因项目数据放到了Mongodb 中，需在Mongodb 中查询数据，网上找了好久总算找到了实现方式

借用本地命令号读取命令行数据

主要是分2步：

1、下载 

sql-to-mongo-db-query-converter 

这个是一个3放插件 作用是将sql语句转成 Mongodb shell 语句

代码如下：

public static void main1(String[] args) throws Exception {try {String sqlQuery = "select sum(id),count(id) from test2 ;";ProcessBuilder processBuilder = new ProcessBuilder("java", "-jar", "D:\\aj-report\\sql-to-mongo-db-query-converter-master\\target\\sql-to-mongo-db-query-converter-1.19-SNAPSHOT-standalone.jar", "-i");Process process = processBuilder.start();// 读取命令行输出BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));BufferedReader errorReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));// 将 SQL 查询语句写入到进程的标准输入流中process.getOutputStream().write(sqlQuery.getBytes());process.getOutputStream().close();// 打印原始的 SQL 查询语句System.out.println("Original SQL Query:");System.out.println(sqlQuery);// 打印转换后的 MongoDB 查询语句System.out.println("\nConverted MongoDB Query:");String line;StringBuffer lineString=new StringBuffer();while ((line = reader.readLine()) != null) {System.out.println(line); // 输出转换后的 MongoDB 查询语句lineString.append(line);}System.out.println("::::::"+lineString.toString());String searchStr = "******Mongo Query:*********";int index = lineString.indexOf(searchStr);if (index != -1) {String result = lineString.substring(index + searchStr.length());System.out.println("截取后sql->mongodb："+result);} else {System.out.println("未找到指定的字符串");}// 打印错误信息System.out.println("\nError Output:");String errorLine;while ((errorLine = errorReader.readLine()) != null) {System.out.println(errorLine);}//            System.out.println("::::::"+lineString.toString());// 检查命令行执行结果int exitCode = process.waitFor();if (exitCode != 0) {System.err.println("Command execution failed with error code: " + exitCode);}} catch (IOException | InterruptedException e) {e.printStackTrace();}}

上述已把sql 转成 Mongodb 可执行语句

2、调用本地Mongodb 命令行

需注意 本地需安装 

mongosh

代码如下：

public static void main(String[] args) {try {// 构建命令
//            String[] command = { "mongosh", "--host", "remote_server_ip", "--port", "27017" };
//
//            // 执行命令
//            ProcessBuilder pb = new ProcessBuilder(command);ProcessBuilder processBuilder = new ProcessBuilder("D:/mongodb-win32-x86_64-windows-7.0.6/mongosh-2.2.0-win32-x64/bin/mongosh.exe");processBuilder.redirectErrorStream(true);Process process = processBuilder.start();OutputStream stdin = process.getOutputStream();BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(stdin));// 发送查询命令writer.write("use test\n"); // 切换到指定数据库writer.write("db.test2.find()\n"); // 执行查询操作writer.write("exit\n"); // 退出 MongoDB Shellwriter.flush();BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));String line;while ((line = reader.readLine()) != null) {System.out.println(line);}int exitCode = process.waitFor();System.out.println("MongoDB Shell process exited with code " + exitCode);} catch (IOException | InterruptedException e) {e.printStackTrace();}}

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