Java 批量生成 DataX JSON 脚本

以下是使用 Java 批量生成 DataX JSON 脚本的示例代码：

import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

public class DataXJsonGenerator {

    public static void main(String[] args) {
        List<String> tables = new ArrayList<>();
        tables.add('table1');
        tables.add('table2');
        tables.add('table3');

        String sourceDbUrl = 'jdbc:mysql://localhost:3306/source_db';
        String sourceDbUsername = 'root';
        String sourceDbPassword = 'password';

        String targetDbUrl = 'jdbc:mysql://localhost:3306/target_db';
        String targetDbUsername = 'root';
        String targetDbPassword = 'password';

        for (String table : tables) {
            JSONObject job = new JSONObject();
            job.put('job', createJobObject(table));
            job.put('content', createContentObject(table, sourceDbUrl, sourceDbUsername, sourceDbPassword, targetDbUrl, targetDbUsername, targetDbPassword));

            try (FileWriter writer = new FileWriter(table + '.json')) {
                writer.write(job.toJSONString());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    private static JSONObject createJobObject(String table) {
        JSONObject job = new JSONObject();
        job.put('setting', createSettingObject());
        job.put('content', createJobContentObject(table));
        return job;
    }

    private static JSONObject createSettingObject() {
        JSONObject setting = new JSONObject();
        setting.put('speed', createSpeedObject());
        return setting;
    }

    private static JSONObject createSpeedObject() {
        JSONObject speed = new JSONObject();
        speed.put('channel', 3);
        speed.put('byte', 1048576);
        return speed;
    }

    private static JSONObject createJobContentObject(String table) {
        JSONObject content = new JSONObject();
        content.put('reader', createReaderObject(table));
        content.put('writer', createWriterObject(table));
        return content;
    }

    private static JSONObject createReaderObject(String table) {
        JSONObject reader = new JSONObject();
        reader.put('name', 'mysqlreader');
        reader.put('parameter', createReaderParameterObject(table));
        return reader;
    }

    private static JSONObject createReaderParameterObject(String table) {
        JSONObject parameter = new JSONObject();
        parameter.put('username', 'root');
        parameter.put('password', 'password');
        parameter.put('column', createReaderColumnObject(table));
        parameter.put('connection', createReaderConnectionObject());
        parameter.put('where', '1=1');
        parameter.put('splitPk', 'id');
        parameter.put('table', table);
        return parameter;
    }

    private static JSONObject createReaderColumnObject(String table) {
        JSONObject column = new JSONObject();
        column.put('id', 'bigint');
        column.put('name', 'varchar');
        column.put('age', 'int');
        column.put('address', 'varchar');
        return column;
    }

    private static JSONObject createReaderConnectionObject() {
        JSONObject connection = new JSONObject();
        connection.put('jdbcUrl', 'jdbc:mysql://localhost:3306/source_db');
        connection.put('table', new ArrayList<>());
        return connection;
    }

    private static JSONObject createWriterObject(String table) {
        JSONObject writer = new JSONObject();
        writer.put('name', 'mysqlwriter');
        writer.put('parameter', createWriterParameterObject(table));
        return writer;
    }

    private static JSONObject createWriterParameterObject(String table) {
        JSONObject parameter = new JSONObject();
        parameter.put('username', 'root');
        parameter.put('password', 'password');
        parameter.put('column', createWriterColumnObject(table));
        parameter.put('preSql', 'TRUNCATE TABLE ' + table);
        parameter.put('connection', createWriterConnectionObject());
        parameter.put('table', table);
        return parameter;
    }

    private static JSONObject createWriterColumnObject(String table) {
        JSONObject column = new JSONObject();
        column.put('id', 'bigint');
        column.put('name', 'varchar');
        column.put('age', 'int');
        column.put('address', 'varchar');
        return column;
    }

    private static JSONObject createWriterConnectionObject() {
        JSONObject connection = new JSONObject();
        connection.put('jdbcUrl', 'jdbc:mysql://localhost:3306/target_db');
        return connection;
    }

    private static JSONObject createContentObject(String table, String sourceDbUrl, String sourceDbUsername, String sourceDbPassword, String targetDbUrl, String targetDbUsername, String targetDbPassword) {
        JSONObject content = new JSONObject();
        content.put('job', createContentJobObject(table));
        content.put('source', createContentSourceObject(sourceDbUrl, sourceDbUsername, sourceDbPassword));
        content.put('destination', createContentDestinationObject(targetDbUrl, targetDbUsername, targetDbPassword));
        return content;
    }

    private static JSONObject createContentJobObject(String table) {
        JSONObject job = new JSONObject();
        job.put('content', createJobContentObject(table));
        job.put('setting', createSettingObject());
        return job;
    }

    private static JSONObject createContentSourceObject(String sourceDbUrl, String sourceDbUsername, String sourceDbPassword) {
        JSONObject source = new JSONObject();
        source.put('jdbcUrl', sourceDbUrl);
        source.put('username', sourceDbUsername);
        source.put('password', sourceDbPassword);
        return source;
    }

    private static JSONObject createContentDestinationObject(String targetDbUrl, String targetDbUsername, String targetDbPassword) {
        JSONObject destination = new JSONObject();
        destination.put('jdbcUrl', targetDbUrl);
        destination.put('username', targetDbUsername);
        destination.put('password', targetDbPassword);
        return destination;
    }
}

这个示例代码将生成三个 DataX JSON 脚本，分别对应三个表格。在这个示例中，我们使用了 fastjson 库来创建 JSON 对象。使用时，需要将 fastjson 库添加到项目的依赖中。

此外，在这个示例中，我们将所有的配置都硬编码在代码中，但实际使用时，可能需要将它们存储在配置文件或数据库中，并在生成 JSON 脚本时读取它们。