DataDictionaryGenerator.java

/**
 * Copyright (c) 2011-2017, James Zhan 詹波 (jfinal@126.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.jfinal.plugin.activerecord.generator;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.sql.DataSource;
import com.jfinal.kit.LogKit;
import com.jfinal.kit.StrKit;

/**
 * DataDictionary 数据字典生成器
 */
public class DataDictionaryGenerator {
	
	protected DataSource dataSource;
	protected String dataDictionaryOutputDir;
	protected String dataDictionaryFileName = "_DataDictionary.txt";
	
	public DataDictionaryGenerator(DataSource dataSource, String dataDictionaryOutputDir) {
		this.dataSource = dataSource;
		this.dataDictionaryOutputDir = dataDictionaryOutputDir;
	}
	
	public void setDataDictionaryOutputDir(String dataDictionaryOutputDir) {
		if (StrKit.notBlank(dataDictionaryOutputDir)) {
			this.dataDictionaryOutputDir = dataDictionaryOutputDir;
		}
	}
	
	public void setDataDictionaryFileName(String dataDictionaryFileName) {
		if (StrKit.notBlank(dataDictionaryFileName)) {
			this.dataDictionaryFileName = dataDictionaryFileName;
		}
	}
	
	public void generate(List<TableMeta> tableMetas) {
		System.out.println("Generate DataDictionary file ...");
		System.out.println("Data Dictionary Output Dir: " + dataDictionaryOutputDir);
		rebuildColumnMetas(tableMetas);
		
		StringBuilder ret = new StringBuilder();
		for (TableMeta tableMeta : tableMetas) {
			generateTable(tableMeta, ret);
		}
		
		writeToFile(ret);
	}
	
	protected void generateTable(TableMeta tableMeta, StringBuilder ret) {
		ret.append("Table: ").append(tableMeta.name);
		if (StrKit.notBlank(tableMeta.remarks)) {
			ret.append("\tRemarks: ").append(tableMeta.remarks);
		}
		ret.append("\n");
		
		String sparateLine = genSeparateLine(tableMeta);
		ret.append(sparateLine);
		genTableHead(tableMeta, ret);
		ret.append(sparateLine);
		for (ColumnMeta columnMeta : tableMeta.columnMetas) {
			genColumn(tableMeta, columnMeta, ret);
		}
		ret.append(sparateLine);
		ret.append("\n");
	}
	
	/*
	-----------+---------+------+-----+---------+----------------
	 Field     | Type    | Null | Key | Default | Remarks
	-----------+---------+------+-----+---------+----------------
	 id		   | int(11) | NO	| PRI | NULL	| remarks here	
	*/
	protected void genCell(int columnMaxLen, String preChar, String value, String fillChar, String postChar, StringBuilder ret) {
		ret.append(preChar);
		ret.append(value);
		for (int i=0, n=columnMaxLen-value.length() + 1; i<n; i++) {
			ret.append(fillChar);	// 值后的填充字符，值为 " "、"-"
		}
		ret.append(postChar);
	}
	
	protected String genSeparateLine(TableMeta tm) {
		StringBuilder ret = new StringBuilder();
		genCell(tm.colNameMaxLen, "-", "---", "-", "+",  ret);
		genCell(tm.colTypeMaxLen, "-", "---", "-", "+", ret);
		genCell("Null".length(), "-", "---", "-", "+", ret);
		genCell("Key".length(), "-", "---", "-", "+", ret);
		genCell(tm.colDefaultValueMaxLen, "-", "---", "-", "+", ret);
		genCell("Remarks".length(), "-", "---", "-", "", ret);
		ret.append("\n");
		return ret.toString();
	}
	
	protected void genTableHead(TableMeta tm, StringBuilder ret) {
		genCell(tm.colNameMaxLen, " ", "Field", " ", "|",  ret);
		genCell(tm.colTypeMaxLen, " ", "Type", " ", "|", ret);
		genCell("Null".length(), " ", "Null",  " ","|", ret);
		genCell("Key".length(), " ", "Key",  " ","|", ret);
		genCell(tm.colDefaultValueMaxLen, " ", "Default", " ", "|", ret);
		genCell("Remarks".length(), " ", "Remarks", " ", "", ret);
		ret.append("\n");
	}
	
	protected void genColumn(TableMeta tableMeta, ColumnMeta columnMeta, StringBuilder ret) {
		genCell(tableMeta.colNameMaxLen, " ", columnMeta.name, " ", "|",  ret);
		genCell(tableMeta.colTypeMaxLen, " ", columnMeta.type, " ", "|", ret);
		genCell("Null".length(), " ", columnMeta.isNullable, " ", "|", ret);
		genCell("Key".length(), " ", columnMeta.isPrimaryKey, " ", "|", ret);
		genCell(tableMeta.colDefaultValueMaxLen, " ", columnMeta.defaultValue, " ", "|", ret);
		genCell("Remarks".length(), " ", columnMeta.remarks, " ", "", ret);
		ret.append("\n");
	}
	
	protected void rebuildColumnMetas(List<TableMeta> tableMetas) {
		Connection conn = null;
		try {
			conn = dataSource.getConnection();
			DatabaseMetaData dbMeta = conn.getMetaData();
			for (TableMeta tableMeta : tableMetas) {
				// 重建整个 TableMeta.columnMetas
				tableMeta.columnMetas = new ArrayList<ColumnMeta>();
				// 通过查看 dbMeta.getColumns(...) 源码注释，还可以获取到更多 meta data
				ResultSet rs = dbMeta.getColumns(conn.getCatalog(), null, tableMeta.name, null);
				while (rs.next()) {
					ColumnMeta columnMeta = new ColumnMeta();
					columnMeta.name = rs.getString("COLUMN_NAME");			// 名称
					
					columnMeta.type = rs.getString("TYPE_NAME");			// 类型
					if (columnMeta.type == null) {
						columnMeta.type = "";
					}
					
					int columnSize = rs.getInt("COLUMN_SIZE");				// 长度
					if (columnSize > 0) {
						columnMeta.type = columnMeta.type + "(" + columnSize;
						int decimalDigits = rs.getInt("DECIMAL_DIGITS");	// 小数位数
						if (decimalDigits > 0) {
							columnMeta.type = columnMeta.type + "," + decimalDigits;
						}
						columnMeta.type = columnMeta.type + ")";
					}
					
					columnMeta.isNullable = rs.getString("IS_NULLABLE");	// 是否允许 NULL 值
					if (columnMeta.isNullable == null) {
						columnMeta.isNullable = "";
					}
					
					columnMeta.isPrimaryKey = "   ";
					String[] keys = tableMeta.primaryKey.split(",");
					for (String key : keys) {
						if (key.equalsIgnoreCase(columnMeta.name)) {
							columnMeta.isPrimaryKey = "PRI";
							break;
						}
					}
					
					columnMeta.defaultValue = rs.getString("COLUMN_DEF");	// 默认值
					if (columnMeta.defaultValue == null) {
						columnMeta.defaultValue = "";
					}
					
					columnMeta.remarks = rs.getString("REMARKS");			// 备注
					if (columnMeta.remarks == null) {
						columnMeta.remarks = "";
					}
					
					if (tableMeta.colNameMaxLen < columnMeta.name.length()) {
						tableMeta.colNameMaxLen = columnMeta.name.length();
					}
					if (tableMeta.colTypeMaxLen < columnMeta.type.length()) {
						tableMeta.colTypeMaxLen = columnMeta.type.length();
					}
					if (tableMeta.colDefaultValueMaxLen < columnMeta.defaultValue.length()) {
						tableMeta.colDefaultValueMaxLen = columnMeta.defaultValue.length();
					}
					
					tableMeta.columnMetas.add(columnMeta);
				}
				rs.close();
			}
		}
		catch (SQLException e) {
			throw new RuntimeException(e);
		}
		finally {
			if (conn != null) {
				try {conn.close();} catch (SQLException e) {LogKit.error(e.getMessage(), e);}
			}
		}
	}
	
	/**
	 * _DataDictionary.txt 覆盖写入
	 */
	protected void writeToFile(StringBuilder ret) {
		FileWriter fw = null;
		try {
			File dir = new File(dataDictionaryOutputDir);
			if (!dir.exists()) {
				dir.mkdirs();
			}
			
			String target = dataDictionaryOutputDir + File.separator + dataDictionaryFileName;
			fw = new FileWriter(target);
			fw.write(ret.toString());
		}
		catch (IOException e) {
			throw new RuntimeException(e);
		}
		finally {
			if (fw != null) {
				try {fw.close();} catch (IOException e) {LogKit.error(e.getMessage(), e);}
			}
		}
	}
}