1. 背景
要画ER图，一个个打费时费力，StarUML文件打开是json。那么就有可能自动生成。
2. 效果
把表结构生成好，自己只要维护关系即可。
3. 代码
import lombok.Data; import java.io.FileWriter; import java.io.IOException; import java.sql.*; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * @author liwei * @version 1.0 * @className MySqlToStarUML * @date 2022/9/21 22:47 */ public class MySqlToStarUML { /** * 自动生成代码入口 * * @author liwei * @date 2022-09-25 00:58:45 * @param args * @return void */ public static void main(String[] args) { localTest(); } public static void localTest() { String driver = "com.mysql.cj.jdbc.Driver"; String url = "jdbc:mysql://localhost:3306/test_nacos?useUnicode=true&characterEncoding=UTF-8"; String userName = "root"; String password = "密码"; String filePath = "D:\test_nacos.mdj"; List<Table> tableList = getTableList(driver, url, userName, password); saveAsFileWriter(filePath, getProject(url, tableList)); System.out.println("===============生成成功================"); } /** * 获取项目字符串 * * @author liwei * @date 2023-03-16 18:37:01 * @param url * 地址 * @param tableList * 表集合 * @return {@link String} */ public static String getProject(String url, List<Table> tableList) { String database = getDBByUrl(url); Project project = new Project(); // 不能使用中文 project.setName(database); project.set_id("AAAAAA_Project"); List<OwnedElement> erddatamodels = new ArrayList<>(); List<OwnedElement> ownedElements = new ArrayList<>(); ERDDataModel erdDataModel = new ERDDataModel(); erdDataModel.setName("Data Model1"); erdDataModel.set_id("AAAAAA_DataModel1"); erdDataModel.set_parent(project.get_id()); erddatamodels.add(erdDataModel); ERDDiagram erdDiagram = new ERDDiagram(); erdDiagram.setName("ERDDiagram1"); erdDiagram.set_id("AAAAAA_ERDDiagram1"); erdDiagram.set_parent(erdDataModel.get_id()); ownedElements.add(erdDiagram); for (Table table : tableList) { table.set_parent(erdDataModel.get_id()); } ownedElements.addAll(tableList); erdDataModel.setOwnedElements(ownedElements); project.setOwnedElements(erddatamodels); return project.toString(); } /** * 通过url获取数据库 * * @author liwei * @date 2022-09-23 09:21:09 * @param url * 地址 * @return {@link String} */ public static String getDBByUrl(String url) { if (null == url || url.isEmpty()) { throw new RuntimeException("地址为空"); } if (url.indexOf(":") == 0 && url.length() <= 1) { throw new RuntimeException("地址有误"); } while (url.indexOf(":") > 0) { url = url.substring(url.indexOf(":") + 1); } if (url.indexOf("?") > 0) { url = url.substring(0, url.indexOf("?")); } if (url.indexOf("/") > 0) { url = url.substring(url.indexOf("/") + 1); } return url; } /** * 保存内容到文件 * * @author liwei * @date 2022-11-22 14:19:47 * @param filePath * 文件路径 * @param content * 内容 * @return void */ private static void saveAsFileWriter(String filePath, String content) { FileWriter fwriter = null; try { fwriter = new FileWriter(filePath); fwriter.write(content); } catch (IOException ex) { ex.printStackTrace(); } finally { try { if (null != fwriter) { fwriter.flush(); fwriter.close(); } } catch (IOException ex) { ex.printStackTrace(); } } } /** * 获取表集合 * * @author liwei * @date 2022-11-22 14:20:24 * @param driver * 驱动 * @param url * 连接 * @param userName * 账号 * @param password * 密码 * @return {@link List< Table>} */ private static List<Table> getTableList(String driver, String url, String userName, String password) { Connection connection; try { Class.forName(driver); connection = DriverManager.getConnection(url, userName, password); } catch (ClassNotFoundException e) { throw new RuntimeException("加载驱动失败，找不到：" + driver); } catch (SQLException e) { throw new RuntimeException("获取数据库连接失败，请检查配置和日志", e); } String database = getDBByUrl(url); String sqlTable = String.format("select * from information_schema.tables where TABLE_SCHEMA='%s'", database); List<Map<String, String>> mapList = runSql(connection, sqlTable); List<Table> tableList = new ArrayList<>(); for (int i = 0; i < mapList.size(); i++) { Map<String, String> map = mapList.get(i); Table table = new Table(); String tableId = String.valueOf(i + 1); table.set_id(tableId); table.setName(map.get("TABLE_NAME")); table.setDocumentation(map.get("TABLE_COMMENT")); String sqlColumn = String.format("select * from information_schema.columns where TABLE_SCHEMA='%s' and TABLE_NAME = '%s'", database, table.getName()); List<Map<String, String>> mapList2 = runSql(connection, sqlColumn); List<Column> columnList = new ArrayList<>(); for (Map<String, String> stringMap : mapList2) { Column column = new Column(); column.setTableId(tableId); column.setName(stringMap.get("COLUMN_NAME")); column.setType(stringMap.get("DATA_TYPE")); String columnType = stringMap.get("COLUMN_TYPE"); if (columnType.indexOf("(") > 0) { column.setLength(columnType.substring(columnType.indexOf("(") + 1, columnType.indexOf(")"))); } else { column.setLength(stringMap.get("CHARACTER_MAXIMUM_LENGTH")); } column.setOrdinalPosition(Integer.parseInt(stringMap.get("ORDINAL_POSITION"))); column.setNullable("YES".equals(stringMap.get("IS_NULLABLE"))); column.setPrimaryKey("PRI".equals(stringMap.get("COLUMN_KEY"))); column.setUnique("UNI".equals(stringMap.get("COLUMN_KEY"))); columnList.add(column); } columnList.sort((c1, c2) -> c1.ordinalPosition - c2.getOrdinalPosition()); table.setColumns(columnList); tableList.add(table); } close(null, connection, null); return tableList; } /** * 关闭连接 * * @author liwei * @date 2022-09-23 09:21:53 * @param pstmt * 预编译 * @param conn * 连接 * @param rs * 结果集 * @return void */ public static void close(PreparedStatement pstmt, Connection conn, ResultSet rs) { try { if(null != rs) { rs.close(); rs = null; } if(null != pstmt) { pstmt.close(); pstmt = null; } if(null != conn) { conn.close(); conn = null; } } catch (SQLException e) { throw new RuntimeException("关闭数据库连接异常", e); } } /** * 运行sql * * @author liwei * @date 2022-11-22 14:21:40 * @param conn * 连接 * @param sql * 执行的sql * @return {@link List< Map< String, String>>} */ public static List<Map<String, String>> runSql(Connection conn, String sql) { if (null == sql || sql.isEmpty()) { throw new RuntimeException("执行的sql不可为空"); } List<Map<String, String>> list = new ArrayList<>(); if(null == conn) { throw new RuntimeException("获取数据库连接失败"); } PreparedStatement pstmt = null; ResultSet rs = null; try { pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); while (rs.next()) { Map<String, String> map = new HashMap<>(); ResultSetMetaData metaData = rs.getMetaData(); int columnCount = metaData.getColumnCount(); for (int i = 1; i <= columnCount; i++) { map.put(metaData.getColumnName(i), rs.getString(i)); } list.add(map); } } catch (SQLException e) { throw new RuntimeException("执行sql异常", e); } finally { close(pstmt, null, rs); } return list; } @Data static class Table extends OwnedElement { private String _type = "ERDEntity"; private String documentation; private List<Column> columns; @Override public String toString() { return "{" + ""_type":"" + _type + '"' + ", "_id":"" + super._id + '"' + ", "_parent":{"$ref":"" + super._parent + ""}" + ", "name":"" + super.name + " " + documentation + '"' + ", "documentation":"" + documentation + '"' + ", "columns":" + columns + '}'; } } @Data static class Column { private String _type = "ERDColumn"; private String name; private String tableId; private String type; private String length; // UNI、PRI private String columnKey; private int ordinalPosition; private Boolean primaryKey; private Boolean unique; private Boolean nullable; @Override public String toString() { return "{" + ""_type":"ERDColumn"" + ", "_parent":{"$ref":"" + tableId + ""}" + ", "name":"" + name + '"' + ", "type":"" + type + '"' + (null != length ? ", "length":"" + length + '"' : "") + (primaryKey ? ", "primaryKey":"" + primaryKey + """ : "") + (unique ? ", "unique":"" + unique + """ : "") + (nullable ? ", "nullable":"" + nullable + """ : "") + '}'; } } @Data static class Project extends OwnedElement { private String _type = "Project"; @Override public String toString() { return "{" + ""_type":"Project"" + ", "_id":"" + super._id + '"' + ", "name":"" + super.name + '"' + ", "ownedElements":" + super.ownedElements + "}"; } } @Data static class OwnedElement { private String _type; private String _id; private String _parent; private String name; private List<OwnedElement> ownedElements; } @Data static class ERDDataModel extends OwnedElement { private String _type = "ERDDataModel"; @Override public String toString() { return "{" + ""_type":"ERDDataModel"" + ", "_id":"" + super._id + '"' + ", "_parent":{"$ref":"" + super._parent + ""}" + ", "name":"" + super.name + '"' + ", "ownedElements":" + super.ownedElements + "}"; } } @Data static class ERDDiagram extends OwnedElement { private String _type = "ERDDiagram"; @Override public String toString() { return "{" + ""_type":"ERDDiagram"" + ", "_id":"" + super._id + '"' + ", "_parent":{"$ref":"" + super._parent + ""}" + ", "name":"" + super.name + '"' + (null != super.ownedElements ? ", "ownedViews":" + super.ownedElements : "") + "}"; } } @Data static class ERDEntityView extends OwnedElement { private String _type = "ERDEntityView"; private String tableId; @Override public String toString() { return "{" + ""_type":"ERDEntityView"" + ", "model":{"" + tableId + ""}" + (null != super.ownedElements ? ", "subViews":" + super.ownedElements : "") + "}"; } } } 
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