java 数据库表反向生成相应的java类

 java 数据库表反向生成相应的java类,同时完成了字段和表名中包含下划线的情况。

 

package cn.tongkuan.common;

import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

 
public class TableToJavaBean {

	private static final String LINE = "\r\n";
	private static final String TAB = "\t";
	String packages = this.getClass().getPackage().getName().replace("common", "model");;
	private static Map<String, String> map;

	static {
		map = new HashMap<String, String>();
		map.put("VARCHAR", "String");
		map.put("INTEGER", "Integer");
		map.put("FLOAT", "float");
		map.put("TIMESTAMP", "Date");
		map.put("CHAR", "String");
		map.put("DATETIME", "Date");
		map.put("TIMESTAMP_IMPORT", "import java.util.Date");
		map.put("DATETIME_IMPORT","import java.util.Date");
	}

	public static String getPojoType(String dataType) {
		StringTokenizer st = new StringTokenizer(dataType);
		return map.get(st.nextToken());
	}
	
	public static String getImport(String dataType) {
		if (map.get(dataType)==null||"".equals(map.get(dataType))) {
		   return null;	
		}else{
		   return map.get(dataType);
		}
	}

 
	public void tableToBean(Connection connection, String tableName) throws SQLException {
		String sql = "select * from " + tableName + " where 1 <> 1";
		PreparedStatement ps = null;
		ResultSet rs = null;
		ps = connection.prepareStatement(sql);
		rs = ps.executeQuery();
		ResultSetMetaData md = rs.getMetaData();
		int columnCount = md.getColumnCount();
		StringBuffer sb = new StringBuffer();
		tableName = tableName.substring(0, 1).toUpperCase() + tableName.subSequence(1, tableName.length());
		tableName = this.dealLine(tableName);
		sb.append("package " + this.packages + " ;");
		sb.append(LINE);
		importPackage(md, columnCount, sb);
		sb.append(LINE);
		sb.append(LINE);
		sb.append("public class " + tableName + " {");
		sb.append(LINE);
		defProperty(md, columnCount, sb);
		genSetGet(md, columnCount, sb);
		sb.append("}");
		String paths = System.getProperty("user.dir");
		String endPath = paths + "\\src\\" + (packages.replace("/", "\\")).replace(".", "\\");
		buildJavaFile(endPath + "\\" + tableName + ".java", sb.toString());
	}
	//属性生成get、 set 方法
	private void genSetGet(ResultSetMetaData md, int columnCount, StringBuffer sb) throws SQLException {
		for (int i = 1; i <= columnCount; i++) {
			sb.append(TAB);
			String pojoType = getPojoType(md.getColumnTypeName(i));
			String columnName = dealLine(md, i);
			String getName = null;
			String setName = null;
			if (columnName.length() > 1) {
				getName = "public " + pojoType + " get" + columnName.substring(0, 1).toUpperCase()
						+ columnName.substring(1, columnName.length()) + "() {";
				setName = "public void set" + columnName.substring(0, 1).toUpperCase()
						+ columnName.substring(1, columnName.length()) + "(" + pojoType + " " + columnName + ") {";
			} else {
				getName = "public get" + columnName.toUpperCase() + "() {";
				setName = "public set" + columnName.toUpperCase() + "(" + pojoType + " " + columnName + ") {";
			}
			sb.append(LINE).append(TAB).append(getName);
			sb.append(LINE).append(TAB).append(TAB);
			sb.append("return " + columnName + ";");
			sb.append(LINE).append(TAB).append("}");
			sb.append(LINE);
			sb.append(LINE).append(TAB).append(setName);
			sb.append(LINE).append(TAB).append(TAB);
			sb.append("this." + columnName + " = " + columnName + ";");
			sb.append(LINE).append(TAB).append("}");
			sb.append(LINE);

		}
	}
	
	//导入属性所需包
	private void importPackage(ResultSetMetaData md, int columnCount, StringBuffer sb) throws SQLException {
		for (int i = 1; i <= columnCount; i++) {
			String im=getImport(md.getColumnTypeName(i)+"_IMPORT");
			if (im!=null) {
				sb.append(im+ ";");
				sb.append(LINE);
			}
		}
	}
	//属性定义
	private void defProperty(ResultSetMetaData md, int columnCount, StringBuffer sb) throws SQLException {
		
		for (int i = 1; i <= columnCount; i++) {
			sb.append(TAB);
			String columnName = dealLine(md, i);
			sb.append("private " + getPojoType(md.getColumnTypeName(i)) + " " + columnName + ";");
			sb.append(LINE);
		}
	}

	private String dealLine(ResultSetMetaData md, int i) throws SQLException {
		String columnName = md.getColumnName(i);
		// 处理下划线情况，把下划线后一位的字母变大写；
		columnName = dealName(columnName);
		return columnName;
	}

	private String dealLine(String tableName) {
		// 处理下划线情况，把下划线后一位的字母变大写；
		tableName = dealName(tableName);
		return tableName;
	}
	//下划线后一位字母大写
	private String dealName(String columnName) {
		if (columnName.contains("_")) {
			StringBuffer names = new StringBuffer();
			String arrayName[] = columnName.split("_");
			names.append(arrayName[0]);
			for (int i = 1; i < arrayName.length; i++) {
				String arri=arrayName[i];
				String tmp=arri.substring(0, 1).toUpperCase()+ arri.substring(1, arri.length());
				names.append(tmp);
			}
			columnName=names.toString();
		}
		return columnName;
	}
	//生成java文件
	public void buildJavaFile(String filePath, String fileContent) {
		try {
			File file = new File(filePath);
			FileOutputStream osw = new FileOutputStream(file);
			PrintWriter pw = new PrintWriter(osw);
			pw.println(fileContent);
			pw.close();
		} catch (Exception e) {
			System.out.println("生成txt文件出错：" + e.getMessage());
		}
	}

	public static void main(String[] args) throws SQLException, ClassNotFoundException {
		String jdbcString = "jdbc:mysql://192.168.224.1/test";
		Class.forName("com.mysql.jdbc.Driver");
		Connection con = DriverManager.getConnection(jdbcString, "root", "root");
		DatabaseMetaData databaseMetaData = con.getMetaData();
		String[] tableType = { "TABLE" };
		ResultSet rs = databaseMetaData.getTables(null, null, "%",tableType);
		TableToJavaBean d = new TableToJavaBean();
		while(rs.next()){
			String tableName=rs.getString(3).toString();
			d.tableToBean(con,tableName);
		}
	}
}

 

评论

3 楼 杰克穷死s 2013-11-10  

还不错，用了，哈，那个好像数据库是int 类型的话，生成的类属性是null的。在静态块里加上int就行了，真是太好用了。

2 楼 不念书的小子 2013-01-08  

冷剑豪 写道

嘿嘿嘿，把你的这部分偷走了，做了一个数据库自动生成实体类的工具类，谢谢哈！不过你的这个有好多地方需要改进呢！

1 楼 冷剑豪 2012-12-28  

嘿嘿嘿，把你的这部分偷走了，做了一个数据库自动生成实体类的工具类，谢谢哈！不过你的这个有好多地方需要改进呢！