根据模板及表元数据生成Service层类

（1），模板service_.ftl文件如下

package com.service;

import com.dto.<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Dto;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.util.PageUtil;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @date: 如 2022/11/27 12:13
 * @desc: <#list mapDataTableComment as listItmCom > ${listItmCom.columnComment} </#list>类服务层
 */
@Service
public class <#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Service {

    @Autowired
    private SqlSessionTemplate sqlSession;
    private static String namePathSpace = "com.dto.<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName}Dao </#list>.";

    // 保存<#list mapDataTableComment as listItmCom > ${listItmCom.columnComment} </#list>
    public int <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>AddSave(<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Dto <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto) {
        int irows = 0;
        int tid = getMaxid();
        testT00_userDto.setTid( tid + "");
        irows = sqlSession.insert(namePathSpace + "<#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>AddSave", <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto);
        return irows;
    }

	// 修改保存<#list mapDataTableComment as listItmCom > ${listItmCom.columnComment} </#list>
    public int testT00_userModifySave(<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Dto <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto) {
        int irows = 0;
        irows = sqlSession.update(namePathSpace + "<#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>ModifySave", <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto);
        return irows;
    }

	// 删除一条<#list mapDataTableComment as listItmCom > ${listItmCom.columnComment} </#list>
    public int testT00_userDel(<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Dto <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto) {
        int irows = 0;
        irows = sqlSession.delete(namePathSpace + "<#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Del", <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto);
        return irows;
    }

    public TestT00_userDto getTestT00_user(<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Dto <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto) {
        return sqlSession.selectOne(namePathSpace + "getTestT00_user", testT00_userDto);
    }

    // <#list mapDataTableComment as listItmCom > ${listItmCom.columnComment} </#list>列表
    public List<<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName}Dto </#list>> queryTestT00_userList(<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Dto <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto) {

        PageHelper.startPage(<#list mapDataTableComment as listItmCom > ${listItmCom.columnName}Dto </#list>.getCurPageIdx(), <#list mapDataTableComment as listItmCom > ${listItmCom.columnName}Dto </#list>.getPageSize(), true);
        List<<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName}Dto </#list>> list = sqlSession.selectList(namePathSpace + "query<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>List", <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto);

        PageInfo<<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Dto> pageInfoTestTud = new PageInfo<<#list mapDataTableComment as listItmCom > ${listItmCom.upperColumnName} </#list>Dto>(list);
        // 计算页数
        int pages = PageUtil.getPages(<#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto.getPageSize(), Integer.parseInt(pageInfoTestTud.getTotal() + "") );
        <#list mapDataTableComment as listItmCom > ${listItmCom.columnName} </#list>Dto.setPages(pages);
        return list;
    }

    // 获取最大id值
    private int getMaxid() {
        int maxID = 0;
        maxID = sqlSession.selectOne(namePathSpace + "getMaxid");
        maxID = maxID + 1;
        return maxID;
    }

}

（2），根据模板及表元数据生成service层类

public class TestCls {

    public static void main(String[] args) throws Exception {
        TestCls testCls = new TestCls();
        String testT00_po = "testT00_user";
        String generFileName = testCls.firTextUpper(testT00_po) + "Service.java";
        testCls.outTemplate(testT00_po, "用户数据"
                , generFileName, "service_.ftl" );

        System.out.println("执行成功！");
    }

    // 输出到模板
    private void outTemplate(String entryInfoPoName, String tableComment
            , String templateFileName , String templFileName ) throws Exception {

        Configuration configuration = new Configuration();
        String templateDir = "F:\\xbl\\myResource\\temp_test_";
        configuration.setDirectoryForTemplateLoading(new File(templateDir));
        Template template = configuration.getTemplate(templFileName);

        Map<String, List<EntryInfoPo>> dataMap = new HashMap<String, List<EntryInfoPo>>();
        List<EntryInfoPo> listEntryInfo = new ArrayList<EntryInfoPo>();
        listEntryInfo = testMetaAddComment();
        dataMap.put("mapDataList", listEntryInfo );

        // 表注释
        dataMap.put("mapDataTableComment", testTableComment(entryInfoPoName, tableComment ));
        String generFileDir = "F:\\xbl\\myResource\\temp_test_\\gener_file_\\";
        File generFile = new File(generFileDir + templateFileName);
        if(generFile.exists()) {
            generFile.delete();
        }
        generFile.createNewFile();

        Writer outputWriter = new OutputStreamWriter(new FileOutputStream(generFile ) );
//        Writer outputWriter = new OutputStreamWriter(System.out );

        template.process(dataMap, outputWriter);
        System.out.println("输出完成！");
        outputWriter.close();
    }

    // 表注释
    private List<EntryInfoPo> testTableComment(String entryInfoPoName, String tableComment) throws Exception {

        List<EntryInfoPo> listTableComment = new ArrayList<EntryInfoPo>();
        EntryInfoPo entryInfoPo = new EntryInfoPo();
        entryInfoPo.setColumnName(entryInfoPoName);
        entryInfoPo.setColumnComment(tableComment);
        entryInfoPo.setUpperColumnName(firTextUpper( entryInfoPoName ) );
        listTableComment.add(entryInfoPo);
        return listTableComment;
    }

    // 首字母大写
    private String firTextUpper(String scontext ) {
        int textLength = scontext.length();
        String sufText = scontext.substring(1, textLength);
        String firText = scontext.substring(0, 1);
        firText = firText.toUpperCase();
        String finText = firText + sufText;
        return finText;
    }

    private List<EntryInfoPo> testMetaAddComment() throws Exception {

        List<EntryInfoPo> listEntryInfoPo = new ArrayList<EntryInfoPo>();
        Connection connection = getDataBaseConnection();
        Statement statement = connection.createStatement();
        ResultSet resultSet = statement.executeQuery("show full columns from t00_user ");
        while (resultSet.next()) {

            String columnComment = resultSet.getString("Comment");
            String columnName = resultSet.getString("Field");
            EntryInfoPo entryInfoPo = new EntryInfoPo();
            entryInfoPo.setColumnName(columnName);
            entryInfoPo.setColumnComment(columnComment);
            listEntryInfoPo.add(entryInfoPo);
        }
        return listEntryInfoPo;
    }
    private Connection getDataBaseConnection() throws Exception {
        // 连接数据库
        Class.forName("com.mysql.jdbc.Driver");
        String databaseUrl = "jdbc:mysql://127.0.0.1:3306/grcdb05?useUnicode=true&amp;characterEncoding=utf8";
        Connection connection = DriverManager.getConnection(databaseUrl, "root", "root");
        return connection;
    }
}

（3），执行（2）步骤生成Service层类，注意把中间的空格替换成非空