使用mybatis自动生成—generatorConfig配置文件

spring boot 使用mybatis自动生成方法：

首先pom.xml添加依赖:

    org.mybatis.generator
    mybatis-generator-core
    1.3.5

在build—>plugins下面添加：

            
                org.mybatis.generator
                mybatis-generator-maven-plugin
                1.3.5
            

接下来是mybatis自动生成的配置文件：

mysql配置：

 

Oracle配置：

这是要注意一下，

使用Oracle数据库的时候，需要重写两个类，因为oracle里的nvachar2类型，mybatis无法识别，会转换成object类型；

package org.mybatis.generator.internal.types;

import java.sql.Types;

import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;

public class MyJavaTypeResolverDefaultImpl extends JavaTypeResolverDefaultImpl{

	public MyJavaTypeResolverDefaultImpl() {
		super();
		//把数据库的 NVARCHAR2 映射成 String
        super.typeMap.put(Types.OTHER, new JdbcTypeInformation("NVARCHAR2", new FullyQualifiedJavaType(String.class.getName())));
   
	}

	
	
}

第二个是IntrospectedColumn，我这里直接贴源码；

/**
 *    Copyright 2006-2016 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.mybatis.generator.api;

import java.sql.Types;
import java.util.Properties;

import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
import org.mybatis.generator.config.Context;
import org.mybatis.generator.internal.util.StringUtility;

/**
 * This class holds information about an introspected column. The class has
 * utility methods useful for generating iBATIS objects.
 * 
 * @author Jeff Butler
 * update wangxinyang 20190123
 */
public class IntrospectedColumn {
    protected String actualColumnName;

    protected int jdbcType;

    protected String jdbcTypeName;

    protected boolean nullable;

    protected int length;

    protected int scale;

    protected boolean identity;
    
    protected boolean isSequenceColumn;

    protected String javaProperty;

    protected FullyQualifiedJavaType fullyQualifiedJavaType;

    protected String tableAlias;

    protected String typeHandler;

    protected Context context;

    protected boolean isColumnNameDelimited;

    protected IntrospectedTable introspectedTable;

    protected Properties properties;

    // any database comment associated with this column. May be null
    protected String remarks;

    protected String defaultValue;
    
    /**
     * true if the JDBC driver reports that this column is auto-increment
     */
    protected boolean isAutoIncrement;
    
    /**
     * true if the JDBC driver reports that this column is generated
     */
    protected boolean isGeneratedColumn;
    
    /**
     * True if there is a column override that defines this column as GENERATED ALWAYS
     */
    protected boolean isGeneratedAlways;

    /**
     * Constructs a Column definition. This object holds all the information
     * about a column that is required to generate Java objects and SQL maps;
     */
    public IntrospectedColumn() {
        super();
        properties = new Properties();
    }

    public int getJdbcType() {
        return jdbcType;
    }

    public void setJdbcType(int jdbcType) {
        this.jdbcType = jdbcType;
    }

    public int getLength() {
        return length;
    }

    public void setLength(int length) {
        this.length = length;
    }

    public boolean isNullable() {
        return nullable;
    }

    public void setNullable(boolean nullable) {
        this.nullable = nullable;
    }

    public int getScale() {
        return scale;
    }

    public void setScale(int scale) {
        this.scale = scale;
    }

    /*
     * This method is primarily used for debugging, so we don't externalize the
     * strings
     */
    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();

        sb.append("Actual Column Name: "); //$NON-NLS-1$
        sb.append(actualColumnName);
        sb.append(", JDBC Type: "); //$NON-NLS-1$
        sb.append(jdbcType);
        sb.append(", Nullable: "); //$NON-NLS-1$
        sb.append(nullable);
        sb.append(", Length: "); //$NON-NLS-1$
        sb.append(length);
        sb.append(", Scale: "); //$NON-NLS-1$
        sb.append(scale);
        sb.append(", Identity: "); //$NON-NLS-1$
        sb.append(identity);

        return sb.toString();
    }

    public void setActualColumnName(String actualColumnName) {
        this.actualColumnName = actualColumnName;
        isColumnNameDelimited = StringUtility
                .stringContainsSpace(actualColumnName);
    }

    /**
     * @return Returns the identity.
     */
    public boolean isIdentity() {
        return identity;
    }

    /**
     * @param identity
     *            The identity to set.
     */
    public void setIdentity(boolean identity) {
        this.identity = identity;
    }

    public boolean isBLOBColumn() {
        String typeName = getJdbcTypeName();

        return "BINARY".equals(typeName) || "BLOB".equals(typeName) //$NON-NLS-1$ //$NON-NLS-2$
                || "CLOB".equals(typeName) || "LONGNVARCHAR".equals(typeName) //$NON-NLS-1$ //$NON-NLS-2$ 
                || "LONGVARBINARY".equals(typeName) || "LONGVARCHAR".equals(typeName) //$NON-NLS-1$ //$NON-NLS-2$
                || "NCLOB".equals(typeName) || "VARBINARY".equals(typeName); //$NON-NLS-1$ //$NON-NLS-2$ 
    }

    public boolean isStringColumn() {
        return fullyQualifiedJavaType.equals(FullyQualifiedJavaType
                .getStringInstance());
    }

    public boolean isJdbcCharacterColumn() {
        return jdbcType == Types.CHAR || jdbcType == Types.CLOB
                || jdbcType == Types.LONGVARCHAR || jdbcType == Types.VARCHAR
                || jdbcType == Types.LONGNVARCHAR || jdbcType == Types.NCHAR
                || jdbcType == Types.NCLOB || jdbcType == Types.NVARCHAR;
    }

    public String getJavaProperty() {
        return getJavaProperty(null);
    }

    public String getJavaProperty(String prefix) {
        if (prefix == null) {
            return javaProperty;
        }

        StringBuilder sb = new StringBuilder();
        sb.append(prefix);
        sb.append(javaProperty);

        return sb.toString();
    }

    public void setJavaProperty(String javaProperty) {
        this.javaProperty = javaProperty;
    }

    public boolean isJDBCDateColumn() {
        return fullyQualifiedJavaType.equals(FullyQualifiedJavaType
                .getDateInstance())
                && "DATE".equalsIgnoreCase(jdbcTypeName); //$NON-NLS-1$
    }

    public boolean isJDBCTimeColumn() {
        return fullyQualifiedJavaType.equals(FullyQualifiedJavaType
                .getDateInstance())
                && "TIME".equalsIgnoreCase(jdbcTypeName); //$NON-NLS-1$
    }

    public String getTypeHandler() {
        return typeHandler;
    }

    public void setTypeHandler(String typeHandler) {
        this.typeHandler = typeHandler;
    }

    public String getActualColumnName() {
        return actualColumnName;
    }

    public void setColumnNameDelimited(boolean isColumnNameDelimited) {
        this.isColumnNameDelimited = isColumnNameDelimited;
    }

    public boolean isColumnNameDelimited() {
        return isColumnNameDelimited;
    }

    public String getJdbcTypeName() {
        if (jdbcTypeName == null || jdbcTypeName.equalsIgnoreCase("NVARCHAR2")) {
            return "OTHER"; //$NON-NLS-1$
        }

        return jdbcTypeName;
    }

    public void setJdbcTypeName(String jdbcTypeName) {
        this.jdbcTypeName = jdbcTypeName;
    }

    public FullyQualifiedJavaType getFullyQualifiedJavaType() {
        return fullyQualifiedJavaType;
    }

    public void setFullyQualifiedJavaType(
            FullyQualifiedJavaType fullyQualifiedJavaType) {
        this.fullyQualifiedJavaType = fullyQualifiedJavaType;
    }

    public String getTableAlias() {
        return tableAlias;
    }

    public void setTableAlias(String tableAlias) {
        this.tableAlias = tableAlias;
    }

    public Context getContext() {
        return context;
    }

    public void setContext(Context context) {
        this.context = context;
    }

    public IntrospectedTable getIntrospectedTable() {
        return introspectedTable;
    }

    public void setIntrospectedTable(IntrospectedTable introspectedTable) {
        this.introspectedTable = introspectedTable;
    }

    public Properties getProperties() {
        return properties;
    }

    public void setProperties(Properties properties) {
        this.properties.putAll(properties);
    }

    public String getRemarks() {
        return remarks;
    }

    public void setRemarks(String remarks) {
        this.remarks = remarks;
    }

    public String getDefaultValue() {
        return defaultValue;
    }

    public void setDefaultValue(String defaultValue) {
        this.defaultValue = defaultValue;
    }

    public boolean isSequenceColumn() {
        return isSequenceColumn;
    }

    public void setSequenceColumn(boolean isSequenceColumn) {
        this.isSequenceColumn = isSequenceColumn;
    }

    public boolean isAutoIncrement() {
        return isAutoIncrement;
    }

    public void setAutoIncrement(boolean isAutoIncrement) {
        this.isAutoIncrement = isAutoIncrement;
    }

    public boolean isGeneratedColumn() {
        return isGeneratedColumn;
    }

    public void setGeneratedColumn(boolean isGeneratedColumn) {
        this.isGeneratedColumn = isGeneratedColumn;
    }

    public boolean isGeneratedAlways() {
        return isGeneratedAlways;
    }

    public void setGeneratedAlways(boolean isGeneratedAlways) {
        this.isGeneratedAlways = isGeneratedAlways;
    }
}

重写的上面这个类，重点在这里：

到这里配置文件就ok了；

-------------------------------------------------------------

在里面配置好数据源，表名，要生成的类名，然后就可以使用了；

对了，这里eclipse还要安装一个插件：

在eclipse的菜单栏点击 help—>Eclipse Marketplace ...

然后在search选项卡中搜索：mybatis

右下角的install，直接安装就好了。

我这里因为是已经安装过的，所以显示installed;

 安装成功之后，在我们的generatorConfig.xml上点击右键：Run As

运行之后，控制台会打印日志，可以查看日志看是否生成成功，成功之后会在上面配置的包下面生成文件。

-------------------------------

还可以使用mybatis-plus的插件，这个配合相应的模版，能生成更多的文件诸如增删改查，从dao到controller都会有相关方法，更加便捷。

有兴趣可以探索一下。

程序员都是懒人，因为懒，所以我们在做一件事情的时候，会去寻找一更优的解决方案。

不将就，the end;