自动生成JPA bean及repository生成简陋工具

因为工具不太灵活，手写了一个，没啥技术难度，纯堆代码量

import java.io.File;
import java.io.FileOutputStream;
import java.nio.charset.Charset;
import java.sql.*;
import java.util.*;/*** JPA dao自动生成工具*/
public class JpaGenerate {//bean所在位置，示例：com.jpa.beanstatic String entityPackage = "com.datasource.entity";static String entityPath = "";//repository，示例：com.jpa.repositorystatic String repositoryPackage = "com.datasource.dao";static String repositoryPath = "";//mysql配置final static String url = "jdbc:mysql://localhost:3306/test";final static String user = "root";final static String password = "123456";//需要自动生成的数据库final static String database = "operation_platform";public static void main(String[] args) throws SQLException {Driver driver = new com.mysql.cj.jdbc.Driver();Properties info = new Properties();info.setProperty("user", user);info.setProperty("password", password);Connection conn = driver.connect(url, info);Statement stat = conn.createStatement();String sql = """select table_name,column_name,column_type,column_key,extra,column_commentFROMinformation_schema. COLUMNSWHERE"""+ "table_schema = '" + database + "' ORDER BY table_name";ResultSet rs = stat.executeQuery(sql);Map<String, List<DatasourceTableField>> fieldMap = new HashMap<>();while (rs.next()) {String table = rs.getString("table_name");if (!fieldMap.containsKey(table)) {fieldMap.put(table, new ArrayList<>());}fieldMap.get(table).add(new DatasourceTableField(rs.getString("column_name"),rs.getString("column_type"),rs.getString("column_comment"),rs.getString("column_key"),rs.getString("extra")));}conn.close();String projectPath = System.getProperty("user.dir").replaceAll("\\\\", "/");entityPath = projectPath + "/src/main/java/" + entityPackage.replaceAll("\\.", "/");repositoryPath = projectPath + "/src/main/java/" + repositoryPackage.replaceAll("\\.", "/");fieldMap.keySet().stream().forEach(key -> {try {createJpaFiles(key, fieldMap.get(key));} catch (Exception e) {throw new RuntimeException(e);}});}static void createJpaFiles(String table, List<DatasourceTableField> list) throws Exception {String tableName = convertTableName(table);String entityFilePath = entityPath + "/" + tableName + ".java";File entity = new File(entityFilePath);if (!entity.exists()) {entity.createNewFile();FileOutputStream outputStream = new FileOutputStream(entity);String fileText = "package " + entityPackage + ";\n\n" + """import jakarta.persistence.*;import lombok.Data;""";boolean time = false;String body = "\n";for (DatasourceTableField field : list) {if (field.columnType.contains("("))field.columnType = field.columnType.split("\\(")[0];String columnName = convertFieldName(field.columnName);switch (field.columnType) {case "int", "smallint" -> {if ("PRI".equals(field.columnKey)) {if ("auto_increment".equals(field.extra)) {body += "    @GeneratedValue(strategy = GenerationType.IDENTITY)\n";}body += "    @Id\n";}body += "    private Integer " + columnName + ";\n";}case "varchar", "text" -> body += "    private String " + columnName + ";\n";case "datetime" -> {time = true;body += "    private LocalDateTime " + columnName + ";\n";}case "double" -> body += "    private Double " + columnName + ";\n";}}if (time) {fileText += "import java.time.LocalDateTime;\n\n";}fileText += """@Entity@Data@Table(name = \"""" + table +"\")\npublic class " + tableName + "{\n" + body + "}";outputStream.write(fileText.getBytes(Charset.forName("utf-8")));outputStream.close();}String repositoryFilePath = repositoryPath + "/" + tableName + "Repository.java";File repository = new File(repositoryFilePath);if (!repository.exists()) {repository.createNewFile();FileOutputStream outputStream = new FileOutputStream(repository);String fileText = "package " + repositoryPackage + ";\n\n" +"import " + entityPackage + "." + tableName + ";\n" +"""import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.stereotype.Repository;@Repository"""+ "public interface " + tableName + "Repository extends JpaRepository<" +tableName + ", Integer> {\n}";outputStream.write(fileText.getBytes(Charset.forName("utf-8")));outputStream.close();}}static String convertTableName(String table) {String tableName = "";if (table.contains("_")) {for (String str : table.split("_")) {tableName += Character.toUpperCase(str.charAt(0)) + str.substring(1);}} else {tableName = Character.toUpperCase(table.charAt(0)) + table.substring(1);}return tableName;}static String convertFieldName(String tableField) {String fieldName = "";if (tableField.contains("_")) {boolean head = true;for (String str : tableField.split("_")) {if (head) {fieldName += str;head = false;} elsefieldName += Character.toUpperCase(str.charAt(0)) + str.substring(1);}} else {fieldName = tableField;}return fieldName;}static class DatasourceTableField {String columnName;String columnType;String columnComment;String columnKey;String extra;public DatasourceTableField(String columnName, String columnType, String columnComment, String columnKey, String extra) {this.columnName = columnName;this.columnType = columnType;this.columnComment = columnComment;this.columnKey = columnKey;this.extra = extra;}}}

由于项目中使用了lombok，所以写死了引入，不需要的直接去掉第85行，那么就需要重新加get set函数，在111行后再遍历一下list对body中添加getset函数即可，这里有一些坑，这个只能用于mysql，我没写其他数据库的连接和查询，然后目录是根据spring boot的结构来的，如果不是spring boot 可以修改64、65行目录，由于偷懒，mysql的数据类型也没写完，有其他类型的可以在94行的switch中添加，最后，此代码需要jdk17，因为使用了多行字符串和17+的switch，低版本的话改下字符串和switch写法也能用