Java自动生成业务代码

前言：

    新业务的开发总是少不了相应的增删查改，而这些功能与其他业务的增删查改又是大径相同，所以为了解决这种纯粹的体力劳动，提高开发效率，开发一个增删查改的代码自动生成是非常有必要的。

技术：freemarker模板

生成的目标文件：entity，dao，controller，service，.sql等五个文件

依赖包：freemarker-2.3.16.jar

             commons.io-2.4.jar

主体代码：

import freemarker.template.Template;
import org.apache.commons.lang3.StringUtils;
import com.arvin.entity.CodeAuto;
import com.arvin.entity.Column;
import org.apache.commons.io.FileUtils;
import java.io.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class CodeAutoUtil {

   public Map<String, Object> getCodeAutoData(CodeAuto codeAuto) {
        Map<String, Object> dataMap = new HashMap<String , Object>();
        dataMap.put("name", codeAuto.name);
        dataMap.put("entityName", StringUtils.capitalize(codeAuto.name));
        dataMap.put("controllerName", StringUtils.capitalize(codeAuto.name) + "Controller");
        dataMap.put("daoName", StringUtils.capitalize(codeAuto.name) + "Dao");
        dataMap.put("serviceName", StringUtils.capitalize(codeAuto.name) + "Service");
        // endpoint 功能
        dataMap.put("funs",codeAuto.funs);
        // domain 列
        List<String> stringList = new ArrayList<String>();
        List<String> strs = new ArrayList<String>();
        for(Column column : codeAuto.columns){
            String columnStr = "public"+" "+ column.type + " " + column.name +";";         //格式:  public String name;
            String str = "`"+column.name+"`"+column.type+"("+parseColumnLength(column.type)+")"+"  "+"NULL,"; //格式: `name` varchar(255) NULL,
            stringList.add(columnStr);
            strs.add(str);
        }
        dataMap.put("params",stringList);
        //sql 建表文件
        dataMap.put("colomns",strs);
        return dataMap;
    }

    public boolean create(CodeAuto codeAuto) throws Exception{
        Map<String, Object> dataMap = getCodeAutoData(codeAuto);
        Template template = FreeMarkerTemplateUtils.getTemplate("Endpoint.ftl");
        File file = FileUtils.getFile(codeAuto.path, codeAuto.name);
        if (!file.exists()){
            file.mkdir();
        }
        Writer out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(FileUtils.getFile(codeAuto.path, codeAuto.name, dataMap.get("controllerName") + ".java")), "utf-8"),10240);
        template.process(dataMap,out);

        template = FreeMarkerTemplateUtil.getTemplate("Dao.ftl");
        out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(FileUtils.getFile(codeAuto.path, codeAuto.name, dataMap.get("daoName") + ".java")), "utf-8"),10240);
        template.process(dataMap,out);

        template = FreeMarkerTemplateUtil.getTemplate("Domain.ftl");
        out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(FileUtils.getFile(codeAuto.path, codeAuto.name, dataMap.get("entityName") + ".java")), "utf-8"),10240);
        template.process(dataMap,out);

        template = FreeMarkerTemplateUtil.getTemplate("Service.ftl");
        out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(FileUtils.getFile(codeAuto.path, codeAuto.name, dataMap.get("serviceName") + ".java")), "utf-8"),10240);
        template.process(dataMap,out);

        template = FreeMarkerTemplateUtil.getTemplate("Sql.ftl");
        out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(FileUtils.getFile(codeAuto.path, codeAuto.name,dataMap.get("entityName") + ".sql")), "utf-8"),10240);
        template.process(dataMap,out);
        return true;
    }
    //数据库字段类型转换为java类型
    private int parseColumnLength(String type) {
        int ret;
        switch (type) {
            case "varchar":ret = 255;break;
            case "char":   ret = 255;break;
            case "text":   ret = 1024;break;
            case "bigint": ret = 11;break;
            case "tinyint":ret = 4;break;
            default:ret = 255;
        }
        return ret;
    }
}

测试代码：

import java.util.ArrayList;
import java.util.List;

import com.arvin.entity.CodeAuto;
import com.arvin.entity.Column;

public class Test {
	public static void main(String[] args) throws Exception {
		//Entity的字段
		Column columnOne = new Column("username","varchar");
		Column columnTwo = new Column("password","varchar");
		Column columnThree = new Column("sex","tinyint");
		List<Column> columns = new ArrayList<>();
		columns.add(columnOne);
		columns.add(columnTwo);
		columns.add(columnThree);
		//Controller的方法
		String[] fun = {"add","delete","query","update"};
		CodeAuto codeAuto = new CodeAuto();
		codeAuto.name = "test";
		codeAuto.diskPath = "E:\\codeAuto\\";
		codeAuto.funs = fun;
		codeAuto.columns = columns;
		CodeAutoUtil cdeAutoUtil = new CodeAutoUtil();
		cdeAutoUtil.create(codeAuto);
	}
}

import org.apache.commons.lang3.builder.ToStringBuilder;
import java.util.List;

public class CodeAuto {
    public String name;
    public String path;
    public List<Column> columns; //entity字段
    public String[] funs; // 功能点（增删查改）

    @Override
    public String toString() {
        return ToStringBuilder.reflectionToString(this);
    }
}

public class Column {
   public String name;//字段名
   public String type;//字段类型
   public Column(String name,String type) {
	this.name = name;
	this.type = type;
   }
}

freemarker配置：

import freemarker.cache.ClassTemplateLoader;
import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateExceptionHandler;

import java.io.IOException;

public class FreeMarkerTemplateUtil {
    private static final Configuration Configuration = new Configuration();
    static{
    	Configuration.setTemplateLoader(new ClassTemplateLoader(FreeMarkerTemplateUtil.class, "/templates"));//模板所在路径
    	Configuration.setDefaultEncoding("UTF-8");
    	Configuration.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
    }

    public static Template getTemplate(String templateName) throws IOException {
        try {
            return Configuration.getTemplate(templateName);
        } catch (IOException e) {
            throw e;
        }
    }  
}

Dao.ftl模板：

package ${name};

import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.data.jpa.repository.JpaRepository;

public interface ${entityName}Dao extends JpaRepository<${entityName}, Long> {
	Page<${entityName}> findAll(Specification<${entityName}> specification, Pageable pageable);
}

Entity.ftl模板：

package ${name};

import org.apache.commons.lang3.builder.ToStringBuilder;

import java.util.Date;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class ${entityName} {

    // JPA 主键标识, 策略为由数据库生成主键
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    public Long id;
    public Date updateTime;
    public Date createTime;
    <#list params as x>
    ${x}
    </#list>

    public ${entityName}() {}

    @Override
    public String toString() {
        return ToStringBuilder.reflectionToString(this);
    }
}

Controller.ftl模板：

package ${name};

import org.carrot.config.support.SuccessResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springside.modules.constants.MediaTypes;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.data.web.PageableDefault;


@RestController
@RequestMapping(value="/api/${name}")
public class ${entityName}Controller {

    @Autowired
    private ${entityName}Service ${name}Service;

    <#list funs as x>

    <#if x?contains("hasQuery")>
    @RequestMapping(value = "/list", method = RequestMethod.GET, produces = MediaTypes.JSON_UTF_8)
    public SuccessResult list(@RequestHeader(value = "token") String token,
                              @RequestParam(required=false) String searchValue,
                              @PageableDefault(sort="updateTime",direction=Sort.Direction.DESC) Pageable pageable) throws Exception {
        return new SuccessResult(${name}Service.list(searchValue,pageable));
    }
    </#if>

   <#if x?contains("hasAdd")>
    @RequestMapping(value = "/add", method = RequestMethod.POST, produces = MediaTypes.JSON_UTF_8)
    public SuccessResult add(@RequestHeader(value = "token") String token,
                             @RequestBody ${entityName} ${name}) throws Exception {
        return new SuccessResult(${name}Service.add(${name}));
    }
    </#if>

    <#if x?contains("hasDelete")>
    @RequestMapping(value = "/delete/{id}", method = RequestMethod.GET, produces = MediaTypes.JSON_UTF_8)
    public SuccessResult delete(@RequestHeader(value = "token") String token,
                                @PathVariable(value = "id") Long id) throws Exception {
        return new SuccessResult(${name}Service.delete(id));
    }
    </#if>

    <#if x?contains("hasUpdate")>
    @RequestMapping(value = "/update/{id}", method = RequestMethod.POST, produces = MediaTypes.JSON_UTF_8)
    public SuccessResult update(@RequestHeader(value = "token") String token, @PathVariable(value = "id") Long id,
                                @RequestBody ${entityName} ${name}) throws Exception {
        return new SuccessResult(${name}Service.update(id, ${name}));
    }
    </#if>

    <#if x?contains("hasQuery")>
    @RequestMapping(value = "/detail/{id}", method = RequestMethod.GET, produces = MediaTypes.JSON_UTF_8)
    public SuccessResult detail(@RequestHeader(value = "token") String token,
                                @PathVariable(value = "id") Long id) throws Exception {
        return new SuccessResult(${name}Service.detail(id));
    }
    </#if>
    </#list>
}

Service.ftl模板：

package ${name};

import java.util.List;
import java.util.Map;

import com.google.common.collect.Lists;
import org.carrot.util.PojoUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.google.common.collect.Maps;

import javax.persistence.criteria.*;

@Service
public class ${entityName}Service {
	
	@Autowired
	private ${entityName}Dao ${name}Dao;
        //根据条件查询全部
	@Transactional()
	public Map<String, Object> list( String searchValue,Pageable pageable) {
		Map<String, Object> maps = new HashMap<String , Object>();
		Page<${entityName}> page${entityName} = ${name}Dao.findAll(new Specification<${entityName}>() {
			public Predicate toPredicate(Root<${entityName}> root, CriteriaQuery<?> query, CriteriaBuilder cb) { // 根据条件获取任务列表

				List<Predicate> predicates = Lists.newArrayList();
				Predicate[] predicateArr = new Predicate[predicates.size()];
				query.where(predicates.toArray(predicateArr));
				return null;
			}
		}, pageable);

		maps.put("list", page${entityName}.getContent());
		maps.put("total", page${entityName}.getTotalElements());
		return maps;
	}

	@Transactional
	    public boolean add( ${entityName} ${name}) {
            ${name}Dao.save(${name});
            return true;
        }

	@Transactional
	public Object delete( Long id) {
		${entityName} temp${entityName} = ${name}Dao.findOne(id);
		if(temp${entityName} != null){
			${name}Dao.delete(id);
			return true;
		}
		return false;
	}

	@Transactional
	public Object update( Long id, ${entityName} ${name}) throws Exception {
		${entityName} temp${entityName} = ${name}Dao.findOne(id);
		if (temp${entityName} != null) {
			PojoUtil.copyProperties(temp${entityName}, ${name});
			${name}Dao.save(temp${entityName});
			return true;
		}
		return false;
	}

	@Transactional(readOnly = true)
	public Object detail( Long id) {
		${entityName} ${name} =  ${name}Dao.findOne(id);
		if(${name} != null) {
			return ${name};
		}
		return false;
	}


}

Sql.ftl模板：

CREATE TABLE if not EXISTS `${name}` (
`id` bigint(11) NOT NULL AUTO_INCREMENT,
<#list colomns as x>
 ${x}
 </#list>
`create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
`update_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',
PRIMARY KEY (`id`) ,
);