利用JDBC生成数据库表对应的Class

简单的实现了Hibernate工具自动生成Class文件的功能。

 

 

package com.xiva.demo.util;

import java.io.File;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Types;

import org.apache.commons.io.FileUtils;

/**
 * 
 * <功能简述> <详细描述>
 * 
 * @author XIVA
 * @version [1.0, 2013-5-1]
 * @see [相关类/方法]
 * @since [产品、模块版本]
 */
public class GenarateDomainClass
{

    private static Connection conn;

    private static StringBuffer classString;

    private static String lineSep = System.getProperty("line.separator");

    private static String fileName;

    static
    {
        try
        {
            Class.forName("org.gjt.mm.mysql.Driver");
        }
        catch (ClassNotFoundException e)
        {
            e.printStackTrace();
        }
    }

    private static void ininConn() throws SQLException
    {
        conn = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/blogsysdb?useUnicode=true&amp;characterEncoding=utf-8", "blogdb",
                "blogdb");
    }

    private static String getDataType(int type, int scale)
    {
        String dataType = "";

        switch (type)
        {
            case Types.LONGVARCHAR: // -1
                dataType = "Long";
                break;
            case Types.CHAR: // 1
                dataType = "Character";
                break;
            case Types.NUMERIC: // 2
                switch (scale)
                {
                    case 0:
                        dataType = "Number";
                        break;
                    case -127:
                        dataType = "Float";
                        break;
                    default:
                        dataType = "Number";
                }
                break;
            case Types.VARCHAR: // 12
                dataType = "String";
                break;
            case Types.DATE: // 91
                dataType = "Date";
                break;
            case Types.TIMESTAMP: // 93
                dataType = "Date";
                break;
            case Types.BLOB:
                dataType = "Blob";
                break;
            default:
                dataType = "String";
        }
        return dataType;
    }

    private static void queryTable(String tableName) throws SQLException
    {

        PreparedStatement preStat = conn.prepareStatement("select * from " + tableName);
        ResultSet result = preStat.executeQuery();
        ResultSetMetaData resultMeta = result.getMetaData();
        int colCount = resultMeta.getColumnCount();
        String clazzName = convertName(tableName, true);
        classString.append("public class " + clazzName + " extends BaseEntity {").append(lineSep);
        fileName = clazzName;
        for (int i = 1; i <= colCount; i++)
        {
            String dbColName = resultMeta.getColumnName(i);
            String colType = getDataType(resultMeta.getColumnType(i), resultMeta.getScale(i));
            String colName = convertName(dbColName, false);
            if (!dbColName.equals(colName))
            {
                classString.append("@Column(name = \"" + dbColName + "\")").append(lineSep);
            }
            classString.append("private " + colType + " " + colName + ";").append(lineSep);
        }
        classString.append("}");
    }

    private static String convertName(String dbname, boolean isTable)
    {
        StringBuffer className = new StringBuffer(32);

        String dbNameLow = dbname.toLowerCase();
        String[] names = dbNameLow.split("_");
        int len = names.length;
        if (len > 1)
        {
            for (int i = 0; i < len; i++)
            {
                String name = names[i];
                if (i == 0 && !isTable)
                {
                    className.append(name);
                    continue;
                }
                className.append(name.substring(0, 1).toUpperCase());
                className.append(name.substring(1));
            }
        }
        else
        {
            className.append(dbNameLow);
        }

        return className.toString();
    }

    public static void ininData(String tableName)
    {
        classString = new StringBuffer(1024);
        classString.append("package com.xiva.domain;").append(lineSep);
        classString.append(lineSep);
        classString.append("@Entity").append(lineSep);
        classString.append("@Table(name = \"" + tableName + "\")").append(lineSep);
    }

    public static void createFile(String path)
    {
        String filePath = path + File.separator + fileName + ".java";
        File file = new File(filePath);
        try
        {
            System.out.println(filePath);
            boolean isCreate = file.createNewFile();
            System.out.println(isCreate);
            FileUtils.write(file, classString, "utf-8");
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }

    /**
     * 
     * @param args
     */
    public static void main(String[] args) throws SQLException
    {
        String tableName = "iv_resource";
        String path = "F:\\WorkSpace\\GitProjects\\xivamsys\\src\\com\\xiva\\domain";
        ininConn();
        ininData(tableName);
        queryTable(tableName);
        createFile(path);
        System.out.println(classString);
    }

}

 

 

生成结果如下所示：

 

package com.xiva.domain;

@Entity
@Table(name = "iv_function")
public class IvFunction extends BaseEntity {
@Column(name = "func_id")
private String funcId;
@Column(name = "func_name")
private String funcName;
@Column(name = "func_desc")
private String funcDesc;
}

 get set 的生成可以通过ctrl + shift + s快捷生成。导入的类，可以通过Ctrl + shift + o,格式化可以通过Ctrl + shift + f；文件路径可以指定。