Hibernate动态筑表

Hibernate动态建表
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背景：由于项目特殊的应用场景，需要实现一个动态创建表的功能。
基本思路：
    查了一些资料同时结合到项目里用到了hibernate，就想到利用hibernate的SchemaExport 来实现动态建表

• 设计两个javabean：FormTable(表的基本属性)、ColumnAttribute（列的基本属性），实现一对多的关系
• Freemaker 可以根据定义好的模板生成 hibernate配置文件

提供完整的源代码下载见附件：dynamic_db_table

lib文件比较多，就不提供了下载了，提供一个lib文件的截图如下：

下面是本人测试的主要代码的片段:

package com.michael;

import java.util.ArrayList;
import java.util.List;

import com.michael.vo.ColumnAttribute;
import com.michael.vo.FormTable;

/**
 * @author Michael
 * 
 */
public class TestMain {
    /**
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
        TestMain test = new TestMain();
        FormTable fromTable = test.initData();

        TableGenerator tg = new TableGenerator(fromTable);
        tg.generatorTable();

    }

    /**
     * 初始化数据
     * @return
     */
    private FormTable initData() {
        FormTable form = new FormTable();
        form.setName("testTable");
        form.setTableName("TB_GEN");

        List<ColumnAttribute> list = new ArrayList<ColumnAttribute>();
        ColumnAttribute attr = new ColumnAttribute();
        attr.setName("collectKey");
        attr.setColumnType("string");
        attr.setColumnName("COLLECTKEY");
        attr.setLength(100);
        list.add(attr);
        ColumnAttribute attr1 = new ColumnAttribute();
        attr1.setName("mibVal");
        attr1.setColumnType("string");
        attr1.setColumnName("MIBVAL");
        attr1.setLength(100);
        list.add(attr1);
        ColumnAttribute attr2 = new ColumnAttribute();
        attr2.setName("dsname");
        attr2.setColumnType("string");
        attr2.setColumnName("DSNAME");
        attr2.setLength(100);
        list.add(attr2);
        ColumnAttribute attr3 = new ColumnAttribute();
        attr3.setName("timestamp");
        attr3.setColumnType("long");
        attr3.setColumnName("TIMESTAMP");
        list.add(attr3);
        form.setFormAttributeList(list);
        return form;
    }

}

TableGenerator.java

package com.michael;

import java.io.StringWriter;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import javax.sql.DataSource;

import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;

import com.michael.vo.FormTable;

import freemarker.template.Template;

/**
 * @author Michael
 * 
 */
public class TableGenerator {

    /**
     * tableVo
     */
    private FormTable tableVo;

    /**
     * 脚本文件
     */
    private String scriptFileName = "d:/test/table.sql";

    /**
     * 构造函数
     * @param tableVo
     */
    public TableGenerator(FormTable tableVo) {
        this.tableVo = tableVo;
    }

    /**
     * 构造函数
     * @param tableVo
     * @param scriptFileName
     */
    public TableGenerator(FormTable tableVo, String scriptFileName) {
        this.tableVo = tableVo;
        if (null != scriptFileName && !"".equals(scriptFileName)) {
            this.scriptFileName = scriptFileName;
        }
    }

    /**
     * 
     */
    public void generatorTable() {
        if (tableVo.getColumnAttrList().isEmpty()) {
            System.out.println(" column attr list size==0 ");
            return;
        }

        Template tl;
        try {
            Map<String, Object> paramMap = new HashMap<String, Object>();
            paramMap.put("entity", tableVo);

            tl = getTemplateConfig("/com/michael/ftl").getTemplate(
                    "template.hb.ftl");
            Writer out = new StringWriter();
            tl.process(paramMap, out);
            String hbxml = out.toString();
            System.out.println(hbxml);
            Configuration hbcfg = this.getHibernateCfg(hbxml);

            // Properties pp = CommonUtil
            // .getPropertiesByResource(Constant.PPFILENAME);
            // DataSource ds = BasicDataSourceFactory.createDataSource(pp);

            createDbTableByCfg(hbcfg);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取freemarker的cfg
     * @param resource
     * @return Configuration
     */
    protected freemarker.template.Configuration getTemplateConfig(
            String resource) {

        freemarker.template.Configuration cfg = new freemarker.template.Configuration();
        cfg.setDefaultEncoding("UTF-8");
        cfg.setClassForTemplateLoading(this.getClass(), resource);
        return cfg;
    }

    /**
     * 处理hibernate的配置文件
     * @param resource
     */
    protected Configuration getHibernateCfg(String hbxml) {
        org.hibernate.cfg.Configuration hbcfg = new org.hibernate.cfg.Configuration();
        hbcfg.configure("/hibernate.cfg.xml");
        Properties extraProp = new Properties();
        extraProp.put("hibernate.hbm2ddl.auto", "update");
        hbcfg.addProperties(extraProp);
        hbcfg.addXML(hbxml);
        return hbcfg;
    }

    /**
     * 根据hibernate cfg配置文件动态建表
     * @param hbcfg
     */
    public void createDbTableByCfg(Configuration hbcfg) {
        SchemaExport schemaExport;
        try {
            schemaExport = new SchemaExport(hbcfg);
            // 设置脚本文件
            schemaExport.setOutputFile(scriptFileName);
            schemaExport.create(true, true);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 根据配置文件、Connection 来动态建表
     * @param conf
     * @param ds
     */
    public void createDbTableByConn(Configuration conf, DataSource ds) {
        SchemaExport schemaExport;
        try {

            schemaExport = new SchemaExport(conf, ds.getConnection());
            schemaExport.setOutputFile(scriptFileName);
            schemaExport.create(true, true);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

Hibernate配置模板template.hb.ftl

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping 
  PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
         "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
    <class
        name="${entity.name}"
        table="${entity.tableName}"
        dynamic-update="false"
        dynamic-insert="false"
        select-before-update="false"
        optimistic-lock="version">
        <id
            name="id"
            column="ID"
            type="long"
            unsaved-value="null">
            <generator class="native" />
        </id>
        <#if entity.columnAttrList?exists>
            <#list entity.columnAttrList as attr>
                <#if attr.name == "id">                
                <#elseif attr.columnType=="string">
        <property
            name="${attr.name}"
            type="java.lang.String"
            update="true"
            insert="true"
            access="property"
            column="${attr.columnName}"
            length="${attr.length}"
            not-null="false"
            unique="false"
        />
        <#else>
        <property
            name="${attr.name}"
            type="${attr.columnType}"
            update="true"
            insert="true"
            access="property"
            column="`${attr.columnName}`"
            not-null="false"
            unique="false"
        />
        
                </#if>
            </#list>
        </#if>
    </class>
</hibernate-mapping>

运行的log信息如下：
2010-12-12 13:57:28 org.hibernate.cfg.Environment <clinit>
信息: Hibernate 3.2.5
2010-12-12 13:57:28 org.hibernate.cfg.Environment <clinit>
信息: hibernate.properties not found
2010-12-12 13:57:28 org.hibernate.cfg.Environment buildBytecodeProvider
信息: Bytecode provider name : cglib
2010-12-12 13:57:28 org.hibernate.cfg.Environment <clinit>
信息: using JDK 1.4 java.sql.Timestamp handling
2010-12-12 13:57:28 org.hibernate.cfg.Configuration configure
信息: configuring from resource: /hibernate.cfg.xml
2010-12-12 13:57:28 org.hibernate.cfg.Configuration getConfigurationInputStream
信息: Configuration resource: /hibernate.cfg.xml
2010-12-12 13:57:29 org.hibernate.cfg.Configuration doConfigure
信息: Configured SessionFactory: null
2010-12-12 13:57:29 org.hibernate.cfg.HbmBinder bindRootPersistentClassCommonValues
信息: Mapping class: testTable -> TB_GEN
2010-12-12 13:57:29 org.hibernate.dialect.Dialect <init>
信息: Using dialect: org.hibernate.dialect.MySQL5Dialect
2010-12-12 13:57:29 org.hibernate.tool.hbm2ddl.SchemaExport execute
信息: Running hbm2ddl schema export
2010-12-12 13:57:29 org.hibernate.tool.hbm2ddl.SchemaExport execute
信息: writing generated schema to file: d:/test/table.sql
2010-12-12 13:57:29 org.hibernate.tool.hbm2ddl.SchemaExport execute
信息: exporting generated schema to database
2010-12-12 13:57:29 org.hibernate.connection.DriverManagerConnectionProvider configure
信息: Using Hibernate built-in connection pool (not for production use!)
2010-12-12 13:57:29 org.hibernate.connection.DriverManagerConnectionProvider configure
信息: Hibernate connection pool size: 20
2010-12-12 13:57:29 org.hibernate.connection.DriverManagerConnectionProvider configure
信息: autocommit mode: false
2010-12-12 13:57:29 org.hibernate.connection.DriverManagerConnectionProvider configure
信息: using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://localhost/jsnmp
2010-12-12 13:57:29 org.hibernate.connection.DriverManagerConnectionProvider configure
信息: connection properties: {user=root, password=****}
drop table if exists TB_GEN
create table TB_GEN (ID bigint not null auto_increment, COLLECTKEY varchar(100), MIBVAL varchar(100), DSNAME varchar(100), `TIMESTAMP` bigint, primary key (ID))
2010-12-12 13:57:30 org.hibernate.tool.hbm2ddl.SchemaExport execute
信息: schema export complete
2010-12-12 13:57:30 org.hibernate.connection.DriverManagerConnectionProvider close
信息: cleaning up connection pool: jdbc:mysql://localhost/jsnmp

生成的脚本文件d:/test/table.sql：

drop table if exists TB_GEN
create table TB_GEN (ID bigint not null auto_increment, COLLECTKEY varchar(100), 
MIBVAL varchar(100), DSNAME varchar(100), `TIMESTAMP` bigint, primary key (ID))

本程序是在mysql5上测试的：


运行测试代码后查看表情况：

从上面截图比较可见已经成功创建好表： tb_gen.