网站开发工程师项目经验,长春市建设工程信息网,安阳到濮阳,推广网站seo主要的目标是简化开发人员在有实体类的情况下时做的重复性工作#xff0c;提高开发效率。
单个实体类的转换工具类
1.EntityToTableConverter工具类
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.Field;
import java.math.BigDecimal…主要的目标是简化开发人员在有实体类的情况下时做的重复性工作提高开发效率。
单个实体类的转换工具类
1.EntityToTableConverter工具类
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.Field;
import java.math.BigDecimal;/*** 将实体类转换为MySQL建表语句并输出到文件中的工具类* Author: 木芒果*/
public class EntityToTableConverter {/*** 将实体类转换为MySQL建表语句并输出到文件中** param clazz 实体类的Class对象* param filePath 输出文件的路径如User.sql,就会在项目根目录下创建一个名为User.sql的文件文件路径为空则将建表语句输出到控制台* throws IOException 如果输出文件时发生错误*/public static void convertToCreateTableStatement(Class? clazz, String filePath) {try {StringBuilder sb new StringBuilder();sb.append(DROP TABLE IF EXISTS );String simpleName clazz.getSimpleName();sb.append(convertCamelToUnderline(simpleName));sb.append(;\n);sb.append(CREATE TABLE );sb.append(convertCamelToUnderline(simpleName));sb.append( (\n);Field[] fields clazz.getDeclaredFields();for (int i 0; i fields.length; i) {Field field fields[i];sb.append( );String fieldName field.getName();if (fieldName ! serialVersionUID) {sb.append(convertCamelToUnderline(fieldName));sb.append( );sb.append(getColumnType(field.getType()));if (fieldName.equals(id)) { // 如果字段名为id则自动设置为主键自动增长sb.append( PRIMARY KEY AUTO_INCREMENT);}sb.append(,\n);}}sb.deleteCharAt(sb.lastIndexOf(,));sb.append(););if (filePath null) {System.out.println(sb);return;}FileWriter writer new FileWriter(filePath);writer.write(sb.toString());writer.close();System.out.println(建表语句已输出到 filePath);} catch (Exception e) {e.printStackTrace();}}/*** 获取字段类型对应的MySQL数据类型** param fieldType 字段类型* return MySQL数据类型*/private static String getColumnType(Class? fieldType) {if (fieldType String.class) {return VARCHAR(255);} else if (fieldType int.class || fieldType Integer.class) {return INT;} else if (fieldType long.class || fieldType Long.class) {return BIGINT;} else if (fieldType double.class || fieldType Double.class) {return DOUBLE;} else if (fieldType boolean.class || fieldType Boolean.class) {return BOOLEAN;} else if (fieldType byte[].class) {return LONGBLOB;} else if (fieldType java.util.Date.class || fieldType java.sql.Timestamp.class || fieldType java.time.LocalDateTime.class) {return DATETIME;} else if (fieldType BigDecimal.class) {return DECIMAL(10,2); // 可根据需要调整精度和小数位数}// 如果遇到无法识别的类型可以根据实际需求进行扩展return VARCHAR(255);}/*** 将驼峰命名法转换为下划线命名法** param camel 驼峰命名法字符串* return 下划线命名法字符串*/private static String convertCamelToUnderline(String camel) {StringBuilder sb new StringBuilder();for (int i 0; i camel.length(); i) {char c camel.charAt(i);if (Character.isUpperCase(c)) {if (i 0) {sb.append(Character.toLowerCase(c));} else {sb.append(_);sb.append(Character.toLowerCase(c));}} else {sb.append(c);}}return sb.toString();}
}2.测试
/*** author 木芒果*/
public class Test {public static void main(String[] args) {//生成sql文件的方式EntityToTableConverter.convertToCreateTableStatement(User.class, user.sql);//直接输出在控制台的方式EntityToTableConverter.convertToCreateTableStatement(User.class, null);}
}整个包中的实体类转换工具类
1.EntityToTableConverter工具类
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;/*** 将整个包下的实体类转换为MySQL建表语句* Author: 木芒果*/
public class EntityToTableConverter {/*** 将指定包下的所有实体类转换为MySQL建表语句并输出到文件中** param packageName 包名* param filePath 输出文件的路径* throws IOException 如果输出文件时发生错误*/public static void convertEntitesToCreateTableStatements(String packageName, String filePath) {try {SetClass? classes getClassesInPackage(packageName);StringBuilder sb new StringBuilder();for (Class? clazz : classes) {sb.append(convertToCreateTableStatement(clazz));sb.append(\n\n);}if (filePath null || filePath.isEmpty()) {System.out.println(sb);return;}FileWriter writer new FileWriter(filePath);writer.write(sb.toString());writer.close();System.out.println(建表语句已输出到 filePath);} catch (Exception e) {e.printStackTrace();}}/*** 获取指定包下的所有类** param packageName 包名* return 类集合*/private static SetClass? getClassesInPackage(String packageName) {try {SetClass? classes new HashSet();String packagePath packageName.replace(., /);ClassLoader classLoader Thread.currentThread().getContextClassLoader();EnumerationURL resources classLoader.getResources(packagePath);while (resources.hasMoreElements()) {URL resource resources.nextElement();if (resource.getProtocol().equals(jar)) {JarURLConnection jarConnection (JarURLConnection) resource.openConnection();JarFile jarFile jarConnection.getJarFile();for (EnumerationJarEntry entries jarFile.entries(); entries.hasMoreElements(); ) {JarEntry entry entries.nextElement();String entryName entry.getName();if (entryName.startsWith(packagePath) entryName.endsWith(.class)) {String className entryName.substring(0, entryName.length() - 6).replace(/, .);Class? clazz Class.forName(className);classes.add(clazz);}}} else if (resource.getProtocol().equals(file)) {File packageDir new File(resource.getFile());if (packageDir.exists()) {File[] files packageDir.listFiles();for (File file : files) {String fileName file.getName();String className;if (fileName.endsWith(.class)) {className packageName . fileName.substring(0, fileName.length() - 6);Class? clazz Class.forName(className);classes.add(clazz);} else if (file.isDirectory()) {String subPackageName packageName . fileName;classes.addAll(getClassesInPackage(subPackageName));}}}}}return classes;} catch (Exception e) {e.printStackTrace();return null;}}/*** 将实体类转换为MySQL建表语句** param clazz 实体类的Class对象* return 建表语句*/private static String convertToCreateTableStatement(Class? clazz) {StringBuilder sb new StringBuilder();sb.append(DROP TABLE IF EXISTS );String simpleName clazz.getSimpleName();sb.append(convertCamelToUnderline(simpleName));sb.append(;\n);sb.append(CREATE TABLE );sb.append(convertCamelToUnderline(simpleName));sb.append( (\n);Field[] fields clazz.getDeclaredFields();for (int i 0; i fields.length; i) {Field field fields[i];sb.append( );String fieldName field.getName();if (fieldName ! serialVersionUID) {sb.append(convertCamelToUnderline(fieldName));sb.append( );sb.append(getColumnType(field.getType()));if (fieldName.equals(id)) { // 如果字段名为id则自动设置为主键自动增长sb.append( PRIMARY KEY AUTO_INCREMENT);}sb.append(,\n);}}sb.deleteCharAt(sb.lastIndexOf(,));sb.append(\n););return sb.toString();}/*** 获取字段类型对应的MySQL数据类型** param fieldType 字段类型* return MySQL数据类型*/private static String getColumnType(Class? fieldType) {if (fieldType String.class) {return VARCHAR(255);} else if (fieldType int.class || fieldType Integer.class) {return INT;} else if (fieldType long.class || fieldType Long.class) {return BIGINT;} else if (fieldType double.class || fieldType Double.class) {return DOUBLE;} else if (fieldType boolean.class || fieldType Boolean.class) {return BOOLEAN;} else if (fieldType byte[].class) {return LONGBLOB;} else if (fieldType java.util.Date.class || fieldType java.sql.Timestamp.class || fieldType java.time.LocalDateTime.class) {return DATETIME;} else if (fieldType BigDecimal.class) {return DECIMAL(10,2); // 可根据需要调整精度和小数位数}// 如果遇到无法识别的类型可以根据实际需求进行扩展return VARCHAR(255);}/*** 将驼峰命名法转换为下划线命名法** param camel 驼峰命名法字符串* return 下划线命名法字符串*/private static String convertCamelToUnderline(String camel) {StringBuilder sb new StringBuilder();for (int i 0; i camel.length(); i) {char c camel.charAt(i);if (Character.isUpperCase(c)) {if (i 0) {sb.append(Character.toLowerCase(c));} else {sb.append(_);sb.append(Character.toLowerCase(c));}} else {sb.append(c);}}return sb.toString();}
}
2.测试
public class Test {public static void main(String[] args) {//生成sql文件的方式EntityToTableConverter.convertEntitesToCreateTableStatements(com.mmg.entity, D:\\test.sql);//直接输出在控制台的方式EntityToTableConverter.convertEntitesToCreateTableStatements(com.mmg.entity, null);}
}
如有更好的想法可以在评论区交流完善此工具类
