MyBatis系列 逆向工程自动生成实体类、Mapper、SQL

说明：MyBatis 需要程序员自己编写sql语句，mybatis官方提供逆向工程,可以针对单表自动生成mybatis执行所需要的代码。MyBatis Generator：简称MBG，是一个专门为MyBatis框架使用者定制的代码生成器，可以快速的根据表生成对应的映射文件，接口，以及实体类。支持基本的增删改查，以及QBC风格的条件查询。但是表连接、 存储过程等这些复杂sql的定义需要我们手工编写。使用逆向工程有其局限性, 逆向工程方法只能执行一次, 如果再次执行就会继续映射文件, 除非我们把之前生成的全都删除
文档查阅：
http://www.mybatis.org/generator/
官网下载：
https://github.com/mybatis/
以下我将实现一个自己的逆向工程，并含有自定义注释功能，项目git地址：https://github.com/gitcaiqing/mybatis_generator_zh.git
1.项目结构

2.创建Maven项目
file–>new–>maven project,填写自己的Goup Id、Artifact Id
3.配置web.xml，路径/WebRoot/WEB-INF/web.xml

  mybatis_generator_zh	
	
	
		
			org.springframework.web.context.ContextLoaderListener
		
	
	
        
        	org.springframework.web.context.request.RequestContextListener
        
    
    
	
		encodingFilter
		org.springframework.web.filter.CharacterEncodingFilter
		
			encoding
			utf-8
		
		
			forceEncoding
			true
		
	
	
		encodingFilter
		/*
	
  

4.Maven引入项目所需jar包，文件pom.xml

  4.0.0
  mybatis_generator_zh
  mybatis_generator_zh
  0.0.1-SNAPSHOT
  
  
    UTF-8
  
  
		
		
		
			mysql
			mysql-connector-java
			5.1.34
		
	
		
     		org.mybatis.generator
     		mybatis-generator-core
     		1.3.2
		
  
  
    
		
			org.apache.maven.plugins
			maven-surefire-plugin
			
				true
			
			2.18.1
		
	
  

5.实现自定义注释，文件
/src/main/java/module/MyCommentGenerator.java

package module;
import static org.mybatis.generator.internal.util.StringUtility.isTrue;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;
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.CompilationUnit;
import org.mybatis.generator.api.dom.java.Field;
import org.mybatis.generator.api.dom.java.InnerClass;
import org.mybatis.generator.api.dom.java.InnerEnum;
import org.mybatis.generator.api.dom.java.JavaElement;
import org.mybatis.generator.api.dom.java.Method;
import org.mybatis.generator.api.dom.java.Parameter;
import org.mybatis.generator.api.dom.xml.XmlElement;
import org.mybatis.generator.config.MergeConstants;
import org.mybatis.generator.config.PropertyRegistry;

/**
 * 自定义注释
 */
public class MyCommentGenerator implements CommentGenerator{

	private Properties properties;
    private Properties systemPro;
    private boolean suppressDate;
    private boolean suppressAllComments;
    private String currentDateStr;

    public MyCommentGenerator() {
        super();
        properties = new Properties();
        systemPro = System.getProperties();
        suppressDate = false;
        suppressAllComments = false;
        currentDateStr = (new SimpleDateFormat("yyyy-MM-dd")).format(new Date());
    }

    public void addJavaFileComment(CompilationUnit compilationUnit) {
        return;
    }

    public void addComment(XmlElement xmlElement) {
        return;
    }

    public void addRootComment(XmlElement rootElement) {
        return;
    }

    public void addConfigurationProperties(Properties properties) {
        this.properties.putAll(properties);
        suppressDate = isTrue(properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_DATE));
        suppressAllComments = isTrue(properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_ALL_COMMENTS));
    }

    /**
     * This method adds the custom javadoc tag for. You may do nothing if you do
     * not wish to include the Javadoc tag - however, if you do not include the
     * Javadoc tag then the Java merge capability of the eclipse plugin will
     * break.
     * 
     * @param javaElement
     *            the java element
     */
    protected void addJavadocTag(JavaElement javaElement, boolean markAsDoNotDelete) {
        javaElement.addJavaDocLine(" *");
        StringBuilder sb = new StringBuilder();
        sb.append(" * ");
        //sb.append(MergeConstants.NEW_ELEMENT_TAG);
        sb.append("@ https://blog.csdn.net/caiqing116");
        if (markAsDoNotDelete) {
            sb.append(" do_not_delete_during_merge");
        }
        String s = getDateString();
        if (s != null) {
            sb.append(' ');
            sb.append(s);
        }
        javaElement.addJavaDocLine(sb.toString());
    }

    /**
     * This method returns a formated date string to include in the Javadoc tag
     * and XML comments. You may return null if you do not want the date in
     * these documentation elements.
     * 
     * @return a string representing the current timestamp, or null
     */
    protected String getDateString() {
        String result = null;
        if (!suppressDate) {
            result = currentDateStr;
        }
        return result;
    }

    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        StringBuilder sb = new StringBuilder();
        innerClass.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        sb.append(" ");
        sb.append(getDateString());
        innerClass.addJavaDocLine(sb.toString().replace("\n", " "));
        innerClass.addJavaDocLine(" */");
    }

    public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        StringBuilder sb = new StringBuilder();
        innerEnum.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        innerEnum.addJavaDocLine(sb.toString().replace("\n", " "));
        innerEnum.addJavaDocLine(" */");
    }

    //属性注释
    public void addFieldComment(Field field, IntrospectedTable introspectedTable,
            IntrospectedColumn introspectedColumn) {
        if (suppressAllComments) {
            return;
        }
        StringBuilder sb = new StringBuilder();
        field.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedColumn.getRemarks());
        field.addJavaDocLine(sb.toString().replace("\n", " "));
        field.addJavaDocLine(" */");
    }

    //属性注释
    public void addFieldComment(Field field, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        
        StringBuilder sb = new StringBuilder();
        field.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        field.addJavaDocLine(sb.toString().replace("\n", " "));
        field.addJavaDocLine(" */");
    }

    //方法注释
    public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
      method.addJavaDocLine("/**");
      addJavadocTag(method, false);
      method.addJavaDocLine(" */");
    }

    //get方法注释
    public void addGetterComment(Method method, IntrospectedTable introspectedTable,
            IntrospectedColumn introspectedColumn) {
        if (suppressAllComments) {
            return;
        }
        method.addJavaDocLine("/**");
        StringBuilder sb = new StringBuilder();
        sb.append(" * ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString().replace("\n", " "));
        sb.setLength(0);
        sb.append(" * @return ");
        sb.append(introspectedColumn.getActualColumnName());
        sb.append(" ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString().replace("\n", " "));
        method.addJavaDocLine(" */");
    }

    //set方法注释
    public void addSetterComment(Method method, IntrospectedTable introspectedTable,
            IntrospectedColumn introspectedColumn) {
        if (suppressAllComments) {
            return;
        }
        method.addJavaDocLine("/**");
        StringBuilder sb = new StringBuilder();
        sb.append(" * ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString().replace("\n", " "));
        Parameter parm = method.getParameters().get(0);
        sb.setLength(0);
        sb.append(" * @param ");
        sb.append(parm.getName());
        sb.append(" ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString().replace("\n", " "));
        method.addJavaDocLine(" */");
    }

    //类注释
    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable, boolean markAsDoNotDelete) {
        if (suppressAllComments) {
            return;
        }
        StringBuilder sb = new StringBuilder();
        innerClass.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        innerClass.addJavaDocLine(sb.toString().replace("\n", " "));
        sb.setLength(0);
        sb.append(" * @author ");
        //sb.append(systemPro.getProperty("user.name"));
        sb.append(" https://blog.csdn.net/caiqing116");
        sb.append(" ");
        sb.append(currentDateStr);
        innerClass.addJavaDocLine(" */");
    }

}

6.配置数据源，实体类，Mapper，SQL生成规则，文件：/generatorConfig.xml

7.创建启动类，执行后即可自动生成实体类、Mapper、SQL，文件src/main/java/module/StartUp.java

package module;
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.exception.InvalidConfigurationException;
import org.mybatis.generator.exception.XMLParserException;
import org.mybatis.generator.internal.DefaultShellCallback;

public class StartUp {
	public static void main(String[] args) throws URISyntaxException {
        try {
        	
            List warnings = new ArrayList();
    		boolean overwrite = true;
    		File configFile = new File("generatorConfig.xml");
    	    ConfigurationParser cp = new ConfigurationParser(warnings);
    	    Configuration config = cp.parseConfiguration(configFile);
    	    DefaultShellCallback callback = new DefaultShellCallback(overwrite);
    	    MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
    	    myBatisGenerator.generate(null);
            System.out.println("Mybatis Generator 逆向生成Dao完成");
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (InvalidConfigurationException e) {
            e.printStackTrace();
        } catch (XMLParserException e) {
            e.printStackTrace();
        }
    }
}