一个自动生成Hibernate ORM映射文件的工具函数

没啥，前几天有人问我如何生成Hibernate的映射文件，我随口说，就那点儿东西，自己随便写个函数不就得了，谁知对方这伙计有够懒，直接就开口说兄弟帮忙了，无奈之下随手应付了一个



import java.io.FileWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.sql.Types;
import java.util.Date;

public class ConfigGenerator
...{

    public static void main(String[] args) throws Exception
    ...{
        String table_name = "user_list";
        String root_path = "C:/";
        String pkgName = "lld.test.hibernate";
        Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
        DriverManager.registerDriver(new com.microsoft.jdbc.sqlserver.SQLServerDriver());
        Connection conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=test", "sa", "sa");
        System.out.println("connected to database successfully.");
        Statement st = conn.createStatement();
        String sql = "select * from " + table_name + " where 1 = 2";
        ResultSet rs = st.executeQuery(sql);
        ResultSetMetaData meta = rs.getMetaData();
        String hbmFile = getHbmFile(root_path, table_name);
        String beanFile = getBeanFile(root_path, table_name);
        System.out.println("output hbm file: " + hbmFile);
        System.out.println("output bean file: " + beanFile);
        
        String beanName = getBeanName(table_name);
        FileWriter outHbm = new FileWriter(hbmFile);
        FileWriter outBean = new FileWriter(beanFile);
        outHbm.write("<?xml version="1.0" encoding="UTF-8"?>");
        outHbm.write(" ");
        outHbm.write("<!DOCTYPE hibernate-mapping PUBLIC");
        outHbm.write(" ");
        outHbm.write("    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"");
        outHbm.write(" ");
        outHbm.write("    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">");
        outHbm.write(" ");
        outHbm.write("<hibernate-mapping>");
        outHbm.write(" ");
        outHbm.write("    <class name="" + pkgName + "." + beanName + "" table="" + table_name + "">");
        outHbm.write(" ");
        
        outBean.write("package " + pkgName + ";");
        outBean.write(" ");
        outBean.write(" ");
        outBean.write("public class " + beanName);
        outBean.write(" ");
        outBean.write("{");
        outBean.write(" ");
        
        StringBuffer toStr = new StringBuffer();
        
        for(int iCol = 1; iCol <= meta.getColumnCount(); iCol++)
        ...{
            String colName = meta.getColumnName(iCol);
            int colType = meta.getColumnType(iCol);
            String propName = getPropertyName(colName);
            String javaType = getJavaType(colType).getName();
            outHbm.write("        <property name="" + propName + "" column="" + colName + ""/>");
            outHbm.write(" ");
            
            outBean.write("    private " + javaType + " " + propName + ";");
            outBean.write(" ");
            outBean.write(" ");
            outBean.write("    public " + javaType + " " + getGetterMethod(propName) + "()");
            outBean.write(" ");
            outBean.write(" {");
            outBean.write(" ");
            outBean.write("        return this." + propName + ";");
            outBean.write(" ");
            outBean.write(" }");
            outBean.write(" ");
            outBean.write(" ");

            outBean.write("    public void " + getSetterMethod(propName) + "(" + javaType + " " + propName + ")");
            outBean.write(" ");
            outBean.write(" {");
            outBean.write(" ");
            outBean.write("        this." + propName + " = " + propName + ";");
            outBean.write(" ");
            outBean.write(" }");
            outBean.write(" ");
            outBean.write(" ");
            
            toStr.append(""" + propName + " = " + this." + propName + " + "rn" ");
            if(iCol != meta.getColumnCount())
            ...{
                toStr.append("              + ");
            }
                
        }

        outHbm.write("    </class>");
        outHbm.write(" ");
        outHbm.write("</hibernate-mapping>");
        outHbm.flush();
        outHbm.close();
        System.out.println("hbm file generated sucessfully!");

        outBean.write("    @Override");
        outBean.write(" ");
        outBean.write("    public String toString()");
        outBean.write(" ");
        outBean.write("    {");
        outBean.write(" ");
        outBean.write("        return " + toStr.toString() + ";");
        outBean.write(" ");
        outBean.write(" }");
        outBean.write(" ");
        outBean.write("}");
        outBean.flush();
        outBean.close();
        System.out.println("bean file generated sucessfully!");
    }
    
    private static String getHbmFile(String root_path, String table_name)
    ...{
        return root_path + table_name + ".hbm.xml";
    }
    
    private static String getBeanFile(String root_path, String table_name)
    ...{
        String beanName = getBeanName(table_name);
        return root_path + beanName + ".java";
    }
    
    private static String getBeanName(String table_name)
    ...{
        String[] segs = table_name.split("_");
        String beanName = "";
        for(int i = 0; i < segs.length; i++)
        ...{
            beanName += segs[i].substring(0, 1).toUpperCase() + segs[i].substring(1, segs[i].length()).toLowerCase();
        }
        return beanName;
    }

    private static String getPropertyName(String col_name)
    ...{
        String[] segs = col_name.split("_");
        String propName = "";
        for(int i = 0; i < segs.length; i++)
        ...{
            if(i == 0)
                propName += segs[i];
            else
                propName += segs[i].substring(0, 1).toUpperCase() + segs[i].substring(1, segs[i].length()).toLowerCase();
        }
        return propName;
    }

    private static String getGetterMethod(String prop_name)
    ...{
        return "get" + prop_name.substring(0, 1).toUpperCase() + prop_name.substring(1, prop_name.length());
    }

    private static String getSetterMethod(String prop_name)
    ...{
        return "set" + prop_name.substring(0, 1).toUpperCase() + prop_name.substring(1, prop_name.length());
    }
    
    @SuppressWarnings("unchecked")
    private static Class getJavaType(int colType)
    ...{
        switch(colType)
        ...{
            case Types.BIT:
            case Types.TINYINT:
            case Types.SMALLINT:
                return Short.class;
            case Types.INTEGER:
                return Integer.class;
            case Types.BIGINT:
                return Long.class;
            case Types.CHAR:
            case Types.VARCHAR:
            case Types.CLOB:
            case Types.LONGNVARCHAR:
                return String.class;
            case Types.FLOAT:
                return Float.class;
            case Types.DOUBLE:
                return Double.class;
            case Types.DATE:
            case Types.TIME:
            case Types.TIMESTAMP:
                return Date.class;
            default:
                return Object.class;
        }
    }
}