java使用snakeyaml生成gpload的control配置文件，需要java语言实现，要求用到build设计模式，配置文件内容模型化并且包含VERSION、DATABASE、USER、HOST、PORT、GPLOAD、INPUT、EXTERNAL、OUTPUT

以下是一个可能的实现，使用了builder设计模式，将配置文件内容模型化为一个Config类：

public class Config {
    private final String version;
    private final String database;
    private final String user;
    private final String host;
    private final int port;
    private final Gpload gpload;
    private final Input input;
    private final External external;
    private final Output output;

    private Config(ConfigBuilder builder) {
        this.version = builder.version;
        this.database = builder.database;
        this.user = builder.user;
        this.host = builder.host;
        this.port = builder.port;
        this.gpload = builder.gpload;
        this.input = builder.input;
        this.external = builder.external;
        this.output = builder.output;
    }

    public String getVersion() {
        return version;
    }

    public String getDatabase() {
        return database;
    }

    public String getUser() {
        return user;
    }

    public String getHost() {
        return host;
    }

    public int getPort() {
        return port;
    }

    public Gpload getGpload() {
        return gpload;
    }

    public Input getInput() {
        return input;
    }

    public External getExternal() {
        return external;
    }

    public Output getOutput() {
        return output;
    }

    public static class ConfigBuilder {
        private String version;
        private String database;
        private String user;
        private String host;
        private int port;
        private Gpload gpload;
        private Input input;
        private External external;
        private Output output;

        public ConfigBuilder version(String version) {
            this.version = version;
            return this;
        }

        public ConfigBuilder database(String database) {
            this.database = database;
            return this;
        }

        public ConfigBuilder user(String user) {
            this.user = user;
            return this;
        }

        public ConfigBuilder host(String host) {
            this.host = host;
            return this;
        }

        public ConfigBuilder port(int port) {
            this.port = port;
            return this;
        }

        public ConfigBuilder gpload(Gpload gpload) {
            this.gpload = gpload;
            return this;
        }

        public ConfigBuilder input(Input input) {
            this.input = input;
            return this;
        }

        public ConfigBuilder external(External external) {
            this.external = external;
            return this;
        }

        public ConfigBuilder output(Output output) {
            this.output = output;
            return this;
        }

        public Config build() {
            return new Config(this);
        }
    }

    public static class Gpload {
        private final String input;
        private final String format;
        private final String delimiter;
        private final String quote;
        private final String errorLimit;
        private final String logErrors;
        private final String tableName;

        public Gpload(String input, String format, String delimiter, String quote, String errorLimit, String logErrors, String tableName) {
            this.input = input;
            this.format = format;
            this.delimiter = delimiter;
            this.quote = quote;
            this.errorLimit = errorLimit;
            this.logErrors = logErrors;
            this.tableName = tableName;
        }

        public String getInput() {
            return input;
        }

        public String getFormat() {
            return format;
        }

        public String getDelimiter() {
            return delimiter;
        }

        public String getQuote() {
            return quote;
        }

        public String getErrorLimit() {
            return errorLimit;
        }

        public String getLogErrors() {
            return logErrors;
        }

        public String getTableName() {
            return tableName;
        }
    }

    public static class Input {
        private final String type;
        private final String path;

        public Input(String type, String path) {
            this.type = type;
            this.path = path;
        }

        public String getType() {
            return type;
        }

        public String getPath() {
            return path;
        }
    }

    public static class External {
        private final String protocol;
        private final String host;
        private final int port;

        public External(String protocol, String host, int port) {
            this.protocol = protocol;
            this.host = host;
            this.port = port;
        }

        public String getProtocol() {
            return protocol;
        }

        public String getHost() {
            return host;
        }

        public int getPort() {
            return port;
        }
    }

    public static class Output {
        private final String type;
        private final String tableName;

        public Output(String type, String tableName) {
            this.type = type;
            this.tableName = tableName;
        }

        public String getType() {
            return type;
        }

        public String getTableName() {
            return tableName;
        }
    }
}

可以使用SnakeYaml来生成配置文件：

public class ControlFileGenerator {
    public static void main(String[] args) throws IOException {
        Config config = new Config.ConfigBuilder()
                .version("1.0")
                .database("mydb")
                .user("myuser")
                .host("localhost")
                .port(5432)
                .gpload(new Config.Gpload("data.csv", "csv", ",", "\"", "100", "true", "mytable"))
                .input(new Config.Input("file", "/path/to/data.csv"))
                .external(new Config.External("http", "example.com", 8080))
                .output(new Config.Output("table", "mytable"))
                .build();

        Yaml yaml = new Yaml();
        String output = yaml.dumpAsMap(config);
        System.out.println(output);
    }
}

输出的内容类似于：

database: mydb
external:
  host: example.com
  port: 8080
  protocol: http
gpload:
  delimiter: ','
  errorLimit: '100'
  format: csv
  input: data.csv
  logErrors: 'true'
  quote: '"'
  tableName: mytable
host: localhost
input:
  path: /path/to/data.csv
  type: file
output:
  tableName: mytable
  type: table
port: 5432
user: myuser
version: '1.0'