

	public String getCreateTableSql(){
		if(null == createTableSql) initSql();
		return createTableSql;
	}
	public String getDropTableSql(){
		if(null == dropTableSql) initSql();
		return dropTableSql;
	}
	public String getInstnerSql(){
		if(null == insertSql) initSql();
		return insertSql;
	}
	public String getUpdateSqlByPID(){
		if(null == updateSql) initSql();
		return updateSql;
	}
	public String getDeleteSqlByPID(){
		if(null == deleteSql) initSql();
		return deleteSql;
	}
	public String getFindSqlByPID() {
		if(null == findSql) initSql();
		return findSql;
	}
	public String getQuerySql(String where) {
		String head = "select * from "+getTableName();
		if(StringUtils.isEmpty(where, true)){
			return head;
		}else if(where.trim().toLowerCase().startsWith("select")){
			return where;
		}else if(where.trim().toLowerCase().startsWith("where")){
			return head+" "+where;
		}else{
			return head+" where "+where;
		}
	}
	public String getQueryRowSql(String where) {
		String head = "select count("+parmaryId.getColumnName()+") from "+getTableName();
		if(StringUtils.isEmpty(where, true)){
			return head;
		}else if(where.trim().toLowerCase().startsWith("select")){
			return where;
		}else if(where.trim().toLowerCase().startsWith("where")){
			return head+" "+where;
		}else{
			return head+" where "+where;
		}
	}
	public String getModifySql(String set) {
		String head = "update from "+getTableName()+" ";
		if(StringUtils.isEmpty(set, true)){
			return "";
		}else if(set.trim().toLowerCase().startsWith("update")){
			return set;
		}else if(set.trim().toLowerCase().startsWith("set")){
			return head+set;
		}else{
			return head+" set "+set;
		}
	}
	public String getDeleteSql(String where) {
		String head = "delete * from "+getTableName();
		if(StringUtils.isEmpty(where, true)){
			return head;
		}else if(where.trim().toLowerCase().startsWith("select")){
			return where;
		}else if(where.trim().toLowerCase().startsWith("where")){
			return head+" "+where;
		}else{
			return head+" where "+where;
		}
	}
}