cast.java

根据提供的XML Schema文件

			current = (Element) simple.item(i);// 遍历该链表
			currenttype = (Element) current.getElementsByTagName("restriction")
					.item(0);// 取约束条件
			simpleType.put(current.getAttribute("name"), currenttype
					.getAttribute("base"));// 取数据类型信息，保存在hash表中
		}
		simpleType.put("string", "string");// 添加上基本的数据类型，目前只支持这几种，这样文件中所有的数据类型都应该映射为这几种基本的类型
		simpleType.put("date", "date");
		simpleType.put("integer", "integer");
		simpleType.put("float", "float");
		return simple;
	}

	private void castToSql() {
		Iterator<String> output = complexType.keySet().iterator();
		while (output.hasNext()) {
			String tablename = output.next();// 取出表名
			String tabletype = complexType.get(tablename);// 取出表类型名
			/*
			 * Iterator<String> tempi = tableType.keySet().iterator();
			 * while(tempi.hasNext()) { System.out.println(tempi.next()); }
			 */
			if (!tableType.containsKey(tabletype))
				continue;
			HashMap<String, String> content = tableType.get(tabletype);// 取出表项内容
			if (tablename.startsWith("#")) {
				content.remove("ParentID");
				tablename = tablename.substring(1);
			}
			sql += "if exists \r\n (select 1 \r\n from  sysobjects \r\n where id = object_id('"
					+ tablename
					+ "') and   type = 'U') \r\n drop table "
					+ tablename
					+ "\r\ngo \r\n\r\n"
					+ "create table "
					+ tablename + " (\r\n";// 如果该表以及存在，首先要删除同名的表，在创建该表

			Iterator<String> attricontent = content.keySet().iterator();
			ArrayList<String> keyname = key.get(tabletype);
			ArrayList<String[]> rest = restriction.get(tabletype);
			while (attricontent.hasNext()) {
				String name = attricontent.next();
				String type = content.get(name);
				if (type.equalsIgnoreCase("integer"))
					type = "int";
				else if (type.equalsIgnoreCase("date"))
					type = "datetime";
				else if (type.equalsIgnoreCase("string"))
					type = "varchar(30)";// 字符串统一成长度为30的可变长字符串类型存储
				sql += " " + name + " " + type;
				if (name.equals("ID"))
					sql += " IDENTITY(1,1)";
				if (name.equals("ID") || keyname != null
						&& keyname.contains(name))
					sql += " not null,\r\n";
				else
					sql += " null,\r\n";
			}
			sql += " constraint PK_" + tablename.toUpperCase()
					+ " primary key  (ID)";
			if (rest != null)// 以下为生成约束条件的建表语句
				for (int i = 0; i < rest.size(); i++) {
					String[] currentrest = rest.get(i);
					String temp = "";
					if (!currentrest[1].equals("-1"))
						temp += currentrest[0] + " >= " + currentrest[1]
								+ " and ";
					if (!currentrest[2].equals("-1"))
						temp += currentrest[0] + " <= " + currentrest[2]
								+ " and ";
					if (!currentrest[3].equals("-1"))
						temp += currentrest[0] + " in " + currentrest[3]
								+ " and ";
					if (!currentrest[4].equals("-1"))
						temp += currentrest[0] + " like " + "'"
								+ currentrest[4] + "'" + " and ";
					if (temp.equals(""))
						continue;
					sql += ",\r\n constraint CK_"
						+ currentrest[0].toUpperCase() + " check("+temp.substring(0, temp.length() - 5) + ")";
				}

			sql += "\r\n) \r\ngo \r\n\r\n";// \r\n作为换行,可实现回车换行
		}
	}

	public void generate() throws Exception {
		castToSql();
		FileWriter myFile = new FileWriter(schemafile.substring(0, schemafile
				.length() - 4)
				+ ".sql");
		myFile.write(sql);// 写入文件
		myFile.close();// 关闭文件
		// System.out.println(sql);
	}

	public void store(String xmlfile) throws Exception {// 指定xmlfile文件，该xml文件应该是符合实例化该实例的xml
		// shema文件规定的合式的xml文件，该方法应该生成一个sql文件，其中包含了存储该xml文件内数据的insert语句
		Element rootElement = getRoot(xmlfile);
		String sql = "";
		sql += generateInsertSql(rootElement, null, 1);
		if (!sql.equals("")) {
			FileWriter myFile = new FileWriter(xmlfile.substring(0, xmlfile
					.length() - 4)
					+ ".sql");
			myFile.write(sql);// 写入文件
			myFile.close();// 关闭文件
			// System.out.println(sql);
		}
	}

	private String generateInsertSql(Element root, String ParentTable,
			int sequence) throws ParserConfigurationException {// 递归生成存储xml文件中数据的插入语句的函数，root是xml中的某级结点，ParentTable是其父亲节点的表名称，sequence是有序属性的顺序值
		String rootname = root.getNodeName();
		String insertsql = "";
		String pre = "";
		String varname = "@" + root.hashCode() + sequence;// 以节点的哈希值加节点顺值作为存储其父亲节点ID值的sql变量名
		if (tableType.containsKey(complexType.get(rootname))
				|| tableType.containsKey(complexType.get("#" + rootname))) {// 如果元素名对应的表存在
			if (tableType.containsKey(complexType.get("#" + rootname)))
				rootname = "#" + rootname;
			// 遍历对应的属性集合
			HashMap<String, String> attriset = tableType.get(complexType
					.get(rootname));
			Iterator<String> output = attriset.keySet().iterator();
			while (output.hasNext()) {
				String attriname = output.next();// 取出属性名
				if (attriname.equals("ID"))
					continue;// ID是自增字段，不用处理
				if (attriname.equals("sequence")) {// 如果是顺序值，从参数知
					insertsql += " " + sequence + ", ";
					continue;
				}
				if (attriname.equals("ParentID")) {// 如果是父亲节点ID值，加上sql变量名
					if (rootname.startsWith("#"))
						continue;
					if (ParentTable != null) {// 如果父亲节点存在，首先需要写入计算父亲节点ID值的sql语句，以备作为其ParentID的值
						pre += "DECLARE " + varname + " INT \r\nselect "
								+ varname + " = count(*) from " + ParentTable
								+ "\r\n";
					}
					insertsql += " " + varname + ", ";
					continue;
				}
				String attritype = attriset.get(attriname);// 取出属性的数据类型
				if (!root.getAttribute(attriname).equals("")) {// 如果为节点的属性
					if (attritype.equals("string") || attritype.equals("date"))
						insertsql += " '" + root.getAttribute(attriname)
								+ "', ";
					else
						insertsql += " " + root.getAttribute(attriname) + ", ";
				} else {// 否则，应该是子节点中的内容
					String con = root.getElementsByTagName(attriname).item(0)
							.getFirstChild().getNodeValue();
					if (attritype.equals("string") || attritype.equals("date"))
						insertsql += " '" + con + "', ";
					else
						insertsql += " " + con + ", ";
				}
			}
			// 遍历完成之后，应该所有的属性均转化成为了插入值
			if (rootname.startsWith("#"))
				rootname = rootname.substring(1);
			insertsql = "insert into " + rootname + " values ("
					+ insertsql.substring(0, insertsql.length() - 2) + ")\r\n";
			if (!pre.equals(""))
				insertsql = pre + insertsql;

			// 接着处理外键信息
			NodeList childnode = root.getChildNodes();
			ArrayList<String> keyrefattri = new ArrayList<String>();
			String tableName = null;
			for (int i = 1; i < childnode.getLength(); i += 2) {
				String attriname = childnode.item(i).getNodeName();// 取出属性名
				if (keyrefToTableName.containsKey(attriname)) {// 如果是一个外键
					tableName = keyrefToTableName.get(attriname);// 取出表名
					if (attriset.containsKey(attriname)
							&& tableName.equals(rootname))
						break;// 需要跳出自己的递归
					if (!keyrefattri.contains(attriname))
						keyrefattri.add(attriname);
				}
			}
			if (keyrefattri.size() != 0) {
				NodeList[] keyreflist = new NodeList[keyrefattri.size()];
				for (int i = 0; i < keyrefattri.size(); i++) {
					keyreflist[i] = root.getElementsByTagName(keyrefattri
							.get(i));
				}
				for (int i = 0; i < keyreflist[0].getLength(); i++) {
					HashMap<String,Node> a = new HashMap<String,Node>();
					for (int j = 0; j < keyreflist.length; j++)
						a.put(keyrefattri.get(j),keyreflist[j].item(i));
					insertsql += insertRef(a, tableName, rootname, i);
				}
			}
		}
		//处理非属性的子节点，递归调用该函数
		NodeList child = root.getChildNodes();
		if (insertsql.equals(""))
			for (int i = 1; i < child.getLength(); i += 2)
				insertsql += generateInsertSql((Element) child.item(i),
						ParentTable, (i-1)/2+1);
		else
			for (int i = 1; i < child.getLength(); i += 2)
				insertsql += generateInsertSql((Element) child.item(i),
						rootname, (i-1)/2+1);
		return insertsql;
	}

	private String insertRef(HashMap<String,Node> a, String tableName,
			String ParentTable, int sequence) {//处理外键关系表的数据的插入sql语句的生成函数
		String insertsql = "";
		String pre = "";
		String varname = "@" + a.hashCode() + sequence;
		HashMap<String, String> attriset = tableType.get(complexType
				.get(tableName));
		Iterator<String> output = attriset.keySet().iterator();
		while (output.hasNext()) {
			String attriname = output.next();// 取出属性名
			if (attriname.equals("ID"))
				continue;// ID是自增字段，不用处理
			if (attriname.equals("sequence")) {// 如果是顺序值，从参数知
				insertsql += " " + sequence + ", ";
				continue;
			}
			if (attriname.equals("ParentID")) {// 如果是父亲节点ID值，加上sql变量名
				pre += "DECLARE " + varname + " INT \r\nselect " + varname
						+ " = count(*) from " + ParentTable + "\r\n";
				insertsql += " " + varname + ", ";
				continue;
			}
			String attritype = attriset.get(attriname);// 取出属性的数据类型
			String con = a.get(attriname).getFirstChild().getNodeValue();
			if (attritype.equals("string") || attritype.equals("date"))
				insertsql += " '" + con + "', ";
			else
				insertsql += " " + con + ", ";
		}
		insertsql = "insert into " + tableName + " values ("
				+ insertsql.substring(0, insertsql.length() - 2) + ")\r\n";
		if (!pre.equals(""))
			insertsql = pre + insertsql;
		return insertsql;
	}

	public static void main(String[] args) {
		try {
			new Cast("testschema.xml").generate();
			new Cast("testschema.xml").store("test.xml");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}