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

淩亂°似流年 2022-06-04 02:52 1607阅读 0赞

**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:

![20171202160834561][]

然后运行MBG，查看生成的代码

![20171202161207867][]

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);
            }
        }

[20171202160834561]: /images/20220604/f2117e5e30164a1ead97ff9d38a58321.png
[20171202161207867]: /images/20220604/927821a4cdf74f47a7d745219cd47f82.png