MyBatis Generator系列(六)----MyBatis Generator Plugin插件之SerializablePlugin

一、SerializablePlugin插件简介

很多时候我们创建的bean需要实现序列化，所有要实现Serializable类，所以MyBatis Generator为我们提供了SerializablePlugin插件用来在代码生成时实现序列化。

二、SerializablePlugin使用

在generatorConfig.xml中配置SerializablePlugin插件:

<plugin type="org.mybatis.generator.plugins.SerializablePlugin" />

然后运行MBG，查看生成的代码

会发现实现了Serializable接口，并增加了private static final long serialVersionUID = 1L;

三、SerializablePlugin源码

SerializablePlugin的代码：

package org.mybatis.generator.plugins;import java.util.List;import java.util.Properties;import org.mybatis.generator.api.PluginAdapter;import org.mybatis.generator.api.IntrospectedTable;import org.mybatis.generator.api.dom.java.Field;import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;import org.mybatis.generator.api.dom.java.JavaVisibility;import org.mybatis.generator.api.dom.java.TopLevelClass;/** * This plugin adds the java.io.Serializable marker interface to all generated * model objects. * <p> * This plugin demonstrates adding capabilities to generated Java artifacts, and * shows the proper way to add imports to a compilation unit. * <p> * Important: This is a simplistic implementation of serializable and does not * attempt to do any versioning of classes. *  * @author Jeff Butler *  */public class SerializablePlugin extends PluginAdapter {    private FullyQualifiedJavaType serializable;      //对应java.io.Serializable的java类型    private FullyQualifiedJavaType gwtSerializable;   //对应com.google.gwt.user.client.rpc.IsSerializable的java类型    private boolean addGWTInterface;                  //是否实现com.google.gwt.user.client.rpc.IsSerializable接口          private boolean suppressJavaInterface;            //是否实现java.io.Serializable接口    public SerializablePlugin() {        super();        serializable = new FullyQualifiedJavaType("java.io.Serializable"); //$NON-NLS-1$ 实例化        gwtSerializable = new FullyQualifiedJavaType("com.google.gwt.user.client.rpc.IsSerializable"); //$NON-NLS-1$ 实例化      }    public boolean validate(List<String> warnings) {        // this plugin is always valid        return true;    }    @Override    public void setProperties(Properties properties) {        super.setProperties(properties);        addGWTInterface = Boolean.valueOf(properties.getProperty("addGWTInterface")); //$NON-NLS-1$        suppressJavaInterface = Boolean.valueOf(properties.getProperty("suppressJavaInterface")); //$NON-NLS-1$    }        @Override    public boolean modelBaseRecordClassGenerated(TopLevelClass topLevelClass,            IntrospectedTable introspectedTable) {        makeSerializable(topLevelClass, introspectedTable);        return true;    }    @Override    public boolean modelPrimaryKeyClassGenerated(TopLevelClass topLevelClass,            IntrospectedTable introspectedTable) {        makeSerializable(topLevelClass, introspectedTable);        return true;    }    @Override    public boolean modelRecordWithBLOBsClassGenerated(            TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {        makeSerializable(topLevelClass, introspectedTable);        return true;    }    /**     *      *@Title makeSerializable      *@Description: 添加序列化     *@Author fendo     *@Date 2017年12月2日 下午4:15:20     *@param topLevelClass     *@param introspectedTable     *@throws     */    protected void makeSerializable(TopLevelClass topLevelClass,            IntrospectedTable introspectedTable) {            if (addGWTInterface) {  //是否要实现com.google.gwt.user.client.rpc.IsSerializable接口             topLevelClass.addImportedType(gwtSerializable);   //import com.google.gwt.user.client.rpc.IsSerializable;            topLevelClass.addSuperInterface(gwtSerializable); //实现接口        }                if (!suppressJavaInterface) {                      //不禁止实现java.io.Serializable             topLevelClass.addImportedType(serializable);   //import java.io.Serializable;            topLevelClass.addSuperInterface(serializable); //实现java.io.Serializable接口            //添加serialVersionUID字段              //最终生成代码private static final long serialVersionUID = 1L;            Field field = new Field();            field.setFinal(true);    //添加final修饰            field.setInitializationString("1L"); //$NON-NLS-1$  赋值为1L            field.setName("serialVersionUID"); //$NON-NLS-1$    设置字段名称为serialVersionUID            field.setStatic(true);  //添加static关键字             field.setType(new FullyQualifiedJavaType("long")); //$NON-NLS-1$  声明类型              field.setVisibility(JavaVisibility.PRIVATE);//声明为私有            context.getCommentGenerator().addFieldComment(field, introspectedTable); //生成注解             //把拼装好的方法DOM添加到topLevelClass中，完成接口的实现和字段的添加             topLevelClass.addField(field);        }    }}

首先是继承PluginAdapter，然后调用validate不需要参数，所以直接返回true，然后通过setProperties方法

@Override  public void setProperties(Properties properties) {      super.setProperties(properties);      addGWTInterface = Boolean.valueOf(properties.getProperty("addGWTInterface")); //$NON-NLS-1$      suppressJavaInterface = Boolean.valueOf(properties.getProperty("suppressJavaInterface")); //$NON-NLS-1$  }  

获取addGWTInterface 和 suppressJavaInterface参数，给成员变量赋值。然后通过modelBaseRecordClassGenerated

@Override  public boolean modelBaseRecordClassGenerated(TopLevelClass topLevelClass,          IntrospectedTable introspectedTable) {      makeSerializable(topLevelClass, introspectedTable);      return true;  }  

调用makeSerializable方法，给BaeRecordClass添加序列化接口。

@Override  public boolean modelPrimaryKeyClassGenerated(TopLevelClass topLevelClass,          IntrospectedTable introspectedTable) {      makeSerializable(topLevelClass, introspectedTable);      return true;  } 

通过modelPrimaryKeyClassGenerated调用makeSerializable方法给PrimaryKeyClass添加序列化接口。

@Override  public boolean modelRecordWithBLOBsClassGenerated(          TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {      makeSerializable(topLevelClass, introspectedTable);      return true;  } 

通过modelRecordWithBLOBsClassGenerated调用makeSerializable方法给RecordWithBLOBsClass添加序列化接口。

添加序列化方法如下:

    /**     *      *@Title makeSerializable      *@Description: 添加序列化     *@Author fendo     *@Date 2017年12月2日 下午4:15:20     *@param topLevelClass     *@param introspectedTable     *@throws     */    protected void makeSerializable(TopLevelClass topLevelClass,            IntrospectedTable introspectedTable) {            if (addGWTInterface) {  //是否要实现com.google.gwt.user.client.rpc.IsSerializable接口             topLevelClass.addImportedType(gwtSerializable);   //import com.google.gwt.user.client.rpc.IsSerializable;            topLevelClass.addSuperInterface(gwtSerializable); //实现接口        }                if (!suppressJavaInterface) {                      //不禁止实现java.io.Serializable             topLevelClass.addImportedType(serializable);   //import java.io.Serializable;            topLevelClass.addSuperInterface(serializable); //实现java.io.Serializable接口            //添加serialVersionUID字段              //最终生成代码private static final long serialVersionUID = 1L;            Field field = new Field();            field.setFinal(true);    //添加final修饰            field.setInitializationString("1L"); //$NON-NLS-1$  赋值为1L            field.setName("serialVersionUID"); //$NON-NLS-1$    设置字段名称为serialVersionUID            field.setStatic(true);  //添加static关键字             field.setType(new FullyQualifiedJavaType("long")); //$NON-NLS-1$  声明类型              field.setVisibility(JavaVisibility.PRIVATE);//声明为私有            context.getCommentGenerator().addFieldComment(field, introspectedTable); //生成注解             //把拼装好的方法DOM添加到topLevelClass中，完成接口的实现和字段的添加             topLevelClass.addField(field);        }    }