MyBatis-generator简单升级

电玩女神 2022-08-28 13:00 192阅读 0赞

## 目的： ##

1.  生成的mapper方法名太长、我想改成自己的风格
2.  实体类集成lombok插件，省去大量get、set方法
3.  生成日期格式化代码：`@JsonFormat(locale = "zh", timezone = "Asia/Shanghai", pattern = "yyyy-MM-dd HH:mm:ss")`
4.  实体类集成swagger，自动生成API文档
5.  某些`<if test="remark != null">`等判断中缺失`remark != ''`判断（要试自己情况决定是否使用）

## 实操 ##

###### 引入Maven依赖，添加`generatorConfig.xml`文件省略 ######

###### 自定义`LombokPlugin`： ######

package com.cong.config;
    
    import lombok.extern.slf4j.Slf4j;
    import org.mybatis.generator.api.IntrospectedColumn;
    import org.mybatis.generator.api.IntrospectedTable;
    import org.mybatis.generator.api.PluginAdapter;
    import org.mybatis.generator.api.dom.java.Method;
    import org.mybatis.generator.api.dom.java.TopLevelClass;
    import org.mybatis.generator.api.dom.xml.XmlElement;
    import java.util.List;
    
    @Slf4j
    public class LombokPlugin extends PluginAdapter { 
    
        @Override
        public boolean validate(List<String> warnings) { 
            return true;
        }
    
        @Override
        public boolean modelBaseRecordClassGenerated(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) { 
            introspectedTable.setSelectByPrimaryKeyStatementId("detail");// 详情接口方法名
            introspectedTable.setDeleteByPrimaryKeyStatementId("delete");// 删除接口方法名
            introspectedTable.setUpdateByPrimaryKeySelectiveStatementId("update");// 更新接口方法名
            topLevelClass.addImportedType("lombok.Data");// lombok
            topLevelClass.addImportedType("lombok.NoArgsConstructor");// lombok
            topLevelClass.addImportedType("io.swagger.annotations.ApiModelProperty");// swagger
            topLevelClass.addImportedType("io.swagger.annotations.ApiModel");// swagger
            topLevelClass.addAnnotation("@Data");// lombok
            topLevelClass.addAnnotation("@ApiModel(" + "\"替换区\"" + ")");// lombok
            topLevelClass.addAnnotation("@NoArgsConstructor");// lombok
            List<IntrospectedColumn> allColumns = introspectedTable.getAllColumns();
            for (IntrospectedColumn column : allColumns) { 
                if (column.getJdbcTypeName().equals("TIMESTAMP")) { 
                    topLevelClass.addImportedType("com.fasterxml.jackson.annotation.JsonFormat");// 日期序列化
                    return true;
                }
            }
            return true;
        }
    
        @Override
        public boolean modelSetterMethodGenerated(Method method, TopLevelClass topLevelClass, IntrospectedColumn introspectedColumn, IntrospectedTable introspectedTable, ModelClassType modelClassType) { 
            return false;
        }
    
        @Override
        public boolean modelGetterMethodGenerated(Method method, TopLevelClass topLevelClass, IntrospectedColumn introspectedColumn, IntrospectedTable introspectedTable, ModelClassType modelClassType) { 
            return false;
        }
    
        @Override
        public boolean sqlMapInsertSelectiveElementGenerated(XmlElement element, IntrospectedTable introspectedTable) { 
            return true;
        }
    }

*  引入包
 *  添加注解
 *  修改接口名

###### 自定义注释生成器`MybatisCommentGenerator` ######

package com.cong.config;
    
    import lombok.extern.slf4j.Slf4j;
    import org.mybatis.generator.api.CommentGenerator;
    import org.mybatis.generator.api.IntrospectedColumn;
    import org.mybatis.generator.api.IntrospectedTable;
    import org.mybatis.generator.api.dom.java.*;
    import org.mybatis.generator.api.dom.xml.XmlElement;
    import java.util.Properties;
    
    @Slf4j
    public class MybatisCommentGenerator implements CommentGenerator { 
        private Properties properties = new Properties();
        private boolean suppressAllComments = true;
        private boolean addRemarkComments = true;
    
        public MybatisCommentGenerator() { 
    
        }
    
        public void addJavaFileComment(CompilationUnit compilationUnit) { 
        }
    
        /** * Mybatis的Mapper.xml文件里面的注释 */
        public void addComment(XmlElement xmlElement) { 
        }
    
        public void addRootComment(XmlElement rootElement) { 
            log.info("addRootComment");
        }
    
        public void addConfigurationProperties(Properties properties) { 
            this.properties.putAll(properties);
            this.suppressAllComments = false;
            this.addRemarkComments = true;
        }
    
        public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) { 
            log.info("addClassComment");
        }
    
        public void addModelClassComment(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) { 
            log.info("addModelClassComment");
        }
    
        public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) { 
    
        }
    
        public void addFieldComment(Field field, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { 
            if (!this.suppressAllComments) { 
                // swagger
                field.addAnnotation("@ApiModelProperty(\"" + introspectedColumn.getRemarks() + "\")");
                if (introspectedColumn.getJdbcTypeName().equals("TIMESTAMP")) { 
                    // 时间类型的自动加上日期format
                    field.addAnnotation("@JsonFormat(locale = \"zh\", timezone = \"Asia/Shanghai\", pattern = \"yyyy-MM-dd HH:mm:ss\")");
                }
            }
        }
    
        public void addFieldComment(Field field, IntrospectedTable introspectedTable) { 
        }
    
        public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) { 
    
        }
    
        public void addGetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { 
    
        }
    
        public void addSetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { 
    
        }
    
        public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable, boolean markAsDoNotDelete) { 
            log.info("addClassComment1");
        }
    }

###### 自定义xml代码生成器 ######

1.  MyJavaMapperGenerator：
    
        package com.cong.config;
        
        import org.mybatis.generator.api.CommentGenerator;
        import org.mybatis.generator.api.dom.java.CompilationUnit;
        import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
        import org.mybatis.generator.api.dom.java.Interface;
        import org.mybatis.generator.api.dom.java.JavaVisibility;
        import org.mybatis.generator.codegen.AbstractXmlGenerator;
        import org.mybatis.generator.codegen.mybatis3.javamapper.JavaMapperGenerator;
        import org.mybatis.generator.config.PropertyRegistry;
        
        import java.util.ArrayList;
        import java.util.List;
        
        import static org.mybatis.generator.internal.util.StringUtility.stringHasValue;
        import static org.mybatis.generator.internal.util.messages.Messages.getString;
        
        public class MyJavaMapperGenerator extends JavaMapperGenerator { 
        
            public MyJavaMapperGenerator() { 
                super(true);
            }
        
            public MyJavaMapperGenerator(boolean requiresMatchedXMLGenerator) { 
                super(requiresMatchedXMLGenerator);
            }
        
            @Override
            public List<CompilationUnit> getCompilationUnits() { 
                progressCallback.startTask(getString("Progress.17", //$NON-NLS-1$
                        introspectedTable.getFullyQualifiedTable().toString()));
                CommentGenerator commentGenerator = context.getCommentGenerator();
        
                FullyQualifiedJavaType type = new FullyQualifiedJavaType(introspectedTable.getMyBatis3JavaMapperType());
                Interface interfaze = new Interface(type);
                interfaze.setVisibility(JavaVisibility.PUBLIC);
                commentGenerator.addJavaFileComment(interfaze);
        
                String rootInterface = introspectedTable.getTableConfigurationProperty(PropertyRegistry.ANY_ROOT_INTERFACE);
                if (!stringHasValue(rootInterface)) { 
                    rootInterface = context.getJavaClientGeneratorConfiguration().getProperty(PropertyRegistry.ANY_ROOT_INTERFACE);
                }
        
                if (stringHasValue(rootInterface)) { 
                    FullyQualifiedJavaType fqjt = new FullyQualifiedJavaType(rootInterface);
                    interfaze.addSuperInterface(fqjt);
                    interfaze.addImportedType(fqjt);
                }
        
                addCountByExampleMethod(interfaze);
                addDeleteByExampleMethod(interfaze);
                addDeleteByPrimaryKeyMethod(interfaze);
                addInsertMethod(interfaze);
                addInsertSelectiveMethod(interfaze);
                addSelectByExampleWithBLOBsMethod(interfaze);
                addSelectByExampleWithoutBLOBsMethod(interfaze);
                addSelectByPrimaryKeyMethod(interfaze);
                addUpdateByExampleSelectiveMethod(interfaze);
                addUpdateByExampleWithBLOBsMethod(interfaze);
                addUpdateByExampleWithoutBLOBsMethod(interfaze);
                addUpdateByPrimaryKeySelectiveMethod(interfaze);
                addUpdateByPrimaryKeyWithBLOBsMethod(interfaze);
                addUpdateByPrimaryKeyWithoutBLOBsMethod(interfaze);
                List<CompilationUnit> answer = new ArrayList<CompilationUnit>();
                if (context.getPlugins().clientGenerated(interfaze, null,
                        introspectedTable)) { 
                    answer.add(interfaze);
                }
                List<CompilationUnit> extraCompilationUnits = getExtraCompilationUnits();
                if (extraCompilationUnits != null) { 
                    answer.addAll(extraCompilationUnits);
                }
                return answer;
            }
        
            public List<CompilationUnit> getExtraCompilationUnits() { 
                return null;
            }
        
            @Override
            public AbstractXmlGenerator getMatchedXMLGenerator() { 
                return new MyXMLMapperGenerator();
            }
        }
    
    生效的在最后，使用自定义的xml生成器
2.  MyXMLMapperGenerator：
    
        package com.cong.config;
        
        import org.mybatis.generator.api.FullyQualifiedTable;
        import org.mybatis.generator.api.dom.xml.Attribute;
        import org.mybatis.generator.api.dom.xml.Document;
        import org.mybatis.generator.api.dom.xml.XmlElement;
        import org.mybatis.generator.codegen.AbstractXmlGenerator;
        import org.mybatis.generator.codegen.XmlConstants;
        import org.mybatis.generator.codegen.mybatis3.xmlmapper.elements.*;
        
        import static org.mybatis.generator.internal.util.messages.Messages.getString;
        
        public class MyXMLMapperGenerator extends AbstractXmlGenerator { 
        
            public MyXMLMapperGenerator() { 
                super();
            }
        
            protected XmlElement getSqlMapElement() { 
                FullyQualifiedTable table = introspectedTable.getFullyQualifiedTable();
                progressCallback.startTask(getString(
                        "Progress.12", table.toString())); //$NON-NLS-1$
                XmlElement answer = new XmlElement("mapper"); //$NON-NLS-1$
                String namespace = introspectedTable.getMyBatis3SqlMapNamespace();
                answer.addAttribute(new Attribute("namespace", //$NON-NLS-1$
                        namespace));
        
                context.getCommentGenerator().addRootComment(answer);
        
                addResultMapWithoutBLOBsElement(answer);
                addResultMapWithBLOBsElement(answer);
                addExampleWhereClauseElement(answer);
                addMyBatis3UpdateByExampleWhereClauseElement(answer);
                addBaseColumnListElement(answer);
                addBlobColumnListElement(answer);
                addSelectByExampleWithBLOBsElement(answer);
                addSelectByExampleWithoutBLOBsElement(answer);
                addSelectByPrimaryKeyElement(answer);
                addDeleteByPrimaryKeyElement(answer);
                addDeleteByExampleElement(answer);
                addInsertElement(answer);
                addInsertSelectiveElement(answer);
                addCountByExampleElement(answer);
                addUpdateByExampleSelectiveElement(answer);
                addUpdateByExampleWithBLOBsElement(answer);
                addUpdateByExampleWithoutBLOBsElement(answer);
                addUpdateByPrimaryKeySelectiveElement(answer);
                addUpdateByPrimaryKeyWithBLOBsElement(answer);
                addUpdateByPrimaryKeyWithoutBLOBsElement(answer);
        
                return answer;
            }
        
            protected void addResultMapWithoutBLOBsElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateBaseResultMap()) { 
                    AbstractXmlElementGenerator elementGenerator = new ResultMapWithoutBLOBsElementGenerator(false);
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addResultMapWithBLOBsElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateResultMapWithBLOBs()) { 
                    AbstractXmlElementGenerator elementGenerator = new ResultMapWithBLOBsElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addExampleWhereClauseElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateSQLExampleWhereClause()) { 
                    AbstractXmlElementGenerator elementGenerator = new ExampleWhereClauseElementGenerator(
                            false);
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addMyBatis3UpdateByExampleWhereClauseElement(
                    XmlElement parentElement) { 
                if (introspectedTable.getRules()
                        .generateMyBatis3UpdateByExampleWhereClause()) { 
                    AbstractXmlElementGenerator elementGenerator = new ExampleWhereClauseElementGenerator(
                            true);
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addBaseColumnListElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateBaseColumnList()) { 
                    AbstractXmlElementGenerator elementGenerator = new BaseColumnListElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addBlobColumnListElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateBlobColumnList()) { 
                    AbstractXmlElementGenerator elementGenerator = new BlobColumnListElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addSelectByExampleWithoutBLOBsElement(
                    XmlElement parentElement) { 
                if (introspectedTable.getRules().generateSelectByExampleWithoutBLOBs()) { 
                    AbstractXmlElementGenerator elementGenerator = new SelectByExampleWithoutBLOBsElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addSelectByExampleWithBLOBsElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateSelectByExampleWithBLOBs()) { 
                    AbstractXmlElementGenerator elementGenerator = new SelectByExampleWithBLOBsElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addSelectByPrimaryKeyElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateSelectByPrimaryKey()) { 
                    AbstractXmlElementGenerator elementGenerator = new SelectByPrimaryKeyElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addDeleteByExampleElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateDeleteByExample()) { 
                    AbstractXmlElementGenerator elementGenerator = new DeleteByExampleElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addDeleteByPrimaryKeyElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateDeleteByPrimaryKey()) { 
                    AbstractXmlElementGenerator elementGenerator = new DeleteByPrimaryKeyElementGenerator(false);
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addInsertElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateInsert()) { 
                    AbstractXmlElementGenerator elementGenerator = new InsertElementGenerator(false);
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addInsertSelectiveElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateInsertSelective()) { 
                    AbstractXmlElementGenerator elementGenerator = new MyInsertSelectiveElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addCountByExampleElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateCountByExample()) { 
                    AbstractXmlElementGenerator elementGenerator = new CountByExampleElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addUpdateByExampleSelectiveElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateUpdateByExampleSelective()) { 
                    AbstractXmlElementGenerator elementGenerator = new UpdateByExampleSelectiveElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addUpdateByExampleWithBLOBsElement(XmlElement parentElement) { 
                if (introspectedTable.getRules().generateUpdateByExampleWithBLOBs()) { 
                    AbstractXmlElementGenerator elementGenerator = new UpdateByExampleWithBLOBsElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addUpdateByExampleWithoutBLOBsElement(
                    XmlElement parentElement) { 
                if (introspectedTable.getRules().generateUpdateByExampleWithoutBLOBs()) { 
                    AbstractXmlElementGenerator elementGenerator = new UpdateByExampleWithoutBLOBsElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addUpdateByPrimaryKeySelectiveElement(
                    XmlElement parentElement) { 
                if (introspectedTable.getRules().generateUpdateByPrimaryKeySelective()) { 
                    AbstractXmlElementGenerator elementGenerator = new MyUpdateByPrimaryKeySelectiveElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addUpdateByPrimaryKeyWithBLOBsElement(
                    XmlElement parentElement) { 
                if (introspectedTable.getRules().generateUpdateByPrimaryKeyWithBLOBs()) { 
                    AbstractXmlElementGenerator elementGenerator = new UpdateByPrimaryKeyWithBLOBsElementGenerator();
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void addUpdateByPrimaryKeyWithoutBLOBsElement(
                    XmlElement parentElement) { 
                if (introspectedTable.getRules()
                        .generateUpdateByPrimaryKeyWithoutBLOBs()) { 
                    AbstractXmlElementGenerator elementGenerator = new UpdateByPrimaryKeyWithoutBLOBsElementGenerator(false);
                    initializeAndExecuteGenerator(elementGenerator, parentElement);
                }
            }
        
            protected void initializeAndExecuteGenerator(
                    AbstractXmlElementGenerator elementGenerator,
                    XmlElement parentElement) { 
                elementGenerator.setContext(context);
                elementGenerator.setIntrospectedTable(introspectedTable);
                elementGenerator.setProgressCallback(progressCallback);
                elementGenerator.setWarnings(warnings);
                elementGenerator.addElements(parentElement);
            }
        
            @Override
            public Document getDocument() { 
                Document document = new Document(
                        XmlConstants.MYBATIS3_MAPPER_PUBLIC_ID,
                        XmlConstants.MYBATIS3_MAPPER_SYSTEM_ID);
                document.setRootElement(getSqlMapElement());
        
                if (!context.getPlugins().sqlMapDocumentGenerated(document,
                        introspectedTable)) { 
                    document = null;
                }
        
                return document;
            }
        }
    
    覆盖`addUpdateByPrimaryKeySelectiveElement`以及`addInsertSelectiveElement`方法，具体的可以根据自己的习惯进行选择，调用的实现类参考系统默认的实现类编写，稍微修改即可，具体代码不解释了。
3.  MyInsertSelectiveElementGenerator：
    
        package com.cong.config;
        
        import org.mybatis.generator.api.IntrospectedColumn;
        import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
        import org.mybatis.generator.api.dom.xml.Attribute;
        import org.mybatis.generator.api.dom.xml.TextElement;
        import org.mybatis.generator.api.dom.xml.XmlElement;
        import org.mybatis.generator.codegen.mybatis3.MyBatis3FormattingUtilities;
        import org.mybatis.generator.codegen.mybatis3.xmlmapper.elements.AbstractXmlElementGenerator;
        import org.mybatis.generator.config.GeneratedKey;
        
        public class MyInsertSelectiveElementGenerator extends AbstractXmlElementGenerator { 
        
            public MyInsertSelectiveElementGenerator() { 
                super();
            }
        
            @Override
            public void addElements(XmlElement parentElement) { 
                XmlElement answer = new XmlElement("insert"); //$NON-NLS-1$
        
                answer.addAttribute(new Attribute(
                        "id", introspectedTable.getInsertSelectiveStatementId())); //$NON-NLS-1$
        
                FullyQualifiedJavaType parameterType = introspectedTable.getRules()
                        .calculateAllFieldsClass();
        
                answer.addAttribute(new Attribute("parameterType", //$NON-NLS-1$
                        parameterType.getFullyQualifiedName()));
        
                context.getCommentGenerator().addComment(answer);
        
                GeneratedKey gk = introspectedTable.getGeneratedKey();
                if (gk != null) { 
                    IntrospectedColumn introspectedColumn = introspectedTable
                            .getColumn(gk.getColumn());
                    // if the column is null, then it's a configuration error. The
                    // warning has already been reported
                    if (introspectedColumn != null) { 
                        if (gk.isJdbcStandard()) { 
                            answer.addAttribute(new Attribute("useGeneratedKeys", "true")); //$NON-NLS-1$ //$NON-NLS-2$
                            answer.addAttribute(new Attribute("keyProperty", introspectedColumn.getJavaProperty())); //$NON-NLS-1$
                            answer.addAttribute(new Attribute("keyColumn", introspectedColumn.getActualColumnName())); //$NON-NLS-1$
                        } else { 
                            answer.addElement(getSelectKey(introspectedColumn, gk));
                        }
                    }
                }
        
                StringBuilder sb = new StringBuilder();
        
                sb.append("insert into "); //$NON-NLS-1$
                sb.append(introspectedTable.getFullyQualifiedTableNameAtRuntime());
                answer.addElement(new TextElement(sb.toString()));
        
                XmlElement insertTrimElement = new XmlElement("trim"); //$NON-NLS-1$
                insertTrimElement.addAttribute(new Attribute("prefix", "(")); //$NON-NLS-1$ //$NON-NLS-2$
                insertTrimElement.addAttribute(new Attribute("suffix", ")")); //$NON-NLS-1$ //$NON-NLS-2$
                insertTrimElement.addAttribute(new Attribute("suffixOverrides", ",")); //$NON-NLS-1$ //$NON-NLS-2$
                answer.addElement(insertTrimElement);
        
                XmlElement valuesTrimElement = new XmlElement("trim"); //$NON-NLS-1$
                valuesTrimElement.addAttribute(new Attribute("prefix", "values (")); //$NON-NLS-1$ //$NON-NLS-2$
                valuesTrimElement.addAttribute(new Attribute("suffix", ")")); //$NON-NLS-1$ //$NON-NLS-2$
                valuesTrimElement.addAttribute(new Attribute("suffixOverrides", ",")); //$NON-NLS-1$ //$NON-NLS-2$
                answer.addElement(valuesTrimElement);
        
                for (IntrospectedColumn introspectedColumn : introspectedTable.getAllColumns()) { 
        
                    if (MyBatis3FormattingUtilities
                            .getEscapedColumnName(introspectedColumn).equals("status") || MyBatis3FormattingUtilities
                            .getEscapedColumnName(introspectedColumn).equals("status_time")) { 
                        continue;
                    }
                    if (introspectedColumn.isSequenceColumn()
                            || introspectedColumn.getFullyQualifiedJavaType().isPrimitive()) { 
                        // if it is a sequence column, it is not optional
                        // This is required for MyBatis3 because MyBatis3 parses
                        // and calculates the SQL before executing the selectKey
        
                        // if it is primitive, we cannot do a null check
                        sb.setLength(0);
                        sb.append(MyBatis3FormattingUtilities
                                .getEscapedColumnName(introspectedColumn));
                        sb.append(',');
                        insertTrimElement.addElement(new TextElement(sb.toString()));
        
                        sb.setLength(0);
                        sb.append(MyBatis3FormattingUtilities
                                .getParameterClause(introspectedColumn));
                        sb.append(',');
                        valuesTrimElement.addElement(new TextElement(sb.toString()));
        
                        continue;
                    }
        
                    XmlElement insertNotNullElement = new XmlElement("if"); //$NON-NLS-1$
                    sb.setLength(0);
                    sb.append(introspectedColumn.getJavaProperty());
                    sb.append(" != null"); //$NON-NLS-1$
                    if (introspectedColumn.getJdbcTypeName().equals("VARCHAR") || introspectedColumn.getJdbcTypeName().equals("CHAR")) { 
                        sb.append(" and ");
                        sb.append(introspectedColumn.getJavaProperty());
                        sb.append(" != ''");
                    }
                    insertNotNullElement.addAttribute(new Attribute(
                            "test", sb.toString())); //$NON-NLS-1$
        
                    sb.setLength(0);
                    sb.append(MyBatis3FormattingUtilities
                            .getEscapedColumnName(introspectedColumn));
                    sb.append(',');
                    insertNotNullElement.addElement(new TextElement(sb.toString()));
                    insertTrimElement.addElement(insertNotNullElement);
        
                    XmlElement valuesNotNullElement = new XmlElement("if"); //$NON-NLS-1$
                    sb.setLength(0);
                    sb.append(introspectedColumn.getJavaProperty());
                    sb.append(" != null"); //$NON-NLS-1$
                    if (introspectedColumn.getJdbcTypeName().equals("VARCHAR") || introspectedColumn.getJdbcTypeName().equals("CHAR")) { 
                        sb.append(" and ");
                        sb.append(introspectedColumn.getJavaProperty());
                        sb.append(" != ''");
                    }
                    valuesNotNullElement.addAttribute(new Attribute(
                            "test", sb.toString())); //$NON-NLS-1$
        
                    sb.setLength(0);
                    sb.append(MyBatis3FormattingUtilities
                            .getParameterClause(introspectedColumn));
                    sb.append(',');
                    valuesNotNullElement.addElement(new TextElement(sb.toString()));
                    valuesTrimElement.addElement(valuesNotNullElement);
                }
        
                if (context.getPlugins().sqlMapInsertSelectiveElementGenerated(
                        answer, introspectedTable)) { 
                    parentElement.addElement(answer);
                }
            }
        }
4.  MyUpdateByPrimaryKeySelectiveElementGenerator:
    
        package com.cong.config;
        
        import org.mybatis.generator.api.IntrospectedColumn;
        import org.mybatis.generator.api.dom.xml.Attribute;
        import org.mybatis.generator.api.dom.xml.TextElement;
        import org.mybatis.generator.api.dom.xml.XmlElement;
        import org.mybatis.generator.codegen.mybatis3.MyBatis3FormattingUtilities;
        import org.mybatis.generator.codegen.mybatis3.xmlmapper.elements.AbstractXmlElementGenerator;
        
        public class MyUpdateByPrimaryKeySelectiveElementGenerator extends
                AbstractXmlElementGenerator { 
        
            public MyUpdateByPrimaryKeySelectiveElementGenerator() { 
                super();
            }
        
            @Override
            public void addElements(XmlElement parentElement) { 
                XmlElement answer = new XmlElement("update"); //$NON-NLS-1$
        
                answer
                        .addAttribute(new Attribute(
                                "id", introspectedTable.getUpdateByPrimaryKeySelectiveStatementId())); //$NON-NLS-1$
        
                String parameterType;
        
                if (introspectedTable.getRules().generateRecordWithBLOBsClass()) { 
                    parameterType = introspectedTable.getRecordWithBLOBsType();
                } else { 
                    parameterType = introspectedTable.getBaseRecordType();
                }
        
                answer.addAttribute(new Attribute("parameterType", //$NON-NLS-1$
                        parameterType));
        
                context.getCommentGenerator().addComment(answer);
        
                StringBuilder sb = new StringBuilder();
        
                sb.append("update "); //$NON-NLS-1$
                sb.append(introspectedTable.getFullyQualifiedTableNameAtRuntime());
                answer.addElement(new TextElement(sb.toString()));
        
                XmlElement dynamicElement = new XmlElement("set"); //$NON-NLS-1$
                answer.addElement(dynamicElement);
        
                for (IntrospectedColumn introspectedColumn : introspectedTable.getNonPrimaryKeyColumns()) { 
                    if (MyBatis3FormattingUtilities
                            .getEscapedColumnName(introspectedColumn).equals("status") || MyBatis3FormattingUtilities
                            .getEscapedColumnName(introspectedColumn).equals("status_time")) { 
                        continue;
                    }
                    XmlElement isNotNullElement = new XmlElement("if"); //$NON-NLS-1$
                    sb.setLength(0);
                    sb.append(introspectedColumn.getJavaProperty());
                    sb.append(" != null"); //$NON-NLS-1$
                    if (introspectedColumn.getJdbcTypeName().equals("VARCHAR") || introspectedColumn.getJdbcTypeName().equals("CHAR")){ 
                        sb.append(" and ");
                        sb.append(introspectedColumn.getJavaProperty());
                        sb.append(" != ''");
                    }
                    isNotNullElement.addAttribute(new Attribute("test", sb.toString())); //$NON-NLS-1$
                    dynamicElement.addElement(isNotNullElement);
        
                    sb.setLength(0);
                    sb.append(MyBatis3FormattingUtilities
                            .getEscapedColumnName(introspectedColumn));
                    sb.append(" = "); //$NON-NLS-1$
                    sb.append(MyBatis3FormattingUtilities
                            .getParameterClause(introspectedColumn));
                    sb.append(',');
        
                    isNotNullElement.addElement(new TextElement(sb.toString()));
                }
        
                boolean and = false;
                for (IntrospectedColumn introspectedColumn : introspectedTable
                        .getPrimaryKeyColumns()) { 
                    sb.setLength(0);
                    if (and) { 
                        sb.append(" and "); //$NON-NLS-1$
                    } else { 
                        sb.append("where "); //$NON-NLS-1$
                        and = true;
                    }
        
                    sb.append(MyBatis3FormattingUtilities
                            .getEscapedColumnName(introspectedColumn));
                    sb.append(" = "); //$NON-NLS-1$
                    sb.append(MyBatis3FormattingUtilities
                            .getParameterClause(introspectedColumn));
                    answer.addElement(new TextElement(sb.toString()));
                }
        
                if (context.getPlugins()
                        .sqlMapUpdateByPrimaryKeySelectiveElementGenerated(answer,
                                introspectedTable)) { 
                    parentElement.addElement(answer);
                }
            }
        }
    
    上述两个类比较一下和默认实现不同的地方就懂了，我相信开始做这个事情的应该很简单就能看懂。

## 修改`generatorConfig.xml`（重点） ##

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
    <generatorConfiguration>
    	
    	<properties resource="mybatis.yml"></properties>
    
    	<context id="DB2Tables" targetRuntime="MyBatis3">
    		
    		<plugin type="com.cong.config.LombokPlugin">
    			<property name="hasLombok" value="true"/>
    		</plugin>
    
    		<plugin type="org.mybatis.generator.plugins.SerializablePlugin" />
    
    		
    		<commentGenerator type="com.cong.config.MybatisCommentGenerator">
    			<property name="suppressAllComments" value="false" />
    			<property name="addRemarkComments" value="true"/>
    		</commentGenerator>
    
    		
    		<jdbcConnection driverClass="${jdbc.driver-class-name}"
    						connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}">
    		</jdbcConnection>
    
    		
    		<javaTypeResolver>
    			<property name="forceBigDecimals" value="false" />
    		</javaTypeResolver>
    
    		
    		<javaModelGenerator targetPackage="com.cong.ums.entity"
    							targetProject="${mybatis.entity}">
    			
    			<property name="constructorBased" value="false" />
    			
    			<property name="enableSubPackages" value="true" />
    
    			
    			
    			
    			
    		</javaModelGenerator>
    
    		
    		<sqlMapGenerator targetPackage="mapping"
    						 targetProject="src/main/resources">
    			<property name="enableSubPackages" value="true" />
    		</sqlMapGenerator>
    
    		
    		<javaClientGenerator type="com.cong.config.MyJavaMapperGenerator"
    							 targetPackage="com.cong.ams.mapper" targetProject="${mybatis.mapper}">
    			<property name="enableSubPackages" value="true" />
    		</javaClientGenerator>
    
    		<table tableName="ums_user" domainObjectName="UmsUser"
    			   enableCountByExample="false" enableUpdateByExample="false"
    			   enableDeleteByExample="false" enableSelectByExample="false"
    			   selectByExampleQueryId="false">
    		</table>
    
    	</context>
    </generatorConfiguration>

详解：

*  plugin  
    引入lombok插件，指定的类一定要继承`PluginAdapter`
 *  commentGenerator  
    注释，指定类实现`CommentGenerator`即可，模仿`DefaultCommentGenerator`默认实现编写即可
 *  javaClientGenerator  
    类生成器，我本来认为xml生成和comment一样自定义生成器即可，但是`sqlMapGenerator`没有type标签，我仔细断点调试之后发现原来这个`Generator`有好多默认实现，而且竟然是在`JavaClientGenerator`里面定义的！！所以自定义`MyJavaMapperGenerator`在这里面指定`XMLMapperGenerator`，在`javaClientGenerator`标签中再指定`MyJavaMapperGenerator`，其实感觉是不太友好的。  
    ![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAc2luZ2xlX2Nvbmc_size_20_color_FFFFFF_t_70_g_se_x_16]

#### 补充 ####

上述所有类需要提取出来单独做一个jar依赖，不要直接在当前项目中写上述代码。

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAc2luZ2xlX2Nvbmc_size_20_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/48a7c0a93a3643528ecb29b0077aeff1.png